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screen printing => Screen Making => Topic started by: alan802 on March 05, 2015, 10:22:44 AM
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There have been a lot of posts pertaining to LED and how much everyone loves theirs and I was wondering what the perspective is since one's opinions on them is mainly shaped by what they were using before.
I'll start, we were using a Richmond Solarbeam with a "10K" bulb and I put that in "" due to the fact that I've had a few guys tell me it's not close to actually being a 10K and more like a 6-7K output. I've said many times that I thought this expo unit was one of the best ever made and even now after using LED for a few months I feel even more solid about that. I can understand the opinions of the LED's being so high, especially if you were burning screens with flouro bulb units or lower powered metal halide units, but I'm really wondering if anyone has come from a 5K and up metal halide to an LED unit that thinks the LED is significantly better or even on par with the MH unit. There are still more pros for our LED than the MH but fully crosslinking the emulsion and getting full exposures is not one of them. Our MH unit outperforms the LED by a big margin when it comes to the most important part of the equation...burning the image completely through the layer of emulsion.
Has anyone come from a 5K Olec or one of the stronger Trilight units from M&R to an LED? I'm just looking for some perspective on how LED opinions have been formed. So if those of you who have gone LED could share what you were using previously and have time to compare/contrast the two I think it would be appreciated. I'm not knocking LED because even with my issues I think it's a better option than MH right now but in my opinion it's not superior in some ways that it's being assumed to be. It deserves praise but I think that we need to tap the brakes a little bit and put things in proper perspective so others who haven't pulled the trigger can get the whole story and one that isn't biased in any way.
* In May, this thread took off again, but devolved into mudslinging and arguments that obscured any real facts and information. I performed a little surgery, but there are probably still some statements that will seem a little odd in their new altered context. Otherwise, most will see it as a great improvement!
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I would assume most going to LED are doing so form lower power MH or even like you said florescent.
We came from an Ameragraph 150. 1200 watt I believe it is. Was great for a couple of years. Slowed way down over time, we were seeing exposure times of over 7 minutes on some screens by the time we retired it, and that was on new bulbs. Clearly was something up with it and I wasn't going to fart around trying to fix it. We haven't noticed any loss in detail ON press vs our MH. I am sure under a microscope some differences are there.
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Douthitt 1k MH
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I've asked many people in the industry (including those who make LED units), what the benefit of upgrading from a 2-screen capable 10k unit to LED would be, and haven't gotten a straight answer besides power consumption and bulb cost. Which is why I haven't looked into LED, and likely won't anytime soon. If my current unit crapped out, I'd probably buy this beast before I bought an LED and save some money in the process:
http://www.ebay.com/itm/Richmond-Screen-Maker-/221706439407 (http://www.ebay.com/itm/Richmond-Screen-Maker-/221706439407)
Maybe that's counterproductive and I'm living in the past, but to me, the ability to quickly burn multiple screens outweighs the power savings of an LED unit with one screen capability. Then again, my shop opened with a 2-screen capable 10k unit under the roof, so I can definitely understand the excitement of someone upgrading from a smaller bulb. I couldn't imagine waiting a few minutes to burn a screen, it would drive me nuts.
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MSP 3140 here.
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While I don't own a LED unit but had the the experience of testing one first hand in our shop, if our current unit broke down beyond repair I would buy one in a heartbeat. We have now a Atlas 5 way old unit that has something of a point light but quarts, using HXT, image mate dual cure 521 emulsion I get burn times of 3 minutes and 1.5 minutes with HXT holding great detail on yellow mesh, using 521 about 6 minutes on yellow just a little less on white mesh still holding good detail. Now exposing those same screens using the Starlight I think we burn at 8 to 10 seconds still holding with great detail, now the only advantage I see the LED over my old unit is speed and the cool factor of using LED and no heat build up on the glass plus the bulb life if I had to buy again yes I might go for the LED unit for those factors. Just got to say this last thing LED vs our old units to me is like Coke vs Pepsi they taste different for sure but in the end they are both still soft drinks and quench your thirst that's my take and I'm sticking to it ;D
darryl
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D- my starlight builds up heat if you burn 10 or so in a row....fyi
we didn't purchase our starlight for speed, we bought it to eliminate a variable. we now have a constant for exposure. a 180 S mesh, 1/1 with HXT is 70 seconds. all the time. every time. forever.
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D- my starlight builds up heat if you burn 10 or so in a row....fyi
we didn't purchase our starlight for speed, we bought it to eliminate a variable. we now have a constant for exposure. a 180 S mesh, 1/1 with HXT is 70 seconds. all the time. every time. forever.
Are you using HXT for everything? If you are doing plastisol runs, do you expose less time, or just run the same across the board? Just curious. I know if I use one for plastisol, I can expose 75% less cook time and be fine, just have to seriously bump up the time for the wb.
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On the other end of the spectrum, I did an install where the customer has been in business for many many years.
In their screen room, they still currently have 3 working competitor DTS machines (two of them are from the same company) and the 3rd is another Co. Now, they added the M&R STEII and will still be using the others. They first, got into DTS approx. 13 years ago or more and may have started and got rid of a 4th brand.
They expose 8 screens at one time. I looked to get the specifics on the exposure light but it was older and the info worn off.
It was a lamp that stands on a pole with one large tube in the center. I think they ma yahve had tow of them but mostly used one. The screen rm guys didn't know how strong the light was, but I imagine it had to be 7-10k
They use Dual Cure emulsion and their larger quantity orders can be over 10,20 and more pieces, but they do tons of low quantity orders at 1-4 colors as well. This is some of the info Al Buffington had been looking for. (large quantity using discharge and LED). Apparently, they had been doing discharge and large quantity for years with DTS but not with LED until now. Thye have have been doing LED for a while now and have not had any issues.
Considering the quantity of work they do per day, the # of screens they can already expose, it becomes interesting for them to make the decision to add another, using LED. The number of screens per day versus exposing one at a time on the STEII should be a wash on exposure time if not more time invested on exposure time compared to exposing 8 at time.
The benefit in this extreme situation (they might find) to be, the time it takes to 1st print a screen, then remove the screen, and load it, x 7 more, versus touching each screen once on the STEII. I can't say for sure. All I know is they decided it was worth going this way. For very large shops, they are looking at every little thing that can save a step that may justify a decision.
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Mike, we have a chart next to the unit that tells us times for selected screen / coating method and we go off that. We also add diazo but we do expose plastisol screens a bit shorter. We had 2 different emulsions and all that mess but we have nothing but HXT now. If I had a MH unit, I think I would pass on this emulsion but with our set up, we are happy...now I just need cts and watch the detail come to life.
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Based off what I learned from my DIY LED project, I'm sticking with my 5k Olec for as long as I can keep it alive. LED will serve as a solid backup if the Olec goes down, but it's not a replacement.
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We're currently using two 1200 watt MH units to keep up with screen production. We use SP-1400 diazo emulsion,
probably one of the more difficult emulsions to fully expose. I'd start exposing with a candle before I switched
emulsions, I like the stuff that much.
Our exposure times are long, 4-600 LTUs, probably roughly five minutes, never timed one though.
Obviously it would be a no brainer if we could significantly reduce that time. Not to mention heat, power
consumption, bulb replacement, etc.
I am absolutely unwilling to sacrifice image quality and complete exposure for the above mentioned benefits however.
I'd sooner buy a couple 8K Olec's and to hell with the bulbs and power costs.
So far I have been unable to get a straight answer, from either manufacturer or user, as to whether or not
I'd have to accept a degradation in screen quality from a LED unit for diazo emulsions. Every time I ask for
quantifiable information all I get back is "it's so fast". I hear whispers from trusted sources that my assumptions are
correct though, this post being yet another one.
It seems the majority of LED units are being used with photopolymer emulsions, which is kind of confusing as
exposure times with most MH units are going to be in the sub-minute range already, and going from 50 seconds
to 10 with the possibility for less complete control seems like a losing game. I guess if you were coming from
fluorescent it would make sense. Indeed, Workhorse's LED user manual states that the machine is intended for
use with photopolymer emulsions.
That one MFG has a generous return policy, but I'd honestly feel bad about sending the thing packing right back if it
doesn't cut the mustard. I'd rather know the straight dope beforehand.
So, really, honestly, diazo and LED, yay or nay?
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Mike, we have a chart next to the unit that tells us times for selected screen / coating method and we go off that. We also add diazo but we do expose plastisol screens a bit shorter. We had 2 different emulsions and all that mess but we have nothing but HXT now. If I had a MH unit, I think I would pass on this emulsion but with our set up, we are happy...now I just need cts and watch the detail come to life.
Thanks for the feed back bro. I'm still using both Chroma blue and HXT and getting tired of having both on hand. I love HXT, If I could expose it faster that would really help to go with it exclusively. That stuff holds such awesome detail and is rock solid, and really good price as well. I've been looking at the Starlight, and the CCI unit, the one CCI has now is kinda big, can do up to 4 23x31 screens at 1 time, stands vertically which is reaaaaaally nice, but I was just told by my rep that they are launching 2 new units that are smaller, can shoot 2 23x31 or 2 25x36 at once, and will have more of the multispectrum led lights than anything on the market today. What is attracting me to that one is the vertical mounting of it, takes up no space at all, and they are developing it around the use of diazo and dual cure emulsions that they make. We will see, we are in the middle of lots of big decisions right now and it gets freakin overwhelming and stressful to say the least. One thing HXT does stink bad when exposing, really noticeable now that I am in a dedicated imaging room. I'm putting a couple of duct hoses on the blowers of my Trilight to send that stank outside, but if we go LED, that wont be an option and will probably have to put an exhaust fan in for use during exposures. In the confined space it gets overwhelmingly stanky , lol. Sorry for the topic derail.
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Stay tuned. We're about to make this comparison, in as scientific a manner as possible. 5kw halide, dialed in with the highest quality bulb, new photocell and good integrator shooting 2up v starlight led shooting 1up. High d max, good d min film. Exposure time, exposure quality, power consumption, resolution will be the main points of comparison. If anyone wants me to add another item to the testing or has suggestions please let me know. I'm hoping to get an accurate handle on of this tech is ready for prime time.
Sent from my SM-G900V using Tapatalk
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What emulsion(s) Chris?
I look forward to your feedback, I know we're pretty similar in our demands from our screens.
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No problems here with sp1400 and our led unit... we've only done a few discharge runs with it at 1000 and 1500 . Plastisol we've done 10k on a screen with no issues. Good enough for us.
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Have you noticed any degradation in image quality/complete exposure? And "Before You Went LED, What Were You Using?"
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Stay tuned. We're about to make this comparison, in as scientific a manner as possible. 5kw halide, dialed in with the highest quality bulb, new photocell and good integrator shooting 2up v starlight led shooting 1up. High d max, good d min film. Exposure time, exposure quality, power consumption, resolution will be the main points of comparison. If anyone wants me to add another item to the testing or has suggestions please let me know. I'm hoping to get an accurate handle on of this tech is ready for prime time.
Sent from my SM-G900V using Tapatalk
Not to give you crap for impending interesting free info, but why MH 2-up and LED 1-up?
Sounds like it would be a little 'off' from an apples to apples type comparison.
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Pretty good thread so far and amazingly has stay on the same topic ;D, but to toss one in the companies that make the LED units, I would think these guys put millions of dollars into it and use some of the best equipment they could possible have to make sure this thing worked like they advertised, now my question is how many of our shops are going to hold up to the standards they used to R&D these units? I know whats going on here is real world testing that we all do in our shops day in and day out which is going to be different...I know some of you have some pretty nice shops with top notch equipment, this is going to be a good tread for people looking into a LED unit.
darryl
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Under a scope I can see slightly less quality with the LED but for the most part it's relatively the same between the two light sources. I do have issues with getting a full exposure according to the expo calculator versus how the screen holds up on press. I've said it a few times here but we've NEVER had screens break down at the squeegee blade edges until we started using the LED unit and now it's an issue even with over-exposing screens. That tells me it's simply not cross-linking the entire layer of emulsion. It passes the calculator test with flying colors but on-press it doesn't pass the test. It's frustrating and I know with a big discharge job we will have problems. Interestingly enough we haven't had hardly any DC jobs since buying the LED. I'm ok with that though.
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Stay tuned. We're about to make this comparison, in as scientific a manner as possible. 5kw halide, dialed in with the highest quality bulb, new photocell and good integrator shooting 2up v starlight led shooting 1up. High d max, good d min film. Exposure time, exposure quality, power consumption, resolution will be the main points of comparison. If anyone wants me to add another item to the testing or has suggestions please let me know. I'm hoping to get an accurate handle on of this tech is ready for prime time.
Sent from my SM-G900V using Tapatalk
Not to give you crap for impending interesting free info, but why MH 2-up and LED 1-up?
Sounds like it would be a little 'off' from an apples to apples type comparison.
I'm guessing that is is a unit size issue, but nonetheless, could still each be done 1-up to even the playing field if needed.
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D- my starlight builds up heat if you burn 10 or so in a row....fyi
we didn't purchase our starlight for speed, we bought it to eliminate a variable. we now have a constant for exposure. a 180 S mesh, 1/1 with HXT is 70 seconds. all the time. every time. forever.
Even with the 2 fans going in the back?
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Still on the fence with LED, there are other things to spend money on first here. But, we've always had Violux 5000S metal halide, would never have considered a lesser source, though when I started, it was for a good sized company that bought good equipment, so later on anything smaller and less expensive was just not considered, not trying to be snooty or anything. I do like the drop in electricity though, and the lack of heat, and of course I keep up with everyone's writings...
Steve
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eb, we HXT with Diazo....it's s hybrid of sorts....yay.... I'll buy a gallon of the 1400 and see what happens. again, I don't give two sh*ts and a f*k about speed so I'm not going to toot the horn of speed....
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Emulsions to be tested are Xenon Nova with Diazo and Murakami Aquasol HVP. This is what we know and use and while the Nova is a photopolymer, it behaves much like a dual cure when sensitized.
Shooting 1up on Starlight (largest model) because the unit will not shoot 23x31 2up. If it was simply 6" wider it would.
We could reposition the halide to the glass optimize for 1up shooting. However, the SW reflector we're using while it is optimized to shoot closer to glass may have inferior resolution if placed that close to glass. The Olec reflectors are engineered to shoot their most collimated/collinear light on a somewhat larger area than 1up 23x31 according to my understanding so this might still not be apples to apples if we optimize the Olec for 1up as it's resolution could potentially get thrown off. Please correct me if I'm wrong on that.
Also, give me all the crap you can sling! Challenge every assumption and consider every angle of this with me. After all, if we aren't as thorough as possible, what's the point? We have an opportunity in our shop to give these two methods a quality comparison, something that appears to not have been done so far. The bulk of the info on LED that we have is not empirical. That's not to say there isn't harder data to back up the claims but aside from "very fast", "lots of LEDs" and "high output LEDS", etc. we're missing critical information from the manufacturers at this point some of it very notably absent, such as the attached for our current halide bulb.
This might take up to a month to see all the results because we're busy and I want to take time to do it right.
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Can I send you a gallon of 1400 to compare on the two units?
While I appreciate your testing as well Homer, I don't know that you'd notice much
difference unless you have a MH unit to compare it to.
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Can I send you a gallon of 1400 to compare on the two units?
While I appreciate your testing as well Homer, I don't know that you'd notice much
difference unless you have a MH unit to compare it to.
Have one on hand. It's a little under a year old but not sensitized. We may be able to sneak this in. I'm open to getting 1400 in the mix to round out the spectrum of emulsions though since we'll then have a pure photopolymer, a dual cure diazo (essentially that's what the nova is or behaves like when sensitized) and a straight diazo.
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We're currently using two 1200 watt MH units to keep up with screen production. We use SP-1400 diazo emulsion,
probably one of the more difficult emulsions to fully expose. I'd start exposing with a candle before I switched
emulsions, I like the stuff that much.
Our exposure times are long, 4-600 LTUs, probably roughly five minutes, never timed one though.
Obviously it would be a no brainer if we could significantly reduce that time. Not to mention heat, power
consumption, bulb replacement, etc.
I am absolutely unwilling to sacrifice image quality and complete exposure for the above mentioned benefits however.
I'd sooner buy a couple 8K Olec's and to hell with the bulbs and power costs.
So far I have been unable to get a straight answer, from either manufacturer or user, as to whether or not
I'd have to accept a degradation in screen quality from a LED unit for diazo emulsions. Every time I ask for
quantifiable information all I get back is "it's so fast". I hear whispers from trusted sources that my assumptions are
correct though, this post being yet another one.
It seems the majority of LED units are being used with photopolymer emulsions, which is kind of confusing as
exposure times with most MH units are going to be in the sub-minute range already, and going from 50 seconds
to 10 with the possibility for less complete control seems like a losing game. I guess if you were coming from
fluorescent it would make sense. Indeed, Workhorse's LED user manual states that the machine is intended for
use with photopolymer emulsions.
That one MFG has a generous return policy, but I'd honestly feel bad about sending the thing packing right back if it
doesn't cut the mustard. I'd rather know the straight dope beforehand.
So, really, honestly, diazo and LED, yay or nay?
You are more than welcome to try our unit and I assure you your diazo will not be an issue. Try the Starlight and you won't have to feel bad about returning it, because you wont!!!!
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And that Rich is why we're trying it. Nobody else is backing their unit with that kind of confidence. ebscreen and also myself just feel bad about the potential of returning something like this, the thought of it just makes my stomach turn given all the hassles with our particular shipment issues. I'm rooting hard for the starlight.
Also, I have an email in to Patrick requesting graphs on the UV output which would be immensely helpful in comparing what our halide bulb is outputting to the LED array's spectral output.
There's a lot of talk going around regarding developments in multi spectral LEDs. Multi spectrum rich exposure light in the correct range is a proven benefit to stencil durability. It seems that most are reporting good imaging but mixed reports on stencil durability. Does M&R plan to look into more spectral rich LEDs and if so, will it be available as an upgrade on existing units?
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Over my many years with NuArc I have serviced and sold many different light sources that have been used in Litho and Screen Print, so I am very familiar with testing and comparing different light sources. In reading thru this and other similar posts concerning the comparison of LED units to MH and other units I feel a couple of important things are being overlooked.
The first is that many of the comments about LED exposure units are treating them like they were all the same thing. That is not true, there are a number of different LED units that are available today and they should not be lumped into one category. So keep in mind that there are a number of differences in LED Exposure Units when comparing units or using someone else's comparisons. The best way to compare or judge is to do a live demo on a unit with your artwork on your screen, then you can judge the results.
The second thing I have found from going into a lot of shops doing demos is that there are also a lot of variables beyond just the brand or type of emulsion. The way the screens are coated, handled and stored can affect the outcome. What one shop considers a good exposure might be unacceptable in another shop. When we began designing our LED units speed was not our main goal; but when our engineering came up with the type of LED's we should use, and the distance between the LED's to give the best overall coverage it was found to be a rather fast exposure unit. In reading the comments about SBQ being the primary emulsion for LED's, I do not feel that is an accurate portrayal of what I see in the field. One shop may be very happy with a particular emulsion and another shop using the same emulsion finds it too fast. So yes, some are using SBQ with our Starlight units, while others have changed to Dual Cures and Diazos to get the results they are looking for. In fact some shops found the SBQ emulsions were too fast and have switched for that reason.
Ron Hopkins
NuArc Sales Mgr.
M&R Sales and Service co.
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Mike, we have a chart next to the unit that tells us times for selected screen / coating method and we go off that. We also add diazo but we do expose plastisol screens a bit shorter. We had 2 different emulsions and all that mess but we have nothing but HXT now. If I had a MH unit, I think I would pass on this emulsion but with our set up, we are happy...now I just need cts and watch the detail come to life.
Thanks for the feed back bro. I'm still using both Chroma blue and HXT and getting tired of having both on hand. I love HXT, If I could expose it faster that would really help to go with it exclusively. That stuff holds such awesome detail and is rock solid, and really good price as well. I've been looking at the Starlight, and the CCI unit, the one CCI has now is kinda big, can do up to 4 23x31 screens at 1 time, stands vertically which is reaaaaaally nice, but I was just told by my rep that they are launching 2 new units that are smaller, can shoot 2 23x31 or 2 25x36 at once, and will have more of the multispectrum led lights than anything on the market today. What is attracting me to that one is the vertical mounting of it, takes up no space at all, and they are developing it around the use of diazo and dual cure emulsions that they make. We will see, we are in the middle of lots of big decisions right now and it gets freakin overwhelming and stressful to say the least. One thing HXT does stink bad when exposing, really noticeable now that I am in a dedicated imaging room. I'm putting a couple of duct hoses on the blowers of my Trilight to send that stank outside, but if we go LED, that wont be an option and will probably have to put an exhaust fan in for use during exposures. In the confined space it gets overwhelmingly stanky , lol. Sorry for the topic derail.
Hey Mike, get your rep to get you a sample of DC Plus, we are FINISHED with HXT and on to DC Plus, its a dual cure and green and we are really digging it. I havent tried discharge with it yet, but a big shop up from us uses it on everything and they do tons of WB and Discharge. Also, I was told that CCI did a scientific study and proved that green emulsions hold better detail than any other color.....
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Mike, we have a chart next to the unit that tells us times for selected screen / coating method and we go off that. We also add diazo but we do expose plastisol screens a bit shorter. We had 2 different emulsions and all that mess but we have nothing but HXT now. If I had a MH unit, I think I would pass on this emulsion but with our set up, we are happy...now I just need cts and watch the detail come to life.
Thanks for the feed back bro. I'm still using both Chroma blue and HXT and getting tired of having both on hand. I love HXT, If I could expose it faster that would really help to go with it exclusively. That stuff holds such awesome detail and is rock solid, and really good price as well. I've been looking at the Starlight, and the CCI unit, the one CCI has now is kinda big, can do up to 4 23x31 screens at 1 time, stands vertically which is reaaaaaally nice, but I was just told by my rep that they are launching 2 new units that are smaller, can shoot 2 23x31 or 2 25x36 at once, and will have more of the multispectrum led lights than anything on the market today. What is attracting me to that one is the vertical mounting of it, takes up no space at all, and they are developing it around the use of diazo and dual cure emulsions that they make. We will see, we are in the middle of lots of big decisions right now and it gets freakin overwhelming and stressful to say the least. One thing HXT does stink bad when exposing, really noticeable now that I am in a dedicated imaging room. I'm putting a couple of duct hoses on the blowers of my Trilight to send that stank outside, but if we go LED, that wont be an option and will probably have to put an exhaust fan in for use during exposures. In the confined space it gets overwhelmingly stanky , lol. Sorry for the topic derail.
Hey Mike, get your rep to get you a sample of DC Plus, we are FINISHED with HXT and on to DC Plus, its a dual cure and green and we are really digging it. I havent tried discharge with it yet, but a big shop up from us uses it on everything and they do tons of WB and Discharge. Also, I was told that CCI did a scientific study and proved that green emulsions hold better detail than any other color.....
Emailing him right now!!! Thanks buddy! I was going to try out some Ulano Orange too, but may not waste time or a vendor's sample gallon
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I wish I could have done what Zoo is going to do. Our Richmond is out of commission but it only needs a new control panel to work but it needed new glass, new bulb, new blanket, and a few other things and we needed something ASAP due to our schedule being beyond full so we had to pull the trigger on an LED quicker than I would have liked to. I understand that the two major issues I have with our Vastex have been upgraded but that doesn't do me any damn good at this point.
Looks like the average would be a 1000-1200 metal halide unit. A few Richmond Solarbeam users as well. Anybody else want to add anything?
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A month? Don't rush yourself now.
Only reason I mention it is the idea that if you could cut that distance by 30%, as you well know, that will be a much larger than 30% increase in light energy delivered to the stencil.
Unfortunately, I am not the wizard of Olec reflectors you are looking for. (I think his last name is "Diehl"? :) )
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Old set-up:
1200W MH
Dual-cure emulsion
4 minutes exposure
5 minute warm-up before first screen
New set-up:
200W LED (1800 diode 5050-SMD retrofit)
pure photo emulsion
25 second exposure
no warm-up time
Not sure if I lost some detail with the emulsion switch, but for now I'm sticking with LED
Getting away from the lamp warm-up time was attractive to me.
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New set-up:
200W LED (1800 diode 5050-SMD retrofit)
Where did you get this. Can you give more details?
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New set-up:
200W LED (1800 diode 5050-SMD retrofit)
Where did you get this. Can you give more details?
It's a DIY... PM sent
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A fricken Workhorse Halogen exposure unit...uggg...
If anyone wants to come test stuff out on our Starlight you are more than welcome. We are in KC, MO.
Also...
Has anyone built a stand to place the Starlight vertically?
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A fricken Workhorse Halogen exposure unit...uggg...
If anyone wants to come test stuff out on our Starlight you are more than welcome. We are in KC, MO.
Also...
Has anyone built a stand to place the Starlight vertically?
Let me know what you need.
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Old set-up:
1200W MH
Dual-cure emulsion
4 minutes exposure
5 minute warm-up before first screen
New set-up:
200W LED (1800 diode 5050-SMD retrofit)
pure photo emulsion
25 second exposure
no warm-up time
Not sure if I lost some detail with the emulsion switch, but for now I'm sticking with LED
Getting away from the lamp warm-up time was attractive to me.
Modified due to a manufacture contact, they are wanting to come test the unit.
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Ask yourself this first. What emulsion in the last 20 years has been developed with LED in mind? Who is selling the LED units? How much research have they really put into this.
It's always the new things that should make our job easier,faster and better that we look for. We used a LED for 3 months and thought we had solved the worlds problems BUT we were wrong. We changed back to MH and our trouble went away after 1 day. When we first placed our LED in service we did all the normal exposure test with excellent results a hard 6 and a soft 7. We were thrilled!!! After a few days we noticed our ink was not clearing in one stroke. Without thinking we blamed it on everything else. We sharpened our Squeegees. We tried different inks and adjusted our pressures and stroke speeds. we checked our screens with a 30 power loop and they all looked great. So we continued to chase our tails for another month until one of our bulb banks went out. The LED unit was giving us such good halftones we even had to choke back some of our art to keep PrePrints looking the same.
All that being said we switched back to MH because of our LED failure and to get it fixed and in one day all of our problems were gone.
EOM is the enemy of led we measured ours before and after exposure and found that we were losing 20 to 35 precent on developing (Rinsing Out) we cannot get it to cross link the 2 sides. I use pure photopolymer and have blazing fast exposure times 15 to 20 seconds. We have a CTS wax jet and do about 60 to 90 screens a day. Our ink side was not the same using LED and we lost most of our ink well not knowing. Im not saying this will happen to everyone but it happened to us and we are glad we switched back. Ask someone in the exposure business who has tested the LED what there thoughts are before making the switch. I wont go back until Emulsion come with a label on it that says LED TESTED and APPROVED!!!!! Don't be fooled by equipment salesmen.
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Yep, metal halide here until emulsion manufacturers catch up.
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Ask yourself this first. What emulsion in the last 20 years has been developed with LED in mind? Who is selling the LED units? How much research have they really put into this.
It's always the new things that should make our job easier,faster and better that we look for. We used a LED for 3 months and thought we had solved the worlds problems BUT we were wrong. We changed back to MH and our trouble went away after 1 day. When we first placed our LED in service we did all the normal exposure test with excellent results a hard 6 and a soft 7. We were thrilled!!! After a few days we noticed our ink was not clearing in one stroke. Without thinking we blamed it on everything else. We sharpened our Squeegees. We tried different inks and adjusted our pressures and stroke speeds. we checked our screens with a 30 power loop and they all looked great. So we continued to chase our tails for another month until one of our bulb banks went out. The LED unit was giving us such good halftones we even had to choke back some of our art to keep PrePrints looking the same.
All that being said we switched back to MH because of our LED failure and to get it fixed and in one day all of our problems were gone.
EOM is the enemy of led we measured ours before and after exposure and found that we were losing 20 to 35 precent on developing (Rinsing Out) we cannot get it to cross link the 2 sides. I use pure photopolymer and have blazing fast exposure times 15 to 20 seconds. We have a CTS wax jet and do about 60 to 90 screens a day. Our ink side was not the same using LED and we lost most of our ink well not knowing. Im not saying this will happen to everyone but it happened to us and we are glad we switched back. Ask someone in the exposure business who has tested the LED what there thoughts are before making the switch. I wont go back until Emulsion come with a label on it that says LED TESTED and APPROVED!!!!! Don't be fooled by equipment salesmen.
not all LED units are the same. Here at M&R a tremendous amount of testing has been done not only by U.S. But emulsion suppliers as well. We have not experienced what you describe. I would not write off all LED units based on your experience.
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I agree with the frustration in the LED units. As all LEDs are not created the same way. I am up for the challenge at the Indy NBM show, let's see what they can do on Diazo emulsions.
www.brownmfg.net (http://www.brownmfg.net)
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Sounds like we need to add some healthy EOM coatings or even thick Cap film into the test mix.
Most shops will not want to have two different units, but maybe that would be ideal.
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We have also seen issues with ink not clearing, and we've had a bunch of screens lock up on us if we used screen opener in them to do a color change or change inks in a screen, it's frustrating having issues that you've never had before. You start to second guess yourself, start to buy into all the great reviews which I'm not casting doubt on, but you have to take some with a grain of salt. There are plenty of guys who post here that when they type something, I treat it as gospel, I don't have to second guess it or wonder if they really did their due diligence. But the reason I say this stuff is one day we're cruising along without any screen making issues, next day strange things start happening and if EVERY fantastic LED review on the forum were completely factual, the issues wouldn't have started happening the very first day you put a new exposure unit into production. I do feel there is a difference in LED output among the different brands, but I've seen conflicting information as well regarding the UV output from competing units. Some are going to shake their heads in disagreement when I say this, some are going to say amen, but I feel very strongly that the best MH units will outperform the best LED units when it comes to fully cross-linking MOST emulsions and it's not that close of a comparison. Now I will admit, we don't have the unit that I consider to be the best LED unit on the market so I can't be 100% sure of this. I have seen and heard a lot from other LED users that came from really good MH units that have had similar experiences to what we've had and they didn't all have the same brand LED.
This is going to sound harsh, but I've had some trust issues with a manufacturer or two with equipment and some of the mistrust is absolutely warranted in my opinion. How could a manufacturer put out an exposure unit that had outrageously long vacuum draw downs? Seems like if something that simple was messed up, the more difficult aspects of building an exposure unit could very well be wrong. One could argue that maybe they spent so much time fine tuning the more important parts of the unit that they overlooked the simple things, but if LED units are being sold with speed being one of the most important variables, isn't vacuum draw down a HUGE part of how fast a unit can expose screens?
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Alan,
does your screen loop allow you to expose, soak, rinse, place in drying rack and tape up two more screens in less time than the draw down of the exposure... if not I am not seeing the issues. I have the same unit as you and was disappointed at first with he 45 second draw down but soon realized it was of little significance in real time screen making for my shop.
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I think like many things out there as soon as someone builds a X then others build it as well, its assumed they are all equal or similar. I think its clear that's not the case with most things. Now I don't assume we have the BEST LED out there, but I do know we aren't having screens lock up on ink changes. We do ink change overs almost daily.
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Success on press notwithstanding, I am now interested in quantitative readings of comparative EOM with all things other than light source being equal.
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Success on press notwithstanding, I am now interested in quantitative readings of comparative EOM with all things other than light source being equal.
Very interested in this as well, simple enough test to perform for those with the tools....
I feel I should mention the reason for us sticking with MH for now is largely because we use diazo emulsion
only. I think (know from experience) that you can underexpose photopolymers to retain detail, baby it through
developing, and post expose in the sun and get a pretty well usable screen. Not ideal in the slightest but probably
pretty common practice.
With diazo we expose for an inordinate amount of time, retain excellent detail, blast with reclaim pressure washer
to develop, and don't post expose. We then beat the brakes off our stencils on press, we're about to print across 600 zips
with discharge. I got 99 problems but a properly exposed screen ain't one.
It would be cool if people mentioned what emulsion(s) they're using as that's the make or break with LED.
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Success on press notwithstanding, I am now interested in quantitative readings of comparative EOM with all things other than light source being equal.
Very interested in this as well, simple enough test to perform for those with the tools....
I feel I should mention the reason for us sticking with MH for now is largely because we use diazo emulsion
only. I think (know from experience) that you can underexpose photopolymers to retain detail, baby it through
developing, and post expose in the sun and get a pretty well usable screen. Not ideal in the slightest but probably
pretty common practice.
With diazo we expose for an inordinate amount of time, retain excellent detail, blast with reclaim pressure washer
to develop, and don't post expose. We then beat the brakes off our stencils on press, we're about to print across 600 zips
with discharge. I got 99 problems but a properly exposed screen ain't one.
It would be cool if people mentioned what emulsion(s) they're using as that's the make or break with LED.
When all other factors are correct, this should not be necessary. For as long as I can remember, even before Photopolymer emulsions were used, underexposure was the most common issue/problem when it came to making screens.
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We use Diazo, never tried anything else on our LED. Never had a reason to yet I guess.
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Indeed. I will say that for a long time with photopolymer we struggled between developing low range halftones and not blasting out the mids.
It was always a delicate dance at the development sink. So much so, that, I don't mean to be rude, but for any kind of serious detail
work I can't see how people aren't using diazo. It was that much of a game changer here that I'm putting up with extensively long exposure
times. The diazo is in the details.
It would also be cool if people would mention what LED unit they are/were using, particularly the fella that conjured this thread from
the grave. While I'm certain not all units/lights are the same, they still are all using LED's. Just like a Chevy is different than a Toyota,
they're both still trucks, and neither is an airplane.
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SP1400 and SP1400W here... Diazo emulsion...
Starlight 2331
no problems with halftones...
SP1400W exposure times on a 160S are at 40 sec... 225S around 22 seconds...
solid 7 step on the stouffer strip.
now that we're going back to standard SP1400 I'll have to redo our exposure times... last year we were around 34 or so for our 160S screens. I'll post up later once I re-dial the SP1400 with our good bucket of emulsion.
no problems on long runs.
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Alan,
does your screen loop allow you to expose, soak, rinse, place in drying rack and tape up two more screens in less time than the draw down of the exposure... if not I am not seeing the issues. I have the same unit as you and was disappointed at first with he 45 second draw down but soon realized it was of little significance in real time screen making for my shop.
I see what you're saying, but I don't want to judge something's speed based on what I can get done in the meantime while it's doing it's thing. Sure, I can tape up film, be on the pressure washer developing another screen while I'm waiting for 65 seconds for the vacuum, but what about all the times when I'm just burning one screen, or there is 2 of us running the developing loop? I can always fill the space with something, but if I had a unit that drew down in 15 seconds I'm saving 50 seconds per shot, times 25-40 shots per day...that's how I am looking at it. You make a damn good point, and I could do things in a way that the extra 50 seconds could be filled doing something else, but I argue that there shouldn't be an exposure unit in the world that takes longer to draw down than it does to burn the image. I'm not right, you're not wrong, it's different perspectives from different people trying to accomplish the same task.
We use pure photopolymer almost exclusively and the Richmond unit spoiled us I guess. We could shoot 55-65 line halftones and develop those halftones well into the difficult ranges on both sides, now it's a lot more difficult. I'm not trying to put this shop on a pedestal, but shooting sim process screens was extremely easy with the Richmond, if we needed to hold dots below the 5% mark sure we'd underexpose a little bit, but if I want to hold those same dots with the LED, I'm going 50% less than I should be, and you all know what's happening with that screen after that. Emulsion locking up during reclaim, weak stencil, yes, we can post expose but that all goes back to the precedent that was set with the MH and not having to do all the extra work to get a 280/34 with 55lpi halftones on it to hold up to 1000 imprints. I'm not liking having to do the "dance", I'd rather just get to the bedroom if you know what I'm saying :). Our whole production philosophy is based off of squeezing every second we can out of every process. When we go CTS I won't have to complain about vacuum times but for the near future I have to deal with it, and also with underexposed screens, weak stencils, on-press breakdown, pinholes, 10 screens per hour being reclaimed, etc. I don't know that CTS will fix all those issues, but I'm sure it will a few.
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I get what you are saying Alan... trying to have the perfect anything in an un-perfect world can be very taxing on ones energy.
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You've already located your fix Alan, CTS!
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We use Diazo, never tried anything else on our LED. Never had a reason to yet I guess.
What brand Brandt?
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We use Diazo, never tried anything else on our LED. Never had a reason to yet I guess.
What brand Brandt?
Chromaline
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Any particular flavor of Chromaline?
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Just saw on Chromaline's website they have a "UV LED compatible emulsion".....
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Just saw on Chromaline's website they have a "UV LED compatible emulsion".....
Diazo? Ill have to look at that.
Any particular flavor of Chromaline?
DZ 307 Blue
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Nope, photopolymer, but the first mention of a LED specific emulsion I've seen yet.
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Nope, photopolymer, but the first mention of a LED specific emulsion I've seen yet.
I was gonna say that seems like a first, not seen any anyway.
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Not to pile on but we just had a real-world failure on a sim process job that I was talking about earlier. The red wasn't quite right, so we took our bright red out, against my better judgement I tried cleaning the screen so there would be no contamination (in hindsight there wasn't much chance of noticeable contamination) and it was more habit than trying to stop it from happening, and the halftone area of the stencil locked up about 70%. The open area of the axe blade (fire fighter design) cleaned just fine, but the fire/flame area was 55lpi halftones and they locked up and we had to break it down and shoot another red screen. So this little issue we're discussing has cost us about 30 minutes today. Luckily we're ahead of schedule and we're not rushing to get things done, but this is a great example of how things in pre-press affect things on press. I could have exposed the screen for 60 seconds and not gotten a lot of the halftones out, or run the risk of underexposure coming back to bite us down the road. I would have post exposed with the sun but it's raining here and I am not in the habit of post exposing screens and I sure hope it doesn't come to that.
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What made you pick the unit you picked? Sounds like it's not working for you at all really.
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What made you pick the unit you picked? Sounds like it's not working for you at all really.
that's what I was thinking, why that unit? Get an M&R in there to compare, perfect time for Rich to put a demo unit in your shop to compare and prove a point. We use HXT with Diazo for added detail and we have zero complaints...... Hell, look at Danny's prints with the STE II or whatever it is, you're telling me LED is bunk? I don't believe all units are the same for a second...
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Not to pile on but we just had a real-world failure on a sim process job that I was talking about earlier. The red wasn't quite right, so we took our bright red out, against my better judgement I tried cleaning the screen so there would be no contamination (in hindsight there wasn't much chance of noticeable contamination) and it was more habit than trying to stop it from happening, and the halftone area of the stencil locked up about 70%. The open area of the axe blade (fire fighter design) cleaned just fine, but the fire/flame area was 55lpi halftones and they locked up and we had to break it down and shoot another red screen. So this little issue we're discussing has cost us about 30 minutes today. Luckily we're ahead of schedule and we're not rushing to get things done, but this is a great example of how things in pre-press affect things on press. I could have exposed the screen for 60 seconds and not gotten a lot of the halftones out, or run the risk of underexposure coming back to bite us down the road. I would have post exposed with the sun but it's raining here and I am not in the habit of post exposing screens and I sure hope it doesn't come to that.
What did you use as a cleaner?
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at Allan, you mentioned cutting back on exposure time by 50% to hold the dots below 5%. Is that correct?
That sounds very odd to me. Don't know anyone that must do that to a hive small dots on LED. No matter the brand from what I've heard. Not that I know a lot of the others.
I've seen people cost 2/2 round and still hold the small dots. ( not that I would choose to do that).
I see a lot of "different" coating techniques. One was even a 1 coat. Period. Only one side (shirt side) was coated....with an auto coater (on all screens) ranging from 110-305. Again I say tho, who am I to question them. This was a mega shop with 21 autos. Been in business for years.
The image quality compared to MH is for what? What more image quality are we looking for than an award winner using LED? That seems to imply one might achieve better than the LED award winners using MH. How much more image quality do we need to define? I'm open to see it. I just haven't seen print results any better or worse with MH over LED by comparable shops.
Gotta run.
(edited for my phone post spelling and word replacement).
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Different shops demand different things from their screens. Different shops also have differing opinions of a quality stencil.
Sim-process plastisol is not the most demanding application we run into, pretty low on the list actually.
It just reminds me of the early dot com craze when everyone was ordering groceries online. Scaled that back pretty quick.
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What made you pick the unit you picked? Sounds like it's not working for you at all really.
I bought into the hype I guess. I was in a bind, crazy busy, the Solarbeam's membrane panel buttons stopped working one day, I knew my supplier had a good unit for sale and we pulled the trigger. I guess I could have waited a few days, but I thought the Vastex was going to kick butt and I hate that my posts make it sound like a piece of junk, it's not as bad as it sounds. But when you come from one of the best expo units ever made, it sure sounds like I want to throw it away. I don't think the Vastex is the best unit, but I don't think it's the worst. And if it weren't for the vacuum time I'd probably be very happy and just work through the other problem of not cooking the stencil thoroughly enough. I'm thinking the M&R doesn't have the same issues because it has about 4 times the amount of diodes as our Vastex, and perhaps they're a better, more complete UV emitter and therefore no Starlight users are having underexposure issues. These really are more 1st world problems, that's why I'm simply trying to give the bad along with the 99% of reviews that are nothing but the good. Most of the CTS talk is that way as well, you hear nothing but the greatness in public, but you get behind the scenes and there are plenty of issues. They're not deal-breaking issues, it's just in stark contrast to what you read on this forum is why it's somewhat jarring to hear about.
at Allan, you mentioned cutting back on exposure time by 50% to hold the dots below 5%. Is that correct?
That sounds very odd to me. Don't know anyone that must do that to a hive small dots on LED. No matter the brand from what ive heard. Not that I know a lot of the others.
You've heard of that technique before haven't you, just not with the LED's I guess? I thought it was VERY common to underexpose to get some of the finer details. The density isn't there with those 5% dots and since our old artist left we've struggled a little with our film density. It's not terrible, but it's not as good as it was a year ago. Sim process screens have always been a breeze, and if you have a strong light source, they should always be.
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What made you pick the unit you picked? Sounds like it's not working for you at all really.
I bought into the hype I guess. I was in a bind, crazy busy, the Solarbeam's membrane panel buttons stopped working one day, I knew my supplier had a good unit for sale and we pulled the trigger. I guess I could have waited a few days, but I thought the Vastex was going to kick butt and I hate that my posts make it sound like a piece of junk, it's not as bad as it sounds. But when you come from one of the best expo units ever made, it sure sounds like I want to throw it away. I don't think the Vastex is the best unit, but I don't think it's the worst. And if it weren't for the vacuum time I'd probably be very happy and just work through the other problem of not cooking the stencil thoroughly enough. I'm thinking the M&R doesn't have the same issues because it has about 4 times the amount of diodes as our Vastex, and perhaps they're a better, more complete UV emitter and therefore no Starlight users are having underexposure issues. These really are more 1st world problems, that's why I'm simply trying to give the bad along with the 99% of reviews that are nothing but the good. Most of the CTS talk is that way as well, you hear nothing but the greatness in public, but you get behind the scenes and there are plenty of issues. They're not deal-breaking issues, it's just in stark contrast to what you read on this forum is why it's somewhat jarring to hear about.
I think a lot of what you hear in relation to CTS is no different than what you did in your LED unit. When you got your Vastex it was all good it seemed. Time marches on and things you thought would be flukes or whatever end up being bigger deals. That's how it was with me with our original CTS. It was Epson based, and that's really all I have to say about it. If your running a EPSON without any issues your the man as our 4880 while a great printer had hiccups pretty often and they were similar to the issues where were seeing in the original CTS we purchased. Even still the unit worked fine otherwise. Final straw with us with Cartridge issues, which were Epson issues and the chip reset would no longer reset a Cartridge. ST has nothing like that so that alone was a huge bonus.
Our current ST, I have not a single complaint about it to this point, the only thing I even had issue with on the new one is learning/adjusting to the difference in curves going from Epson/accurip to ST. There were differences but we got it now.
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The earliest discussions I had with some knowledgeable industry guys all told me the same thing about CTS, "hold on a little while longer, it's almost right" which was right in line with what I saw and what I'm seeing now, and Brandt's experience plays that out right on the money. I think it's right, the little nagging issues that I have always hated dealing with are likely behind the major CTS players and LED seems to be playing the same way. I do think it's a much shorter curve to get LED right versus the CTS machines, but I still think the first few years are spent fine-tuning them, which is no different than any equipment in any industry. In our case it was just the luck of having ours go down, in my mind thinking I didn't have time to wait a week or so for a new unit, and the convenience of my favorite supplier, whom I trust completely, having one in stock, it was a win-win for everyone involved. Despite my complaints, it's still a better option than most exposure units out there, I just need to get used to a few things and bite the bullet and buy the upgraded vacuum system from Vastex, get our D-max back to optimum levels so I can burn 55lpi halftones on a 280 for the right time to fully expose the entire stencil. But I will still complain that right now I have 3 280 mesh screens that the emulsion is locked up in and it's going to take about an hour to get those screens back. I'm seriously considering buying 3 new shurloc panels and use the old "razor blade reclaim" technique.
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The thing that you guys aren't used to is Alan being brutally honest! Other sugar coat the negatives of their purchases to save face, stay in good graces with manufacture, whatever. Alan doesn't do that, he doesn't hold pinches, he tells it like it is.
Might be why no one is beating the door down to get demo products in his shop. :)
Just because someone has no issues to report early (maybe because there weren't any to report), doesn't mean when there are some later that they must have been sugar coating or saving face with initial reports, that's frankly a reach at best. It's interesting that the same perception could be applied to even Alan at this point. After all early it was all fine basically, but now there is more. Was he withholding it? Doubt that seriously, he just didn't rush to the internet to chat about it. I guess the difference here is I didn't perceive Alan as trying to save face as if there was some screen printing cover up or something. He's just had more time with it and its not working out completely how he hoped. His experience changed. Speaking for myself, that sounds a lot like my i-Image experience interestingly.
I cannot speak for other manufacturers but we always offer a trial period if requested and all of our product comes with a money back guarantee. I don't think it's a fair statement that manufacturers are not rushing to Alan because they are afraid of brutal honesty. Ask and you shall receive!
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(https://pastorcarlo.files.wordpress.com/2011/06/mythbusted-004.jpg)
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This is a huge reason why I was asking before about UV light wavelengths and emulsion sensitivity.
We as the consumers, are VERY much in the dark about the true science behind why things are working/not working.
the emulsion manufacturers won't tell us
the equipment manufacturers are very tight lipped too...
until we get both pieces answered, and not just "call us and we'll tell you if you ask" and put in a chart somewhere, we can't make educated decisions.
Heck, even if the emulsion manufacturers gave us a chart that said "this emulsion works best with this LED unit", that might be a good start... but honestly, I'd like to make that decision.
First emulsion manufacturer that starts that kind of testing and information, along with the typical viscosity, solids %, etc, will likely get our business... I HATE secrets like this that cause US to have to do so much testing/experimenting/etc...
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This is a huge reason why I was asking before about UV light wavelengths and emulsion sensitivity.
We as the consumers, are VERY much in the dark about the true science behind why things are working/not working.
the emulsion manufacturers won't tell us
the equipment manufacturers are very tight lipped too...
until we get both pieces answered, and not just "call us and we'll tell you if you ask" and put in a chart somewhere, we can't make educated decisions.
Heck, even if the emulsion manufacturers gave us a chart that said "this emulsion works best with this LED unit", that might be a good start... but honestly, I'd like to make that decision.
First emulsion manufacturer that starts that kind of testing and information, along with the typical viscosity, solids %, etc, will likely get our business... I HATE secrets like this that cause US to have to do so much testing/experimenting/etc...
Here is where the problem lies. Manufacturers like M&R who do the research and then freely give the information either on forums or even to end users end up being the research and development people for all the other manufacturers for free. Then our product is more costly due to the research cost the others don't have. As most people look at cost first that put you at a disadvantage immediately. The Starlight is a perfect example. We have more cost in our LED bank than some have as a retail price for their retail unit. Our vacuum is quiet and pulls down in 15 seconds. Guess what? That has a cost. We won't reveal why ours works better so we rely on end users to tell others. I also encourage end users to tell good or bad .If there is no bad and people think that is being withheld that ends up being their loss. We do a tremendous amount of testing,so much I can't even imagine the amount of screen meshes, emulsions, coats, and squeegee strokes with various inks. We even hired Lon Winters as an outside consultant for two solid weeks to coat screens, image, and test. I seriously doubt any other manufacturer has done these type of test to this degree. Can't give that away for free to the competition and that is why it's not all posted.
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This is a huge reason why I was asking before about UV light wavelengths and emulsion sensitivity.
We as the consumers, are VERY much in the dark about the true science behind why things are working/not working.
the emulsion manufacturers won't tell us
the equipment manufacturers are very tight lipped too...
until we get both pieces answered, and not just "call us and we'll tell you if you ask" and put in a chart somewhere, we can't make educated decisions.
Heck, even if the emulsion manufacturers gave us a chart that said "this emulsion works best with this LED unit", that might be a good start... but honestly, I'd like to make that decision.
First emulsion manufacturer that starts that kind of testing and information, along with the typical viscosity, solids %, etc, will likely get our business... I HATE secrets like this that cause US to have to do so much testing/experimenting/etc...
Here is where the problem lies. Manufacturers like M&R who do the research and then freely give the information either on forums or even to end users end up being the research and development people for all the other manufacturers for free. Then our product is more costly due to the research cost the others don't have. As most people look at cost first that put you at a disadvantage immediately. The Starlight is a perfect example. We have more cost in our LED bank than some have as a retail price for their retail unit. Our vacuum is quiet and pulls down in 15 seconds. Guess what? That has a cost. We won't reveal why ours works better so we rely on end users to tell others. I also encourage end users to tell good or bad .If there is no bad and people think that is being withheld that ends up being their loss. We do a tremendous amount of testing,so much I can't even imagine the amount of screen meshes, emulsions, coats, and squeegee strokes with various inks. We even hired Lon Winters as an outside consultant for two solid weeks to coat screens, image, and test. I seriously doubt any other manufacturer has done these type of test to this degree. Can't give that away for free to the competition and that is why it's not all posted.
How about EOM measurements pre/post exposure with MH/LED as discussed earlier in the thread? Or magnified photographs even? I don't think either
would give anything away to your competition other than bragging rights.
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Let's get this back on track:
How about EOM measurements pre/post exposure with MH/LED as discussed earlier in the thread? Or magnified photographs even? I don't think either
would give anything away to your competition other than bragging rights.
funny that you post this... as part of my emulsion issues, I JUST ran that same test about 15 minutes ago.
screen was underexposed as far as the stouffer strip is concerned (I talked to Al at Murakami and found out that we have bad diazo)... so I'll re-run this test when we have better screens...
but... with 4-5 solid steps on the stouffer strip:
EOM measurements matched both pre-exposure and post-exposure with no change ... (55 microns mesh, 82 microns mesh+emulsion)
not so sure that EOM is a good indicator of poor exposure or not.
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not so sure that EOM is a good indicator of poor exposure or not.
I was wondering if it would be a viable test. Indications to the negative are as good as to the positive for me.
I'd wager emulsion mfgrs probably know what a good indicator would be? Shade tree is wiping a white shirt on the back
of the screen post development.
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There have been a lot of posts pertaining to LED and how much everyone loves theirs and I was wondering what the perspective is since one's opinions on them is mainly shaped by what they were using before.
I'll start, we were using a Richmond Solarbeam with a "10K" bulb and I put that in "" due to the fact that I've had a few guys tell me it's not close to actually being a 10K and more like a 6-7K output. I've said many times that I thought this expo unit was one of the best ever made and even now after using LED for a few months I feel even more solid about that. I can understand the opinions of the LED's being so high, especially if you were burning screens with flouro bulb units or lower powered metal halide units, but I'm really wondering if anyone has come from a 5K and up metal halide to an LED unit that thinks the LED is significantly better or even on par with the MH unit. There are still more pros for our LED than the MH but fully crosslinking the emulsion and getting full exposures is not one of them. Our MH unit outperforms the LED by a big margin when it comes to the most important part of the equation...burning the image completely through the layer of emulsion.
Has anyone come from a 5K Olec or one of the stronger Trilight units from M&R to an LED? I'm just looking for some perspective on how LED opinions have been formed. So if those of you who have gone LED could share what you were using previously and have time to compare/contrast the two I think it would be appreciated. I'm not knocking LED because even with my issues I think it's a better option than MH right now but in my opinion it's not superior in some ways that it's being assumed to be. It deserves praise but I think that we need to tap the brakes a little bit and put things in proper perspective so others who haven't pulled the trigger can get the whole story and one that isn't biased in any way.
Lets bring the topic back on track, going back to the original post.
I still like and think a MH is a good product/device. If I were given one (Alan, if you want to ship me yours), I'll take it. :)
I assume Alan has an EOM metor. He's pretty well known for knowing his screens, coating, mesh and emulsions so it would go hand in hand that he would have one of these. So let me ask, what is a typical eom on a 280, 230, and a 110? You probably have an average where you like to be.
I'm looking at (why) even with the MH, one would need, or choose to cut back on exposure time (intending to hold smaller dots) than normal exposures of non halftone work.
For me, this says that the EOM may be thick. Now, thats not a bad thing. Some shops as we know, intend and prefer a thicker emulsion. Where I'm going with this, is that (maybe), just maybe, and I'm guessing here and speaking for myself not knowing details, that a MH could be as strong or stronger than some LED. The reason being, (here's the guessing part) is that maybe a MH is more (or as) intense for longer periods of time. This possibly signifies why even with a MH, one would cut back on exposure time to hold more dots...
Normally, I would say this would be due to possibly a thicker emulsion layer than normal or what is a (standard, typical or average) EOM layer. I can understand the need or procedure and yes, have heard of people purposely doing underexposure for many years More so, I beleive it to be an older or maybe old school technique. With that, I would imagine that the desire for thicker layers of emulsion is more geared towards high wall printing or sharp edge where the ink is laid down thick enough for a 1 hit on an underbase. For halftone purposes or as it pertains to halftones, doing underexposure to obtain small dots (to me), was considered a work around or a band aid to other issues. A typical thicker layer is one good thing. Thicker or rather excessively thicker layers, and halftones don't work well together.
If a thicker than normal layer of emulsion, is indeed the case, then I can understand some thicker layers of EOM needing exposure time adjustments to cook it all the way thru. If you are not accommodating the thick emulsions and holding halftones due to under expsoure, then you are deteriorating the back of the emulsion while holding halftones. I don't think the two (really thick layers as well as fine halftones) can live together on the same screen (UNLESS, your halftones can take it or in other words, unless you use a much lower LPI.
For an an example in the extreme direction, take cap film at 400 micron on a 110 mesh. That is not going to hold 22 lpi well in the lower end dots. A 22lpi would be a good lpi to use on a 110 mesh (intending to hold the small dots) on that mesh. YOU CAN, hold more dots...by decreasing exposure,...but the back is not going to provide as good of an image due to it not being exposed long enough for the stencil to fully cross link and cook (that thick). It's a tight battle. Now again, this is an example in the extreme direction. The low LPI helps to achieve this on the 110 alone, but given that the emulsion layer is sooo thick, it would require a longer exposure time to achieve a great stencil.
So yes, if your exposure times need to be decreased to hold smaller dots, I would assume you have an emulsion layer thickness that is well above the average. Again, in many cases, I would do the same for a desired look on specific type of prints like especially in the case of an athletic print with white ink on red 50/50's.
With halftones, you have a point of diminishing return on the emulsion layer thickness. This leaves me to consider, is is really a question of MH or LED, or is it a question of techniques and needs? As it's been mentioned, there was and is a need or preference to cut back on exposure times in both devices, being the MH and the LED device. The preference comes from the true desire for having a thicker layer of EOM. From what I remember having been told and read from some good people in the emulsion industry, an average EOM might be in the area of 20% for lower mesh such as 110 up to 230 and 15-10% on high mesh like 305 and 350 mesh. These %'s of EOM suggestions are simply that, suggestions or averages for what has been determined "good" stencil thickness's for various mesh.
Having a EOM meter, can take that guess work out. Those who do not have an auto coater....but want to print fine halftones and repeat the same image at every reorder, should want to get a EOM meter. As we all know, Bob does not coat the same 1:1 sharp as Mary does, nor does Bob do the same coat tomorrow.
Anyone can jump in to correct me on those percentage averages because I'm just going be memory.
Does that make sense?
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I know a guy that needed a DTG. He bought one and paid a high price for it. He loved it! He used it for a month and his business changed a little but just enough for him to not need the DTG. It didn't do what he now needs. So, he put it up on line for sale at 30% off the original price. 3 times he lowered the price. No takers. He then stored it for another year or two and tried to sell it again for almost giving it way just to make room. No takers. So he decided to trash it. He loved it at first, but things changed but it was still a good machine that could be useful to someone with a different perception. The product was not a bad product, the need was just not there like it was, and his perception of its value changed. Things change.
Someone listening to that story might think there must have been something bad about the Co that made it less attractive to buyers, or the product was junk. Most often, there is more to the story (the back of the back story) than we hear or are told directly.
I like the analogy of "the big meeting".
It's not what is said in the "big meeting" that people want to hear, it's the smaller meetings after the big meeting that contains the real juice. It may not be accurate, but it's juicy.
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Ill send him a message about this post, maybe he will chime in and make this interesting.
Hopefully he'd do it in it's own thread in Running and Growing a Business
Yes. That would be nice. It would be great to see this topic get back on track. I had a few things I wanted to add, but was waiting to gather more data before I did. Now I'm not to sure its worth it.
Murphy37
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Does this have anything to do with the thread? If I coat and dry a screen and then measure the EOM and get "X" microns, then expose and develop it and let it dry, measure again and get "X-4" microns, wouldn't that mean some emulsion went down the drain, thus underexposed? (How's that for a run-on sentence?)
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Did anybody else miss in the post how Alan was saying his films aren't as dense as they were before his artist left?
That's huge right there....too low a dmax and you will struggle to cook your emulsion without exposing right through your stencil.
Just sayin.
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Does this have anything to do with the thread? If I coat and dry a screen and then measure the EOM and get "X" microns, then expose and develop it and let it dry, measure again and get "X-4" microns, wouldn't that mean some emulsion went down the drain, thus underexposed? (How's that for a run-on sentence?)
That was the premise I proposed, I believe, though I must confess that I have missed some posts here since then. I think that it was in this thread, LOL!
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Like when I under expose an 83 mesh, lose half the emulsion on the back & the damn image starts to fall away from the screen 1k prints in. This has happened to me both with MH & LED. Under exposed is under exposed, & both are my fault. I don't know if this is what is going on with Alan's problem. Just saying.
Murphy37
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Sorry Andy. I wasn't reading all of the posts.
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how underexposed do you have to be, or how aggressively are you rinsing the inside of the screen?
My tests here over the last few days have shown that I can be at least 3 steps underexposed, and the emulsion doesn't get any thinner.
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Sorry Andy. I wasn't reading all of the posts.
That is understandable on these long ones, especially when they get a second life, (and a bit of a change of direction)
I figure that remaining EOM has to be at least one measurable indicator of exposure "completeness" though according to jvanick contains some latiitude.
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how underexposed do you have to be, or how aggressively are you rinsing the inside of the screen?
My tests here over the last few days have shown that I can be at least 3 steps underexposed, and the emulsion doesn't get any thinner.
Yeah, I've never had a slimy backside (too much info? ;) ) but have been under exposed according to stouffer strip.
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I mentioned our D-max wasn't as good as it once was, but over the years it's gone from horrible, to great, to average, back to great, and today it's above average. If your D-max is low, you'll overcook the emulsion in those areas, unless you know that going in and are underexposing on purpose to get around your weak films, which I'll admit we have done more recently. If we had a significant dropoff in D-max and never noticed it we would still be shooting screens for the same amount of time and wouldn't have been underexposing screens most likely. The LED's on our unit simply don't fully cross-link the emulsion we've used since buying it, that's the problem. There are ways around the issues, and I'll likely start looking for a more LED friendly emulsion, but I don't want to do that. Some of you will just have to trust that I've put a lot of time and effort into these problems and it's really simple to figure out. Our D-max has drifted over the years, but our MH unit stayed the same, we struggled on some higher mesh screens and halftones with inkjet film, Epson printer, Accurip, etc. but everyone would. We went about 7 years from wearing out emulsion and those days were because I didn't know what the hell I was doing and was using 85 duro blades and 50psi on the heads just to clear ink from a screen, and those settings will break down even the most hardy emulsions. So you go from being able to get 2500 strokes out of a discharge screen shot with the Richmond to 5 on our first DC screen shot with the LED...5 strokes, that's not a typo, 5. When you've got a blowtorch and weak film you're going to have some complications.
If you have imagesetter type film, and a blowtorch you can get away with just about anything and get your detail out of the screen. With the crazy good exposure latitude with the emulsions we were using and a great light source and great film, it's hard to screw up. Anything less than optimum tools you will see a decline in reproduction of your artwork from film to screen. I've never been one to try and get a 65lpi 3% halftone dot on a 305 because I don't think it's worth our time to try and do, and I can live with some of the issues we're having with our screens because there isn't much I can do about it. I made a decision and I have to live with it. I made the wrong decision, and I can freely admit that to all of you guys because it doesn't bother me to disclose that to you. Many wouldn't come close to admitting they bought something they shouldn't have, or took a job they shouldn't have, or whatever the case may be. I can't go back and change the decision now, and there was the question in my mind on whether or not I should contact M&R and see how fast they could get a Starlight to me, or Richmond to see if they could overnight a new touch panel, or run with the easiest, most convenient route and a piece of equipment from a good manufacturer, and one of the best suppliers in the industry, and we all know what I did. I did weigh the other options quite heavily, and I thought that I might could get with the big guy in Chicago and have a Starlight here really quickly, but I didn't want to call on anyone to get us out of a bind if I had other options that I felt were good at the time. And as far as the Vastex goes, I would venture to guess it's still one of the better LED's on the market, but trusting many others here and our own experiences with our LED, I would also wager a heavy sum that the Starlight would have been the better choice for us. I don't know for sure but I think the larger Starlight comparable to our Vastex has 3 to 4 times the diodes in it. Although I'll contend that single-point is best, that many more diodes, given that they are of equal or better (likely the case here) output, the Starlight would spank the competition. And if Starlight users can shoot a 180/48 with 15% EOM, pure photpolymer emulsion for 15 seconds and use that screen for a 2K piece discharge job with no breakdown, we have a winner winner chicken dinner in the LED contest.
Our film density was off, but that kept us from getting some of the fine lines and details and maybe a few dozen exposures we had to adjust, but I look at every piece of film that we burn now and I know how to adjust things on the fly, so it's not the problem in the grand scheme of things. With our equipment and the way we do things, our LED simply isn't as good as our 15 year-old Richmond MH unit, end of story.
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* This thread started in March, and in May, took off again, but devolved into mudslinging and arguments that obscured any real facts and information. I performed a little surgery, but there are probably still some statements that will seem a little odd in their new altered context. Otherwise, most will see it as a great improvement!
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Sorry lost interest. Perhaps able to contribute but do not care for split threads. Busy and not able to comment much however this is why I do not. There is another.
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I am still working on exposure times for our new Workhorse LED. Have gotten them pretty down packed for the last 7 gallons of Saati textile PV day in and out. I am switching over to Ulano Orange after I finish this last half gallon so have to start testing now. I am hoping to see improvement over current textile PV times. I am at 3 minutes for a 1/1 round coat at 10-12 seconds per side on a 125 - 158 white mesh on average.
I really want to cut that in half with Orange? I know some people have said times in the 18-45 second range, but I don't need it THAT fast since we can't wash them out that fast.
Prior I was using the Point 1000 (I know it isn't the best, but was told it would work). I never got the point 1000 to give me 100% exposure and couldn't use it form a lot of screens without letting it cool down since it got too hot. But the Workhorse LED has been great. Outputting film at a 10 deposit level on accurip for really dark films, awesome results so far.
Detail has held very well too, even when doing really high detail/text artwork on 125 mesh.
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I am having MAJOR issues here since switching back to SP1400... it may be related to viscosity changes after switching, but I really don't know at this point.
I'll keep updating as I learn new info, bit something is NOT right and it's driving me to drink heavily, which is not what I need when we have over 50 jobs in the backlog and screens are breaking down on press.
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I am having MAJOR issues here since switching back to SP1400... it may be related to viscosity changes after switching, but I really don't know at this point.
I'll keep updating as I learn new info, bit something is NOT right and it's driving me to drink heavily, which is not what I need when we have over 50 jobs in the backlog and screens are breaking down on press.
So are you having breakdown issues?
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What kind of ink Jvanick? You were my one positive response on SP1400
and LEDs!
Probably pertinent for anyone having or not having issues to mention the kind of inks.
Plastisol and discharge are worlds apart when it comes to stencil durability.
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Plastisol is even breaking down right now. Horizontal chatter marks.
We ran 20k on sp1400w in November last year with no problems. ..
We ran 20 (twenty) pcs today and we were starting to have issues...
It may be viscosity issues, starting to track EVERY variable...
But at this point, we have no idea what's going in as we can pull older screens off the shelf and have no issues.
Seriously, I am pulling my hair out here.
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I am having MAJOR issues here since switching back to SP1400... it may be related to viscosity changes after switching, but I really don't know at this point.
I'll keep updating as I learn new info, bit something is NOT right and it's driving me to drink heavily, which is not what I need when we have over 50 jobs in the backlog and screens are breaking down on press.
I could look it up but I am feeling lazy, what exposure unit are you running? LED I presume.
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I'm tossing a guess your emulsion was frozen at one point.
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We're on a starlight...
This is 3 different batches of emulsion... however, I guess it's possible that our supplier screwed up and let it freeze in their warehouse over the winter...
I have a gallon of Ulano Proclaim EC coming in today that I'm going to give a shot...
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stupid question but are all the LED's turning on? Have you tried cooking a screen for 5+ minutes to see what happens?
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That's the rub here... if I take an old screen that was coated a month or so back with SP1400-W and throw it at the normal time (40 sec), NO issues at all.
-J
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And you were running the Starlight in November with great results on the 1400? If so that's enough for me to say you got a bad batch of emulsion and your supplier should replace at zero cost. If the Ulano fails then I'd say you've got a problem you need to try and hammer out, but if it passes then there's a 99% chance the 1400 emulsion was junk.
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Other than under exposure or bad emulsion, take a look at stencil moisture content. If the moisture level in the stencil is not at an acceptable level before exposure it does not matter how long you expose, you will never get good results.
edit: that should read "below an acceptable level"
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We're on a starlight...
This is 3 different batches of emulsion... however, I guess it's possible that our supplier screwed up and let it freeze in their warehouse over the winter...
I have a gallon of Ulano Proclaim EC coming in today that I'm going to give a shot...
If you send me you UPS OR FEDEX shipper number I will send you out a sample of the 1400 no charge. At least then you have an new batch from a new supplier with a different lot number. This will remove a lot of variables.
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Today I decided to crank up the burn times and I did the white shirt wipe test on the squeegee side of the screen on a 150/48 with 20% EOMR, FAIL. Damn, I really thought 90 seconds would more than cook a 150. Needless to say the 120/54 with similar EOMR but a bit thicker stencil overall didn't pass the test either. There were days in the beginning that we were shooting a 150 for 15 seconds and getting a usable screen for plastisol, although it would break down at the squeegee edges. I'm going to keep going up in burn times and keep everyone updated. Oh yeah, pure photopolymer emulsion, orange color, good emulsion, but not as good as HVP. It's River City's house brand and I don't know if anyone here is using it but for the price it's hard to beat. I think I'm going to get a gallon of the HVP and work it in with the current screens to see if I can find something.
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I wish every manufacture was willing to send you a demo unit to put through the test Alan.
A true independent shoot out would be great!
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@ Alan, humidity has been really bad here in CenTex for the past few days. Moisture content in your stencil, pre-exposure, is worth looking at.
I measured 78% percent today in our production area and we were having a bit of a tackiness issue this morning running discharge on 225S coated 1/1 with SP1400. Applied hardener to the next DC ubase screen and that seems to have helped.
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Orion are you using an LED exposure unit?
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No eb, and I don't foresee bringing one in here any time in the near future.
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@ Alan, humidity has been really bad here in CenTex for the past few days. Moisture content in your stencil, pre-exposure, is worth looking at.
I measured 78% percent today in our production area and we were having a bit of a tackiness issue this morning running discharge on 225S coated 1/1 with SP1400. Applied hardener to the next DC ubase screen and that seems to have helped.
I've been watching it closely, it's been tough keeping it below 45% in the screen room but we've managed to keep it around 40 most of the last week. The screens have been tackier after washout but I think we're able to get them developed quick enough to keep the moisture from affecting exposure, but I know the screens are drawing in moisture pretty quickly.
Anyone have any idea how fast a dry, coated screen can go from dry to moist in a humid environment?
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Anyone have any idea how fast a dry, coated screen can go from dry to moist in a humid environment?
I wish I did. Purchased a humidity sensor, the type used for lumber typically, and had one of my crew file the pointy tips down and polish but it won't read on a screen, not enough surface area I guess.
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Anyone have any idea how fast a dry, coated screen can go from dry to moist in a humid environment?
I wish I did. Purchased a humidity sensor, the type used for lumber typically, and had one of my crew file the pointy tips down and polish but it won't read on a screen, not enough surface area I guess.
Well, that saved me from doing that myself. ;)
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after a whole lot of testing with Al from Murakami ... I don't think we have a bad batch of emulsion, at least now...
I think that there's a combination of issues going on:
1. we had EOM of around 30%, which he feels is too high... started coating 1/1 sharp on our 160S mesh and the EOM is now down around 10%, too low for me to be super comfortable with, but we'll work that out...
2. exposure times are definitely longer than the SP1400-W, why, I have no idea, but we're now settling in around a minute or so.
3. our first and second batches of emulsion had expired/bad diazo, which started this whole debacle...
We are playing with Ulano Proclaim EC as well now too... shot a few really good screens with it, at roughly the same as the SP1400... (about a minute on a 160S)... I am digging the fact that it's a dual cure that you don't have to sensitize, and it has a shelf life of 18 months... with that being the case, I might get some Pure Photopolymer that's better suited to the Starlight and have 2 emulsions... 1 for waterbase/discharge jobs, 1 for pure plastisol... still haven't made up our mind on this yet.
Kev from River City is sending me a sample of SP1400 from his warehouse too, so we'll be testing that as soon as it gets here.
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Yeah, 30% would cause some problems for us. The MH unit didn't really struggle with thicker stencils but the Vastex definitely does. For low mesh I still like to be around 20-25%, middle mesh counts 15-20% and high mesh counts are 10-15%.
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My shop-HVP 2 over 1 on everything every time - vastek LED set 30/ 110-135 mesh 25/ 150 -180 mesh 20/225 15/ 280 and up- works every time we have no issues at all - my shop
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My shop-HVP 2 over 1 on everything every time - vastek LED set 30/ 110-135 mesh 25/ 150 -180 mesh 20/225 15/ 280 and up- works every time we have no issues at all - my shop
Wow, our screens won't reclaim at those numbers anymore. That looks really close to the numbers I got when using the expo calculator and we used similar numbers for months. We coat most S thread with a 1/1, glisten method, but a really slow coating speed so I usually get a glisten with one stroke. I don't have to use the 2/1 until I get to the 280's.
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so far, really liking the Proclaim EC... shot a bunch of screens this morning with it... it's almost like a pure photopolymer in that the open areas literally just fall out of the screen after a minute or 2 in our post-exposure soak tank. (new kitson terminology)
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I'm up to 100 seconds now, still got slime. I coated a few screens with Saati PHU and a few with HVP. I'll get them into production this afternoon or tomorrow morning and report back.
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I'm up to 100 seconds now, still got slime. I coated a few screens with Saati PHU and a few with HVP. I'll get them into production this afternoon or tomorrow morning and report back.
At that kind of time what would be the point of LED. What were your times on your MH unit before it bit the dust?
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Yeah seriously, my home-made unit was around 40 seconds to get 100% slime free lol
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I'm up to 100 seconds now, still got slime. I coated a few screens with Saati PHU and a few with HVP. I'll get them into production this afternoon or tomorrow morning and report back.
At that kind of time what would be the point of LED. What were your times on your MH unit before it bit the dust?
With an 18 month old bulb we were around 50 seconds for the thickest stencils and about 15 seconds for 305's.
I wasn't patient enough to wait on the PHU and HVP and shot them when they were a tad bit moist. I did the PHU for 60 seconds and it failed, but it was a lot better than previous test screens, the HVP for 90 seconds and it passed, but was a bit soft feeling. Both 150/48's with 20 micron EOM. I then put them in the dip tank for 5 minutes and the emulsion came right off. So with different emulsion I'm going back in the right direction. By tomorrow I'll start backing down on the times till I get a failure.
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I'm up to 100 seconds now, still got slime. I coated a few screens with Saati PHU and a few with HVP. I'll get them into production this afternoon or tomorrow morning and report back.
At that kind of time what would be the point of LED. What were your times on your MH unit before it bit the dust?
With an 18 month old bulb we were around 50 seconds for the thickest stencils and about 15 seconds for 305's.
I wasn't patient enough to wait on the PHU and HVP and shot them when they were a tad bit moist. I did the PHU for 60 seconds and it failed, but it was a lot better than previous test screens, the HVP for 90 seconds and it passed, but was a bit soft feeling. Both 150/48's with 20 micron EOM. I then put them in the dip tank for 5 minutes and the emulsion came right off. So with different emulsion I'm going back in the right direction. By tomorrow I'll start backing down on the times till I get a failure.
So your thinking emulsion is your issue.
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At that kind of time what would be the point of LED
Good question.
150/48, 2/1 round edge coat, Xenon Nova with diazo added
Starlight 3140 shooting 1up: 230s
5k Olec with super wide reflector shooting 1 or 2up: 135ltu ≈ 135s
Give or take on the LTU : Seconds, of course, will vary with bulb strength. Above was taken on a medium aged, Olec OEM L-1250 and we do have our setup set to 1ltu=1s as far as calibration goes.
LED is not "fast". Yes, it is fast at shooting PP emulsions. All units are fast at shooting PP emulsions. PP emulsion is a secondary priority in our testing but our halide is just about perfectly equal in speed shooting a PP as the Starlight and is 2x as fast considering 2up shooting.
5k halide will produce roughly 2-3x more fully cross linked, diazo emulsion screens in a shift than LED, depending on your setup. Electricity, bulb, photocell and reflector costs are the trade off, or the point if you like.
If the Starlight were built to shoot 2up, the gap would narrow significantly but halide would still be faster. Keep in mind that our halide unit is setup for 2up shooting, if we had it optimized for 1up it would blow LED out of the water on times. Years ago we did shoot 1up and I recall shooting HVP screens at around 7s.
A little food for thought. It looks like the Starlight is in fact going to replace our halide setup, should be final on that next month, so please don't misinterpret this as a "flame" or whatever you call it on LED or one brand or another, just some facts for your consideration. Still going to make good on posting more complete test results comping halide to LED.
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So I'm getting an olec next month? :D
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So I'm getting an olec next month? :D
Haha, you have been sooo patient! Probably yes. We have a heat issue with the LED but I think it can be engineered away pretty easily.
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I told you I wasn't in a rush :D If the damn things ever came up used in this part of the world I would have gotten one, but I search daily and there has been nothing...
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H
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At that kind of time what would be the point of LED
Good question.
150/48, 2/1 round edge coat, Xenon Nova with diazo added
Starlight 3140 shooting 1up: 230s
5k Olec with super wide reflector shooting 1 or 2up: 135ltu ≈ 135s
Give or take on the LTU : Seconds, of course, will vary with bulb strength. Above was taken on a medium aged, Olec OEM L-1250 and we do have our setup set to 1ltu=1s as far as calibration goes.
LED is not "fast". Yes, it is fast at shooting PP emulsions. All units are fast at shooting PP emulsions. PP emulsion is a secondary priority in our testing but our halide is just about perfectly equal in speed shooting a PP as the Starlight and is 2x as fast considering 2up shooting.
5k halide will produce roughly 2-3x more fully cross linked, diazo emulsion screens in a shift than LED, depending on your setup. Electricity, bulb, photocell and reflector costs are the trade off, or the point if you like.
If the Starlight were built to shoot 2up, the gap would narrow significantly but halide would still be faster. Keep in mind that our halide unit is setup for 2up shooting, if we had it optimized for 1up it would blow LED out of the water on times. Years ago we did shoot 1up and I recall shooting HVP screens at around 7s.
A little food for thought. It looks like the Starlight is in fact going to replace our halide setup, should be final on that next month, so please don't misinterpret this as a "flame" or whatever you call it on LED or one brand or another, just some facts for your consideration. Still going to make good on posting more complete test results comping halide to LED.
For what its worth, we are shooting Chromaline Diazo on 158's at 43 seconds on our Starlight. 1 up of course. No Vacuum.
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Back to my saga. I have been experimenting with different emulsions this week, and it looks like HVP is again the winner in our shop. I shot a few screens this morning with the Orange, HVP and a new prototype blue (film won't stick to this emulsion at all) and put them to the white-shirt-swipe-on-the-squeegee-side (slime test) to test for full exposure. I got up to 2 minutes on the Orange and Blue emulsions and couldn't get the small details like the registration marks to spray out but there was still a lot of emulsion coming off on the white shirt. Right now I'm down to 40 seconds on the HVP without slime and I'm inching my way down in exposure time until I get some slime with the HVP.
I think the Blue emulsion might be a winner for a good metal halide shop, fresh film and screens that had been coated for an hour in very humid conditions didn't cause the film to stick so that's good news. It dries very quickly, and the big open areas fell out of the screen with very little effort, I just had problems with the small stuff. It reclaims very fast as well. I'd like to see how it runs on an MH unit though. I will be dropping the Orange emulsion from production, and I have about 3-4 gallons left if someone wants to try it out. I'd put some in a quart and ship it to you on your UPS account if you want some.
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Is that kevin's orange stuff? How well does it hold halftones? I The SP1400 hasn't given me a single issue, but it does take a long time to expose, and really isn't necessary on lots of my short run stuff.
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Is that kevin's orange stuff? How well does it hold halftones? I The SP1400 hasn't given me a single issue, but it does take a long time to expose, and really isn't necessary on lots of my short run stuff.
Yes, that's the one. I'd say it's good with halftones, it's not something that jumps out at you either way, good or bad, definitely not a weak spot. Something tells me that it would run great with an MH unit, along with the new Blue.
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our starlight and HVP, back when we used it was something like 15 seconds...give or take. currently, our longest exposure with a diazo emulsion is 60 seconds.....the number of LED's is the factor here, the Vastex unit appears to have about half the amount our starlight has....
I'd send it back.
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I've never really like the Vastex or Lawson equipment, for some reason it just don't seem right, but I know tons of people use there equipment and make tons of money. I will say this the Starlight that Ron Hopkins brought to our shop was nice as F and If I get back in the market for an exposure unit it will be at the top of our list for sure. The screens we burned where at 8 to 10 sec with HXT emulsion, I will say this a MH point light is going to do a better job because the light is going straight thru the unblocked emulsion cross linking it better.
D
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We keep seeing mention of better this or that with MH, has anyone printed the same exact artwork with each unit and seen any real measurable difference on press? That's a honest question, haven't seen anyone say one way or another so I am curious.
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We keep seeing mention of better this or that with MH, has anyone printed the same exact artwork with each unit and seen any real measurable difference on press? That's a honest question, haven't seen anyone say one way or another so I am curious.
It wouldn't be that easy to see once you finally got a good enough screen on press.
My biggest issue is with things like happened yesterday. I had to shoot 5 screens of this one halftone image to get 1 good enough to go to press. So I not only wasted 4 screens, but the extra time it took to shoot 4 more, then the biggest killer of time is to reclaim and coat those to get them back into the production loop.
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We keep seeing mention of better this or that with MH, has anyone printed the same exact artwork with each unit and seen any real measurable difference on press? That's a honest question, haven't seen anyone say one way or another so I am curious.
Can't give you the scientific answer I would like to yet but yes, we have printed some halftone jobs, same films on both MH and LED and we didn't require any adjustments to the art or films. This is for repeat, retail line merch so we have control print samples on hand and all matched up.
What wasn't apples to apples however is our MH has a haggard old blanket on it. LED is brand new with a pressure sensor. I'm sure other shops are similar, by the time they upgrade to LED the old unit is probably lacking good vac pressure/draw down v. the brand spankin' new one. This alone is going to make you equate the new machine with better, or on par, resolution.
Time never seems to be on my side for this but I do have the tools on hand to actually measure undercutting. But maybe it's a moot point? If the prints come out the same and the screens hold up, I have to wonder why bother measuring the difference. There is undoubtedly a difference- point source light beats multiple point for fine detail, nobody's arguing that -but it really doesn't appear to be enough of a difference to matter for textile printers. Fully cross linked LED seems to be on par with fully cross linked MH expos. Those printing other items like flatstock and circuit boards, etc. may have a different experience here. We ain't printing 100lpi with 420tpi mesh.
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I think the point that some are overlooking is as people have mentioned before. Not all LED's are the same and with that, neither is the price. There is a place and a time for everything. Vastex is a good company and they make good products that fit your budget. That seems to be the kicker. It's a good product for many out there and maybe a better choice at the time than another one. There are plenty of 6 color manual press companies and you would all agree that each is a different level of quality.
You get what you pay for and you should be paying for what you need at the time. Vastex shines in many areas for what they specialize in and who they cater to in the industry. Maybe their LED unit is not designed to be reading mesh under a loop and looking at 2% in a 65lpi. It would work and save someone money in specific areas compared to other light sources I'm sure. Again tho, I might not try to compare it to a traditional light source aka 8k MH that is capable of holding 2% in a 65lpi but the times might be much faster in other areas to compare to. That's a different side to look at. Each of you do a thing called screen printing on apparel but each of you do something better than another and you all have different prices. Comparing a screen printer to another is not exactly apples to apples, well, more like Granny Smiths to Machintosh, apples but they are both round and both tasty to the right person. Same for LED units.
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I am gonna have to stand up for Vastex here. They make top notch stuff in my book, the 2000 is a very impressive piece of equipment for example.
'not really sure what's going on with Alan's unit, there is a problem with it that should be taken up with the manufacturer and it should be sorted out. But I will say that the Vastex unit we tested was top notch and in few ways better than the Starlight. This is not to knock on the M&R unit as it is impressive, but if I had to chose between the two, I would take the Vastex right now. In part because I ran some tests and Vastex had the most uniform light coverage amongst the units we tested. It also helps that I know what is going on with their light source and how it's designed including the light wavelength.
Going back to the measurements, yes, Richard and I took them and the difference between the MH and LED was very small and addressable in the RIP. The undercutting was about 2% and since it is adjustable with a curve, it would be hard to imagine anybody needing to use an MH to get a better dot.
The issue here is related to the LED unit's ability to penetrate all the way through te stencil and potentially the need to have multispectrum wavelength for full exposure*. It is possible that the Aquasol HV is more in tune with the wavelength Vastex unit is producing. It is the emulsion we tested it with and had really good results with. We were slightly underexposed at 9 seconds and had to bump up to 13-15, but after that we had no issues. We had no issues on the press at 15 seconds and I can honestly say that I wouldn't have any reservations with using their unit.
All that said and done, we did not buy one as it did not really solve any problems we have. Yes the exposure times would be shorter and the operating expenses would be lower, but we still have things much higher on the priority list.
pierre
*emultions don't really crosslink completely as I understand, it is just a fraction of the total molecules that's needed for what we call full exposure.
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it would be hard to imagine anybody needing to use an MH to get a better dot.
That's pretty much was I was suspecting was the case but I am not smart enough nor have the free time to prove or disprove it one way or another. The only thing I just know that when we went to LED, we've not noticed any differences on press and that is where it really matters. After all we aren't selling cross linking, exposure times, how easy it washes out and so on. We are selling tshirts!
It wouldn't be that easy to see once you finally got a good enough screen on press.
My biggest issue is with things like happened yesterday. I had to shoot 5 screens of this one halftone image to get 1 good enough to go to press. So I not only wasted 4 screens, but the extra time it took to shoot 4 more, then the biggest killer of time is to reclaim and coat those to get them back into the production loop.
Vastex makes quality products and I am a fan of theirs. Are you certain at this point that you don't have something wrong with that unit? Have you discussed any of this with them? Just being flat honest, outside someone dialing in the wrong exposure time for the screen being used and our first couple days of running the unit we haven't re-shot a single screen due to something with our LED unit. That's not me championing M&R either, I am just saying that I suspect regardless of brand you shouldn't be needing to re-shoot screens past the point where you have your exposure times figured out and such.
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The Sun
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The Sun
I still do use the Sun, on screens that are too big for my exposure unit. It takes a little adhesive spray and you lose your film. It's just that they can't easily be stored with spray adhesive on them
I'm still using a metal halide. A NuArc 2125 which is about an 800 watt unit, and its sloooow.
I need to upgrade.
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*This is a long one*
I've been holding off a bit. As I wanted to do a bunch of testing before I gave my thoughts.
On the LED vs MH debate. I am only coming from the point of the unit we had ( Richmind Solarbeam, using a 10k bulb. ) To what we have now ( M&R I-image STE II with LED. )
There are a few other variables, like using film with the MH, as we were doing & not using film with the LED, as we are now.
As far as I can tell, the LED ( in our unit ) is having absolutely no problem fully curing/crosslinking, or zero slime/ residue on the squeegee side.....or how ever you want to put it. When I say fully crosslinked, I mean absolutely NO soft emulsion, except the image being rinsed out.
-Emulsion: Kiwo ONE-COAT : SBQ with Diazo
http://www.kiwo.com/polycol-one-coat
-1/1 coating
-20% EOM-on average, based on 156-110
-10k MH unit-
-156-T-white mesh : 48 sec.
-150-S-yellow mesh : 90 sec.
-M&R LED unit-
-156-T-white mesh : 27 sec.
-150-S-yellow mesh : 55 sec.
(*Thread jack*) Sorry
I also had the pleasure of doing some testing, pre-release of a new Kiwo emulsion, Multi-Tex that just hit the market this moth. Check it out!
http://www.kiwo.com/polycol-multi-tex
Its looking very promising....... I still need to do a bit more testing. ( tho I did get 2k DC prints with it on one image & another 2k DC prints with a second print, that I feel I could have gotten another 1k prints out of it......Without hardener, with out post expose, with LED exposure )
(*Back to it*)
I have exposed just over 600 screens in the month we have had our M&R unit. Many of these screens have been on reorders, jobs that were burned on our MH & now our LED. I see no compromise in quality exposure with our LED unit.
Many of these screens have also been, clean & save screens, ones we catalog & reprint ( some have already come back through the schedule ) cleaned multiple times. No problems. No lockups.
A large amount of them have gone through the full process of reclame/recoat/reprint, many times. No problem. No lockups.
I had screen up on press last week, it was a quick on the fly reburn for a DC job. The old screens were pulled off the shelf & had quite a bit of use on them already, but we went to press anyway. About mid way through the order one of the screens gets a heavy wipe-down & some of the small detail gets taken out. So I send the guys working on that press to an early lunch hoping to get as much time as I can before they get back for the screen to dry. It gets about an hour ( maybe ) I rush it along & get it on press. Not having that high of expectations, I'm expecting the worst, hoping for the best. Well that screen lasted another 800 prints being double stroked & when done with the order, I would say the screen had very little to no signs of breaking down. ( this was with Kiwo One-Coat emulsion, no hardener, no post exposure )
I have also done a few low mesh with a very thick EOM, 400 micron stencil, & after getting my time dialed in the screen was not under exposed at all & still I was kind of holding the reg marks ( we use .5 line width for reg marks )
I'm not saying it hasn't been without a bit of a learning curve, but nothing that didn't take 3 or less screens to get dialed in & this was just really the first few screens we shot of each mesh.
I would agree there are some differences in having a single point light source to having a multi point source, & I feel you may see the biggest problems with this if you have the need/want to underexpose.
Well maybe this all helps someone?
Murphy37
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*This is a long one*
I've been holding off a bit. As I wanted to do a bunch of testing before I gave my thoughts.
On the LED vs MH debate. I am only coming from the point of the unit we had ( Richmind Solarbeam, using a 10k bulb. ) To what we have now ( M&R I-image STE II with LED. )
There are a few other variables, like using film with the MH, as we were doing & not using film with the LED, as we are now.
As far as I can tell, the LED ( in our unit ) is having absolutely no problem fully curing/crosslinking, or zero slime/ residue on the squeegee side.....or how ever you want to put it. When I say fully crosslinked, I mean absolutely NO soft emulsion, except the image being rinsed out.
-Emulsion: Kiwo ONE-COAT : SBQ with Diazo
[url]http://www.kiwo.com/polycol-one-coat[/url] ([url]http://www.kiwo.com/polycol-one-coat[/url])
-1/1 coating
-20% EOM-on average, based on 156-110
-10k MH unit-
-156-T-white mesh : 48 sec.
-150-S-yellow mesh : 90 sec.
-M&R LED unit-
-156-T-white mesh : 27 sec.
-150-S-yellow mesh : 55 sec.
(*Thread jack*) Sorry
I also had the pleasure of doing some testing, pre-release of a new Kiwo emulsion, Multi-Tex that just hit the market this moth. Check it out!
[url]http://www.kiwo.com/polycol-multi-tex[/url] ([url]http://www.kiwo.com/polycol-multi-tex[/url])
Its looking very promising....... I still need to do a bit more testing. ( tho I did get 2k DC prints with it on one image & another 2k DC prints with a second print, that I feel I could have gotten another 1k prints out of it......Without hardener, with out post expose, with LED exposure )
(*Back to it*)
I have exposed just over 600 screens in the month we have had our M&R unit. Many of these screens have been on reorders, jobs that were burned on our MH & now our LED. I see no compromise in quality exposure with our LED unit.
Many of these screens have also been, clean & save screens, ones we catalog & reprint ( some have already come back through the schedule ) cleaned multiple times. No problems. No lockups.
A large amount of them have gone through the full process of reclame/recoat/reprint, many times. No problem. No lockups.
I had screen up on press last week, it was a quick on the fly reburn for a DC job. The old screens were pulled off the shelf & had quite a bit of use on them already, but we went to press anyway. About mid way through the order one of the screens gets a heavy wipe-down & some of the small detail gets taken out. So I send the guys working on that press to an early lunch hoping to get as much time as I can before they get back for the screen to dry. It gets about an hour ( maybe ) I rush it along & get it on press. Not having that high of expectations, I'm expecting the worst, hoping for the best. Well that screen lasted another 800 prints being double stroked & when done with the order, I would say the screen had very little to no signs of breaking down. ( this was with Kiwo One-Coat emulsion, no hardener, no post exposure )
I have also done a few low mesh with a very thick EOM, 400 micron stencil, & after getting my time dialed in the screen was not under exposed at all & still I was kind of holding the reg marks ( we use .5 line width for reg marks )
I'm not saying it hasn't been without a bit of a learning curve, but nothing that didn't take 3 or less screens to get dialed in & this was just really the first few screens we shot of each mesh.
I would agree there are some differences in having a single point light source to having a multi point source, & I feel you may see the biggest problems with this if you have the need/want to underexpose.
Well maybe this all helps someone?
Murphy37
We just tried out the new KIWO emulsion to, and we were coating 1/1 sharp side. They told us that we should start coating 2/1 or 2/2 round edge, which we started doing with our PHU, and we are getting really really great screens now. On our STE II we are exposing at 14-20 seconds, and on our richmond solar beak with a 7K light, we are exposing at 22 LU.
We don't have an EOM meter, so can't chime in on our EOM, but i'm hoping to have one next month.
-
*This is a long one*
I've been holding off a bit. As I wanted to do a bunch of testing before I gave my thoughts.
On the LED vs MH debate. I am only coming from the point of the unit we had ( Richmind Solarbeam, using a 10k bulb. ) To what we have now ( M&R I-image STE II with LED. )
There are a few other variables, like using film with the MH, as we were doing & not using film with the LED, as we are now.
As far as I can tell, the LED ( in our unit ) is having absolutely no problem fully curing/crosslinking, or zero slime/ residue on the squeegee side.....or how ever you want to put it. When I say fully crosslinked, I mean absolutely NO soft emulsion, except the image being rinsed out.
-Emulsion: Kiwo ONE-COAT : SBQ with Diazo
[url]http://www.kiwo.com/polycol-one-coat[/url] ([url]http://www.kiwo.com/polycol-one-coat[/url])
-1/1 coating
-20% EOM-on average, based on 156-110
-10k MH unit-
-156-T-white mesh : 48 sec.
-150-S-yellow mesh : 90 sec.
-M&R LED unit-
-156-T-white mesh : 27 sec.
-150-S-yellow mesh : 55 sec.
(*Thread jack*) Sorry
I also had the pleasure of doing some testing, pre-release of a new Kiwo emulsion, Multi-Tex that just hit the market this moth. Check it out!
[url]http://www.kiwo.com/polycol-multi-tex[/url] ([url]http://www.kiwo.com/polycol-multi-tex[/url])
Its looking very promising....... I still need to do a bit more testing. ( tho I did get 2k DC prints with it on one image & another 2k DC prints with a second print, that I feel I could have gotten another 1k prints out of it......Without hardener, with out post expose, with LED exposure )
(*Back to it*)
I have exposed just over 600 screens in the month we have had our M&R unit. Many of these screens have been on reorders, jobs that were burned on our MH & now our LED. I see no compromise in quality exposure with our LED unit.
Many of these screens have also been, clean & save screens, ones we catalog & reprint ( some have already come back through the schedule ) cleaned multiple times. No problems. No lockups.
A large amount of them have gone through the full process of reclame/recoat/reprint, many times. No problem. No lockups.
I had screen up on press last week, it was a quick on the fly reburn for a DC job. The old screens were pulled off the shelf & had quite a bit of use on them already, but we went to press anyway. About mid way through the order one of the screens gets a heavy wipe-down & some of the small detail gets taken out. So I send the guys working on that press to an early lunch hoping to get as much time as I can before they get back for the screen to dry. It gets about an hour ( maybe ) I rush it along & get it on press. Not having that high of expectations, I'm expecting the worst, hoping for the best. Well that screen lasted another 800 prints being double stroked & when done with the order, I would say the screen had very little to no signs of breaking down. ( this was with Kiwo One-Coat emulsion, no hardener, no post exposure )
I have also done a few low mesh with a very thick EOM, 400 micron stencil, & after getting my time dialed in the screen was not under exposed at all & still I was kind of holding the reg marks ( we use .5 line width for reg marks )
I'm not saying it hasn't been without a bit of a learning curve, but nothing that didn't take 3 or less screens to get dialed in & this was just really the first few screens we shot of each mesh.
I would agree there are some differences in having a single point light source to having a multi point source, & I feel you may see the biggest problems with this if you have the need/want to underexpose.
Well maybe this all helps someone?
Murphy37
We just tried out the new KIWO emulsion to, and we were coating 1/1 sharp side. They told us that we should start coating 2/1 or 2/2 round edge, which we started doing with our PHU, and we are getting really really great screens now. On our STE II we are exposing at 14-20 seconds, and on our richmond solar beak with a 7K light, we are exposing at 22 LU.
We don't have an EOM meter, so can't chime in on our EOM, but i'm hoping to have one next month.
Yes, this new one is supposed to be a very fast exposer.
We use the round edge 1/1
I haven't spent enough time with this new one to say much about it. But its initial testing went very well.
Murphy37
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At FESPA I saw a LED that is sold by Saati USA, 300W and costs $500.
It will work like a spot light.
They say exposure for a pure photopolymer emulsion will be about 45 set at a lamp distance of 36", at this distance I can expose two 23X31" screens.
I am ordering this unit.
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At FESPA I saw a LED that is sold by Saati USA, 300W and costs $500.
It will work like a spot light.
They say exposure for a pure photopolymer emulsion will be about 45 set at a lamp distance of 36", at this distance I can expose two 23X31" screens.
I am ordering this unit.
Need more info please.
I looked for this on saati sites. No joy....
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Need more info please.
I looked for this on saati sites. No joy....
I think he may be talking about the same one Greg was testing in his setup at Mind's Eye.
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At FESPA I saw a LED that is sold by Saati USA, 300W and costs $500.
It will work like a spot light.
They say exposure for a pure photopolymer emulsion will be about 45 set at a lamp distance of 36", at this distance I can expose two 23X31" screens.
I am ordering this unit.
I have two of their units here and we are testing them. One is the 300W prototype and the other is the 450W water cooled single point light source. Give me few weeks to get some results. We burned few (3) screens with the 300W unit, but that was just preliminary testing. We were at 2 min for the 110 mesh to get no slime on the back.
pierre
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What emulsion were you testing?
I have a problem, my unit works well but I have flouresent tubes and have to improve on this.
All the alternatives are really expensive, I was looking into putting rows of LEDS into my unit but this lamp looks like a great option.
Greg from Saati said the 300W unit can expose Textel PHU in under 1 min at a distance of 36".
This works well for me and at $500 it's a reasonably priced solution.
My son is coming back to Israel on the 11th June and can bring one with him so I have about a week to decide.
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What emulsion were you testing?
I have a problem, my unit works well but I have flouresent tubes and have to improve on this.
All the alternatives are really expensive, I was looking into putting rows of LEDS into my unit but this lamp looks like a great option.
Greg from Saati said the 300W unit can expose Textel PHU in under 1 min at a distance of 36".
This works well for me and at $500 it's a reasonably priced solution.
My son is coming back to Israel on the 11th June and can bring one with him so I have about a week to decide.
Aquasol HV.
My suggestion would be to buy it as long as you can send it back if it does not work out. 'worst case scenario is you are out of shipping money. I doubt I can have and decision quality information in the next few days. . .
pierre
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What emulsion were you testing?
I have a problem, my unit works well but I have flouresent tubes and have to improve on this.
All the alternatives are really expensive, I was looking into putting rows of LEDS into my unit but this lamp looks like a great option.
Greg from Saati said the 300W unit can expose Textel PHU in under 1 min at a distance of 36".
This works well for me and at $500 it's a reasonably priced solution.
My son is coming back to Israel on the 11th June and can bring one with him so I have about a week to decide.
Pardon me for my lack of knowledge about your business/shop, but It seems out of place. You have at least one auto (with a DGT printer in one station) and you want a $500.00 exp unit? Seems like for the cost, it would be under purchasing for your shop. I don't know. Could be very wrong.
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What emulsion were you testing?
I have a problem, my unit works well but I have flouresent tubes and have to improve on this.
All the alternatives are really expensive, I was looking into putting rows of LEDS into my unit but this lamp looks like a great option.
Greg from Saati said the 300W unit can expose Textel PHU in under 1 min at a distance of 36".
This works well for me and at $500 it's a reasonably priced solution.
My son is coming back to Israel on the 11th June and can bring one with him so I have about a week to decide.
Pardon me for my lack of knowledge about your business/shop, but It seems out of place. You have at least one auto (with a DGT printer in one station) and you want a $500.00 exp unit? Seems like for the cost, it would be under purchasing for your shop. I don't know. Could be very wrong.
Dan, $500 is a lot less than an M&R, VASTEX, or any other brand exposure unit, this is just for the light source, and even a powerful single point light should cost less than an entire bank of small ones.
Does anyone else even have an LED light source that can be used at different distances from a wall mounted vacuum frame?
-
At FESPA I saw a LED that is sold by Saati USA, 300W and costs $500.
It will work like a spot light.
They say exposure for a pure photopolymer emulsion will be about 45 set at a lamp distance of 36", at this distance I can expose two 23X31" screens.
I am ordering this unit.
I have two of their units here and we are testing them. One is the 300W prototype and the other is the 450W water cooled single point light source. Give me few weeks to get some results. We burned few (3) screens with the 300W unit, but that was just preliminary testing. We were at 2 min for the 110 mesh to get no slime on the back.
pierre
I had one of the 300watt ones. It didn't live up to the claims they had made to me about exposure times. On the SP-1400 it was worse than our 1k MH unit I've had since we opened. That was a annoying sticking point from them, they said I'd be better off switching to their newer hybrid H-something. Then we thought maybe the unit I got was damaged..... All in all I ended up returning it. It performed below our 1k Workhorse we have had for 10 years.
Important to note though, ALL the use and screens we did with it were for DC, WB or HSA inks. Didn't try it on anything for plastisol.
-
At FESPA I saw a LED that is sold by Saati USA, 300W and costs $500.
It will work like a spot light.
They say exposure for a pure photopolymer emulsion will be about 45 set at a lamp distance of 36", at this distance I can expose two 23X31" screens.
I am ordering this unit.
I have two of their units here and we are testing them. One is the 300W prototype and the other is the 450W water cooled single point light source. Give me few weeks to get some results. We burned few (3) screens with the 300W unit, but that was just preliminary testing. We were at 2 min for the 110 mesh to get no slime on the back.
pierre
I had one of the 300watt ones. It didn't live up to the claims they had made to me about exposure times. On the SP-1400 it was worse than our 1k MH unit I've had since we opened. That was a annoying sticking point from them, they said I'd be better off switching to their newer hybrid H-something. Then we thought maybe the unit I got was damaged..... All in all I ended up returning it. It performed below our 1k Workhorse we have had for 10 years.
Important to note though, ALL the use and screens we did with it were for DC, WB or HSA inks. Didn't try it on anything for plastisol.
we are on a 1.2kW MH and I am expecting the times to go up with the 300W and be around the same with the 450W units. This is not a time saving excersize for us. . .
pierre
-
What emulsion were you testing?
I have a problem, my unit works well but I have flouresent tubes and have to improve on this.
All the alternatives are really expensive, I was looking into putting rows of LEDS into my unit but this lamp looks like a great option.
Greg from Saati said the 300W unit can expose Textel PHU in under 1 min at a distance of 36".
This works well for me and at $500 it's a reasonably priced solution.
My son is coming back to Israel on the 11th June and can bring one with him so I have about a week to decide.
Pardon me for my lack of knowledge about your business/shop, but It seems out of place. You have at least one auto (with a DGT printer in one station) and you want a $500.00 exp unit? Seems like for the cost, it would be under purchasing for your shop. I don't know. Could be very wrong.
Dan, $500 is a lot less than an M&R, VASTEX, or any other brand exposure unit, this is just for the light source, and even a powerful single point light should cost less than an entire bank of small ones.
Does anyone else even have an LED light source that can be used at different distances from a wall mounted vacuum frame?
I digress. I'ts none of my business why people make the decisions they do.
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I would be suspect that as every manufacture is producing LED units that cost thousands that any unit that cost $500 bucks can't be much to write home about. Comes off to me like a late night TV advert... but wait there is more....act now and we will throw in a brand new 12 color auto with your purchase.....just pay processing, shipping and handling.
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I would be suspect that as every manufacture is producing LED units that cost thousands that any unit that cost $500 bucks can't be much to write home about. Comes off to me like a late night TV advert... but wait there is more....act now and we will throw in a brand new 12 color auto with your purchase.....just pay processing, shipping and handling.
We are not comparing apples to apples here. This is just the core. This is not an exposure unit, just the light source.
http://www.theshirtboard.com/index.php?action=dlattach;topic=13347.0;attach=13534 (http://www.theshirtboard.com/index.php?action=dlattach;topic=13347.0;attach=13534)
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honestly, our 7.5k lights run about $250-300...so that's not bad for a bulb you should never have to replace.
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I would be suspect that as every manufacture is producing LED units that cost thousands that any unit that cost $500 bucks can't be much to write home about. Comes off to me like a late night TV advert... but wait there is more....act now and we will throw in a brand new 12 color auto with your purchase.....just pay processing, shipping and handling.
We are not comparing apples to apples here. This is just the core. This is not an exposure unit, just the light source.
[url]http://www.theshirtboard.com/index.php?action=dlattach;topic=13347.0;attach=13534[/url] ([url]http://www.theshirtboard.com/index.php?action=dlattach;topic=13347.0;attach=13534[/url])
My bad, his post didn't come off as if it was just the bulb.
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A few things I'd like to add here before it gets covered up. Let's get my points out in the open more clearly with what I know for sure. We are having tons of issues with different emulsions with the LED. With the MH we had ZERO issues with any emulsion at any time and even when we were shooting a new emulsion for the first time we rarely had a screen that we couldn't use on press. The fact is our LED is much more picky about the emulsion it can work with, and the HVP is the only emulsion out of about 6 that it has been able to cross-link all the way through. To eliminate the possibility of our films being the problem, I've got a few older imagesetter pieces of film I'm using to test on the bottom of every screen we shoot. This film I'm using to test is of the highest quality there is when it comes to film so I'm not concerned with the issue being our film any longer.
I haven't called or emailed them about our issues and don't plan on it. They've read this thread, and the others, and with my past conversations and comms with them yielding absolutely nothing but frustration and insinuations that we didn't know what we were doing around here, that's why I haven't reached out to them directly. Now that I have more time on my hands I may change my tune on that but my lack of confidence that a conversation with them directly would help us get durable stencils and fine detail on our screens is warranted in my opinion. I can go into detail on each of those issues if anyone wants to know that badly. It's something that I'm sure most everyone here would feel the same way had they been handled that way. I think the main issue I had with the first problem was it was a fairly well known issue that I had heard from several other users so when I was told that this was the first they had heard about a pallet rubber issue and WE were overflashing we didn't get started on the right footing. But almost identical insinuations with other problems we had have kept that relationship very strained.
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Let's look at 2 things:
How many milli watts of light on the squeegee side during exposure? This is the area that will break down first. So what lamp or light is going to have the most power to reach this side of the emulsion? 5k/8k MH or any other lamp of your chosing? No doubt in my mind and in my observations, the MH 5k and 8k systems expose the squeegee side better. LED and fluo tubes use shorter distance from emulsion to light to overcome this. But if you give the exposure enough time to expose the inside of the screen you can wind up with under cutting of details. Getting an image on the screen is easy. Getting it fully exposed is another issue and can vary by manufacturer with LED units. Plastisol? no problems, Discharge and HSA inks? Takes a bit of fine tuning of the coating method, opacity of film/image, pushing the time as much as possible and using my emulsion of course. I sell it cause I have used it with great success in my business. Just the facts, try it, you'll like it, or I'll help you find the magic if you need it.
Second what is the spectral output of the light? MH = multi spectral, has all possible wavelengths from white light to 405/420 UV. Emulsions like multi-spectral light with lots of amplitude. So a multi spectral LED? usually this is spill over wavelengths, or spikes in just a few wavelengths, or a single spike with some wavelengths to either side, but so far it isn't the amplitude or multi spectral output that MH provides and emulsions like for complete exposure. It's not like the sensitizer has changed, it's that the new light has changed and causing failure. 6-9 second exposures? These are images, for plastisol only. What I have found is that your old coating techiques can be part of the problem. While you may have coated 2:2 or 2:3 and achieved good exposure on your MH unit, the same coating may be too thick for the weak LED or fluo light to penetrate the entire emulsion thickness. The inside is soft. Any post exposure or hardening is a band aid on a weak exposure. I have found that coating less can help get stronger exposures. Try a 1:2 sharp on these systems. Should still yield 7-10% EOM. DTS with LED uses stronger light, Film and LED uses a weaker light on the same system since the film and glass cut down the amplitude of the light. I am still in the Metal Halide camp, especially for large shops. LED's have significant through put advantages. Just need to fine tune the process of coating, time. In most LED exposures the print side is exposed well, the inside can be soft. Strong film or CTS opaque imagery helps achieve longer times on LED to expose the emulsion. Try using a little less emulsion, it seems to expose better than 15-20% Eoms.
Bake the Cake, no baker has ever sold bread under cooked. So why is obtaining the fastest 'cook time' of emulsion so important and like a screen printing merit badge? I can expose in 9, me? 8? another 6!!! to the point that we hit it with a flash bulb and get a strong screen? Not possible. Cook your emulsions up to the point of of overexposure. It's not how fast you cook it, it's how well you cook it that will give the best results on press, with less breakdown, pinholes and also allows SBQ emulsions to reclaim easier and avoid lock in. (And for these reasons an MH unit is like a commercial bakers oven and not a small household oven cooking for an entire bakery). Short cut the light energy with lamp choice or time and your exposure will be weaker. Give emulsion the energy it needs for the right amount of time and the screen will be very durable.
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after having gone through ALL sorts of fun (Alan B can attest to ;) here, I totally agree with the thickness of emulsion playing a MAJOR roll in exposure results.
when we switched from SP1400W back to SP1400 we had a bunch of problems happening, and really couldn't figure out why our results were so different... well it turns out that SP1400 is slightly thinner than SP1400W, so our 1/1 round technique on our 156 and 160S screens was resulting in nearly 30%!!! EOM vs the 17-20% we were getting on SP1400... add to the fact that I was told that SP1400W was a slower exposing emulsion than 1400, we were totally undercooking screens... we've settled back in at around 65-70 seconds on a SP1400 screen to get to 7 solid steps on the stouffer strip, however, even still with 7 or 8 solid steps and 70-80 seconds exposure, if you wipe the back of the screen with a white shirt, you get emulsion color coming off... it's not until you hit 9 or more steps that I'm not seeing the color anymore.
we've got a pretty good running log here that we're recording emulsion, exposure time, eom, stouffer results, coating technique and on-press notes for nearly every screen we burn.
some emulsions we've tested since seem to be far more tolerant of underexposure on press than others, but I can tell you with certainty that 5-10% difference in EOM will result in differing stouffer strip results.
part of me still wonders if it's a color of emulsion situation.. when I have time I'd LOVE to get some undyed emulsions in here and figure out what to dye them with to do my own testing...
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I was told by a CCI rep that they have done a scientific study that proves that GREEN emulsion makes better stencils and holds better detail!
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Let's look at 2 things:
How many milli watts of light on the squeegee side during exposure? This is the area that will break down first. So what lamp or light is going to have the most power to reach this side of the emulsion? 5k/8k MH or any other lamp of your chosing? No doubt in my mind and in my observations, the MH 5k and 8k systems expose the squeegee side better. LED and fluo tubes use shorter distance from emulsion to light to overcome this. But if you give the exposure enough time to expose the inside of the screen you can wind up with under cutting of details. Getting an image on the screen is easy. Getting it fully exposed is another issue and can vary by manufacturer with LED units. Plastisol? no problems, Discharge and HSA inks? Takes a bit of fine tuning of the coating method, opacity of film/image, pushing the time as much as possible and using my emulsion of course. I sell it cause I have used it with great success in my business. Just the facts, try it, you'll like it, or I'll help you find the magic if you need it.
Second what is the spectral output of the light? MH = multi spectral, has all possible wavelengths from white light to 405/420 UV. Emulsions like multi-spectral light with lots of amplitude. So a multi spectral LED? usually this is spill over wavelengths, or spikes in just a few wavelengths, or a single spike with some wavelengths to either side, but so far it isn't the amplitude or multi spectral output that MH provides and emulsions like for complete exposure. It's not like the sensitizer has changed, it's that the new light has changed and causing failure. 6-9 second exposures? These are images, for plastisol only. What I have found is that your old coating techiques can be part of the problem. While you may have coated 2:2 or 2:3 and achieved good exposure on your MH unit, the same coating may be too thick for the weak LED or fluo light to penetrate the entire emulsion thickness. The inside is soft. Any post exposure or hardening is a band aid on a weak exposure. I have found that coating less can help get stronger exposures. Try a 1:2 sharp on these systems. Should still yield 7-10% EOM. DTS with LED uses stronger light, Film and LED uses a weaker light on the same system since the film and glass cut down the amplitude of the light. I am still in the Metal Halide camp, especially for large shops. LED's have significant through put advantages. Just need to fine tune the process of coating, time. In most LED exposures the print side is exposed well, the inside can be soft. Strong film or CTS opaque imagery helps achieve longer times on LED to expose the emulsion. Try using a little less emulsion, it seems to expose better than 15-20% Eoms.
Bake the Cake, no baker has ever sold bread under cooked. So why is obtaining the fastest 'cook time' of emulsion so important and like a screen printing merit badge? I can expose in 9, me? 8? another 6!!! to the point that we hit it with a flash bulb and get a strong screen? Not possible. Cook your emulsions up to the point of of overexposure. It's not how fast you cook it, it's how well you cook it that will give the best results on press, with less breakdown, pinholes and also allows SBQ emulsions to reclaim easier and avoid lock in. (And for these reasons an MH unit is like a commercial bakers oven and not a small household oven cooking for an entire bakery). Short cut the light energy with lamp choice or time and your exposure will be weaker. Give emulsion the energy it needs for the right amount of time and the screen will be very durable.
Ta-da!!! ;D
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The color of emulsion? The resolution of our emulsions is built into the base components, we add the color for contrast. Green, Red and Blue are chosen since they have the least halation issues. Our highest resolving emulsion is actually a very transparent aqua, but it's nearest similar emulsion is red, almost identical resolution, identical components, just contrast needed for hand vs auto registration.
Getting back to the thread: I just had a chat with Dan. The key point here is this: LED has a narrow latitude, you need to control EOM more accurately, control the temp and humidity of your room better. (A cold day with a short exposure on and LED will be different than a hot day short exposure, the molecules and senstizer work better on a warm day than a cold day.) My Phoenix AZ printers can expose the same SBQ far faster than I can in LA due to low humidity and warmer rooms. Exposure is completely printer dependent. What works on an MH Tri Light in a shop by the beach can be longer than what works inland by only 20-30 miles due to humidity drop. Age of the lamp? What voltage 208 or true 240?, distance from lamp, eom?, so many variables. The same applies to LED in terms of shop conditions, and ambient conditions.
The recipe for LED is narrow. Having breakdown issues? Hit a hard 7 on less coats to see if that helps. Thinner is better with weak light. MH has lots of things LED doesn't have. A pinpoint light source, with engineered reflectors for more collimated light. LED's as we currently know them are chaotic light. The rays are hardly parallel. Sometimes going for maximum exposure under cuts the image, so we find recipes that work, and find a balance. (By the way I am old, like I started with carbon arcs and the sun. I am a big fan of the sun, 93 million miles away, 23k or more lamp strength, very parallel rays, almost too fast, but I digress.)
Most of us aren't printing over 20k print runs, so fine tune the process for your printing. Optimize your coating. How? Coat 1:1 sharp. Then coat a second coat 2/3 of the way up on the inside, then another 1/3 of the screen length. This will yield 1:1, 1:2, 1:3 coating on the same screen. Attach a very detailed image suitable for the mesh count used. Use lots of tape to keep in place, or if you have DTG you are way ahead of the curve.
Now if you can block out the bottom of the screen, block out 2/3 of the screen so that 1/3 of the screen can be exposed in the 1:1, 1:2 and 1:3 coatings. A doubled up black trash bag works fairly well, or the hard to find ruby or amberlith. Expose the visible 1/3 of the 3 coating types with 25% of the current time for this particular mesh. Move block out medium over to leave 2/3 of screen to be exposed. Expose for 25% of current time again. Then remove the block out material and expose the entire screen with current time for the mesh used.
This will yield 9 different variations on one screen
1:1 Coating
Current time, Current time + 25%, Current time +50%
1:2 Coating
Current time, Current time + 25%, Current time +50%
1:3 Coating
Current time, Current time + 25%, Current time +50%
This will help you determine where the squeegee side has been exposed properly, where details are holding and where the details get lost due to too much emulsion thickness.
PM me if you want more info. This is a variation on a step test, but adding the different coats on the squeegee side helps see what coating works for you. Thinner has been better in most LED tests I have done. SP-1400 coated 2:3 dull has now where near the strength as 1:2 sharp. Thickness of emulsion helps, as long as the lamp used can expose it completely. MH is a little better at thicker coatings, but an LED is so fast and does produce good screens for all textile printing, it just requires a more careful recipe.
By the way I have a large printer who coats Aquasol HV once on the squeegee side. Thats it. Running 20K of discharge quite often. I don't recommend it, but they get great results and are a premier contract printer.
Al
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Real good stuff Al,
Couple things.
1, I agree 99%. the 1% is the word "weak". LED is not weak. Maybe in strength when comparing to a 5k MH or higher it is less than, but not weak at all. Strong enough for the majority. Weak is a bad word. lol.
2, The conversation does not separate or differentiate when using the term LED. Like it's been mentioned before, Not all LED's are the same.
3, Much of what you are pointing (where LED lacks in total cross linking) to make a stencil durable enough... is pertaining to very high numbers where the vast majority of shops don't live. 10, 20 and 50k orders.
Another overlooked factor is (when doing those orders of 10, 20 and 50k is
A, you can afford to stop the press for the 15 min and change out the old and in with a new screen.
B, These orders don't happen every day for the vast majority so it's not a common problem when it is a problem.
Just some extra notes.
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Dan, I think Buffington was speaking in the terms of "frequency amplitude" when he used the term weak.
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Every time Al lays down some knowledge like that a little part of me dies.... I realize I've "been in the business" for 18 years and don't know jack sh!t ;D
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Dan, I think Buffington was speaking in the terms of "frequency amplitude" when he used the term weak.
That maybe so. I realize he's trying to make things more clear. It is clear more most of us. If using the term in multiple areas of a long thread (I like on long threads by the way) then the term weak in conjunction with LED may unintentionally miss guide the lesser minded people to assume an LED system is a weak light source. Not so. Sure, Al knows that and many of us know he's not saying that, but for some people, they will be running off quoting Al as saying (after his own research" Al is quoted as calling the LED systems a weak light source. We've seen it happen right here on this very forum. Weak, shouldn't even be used in the same sentence to discuss the LED. Less than something else maybe in different scenarios, but not weak. That's just my preference and it's nothing really related to Al himself. Al is invited to say what ever, when ever he wants and I'm not debating if he's wrong or not. Just that this specific terminology can leave room for error. No ham intended to anyone.
TCT, LOL. Yes, These are the post that I crave tho. When Al, Greg, Richard , Rick Roth or Coudrey comes in, I get a little giddy cus I know they are gonna say something juicy.
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If we all chipped in our hourly rate spent reading/typing on this thread we could have gone together and have bought Alan another brand LED to try. Haha
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Every time Al lays down some knowledge like that a little part of me dies.... I realize I've "been in the business" for 18 years and don't know jack sh!t ;D
^^^^^^THIS^^^^^^
BUT!... If there weren't anything left to learn, you'd be bored. Burned out even.
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here's my current (05/2015) thinking on this subject. It is constantly changing as more information is revealed and it is pretty significantly different from what it was just 6 or so months ago.
400nm light is the same no matter how it's produced. What am I trying to say? LED or MH or Arc light, it does not matter. When the photon is moving at 400nm it does not know what excited it and got it moving. As long as it is at 400nm, it has EXACTLY the same properties regardless of how it started. This in turn means that the unit that reads 1mW of power is the same 1mW regardless of where it started, MH or LED.
OK, going on. . . so if an MH light produces 5KW and by the inverse square low it is showing 1mW when it hits the stencil, it is EXACTLY the same as the 450W LED that is closer and reads the same 1mW at the stencil. Same wavelength, same power. They will both penetrate and crosslink EXACTLY the same.
So manufacturers use the weaker LEDs and place them closer to the stencil. This generates the same results as the more powerful, further away source FOR THAT PARTICULAR WAVELENGTH!
Now that we have that out of the way, so what is causing the difference? Well, what is different with the lights? MH is a multispectrum light and thus produces multiple frequencies whereas LEDs produce only one at a time. The wavelength produced by the LED might not be the OPTIMAL frequency for crosslinking. MH is a shotgun approach and it will crosslink regardless of the emulsion. For example, 400nm LED hitting an emulsion that exposes at 350nm can stay on the whole day and it will not crosslink. MH, while it might not produce much at that frequency it produces some, so it will eventually expose. Again, think shotgun vs sniper. MH will eventually get it done, while if the sniper aim is off if it will miss no matter how many times you fire.
So if your emulsion is not in tune with your exposure wavelength, there will be problems with achieving complete exposure! This might manifest itself in very long exposure times as the sensitivity at particular wavelength might be marginal or in some cases it will not expose at all.
There are additional factors that come into play here, but the correct matching will be of the utmost importance.
pierre
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Again, think shotgun vs sniper.
this about sums up this thread for me
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So forgive me if this is a stupid question, but wouldn't an easy solution be to create groups of 3-4 LEDs, each producing a different wavelength, and lay those out in strips? Would this not emulate the multi-spectral properties of a MH?
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so physics aside, lets look at the reality of our world. . .
manufacturers are placing the source closer to the stencil to get more power delivered. This in turn has potential to cause undercutting. Having proper spacing and lenses on the LEDs is part of proper design. There are compromises that have to be made in any design. This is what differentiates the units (where the compromises were made). Design will impact the field strength, uniformity, wavelength and so on. . .
On the emulsion side, the actual wavelength is in some cases not set in stone (as I understand). When an organic compound is part of the emulsion, it is not exactly the same every time (since it is not produced in laboratory conditions, but rather by mother nature. Think oil, middle eastern crude is very different from the stuff pulled up in Texas, but they are both oil.) This can introduce variations we normally don't expect to see. MH with it's multispectrun approach should cope with it better. Further more, crosslinked emulsion has different light blocking properties than the stuff that has not be crosslinked so it will impact the penetrating power. This means that the wavelength with better penetrating properties MIGHT be more suitable for exposure. Now, we can not switch to something that penetrates without crosslinking, so again we are faced with selecting the right wavelength for the LEDs to get both the penetrating and exposing in balance.
more to come if I can find time. . .
pierre
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So forgive me if this is a stupid question, but wouldn't an easy solution be to create groups of 3-4 LEDs, each producing a different wavelength, and lay those out in strips? Would this not emulate the multi-spectral properties of a MH?
it would, but at the expense of the total power at required frequency. If you split it across four different wavelengths, the usable power could be as low as one quarter of the rated power.
pierre
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So forgive me if this is a stupid question, but wouldn't an easy solution be to create groups of 3-4 LEDs, each producing a different wavelength, and lay those out in strips? Would this not emulate the multi-spectral properties of a MH?
it would, but at the expense of the total power at required frequency. If you split it across four different wavelengths, the usable power could be as low as one quarter of the rated power.
pierre
...Unless we get the screen 4 times closer. :P
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Clustering different wavelength leds would also add to inconsistent coverage. They can't all physically exist in the same space,
so you'd have offsets from each wavelength. Could you imagine a large coverage halftone pattern where only every quarter of a square
inch on screen is receiving the correct crosslinking wavelength? And you thought moire was bad. Cringe.
You could likely increase the distance from the source until it all evened out but then you'd be back at square one.
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So forgive me if this is a stupid question, but wouldn't an easy solution be to create groups of 3-4 LEDs, each producing a different wavelength, and lay those out in strips? Would this not emulate the multi-spectral properties of a MH?
it would, but at the expense of the total power at required frequency. If you split it across four different wavelengths, the usable power could be as low as one quarter of the rated power.
pierre
...Unless we get the screen 4 times closer. :P
actually you would also have to have all the different color LEDs bunched together at a single point or you'd have gaps in the field. So there is more to it than one line I posted.
There is already a multispectrum LED unit on the market. I've talked to the designer, but had not had the chance to test. Reallity is, without a UV spectrum radiometer it is hard to analyze what's going on. I have been looking into getting or renting one, but who knows when I'll have the time to do it. . .
pierre
EDIT: eb beat me to it!
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Actually, you wouldn't have to worry about that if the light geometry was correct--even if the different wavelength LEDs/junctions were offset from each other by half the distance between the first junctions, as long as all the junctions of the same type provide an even pattern of collimated light, I couldn't see there being issues.
But--four times the LEDs, four times the power, four times the heat, and a pretty serious price increase.
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LED is here to stay. As much as I like MH units for there long run durability, we simply rarely see the 90k runs of discharge or HSA here in the states. So for almost 99% of the US printers with shorter run lengths, LED works just fine. Thanks Pierre for reminding me that the inverse square law does help with strength for LED's. And as pointed out select an emulsion that matches the nm output of your lamp. In almost all cases if there is any SBQ, post exposing in the sun helps complete the exposure and aids in reclaiming.
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3 wavelengths out of one LED is possible. The adhesive LED strips that most of these units are using have the 5050 type LED in them. EACH 5mm LED has 3 diodes in it that emit light. The only problem is LED's of different wavelengths have different power requirements so you'd have to isolate each diode and supply it independently. If you look at pics of a 5050 led strip you'll see current-limiting resistors between each LED.
My opinion was summarized already previously but it boils down to light penetration or "strength". SOME LED's don't emit enough light to penetrate thick emulsions in a timely manner. The M&R unit, based on what I've read here from reviews/opinions and exposure tests, uses MUCH more current than other models (which in my opinion equates to higher quality LED components). It generates a lot of HEAT. That should be one clue that it's a bright mofo.
If anything comes of this discussion, I'd hope the manufacturers will take notice of the large variation in results from end users. It would be in their best interest to post tangible and repeatable test results for their units using specific emulsions, specific mesh counts, and specific EOM coating (not just saying we coated with a round edge 1/1 etc.).
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LED will end up being cheap in a few years and people will not be using MH units unless they are dinosaurs I suspect.
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Great conversation.
I think it all circles back to LEDs creating the need to match emulsions to spectral output. This has been done for special uses in the past but not generally speaking. Alan or someone with better knowledge could clarify for me.
The best thing I can see happening at this point is the industry settling on a standard wavelength or, at the least, a set of them. It would limit certain uses but really fine tune the bulk of the work being done in our industry with screen imaging. It would also level things out and allow buyers to compare apples to apples on exposure units and their outputs. Some shops would be ok with less expensive models with less output with others shelling out for the big gun units, but at least it would all be spectrally matched and nobody would be experiencing screen failures, just differences in exposure speeds and resolution quality basically.
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LED will end up being cheap in a few years and people will not be using MH units unless they are dinosaurs I suspect.
Nothing to do with price, everything to do with fully cross-linking screens while retaining detail. It ain't there yet.
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LED will end up being cheap in a few years and people will not be using MH units unless they are dinosaurs I suspect.
Nothing to do with price, everything to do with fully cross-linking screens while retaining detail. It ain't there yet.
Sorry to disagree but I think its more than there. Have you played with one of ours?
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I have not, but the emulsion manufacturer that brought this back up has, and the dance he's describing
to obtain quality screens doesn't sound very fun. Using only diazo emulsion, I don't know that
we'd save any time over our current setup either, so all in all, a net loss. So far.
Anyone have any 5K or higher MH units for sale?
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LED will end up being cheap in a few years and people will not be using MH units unless they are dinosaurs I suspect.
Nothing to do with price, everything to do with fully cross-linking screens while retaining detail. It ain't there yet.
The context of my post wasn't about today's price. I did clearly say end up being cheap. Which yes doesn't have anything to do with price today, correct. My point was in a few years when LED's are super cheap and the price on these units go down nobody is going to buy a MH anymore in the typical shop.
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As I mentioned in a previous post, 99% of the printing you will do in the US can be done very well with the LED. The fine tuning process has one major advantage. It is consistent. The main drawback of MH is shooting with a bulb that is way past it's prime and has lost a lot of the punch it once had. If the client is still using seconds instead of light units the break down issue is huge with poor UV light and exposure will be inconsistent. The longevity of the lamps in LED and the consistency is a great sales point. Both camps have valid arguments. If I was a small to medium shop I'd fine tune my emulsion and coating techniques to use an LED. If I was a 20-40 auto shop with tons of long print runs, lots of discharge and HSA I would go w 2 MH units for multiple screen shots at one time. Check out my previous post on how to set up a coating/exposure test for LED. I use this technique all the time. 1 screen, 3 different coating techniques, evaluated at 3 different exposure times. Takes all of 15 minutes to do this and will answer a lot of questions on how much to coat and how much time for a strong exposure.
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LED will end up being cheap in a few years and people will not be using MH units unless they are dinosaurs I suspect.
Nothing to do with price, everything to do with fully cross-linking screens while retaining detail. It ain't there yet.
The context of my post wasn't about today's price. I did clearly say end up being cheap. Which yes doesn't have anything to do with price today, correct. My point was in a few years when LED's are super cheap and the price on these units go down nobody is going to buy a MH anymore in the typical shop.
Which means you are clearly misreading my post. Doesn't matter if it cost twenty thousand dollars or twenty thousand pennies, if it
doesn't do what we need it to do I ain't a buyin'.
We print a helluva lot more than plastisol on Gildans.
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He's gotta be in the elite group. He might need more than the majority.
Better image quality than your every day award winner.
Maybe the 2% dots on 85lpi type and he doesn't need it to be fast.
same screens to last an entire production run of 20-50k orders on average. Give or take 10k.
It's possible and if so, more power to him and good for him.
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Was that meant for a PM?
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Was that meant for a PM?
Not at all. Does it read like one?
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Sure does. Just never thought I'd be talked to like the from either a board owner or a salesman for a company,
but whatever.
Let's see 2% dots at 85 lpi, diazo emulsion.
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Hell, let's see any kind of real quantifiable science from your company on this technology.
I'm not a big fan of end user testimony. End users are subjective, as is their results. And as real
as buyers remorse is, so is the opposite.
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Sure does. Just never thought I'd be talked to like the from either a board owner or a salesman for a company,
but whatever.
Let's see 2% dots at 85 lpi, diazo emulsion.
What do you mean talked to that way? LOL. Do you read a tone in there? Not intended. I'm saying, you must be in that elite group of shops that do that type of work.
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If you were speaking to me, you'd say "you".
If you were speaking ABOUT me to someone else, you'd say "he".
But I'm no English major....
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Was that meant for a PM?
Not at all. Does it read like one?
eb just answered this as I was typing, but here's my take on it anyway.
To some, it could appear a little "removed" or "distant" talking about him like he's not here. That may be why he assumed that it may have been meant as a private message to someone else.
I think that eb is just saying that this particular tech is still quite new, and until it's proven in the real world, with all emulsions, he doesn't want to be a beta user at retail prices, a situation all too common as tech moves quicker and quicker.
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Hell, let's see any kind of real quantifiable science from your company on this technology.
I'm not a big fan of end user testimony. End users are subjective, as is their results. And as real
as buyers remorse is, so is the opposite.
Wish it were my Co. LOL. What do you mean by "quantifiable" science? What exactly are your needs in a quantifiable scientific form? Probably based on all of the unbiased info from 3rd party experts with Pro's and Cons in both directions, I would guess that if you don't see it now, you won't see it later and there is nothing wrong with that for you. That doesn't make you wrong or others right.
You probably would prefer some additional 3rd parties to give you more answers. If you are in the arena of large volume orders above 10k on a regular basis, then you might not ever need to do anything different than what you are already doing. Something is working for you.
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If you were speaking to me, you'd say "you".
If you were speaking ABOUT me to someone else, you'd say "he".
But I'm no English major....
Well, at the time, I wasn't directing it to anyone specific when I was talking about you. If we were here like we are now, talking back and fourth, I'd say you, speaking to you. If I am directing the post to the general viewers, I'd say he, this guy, Eb, defining you, but not specifically and or only talking to you.
I'm certainly no English major either. I just type. No offence.
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Two percent
What do you mean by "quantifiable" science?
A closeup of two percent dots at eighty five lpi would be a start.
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Two percent What do you mean by "quantifiable" science?
A closeup of two percent dots at eighty five lpi would be a start.
I will see about getting that for you. Even better send me a file of your own for us to try.
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(FROG)
eb just answered this as I was typing, but here's my take on it anyway.
To some, it could appear a little "removed" or "distant" talking about him like he's not here. That may be why he assumed that it may have been meant as a private message to someone else.
I think that eb is just saying that this particular tech is still quite new, and until it's proven in the real world, with all emulsions, he doesn't want to be a beta user at retail prices, a situation all too common as tech moves quicker and quicker.
I can see that. I'll add tho, (he was't here at the time), so I was indeed talking about him. He was the topic. His needs and not needing LED.
It is only sort of new. I think the LED's have been out now around 3 years maybe. I don't have a date. There are many many users now and each using various emulsions...and various inks, and coating in various ways. Some very different, many very norm. He just asked for Quantifiable science. I'd say we don't have any, because (we) don't do the production. I'd guess that the customers M&R has would or should be able to be used as "quantifiable" science. I mean, one shop that does 5 million in sales (using the LED system) is good information, but lets take that further. Average that number out to the total number of customers producing shirts with both plastisol and discharge/dual cure and pure photopoly, in various coating techniques and eom. X that by pffft, I can't even gather a number of shirts sold and dollars made. Has it increased production for them? Yes. Efficiency? Yes. Image quality? Yes. Profitability? Yes. I donno. Sounds good. I think that's quantifiable but I'm not here to sell someone. They buy or they don't. Thats someone else's area. Am I protecting my job? Nope, but it if does, then ok. I can tell you I'd be fired tonight if I were not saying something that wasn't true. I'll tell you what I am doing. I'm telling it like it is. Thats it.
As I've seen myself, once you think you've seen and done every emulsion, there is another new one out. I don't even think about the emulsion (type) anymore. Put it up there on the screen, we'll burn it. It will be a never ending story, just like the new white ink. There has never in my experience been an emulsion that LED has not worked with. To what degree of durability would be questioned by those who are reaching, but I will say by my own testing that it works with every emulsion. Some faster, some not as fast as most consider fast. Dual Cures? No prob. Been there done that. Customers are still using the same DC they were before I got there. People that have been running a business for 15-20 years, don't buy one of these and say, oh well, I guess I'll have to decrease my production now, or stop doing discharge printing or, or, No. They say the opposite.
Is LED for everyone? For the most part yes. Like has been defined tho, there is a % of printers out there that this might not benefit. Not that it can't, but that they can stay where they are and not need to bother. If I were in that category, I'd continue doing what I'm doing also, if I didn't see a good reasons to change. They tho, apparently are not the vast majority and apparently not very profitable to design something specifically for them. Probably because there just aren't that many of them and what is out there now, covers that target audience very well. Eb, might be one of them. I don't know his business but I assume that since it's not for him, It doesn't fit his needs. Nobody gets forced into going LED.
There are still very good printers out there using wood frames and vellum making a good living and on the other end of the spectrum, there are other printers out there that are still using we photo films from an imagesetter and a 10k MH with 3000 newmans in the shop doing 10-50k piece discharge orders. I'm sure M&R would sell to either of that group if they called and wanted one, but the more obvious target audience is in between there somewhere.
I am a Tech installer by day. I install the machines and I train on the operation and maintaining it. I never considered that to make it (my Co), but I do take some ownership in what I do. I do a good job. ;) I'm proud of not only of who I'm working for, but also, what I work with. If the product was not as advertised, I would not be working for them doing what I am doing. In my opinion, it's more than advertised. They could highlight some other areas that it benefits that most don't think about. It's a hard decision of when is THE time to make a move. Even with that said, I am not a forceful person. I don't want to push anyone to decide to buy one. That's not my department. A purchase like this should/cannot be made lightly and it shouldn't be one that you make just based on popular vote. It has to make sense for you. Take you'r time. I might not be there when you're ready if you (anyone) takes too long, but I'm pretty sure M&R will be. If or when I get another shop going, Yes, I would be getting one eventually.
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Nice coincidence. I installed one of the machines for a member on here. After install, we tested a file at 75lpi, printed with black ink on a white Gildan G5000 (I'm pretty sure that is what it was) and held on the shirt, the 2% dots while I was there. Shadow tones were up in the 98 range but that is with some curve adjustments I left them. I took pictures close up but were just phone pics.
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Pure photopolymers exhibit a very narrow exposure latitude. Seems to me with the speed of LED, dialing in variables in the exposure process may be complicated. Without tight control on all aspects of screen processing no matter emulsion choice nor light source, weaknesses will show in pre-press, on-press and reclamation.
Food for thought:
Dennings (http://static1.squarespace.com/static/53306342e4b083dcd0603c96/t/533db748e4b05289c3d9ce6c/1396553544126/Understanding+the+Emulsion+Curing+Process+%26+Determining+Exposure+Distance.pdf)
Grigar (http://www.vastex.com/Articles/Emulsion-Information-for-the-Screen-Printer.php)
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I can tell you from my experience, it is complicated. Typically, or most times, it's difficult because they weren't doing their process as accurately anyways. We all know of and have been taought at shows and seminars the "suggested" methods but it's very easy to have employees that quickly stray from the suggestions or even New requirements you bring back from the shows and seminars. We are all guilty of this in some degree. Once I go thru what are supposed to be average or typical processes, things get back on track and people say "that's why". That might not be exactly what you were referring to but it's a big factor.
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LED will end up being cheap in a few years and people will not be using MH units unless they are dinosaurs I suspect.
Nothing to do with price, everything to do with fully cross-linking screens while retaining detail. It ain't there yet.
The context of my post wasn't about today's price. I did clearly say end up being cheap. Which yes doesn't have anything to do with price today, correct. My point was in a few years when LED's are super cheap and the price on these units go down nobody is going to buy a MH anymore in the typical shop.
Which means you are clearly misreading my post. Doesn't matter if it cost twenty thousand dollars or twenty thousand pennies, if it
doesn't do what we need it to do I ain't a buyin'.
We print a helluva lot more than plastisol on Gildans.
It aint always about you. The typical customer would never know the difference between above average print and ultra high end print unless you show them. So I didn't miss a thing, the context of my post remains that as LED gets cheaper most shops will be using it in a few years. I certainly didn't say YOU would be using it.
If your super high end shop (which remains to be seen) needs the next level go for it. Why are you even bothering in these discussions if your are proclaiming to be so far above this technology?
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Update:
So we're burning about 30 screens a day now so I'm getting lots of opportunity to dial in everything and so far we're still struggling with what I consider the basics.
Chromablue "type" emulsion, 150/48 yellow, 15%EOM: 30 seconds, I'm getting great washout action on the image areas that are larger than our registration marks, it's superb actually. But my problem is I'm getting overexposure symptoms on the small stuff like our regi marks and art info we put on our film. So we've got great washout and poor washout on the same screens, under and overexposure, along with a decent amount of slime when wiped with a white shirt, but when you rub with your finger or lightly with a fingernail you don't get any colored residue. So it's noticeable undercutting. 45 seconds yields great washout still but getting much tougher to get the regi marks out without breaking the stencil outside the image area. Still slimy. 75 seconds is where we can't get the regi marks out while still retaining any edge definition but the larger images are fine, still got slime. 120 seconds is identical to the 75 seconds except regi marks will not develop at all.
HVP, same screen EOM and variables other than emulsion: 30 seconds and we're getting great washout on small and large image areas, very little slime and barely noticeable on the white shirt, but you can get a faint bit if you rub with any pressure. The HVP is also retaining the regi marks up into the 100-120 second ranges and on the 120/54 mesh counts you can get some slime but the higher mesh counts with thinner stencils are very workable and we've managed to not have any breakdowns on press with either emulsion.
So the Chromablue emulsion is a double edged sword, it's great to not need to use baby powder, it dries incredibly fast, hasn't broken down on press with the last batch of screens I coated. But it is not as user friendly and the undercutting is very bad. The HVP is way easier and exhibits much more exposure latitude and it looks like the clear winner and a no-doubter to use instead of the other emulsions. I've got a few more screens to burn for the day and I'm going to go to the extremes with burn times, high and low with the remaining screens and report back.
I've got some options on the table now I'm considering. I won't go public with them as I need to make this decision on my own without any outside influence. I'd like to share that and get some input but even though most know most of what we're dealing with there are little nuances of our operation that are very different from the average shop so this problem needs to be fixed internally due to those circumstances. I feel like I have 3 good options and no bad options but even the smallest detail can make a big difference long-term.
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I will see about getting that for you. Even better send me a file of your own for us to try.
I'll make it even easier and send yous guys a film and a quart of our emulsion. We use SP-1400.
Is there any way for you to test durability after exposure?
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It aint always about you. The typical customer would never know the difference between above average print and ultra high end print unless you show them. So I didn't miss a thing, the context of my post remains that as LED gets cheaper most shops will be using it in a few years. I certainly didn't say YOU would be using it.
Sure. Personally I hate loss of image quality at any point. Some of it is inevitable (fabric weave, etc) and some of it is avoidable. I'll avoid
the avoidable even if it means sticking with dinosaur technology. Hell, the edges of raster text makes me wanna puke though you'll never
see it on the shirt.
If your super high end shop (which remains to be seen) needs the next level go for it. Why are you even bothering in these discussions if your are proclaiming to be so far above this technology?
Why do you feel the need to jump in a post regarding the science of exposure to tell us that as things get cheaper more people will buy them?
Thanks for the economic pearl of wisdom there Captain Obvious, but it has nothing to do with the discussion at hand. And quite honestly, it's more
of the same as far as I've seen on the subject. Plenty of people use cheap toilet paper....
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Sure. Personally I hate loss of image quality at any point. Some of it is inevitable (fabric weave, etc) and some of it is avoidable. I'll avoid
the avoidable even if it means sticking with dinosaur technology. Hell, the edges of raster text makes me wanna puke though you'll never
see it on the shirt.
Me too, but if the difference doesn't make it to the shirt, then it don't matter much does it?
Why do you feel the need to jump in a post regarding the science of exposure to tell us that as things get cheaper more people will buy them?
Thanks for the economic pearl of wisdom there Captain Obvious, but it has nothing to do with the discussion at hand. And quite honestly, it's more
of the same as far as I've seen on the subject. Plenty of people use cheap toilet paper....
My original point was about the coming domination of LED was more or less a reply in support of this comment:
LED is here to stay. As much as I like MH units for there long run durability, we simply rarely see the 90k runs of discharge or HSA here in the states. So for almost 99% of the US printers with shorter run lengths, LED works just fine.
So again not about ebscreen, but you went on to thump your chest and create extra drama when there was not any to that point. In case you have missed how forums, within threads side discussions happen that may not be fully on topic. It's not always about you.
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Update:
But my problem is I'm getting overexposure symptoms on the small stuff like our regi marks and art info we put on our film.
Alan do the reg marks wash out OK with pressure washer ? I see some of the same issue with HVP but a quick power wash opens everything right up for me.. I am relating this issue it to poor density on edges of image on film, take a piece of lino film and see if you get same results.
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I don't want to get in to a "who's supplies and equipment are best", but here is what we are able to consistently do.
We do a little 4 color process work. We use Kiwo Poly Plus S on 355-31 mesh. It is imaged and exposed on an M&R STE 2 head machine. We run 65 LPI and can hold (not saying print, but hold) a 2% dot. This what what all the components of our system allow us to do. So I can get a 2% dot. Pfffftttt. Doesn't mean the world to me right now. To me, the CTS is nothing new, but integrating the lightbar into the machine is big, making my entire SYSTEM more efficient.
(If I ever make time, I want to play with 75LPI, just for fun)
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Update:
But my problem is I'm getting overexposure symptoms on the small stuff like our regi marks and art info we put on our film.
Alan do the reg marks wash out OK with pressure washer ? I see some of the same issue with HVP but a quick power wash opens everything right up for me.. I am relating this issue it to poor density on edges of image on film, take a piece of lino film and see if you get same results.
We use the pressure washer for everything, it takes some work getting the fine lines and halftones out without wiping them out in the process.
Another couple of wrenches in my plans, the Chromablue emulsion reclaims like a freaking BOSS (Yeah, I said boss cause it's the cool word of the year among the cool kids). The other problem I have with settling in on a specific emulsion is that the Blue is working MUCH better for detail and even holding the line on the slime test at shorter burn times. I haven't had any big jobs to test yet to see if we have breakdown at the edges but that's one of my biggest concerns. The little bit of slime I'm getting doesn't seem to be causing any drip down problems that you can have in your open stencil and if I can get through this 500 piece job we got scheduled this afternoon without any breakdown I'm not sure what the hell I'm going to do. I shot a 120/54 at 24 seconds and had essentially the same amount of slime as the 60 second screens and I'm going to put a 150/48 through at 15 seconds and see what happens, and that's the 500 piecer...I'll be in touch with results. As the press turns.
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I don't think we've ever really gotten a 2% dot on anything above a 40lpi but I could be off. I have only recently gotten involved in the lpi outputs our artists were doing and trusted our old artist to do what he felt best. I have the OYO test film here I might just throw in on a 305 and see what I can get, but I doubt it will be close to 2% at any of the lpi settings it has.
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...AND WHY DO YOU NEED A 2% DOT?????
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We don't need a 2% dot, ever.
But if you're the rep for a company and you claim your machine can do it, at 85 lpi, I'd like to see it.
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...AND WHY DO YOU NEED A 2% DOT?????
I don't think we've ever really gotten a 2% dot on anything above a 40lpi but I could be off. I have only recently gotten involved in the lpi outputs our artists were doing and trusted our old artist to do what he felt best. I have the OYO test film here I might just throw in on a 305 and see what I can get, but I doubt it will be close to 2% at any of the lpi settings it has.
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We don't need a 2% dot, ever.
But if you're the rep for a company and you claim your machine can do it, at 85 lpi, I'd like to see it.
WORD
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Well I said I can hold one. Didn't even say I could print it. I think my comment about getting a @5 dot was something like "Pfffftttt", which meant big effing deal. The whole point of my post was the big reason I went LED was it made my SYSTEM better. Just trying to offer a different perspective, but obviously I missed. (slinking back into my hole now)
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I think I need to get some perspective on what exactly is a 2% dot. I wonder if we're all on the same page as to what is a 2% dot, 98% dot, 65lpi, 85lpi, etc?
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We don't need a 2% dot, ever.
But if you're the rep for a company and you claim your machine can do it, at 85 lpi, I'd like to see it.
WORD
IMO if most in this thread worked more on snooping out hidden profits, streamling workflow, training staff to be responsible and instead of 2%-5% or even 7% dots you all would be much better of and many dollars richer.. unless you are a puppet on a BLUE string.. then 2% dots make difference... just sayin
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Last comment. FWIW, I can hold a 2% dot on my wax machine too. It's not about blue or black. BIG DEAL! And at times it does matter. Matching PMS colors with 4CP is not real easy.
Barth out
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Last comment. FWIW, I can hold a 2% dot on my wax machine too. It's not about blue or black. BIG DEAL! And at times it does matter. Matching PMS colors with 4CP is not real easy.
Barth out
Dave I get it and wax is on its way to my shop....yes your shop does benefit from 2%.. sometimes.... there are probably less than 10 members on this board who could even identify and explain the world of less than 5% dots. If they are chasing 2% because of the challenge cool but if we are talking business and making money then I think I am spot on. To me it is like you cant see the Forrest through the trees kind of thing I make a very solid living printing 3 and 4 color spot color corporate logos.
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I think I need to get some perspective on what exactly is a 2% dot. I wonder if we're all on the same page as to what is a 2% dot, 98% dot, 65lpi, 85lpi, etc?
Strongly doubt it. Particularly with any kinds of curves for your output. 2 percent may output as 5 or higher, etc.
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Let me refresh the steps on how we got to the 85lpi 2% dot idea.
I listed that in a post below, listing a few examples of what someone who doesn't have a need for an LED DTS might be. For example, Simone searching out better image quality than DTS. eb has mentioned he didn't see a DTS putting out exceptable image quality in his opinion. That's fine. There might be some out there that don't like what these machibes put out. At that time, I mentioned that I felt these machines do out out excellent image quality and asked the question (what is better than) Award winning prints off of an LED DTS? great is geat no matter how you slice it. Now, can you knit pick amongst the award winners and ask what of these award winners is THE best out of all f them (and what did they use for imaging screens) Sure. That's where you would have to be tho, as it pertains to (is it good enough) image quality. Yes, it is.
Back to the 85-2%.
Nobody at M&R or Myself is "promoting" the idea of printing 85lpi at all, let alone 2% dots in production. Who does that in production? Well, maybe Target Graphics but that's another topic.
Then, when I asked Eb to give me an idea of what he thinks is "quantifiable results), HE said show me 85lpi 2% dots. Then, Rich replied and said he would see if he could get a picture. We for sure can show you a picture that it is capable of outputting 2% dots at 85lpi. (We) may even be able to print it on a shirt. I'll have to try that. :)
Can we? Yes. Would we suggest (now, with an I-Image, YOU too can print (or should) print 85lpi in production)? NO. I would not, but testing this is just fun stuff, Its Only to show that it can be done. You have to test things and see where your limits are, or rather (I choose to). I have tested many other things that I would not normally do in production. In addition, not everyone can. To do so, you have to pay attention to those variables. If you have no time for that, then you might be ok with 7% in the 55lpi and losing below that. Is done every day and yes, people are still profitable.
I've never tested 85lpi printed while with M&R. Still tho, sure you can. It's capable of even more than that but you have outside physical limitations such as thread diameter EOM etc. You wanna see 100lpi? It can do that also, but nobody really uses 500 mesh in here and why should they.
So let's get real and not plant anything that wasn't said.
Like I did say below, I myself had tested a 75lpi at a customers and held a 2% (on the shirt). This was just to say we did.
Now, I'll justify why you would even try. Because when you have reached for the stars, and have not been able to get there, you look back and can see you did achieve going farther than you would have, if you didn't try at all. Knowing (how) to do more, will make the less difficult everyday spot color work easier. I've seen it. Going there tho, is not needed for everyone. I just happen to like doing that kind of stuff.
That should have cleared that up. It's in black and white below, but so was the previous info.
That's the WORD.
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I think I need to get some perspective on what exactly is a 2% dot. I wonder if we're all on the same page as to what is a 2% dot, 98% dot, 65lpi, 85lpi, etc?
Strongly doubt it. Particularly with any kinds of curves for your output. 2 percent may output as 5 or higher, etc.
eb's statement above is right on. Each device puts down various sizes of a 55lpi. A 5% dot of 55 Lpi on an ebson using one RIP will be slightly different on another.
I always loved the wet film imagesetters at 2400 dpi and higher. Those are probably the benchmark for what the size of a 5% dot in a 55lpi is because it's the best we could get or want. Most of us would be blown away at how small they really are and how much harder it would be to hold them with your current go to process to hold a 5% 55lpi from your current or typical digital films.
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HE said show me 85lpi 2% dots. Then, Rich replied and said he would see if he could get a picture. We for sure can show you a picture that it is capable of outputting 2% dots at 85lpi. (We) may even be able to print it on a shirt. I'll have to try that. :)
Reminds me of the Jim Crammer Pump and Dump.... just like fishing BULLSHIT without pictures and verifiable analysis... Rich once challenged one of my post as he wanted to make certain uneducated folks were not tainted by miss information.. lead by example.. just saying
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Im hoping that maybe you just misunderstand. We didn't say we can't or don't have pictures. In fact, I still have the actual shirt sample. We printed two. One for customer and one for me.
Now, mind you, my sample was put ink in it and print one strike off and with what they had. No special tweaking on press. We did do some careful work in the screen room with fine tuning exposure time and washout processes but that's about it. It isn't really a myth or rocket science. Just following standard procedures. If you were to try and change up some processes, you too could also print 75lpi on your current device I'll guess. Just for fun.
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Dan you've got me saying a bunch of stuff up there that I've never said. I could pick it apart but I don't have the time.
DTS is new to this conversation and added by you. I'll add that you specifically left out diazo emulsions in your previous
long post.
Again, two percent dots mean nothing to me. In this particular case all two percent dots means is that an LED
exposure unit can in fact hold detail without undercutting. Add to that a durable screen that will last on press and you'd have
me sold yesterday. The fact is I've yet to see any of that information, from the manufacturer, in any sort of provable form.
Hell, I've yet to see a single closeup of an LED exposed screen! Let alone a before/after EOM reading, or, god forbid, some
scientific way to actually measure stencil durability! Should that be so difficult or secretive for a company that is producing
and selling these machines?
The fact is also that in this thread alone several people have complained about the very issues I'd be concerned with having
if we were to go LED. And not just from one manufacturer. The fact is also that an emulsion manufacturer, a key player
in this technology, and one who's products we use, has strongly confirmed several other issues I would be concerned with
as well. I commend him for that as a major player that's like Firestone letting Ford know that the Explorer was a POS.
I'd be careful too.
With the assumption that nearly everyone under-exposes, I'd venture to say that we over-expose. That is we bake the entire cake.
We do not have undercutting in the slightest. I can not for the life of me remember the last time we had any sort of issue related to
a fully cross linked screen. Breakdown on press has not happened once in at least five years. 1 screen that fails during production
costs a hell of a lot more than the time it takes to properly expose it in the first place. I will not be inviting that possibility into my shop until
I am even remotely convinced it isn't a possibility.
I also won't be purpose coating screens just to suit the whims of a fancy pants LED unit. We coat all meshes 2/1 with SP-1400 and it works for
everything we need it to.
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We're seeing the undercutting on the other emulsions besides the HVP. I would think it would be the same or very close to the same with all PP emulsions with similar stencil thicknesses. But with the Chromablue and Orange you see it is WAY worse.
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Again, read below. But anyways, as long as you get the results you want, then hey, no argument. Heck, I'm not even trying to convince you. I'm just laying it out like it really is. All that I know and have done.
Why? I guess because you imply its not true, needed or possible or as advertised. That's all. It kinda bugs me. I think you like that tho. ;). Anyhow, this thread really has been pretty educational for many and I can appreciate your input.
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Well, here is some quantifiable results to those interested. ABuffington had been asking for this kind of feedback.
I just spoke with a customer who has an STE that just ran a 25k order. White ink on Royal using Dual Cure emulsion. 156 mesh coated 2/1. No breakdown at all. They used the same screens on all.
He said I could quote him so I'll pass that on to Rich and if you want to know who, so you can ask more questions, you and Rich can work that out.
I didn't get wether he used round or sharp side nor EOM. Also, t's not for me to get into what type of emulsion brand used because we can't really say or lead anyone to imagine one is better than another. It depends on how it's used maybe. All I know is it's a Dual Cure. Maybe even a hybrid.
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Again, read below. But anyways, as long as you get the results you want, then hey, no argument. Heck, I'm not even trying to convince you. I'm just laying it out like it really is. All that I know and have done.
Thing is, speeding up exposure, and not having to buy bulbs every six months would be awesome.
Why? I guess because you imply its not true, needed or possible or as advertised. That's all. It kinda bugs me. I think you like that tho. ;). Anyhow, this thread really has been pretty educational for many and I can appreciate your input.
Well, that's my point to a T as well. Burden of proof is on your side however. Hearsay doesn't count as proof, and for a company that
manufacturers machines, you think you'd be all over this scientific testing thingamajig.
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proof is in the pudding. happy productive, prosperous customers. I don't think anyone needs to prove anything. The customers are proving it. Don't want one, don't like one? There will be others who will. let them eat the cake they bake. I've said enough.
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Alan,
Thanks for your honest opinion of the LED units. This is the first that I heard they were not awesome in every way.
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I am the LAST person that should pour gas on this fire... But what you guys are not saying is key, Leds have come a long way in recent years, In fact they made the crt television obsolete in just the last 10 years, Same thing is going to happen here and there just wont be a choice anymore for any of us... Parts for M/H lamps will be sold off to the highest bidders and GAME OVER.
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To say LEDs will take over the market in the future is pointless. If LEDs take over the market it will not be the LEDs we have now. It will be the LEDs of the future with major improvements and all the bugs worked out. It is good that people are wanting more from the manufactures. That is how you get better equipment. To say that we have to deal with lost information on our screens with LEDs is just insane.
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Its not pointless... The tech may not have the bugs worked out of it yet, but rest assured leds will be industry standard in our lifetime.
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And furthermore.... I would also be of the opinion of, Someone who saw it coming, got in early, and understood its shortcomings and sequential improvements of not only the unit, but the chems involved with making the best screen.... Would be a industry leader, Making money while the competition was floundering with the "NEW SYSTEM".
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Alan, if you want, PM me and you can come play around on our STE II and do some testing. I'm no where near as thorough as you with notation, but we RARELY ever have screen breakdowns. In Fact I'd assume once we get our auto coater, It'll be even less!
I'd be really interested to see if the STE is doing anything different than yours.
I'd love the chance to pick your brain about EOM and coating too.
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I will see about getting that for you. Even better send me a file of your own for us to try.
I'll make it even easier and send yous guys a film and a quart of our emulsion. We use SP-1400.
Is there any way for you to test durability after exposure?
we will send you the screen to test yourself. Send the digital file as well
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This was just too cool to pass up. I checked in and Bazinga! here's 244 making the 244th reply on this thread!
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This was just too cool to pass up. I checked in and Bazinga! here's 244 making the 244th reply on this thread!
Wow! That's cool! I will say this and back out. We as a major manufacturer of exposure equipment will state without doubt LED is not only the future but now as well. Our NuArc division used to produce over 45 MV units per month on a regular basis. That has been replaced with LED to the tune of 90% with LED. It will even be more shortly due to customer demand. Quite a few emulsion companies have came to NuArc and done testing and were surprised from the results. It's just like a bucket of plastisol. The ink manufacturer states on the bucket two minutes retention time at a certain temperature to cover their butts for cure issues. Emulsion manufacturers are going to tell you what has worked successfully in the past to be safe. It's a new world. Learn and accept it or stY where you are safe and let others take a step ahead. There is always a choice. We as a mNufacturer will not post information our competitors lack. Come to our plant and we will be happy to demonstrate the results all day in a scientific way as well as real life.
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To say LEDs will take over the market in the future is pointless. If LEDs take over the market it will not be the LEDs we have now. It will be the LEDs of the future with major improvements and all the bugs worked out. It is good that people are wanting more from the manufactures. That is how you get better equipment. To say that we have to deal with lost information on our screens with LEDs is just insane.
While I agree 100% that it will not be the LEDs we have now...and I'm sure LED has already taken over the market for all new mid-sized and up shops, LCD took over for CRT and aside from size, weight and power reductions it took over a decade for LCD to get close to the quality and flexibility of CRTs. Hell, the prevalent audio format is MP3...a subset of the prevalent video format, MPEG.
All of these things have one thing in common; they lose (sometimes massive amounts) of information. That is actually their strength. Now, with 10-20 years of development behind these technologies they are finally getting as good as and in some scenarios better than what they replaced...
...and I think LED will follow the same path. After another 5 to 10 years of development we'll think we were insane for not changing over sooner.
I have been following this thread extremely closely as I have the itch to switch but from all I've read so far I think another year or five of development is required. (I'm playing it super safe even though I apparently have the most ideal set of variables on my side given my run sizes, durability requirements and the emulsion I use.)
Thanks for all of the thought and conversation in this thread guys. I'll continue to follow it until the bitter end.
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we will send you the screen to test yourself. Send the digital file as well
Now we're talking. We use the presses that are slightly lighter blue in color and require pins.
Will that be an issue?
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While I agree 100% that it will not be the LEDs we have now...and I'm sure LED has already taken over the market for all new mid-sized and up shops, LCD took over for CRT and aside from size, weight and power reductions it took over a decade for LCD to get close to the quality and flexibility of CRTs. Hell, the prevalent audio format is MP3...a subset of the prevalent video format, MPEG.
All of these things have one thing in common; they lose (sometimes massive amounts) of information. That is actually their strength. Now, with 10-20 years of development behind these technologies they are finally getting as good as and in some scenarios better than what they replaced...
...and I think LED will follow the same path. After another 5 to 10 years of development we'll think we were insane for not changing over sooner.
I have been following this thread extremely closely as I have the itch to switch but from all I've read so far I think another year or five of development is required. (I'm playing it super safe even though I apparently have the most ideal set of variables on my side given my run sizes, durability requirements and the emulsion I use.)
Thanks for all of the thought and conversation in this thread guys. I'll continue to follow it until the bitter end.
Interesting analogy/parallel. I'm feverishly clutching to my vinyl records and letterpressed business cards though.
And while my carbureted inline six won't die, I wouldn't argue with a more efficient boat motor.
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we will send you the screen to test yourself. Send the digital file as well
Now we're talking. We use the presses that are slightly lighter blue in color and require pins.
Will that be an issue?
No issue
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Sean,
LMK when you get the screen I would love to come up and watch you print this 2% dot.
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Has someone actually said they could for certain print a 2% dot on a shirt? I missed that if so.
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2% dot for one shop maybe a 12 percent dot for another shop, not even talking LPI here. Unless you have calibrated your output you have no idea what a real 2% dot is. Pierre can add more on this. If a manufacture said they can hold a 2% dot what did they say they can hold it on...film, screen or shirt. Each one of those is steps in the process to calibrate the dots. A 2% dot on film could be a 4% dot on the shirt. A true 2% dot on the shirt would have to be less then a 2% dot size on film or even with the direct to screen process. Ink gain, even if you think you have non, is there. Fighting to hold a 2% dot is a goal. It will make you a better printer but needing to hold a 2% dot is borderline insane and unrealistic all the time.
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Has someone actually said they could for certain print a 2% dot on a shirt? I missed that if so.
Yes the other Blue puppet was threatening to post pics of 2% on a Gildan or something... I hear there is a screen with 2% dots headed to Northern California for testing... stand by.. you might learn something
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Has someone actually said they could for certain print a 2% dot on a shirt? I missed that if so.
Yes the other Blue puppet was threatening to post pics of 2% on a Gildan or something... I hear there is a screen with 2% dots headed to Northern California for testing... stand by.. you might learn something
Which post? Quote it, I seriously missed it.
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I'm still trying to figure out how this became such a big pissing match :o
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I'm still trying to figure out how this became such a big pissing match :o
I'm not certain and I watched it happen apparently. I've been a hawk on this thread. Tons of great info...and at this point I'd love to see a proper 2% dot on your average 18 singles tee. I'm not taking sides. I'm here in the name of science. ;D
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When I speak of a 2% dot I'm talking about what's on our exposure calculator because I know our film is no longer calibrated properly. I've got a lot of old imagesetter film and a few pieces of film from Exile (OYO) that are of much higher quality and calibration than what we're outputting on our old Epson. I did some quick testing on Thursday on a few mesh counts and on the LED unit I couldn't get anything under a 10%, 65lpi on a 280. I should have some time to play with it today and fine tune the burn time and I'm hoping to be able to get at least a 5% in the 65lpi column but with the test I did Thursday I'm not going to hold my breath.
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We've successfully held the calibrated 4-5% dot at 55lpi on 330S mesh on the Vastex unit. Same thing with 3140 was holding 3%. BUT . . . . the exposure system was dialed in for the 3140 so changes in the RIP can be made to compensate for it. I am certain that with proper tools LED unit will expose 3%.
For anybody trying to see the calibrated 2% dot on a 305, it is not going to happen with ANY unit!!! As I understand, the physical limitation of the mesh is 3%. At that point the dots become too small to hold on. It would be possible to calculate the dot size and compare it to the opening size, but I'll take the expert's word on it. Anybody printing a 2% at 55lpi on a 305 and holding it is either not calibrated, on the wrong mesh or wrong lpi.
pierre
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2% dots are smaller than the thread diameter in most halftone line counts, so the thread will block any dot even though my emulsion can image it. Imagesetters have the best chance of capturing 2% dots, while most other methods except wax are too transparent a dot to image easily with ink jet methods where the 2% dot is formed by only a few small transparent pico liter dots. The emulsion is capable, but vignette moire along the edge of a halftone fading into shirt will have moire stripes as it approaches these lower percentages. At the other end (98%) like Pierre mentions, the dots fall off, or in some cases are imaged in the open area of the mesh and fall off immediately with nothing to adhere to. You could try our 420 or 460 mesh if you really want to image every dot possible with image setter film. Or if you have to image a 133 LPI 2% we do have Stainless 840 TPI at 16,700.00/yard! We make incredibly high resolution screens for electronics, but hey these are t shirts we are printing!
Wasatch has a cool feature I haven't played with much, but would like to is you can tell the RIP to change to random stochaistic dots below a certain percentage. This can image a bit better due to random distribution of the dots. This is common in UV printing where the entire yellow plate in CYMK can be entirely stochaistic while CMK are halftones. (Prevents dot stacking moire) However I haven't heard of anyone trying this feature in Wasatch SP RIP for t-shirt printing. I will test some positives today to see how that goes. IMO a curved linearization of 5-95% dots is a lot easier to image in a t-shirt shop with common mesh counts.
Al
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I just shot 3 305's at various times with my least desirable emulsion (I'll reclaim and coat these same screens with my other 2, better emulsions) and wasn't able to get a 10% out with the 65lpi column. I'll break down my results in a very simple way without going into a ton of boring detail, these are the basic, bare bones results in terms of halftones replicated on 305/34 roller frames stretched to 22 newtons. I have a sample film from our Epson with 65 & 85lpi halftones from 0-100% and the Imagesetter film in 65, 85 and 100lpi, 0-100%, burned on the same screens and I'll give the results for both. And I'm trying to keep it objective and only count the boxes that I got the VAST majority of the halftones out and in good shape. I know there is some subjectivity involved in what one would consider a good box and a bad box but I'm doing my best to make it as fair and balanced as I can so we can deduct better info from the tests.
65lpi, Imagesetter quality film, I'll give the range of halftones I was able to replicate. Keep in mind this is my worst emulsion but we have to start somewhere and these are the screens I have so it's where we're starting.
45 SECONDS:
Imagesetter-65lpi=40-97%
85lpi=53-96%
100lpi=75-94%
Epson-65lpi=23-90%
85lpi=36-85%
20 SECONDS:
Imagesetter-65lpi=23-93%
85lpi=35-90%
100lpi=57-87%
Epson-65lpi=10-90%
85lpi=28-81%
12 SECONDS:
Imagesetter-65lpi=19-97%
85lpi=30-90%
100lpi=49-87%
Epson-65lpi=15-90%
85lpi=28-81%
I know this looks like a bunch of junk numbers and when I look at them it doesn't do much for me other than tell me that I need to try a new emulsion because this one isn't good enough. And I might entertain a dual cure emulsion but PP emulsions are here to stay in our shop. Only recently have I put even a second of thought in a dual cure due to the results we've always been able to achieve with our expo unit and PP emulsions. But with our recent problems I am now thinking about things that weren't in my wheelhouse this time last year.
I should have the HVP or Chromablue Test emulsion ready to test this afternoon. I need to do a coat job today anyway.
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In my tests here in the lab it is crucial that the D-max and EOM be as good as they can be.
When looking at halftones and EOM, an EOM of 6-7% is typical for graphics printing on 300+ mesh counts.
Textile companies tend to coat more EOM than this, often in the 15-30% range. So if the emulsion thickness is far greater than the width of the dot
undercutting will probably occur. If this was an ink jet halftone the D-max in lower halftone percentages is nowhere near as good as imagesetter film,
so less time is used and underexposure can result causing halftones to fill in with unexposed emulsion during development.
All exposures are a balance of film/image D-max, emulsion thickness and type, light source, distance to light, and mesh color. You can only expose as long as the film's d-max will allow before burn through occurs, you can only image fine resolution dots if the emulsion thickness is geometrically capable of imagery without halation. The light source plays a crucial part in how well halftones can be imaged, how strong the vacuum draw down is (DTS has a significant advantage here), age of the lamp, with time of exposure the area we use most. Controlling the first ones as well as you can, followed by a time study helps in the quality of image on the stencil and prevents emulsion from breaking down before it should while holding "printable" halftones. The reality is most dots below 5% can land in the wales of the t-shirt weave and never print due to nothing but air in the open part of the knit.
Al
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Don't forget the D-Min in your equation which the transparency of the fiml
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Man am I late to this party. We had (have) a 6K Trilight. I love the Tri-Light. It was one of the best purchases we ever made.
We bought a STE a few months ago that has LEDs for exposure. I don't feel like we have the LEDs dialed in with the Aquasol HV we use. For whatever reason we have to expose on almost the slowest setting to get the LEDs to expose the Aquasol HV.
Granted, no one has to tape up films anymore (except this week we're back to films again) we were burning more screens per hour with the tri-light.
We could have gotten the STEII (we just couldn't afford it) but since we're doing a pure photopolymer I didn't think we'd need it. I guess I was wrong. :-\
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We've successfully held the calibrated 4-5% dot at 55lpi on 330S mesh on the Vastex unit. Same thing with 3140 was holding 3%. BUT . . . . the exposure system was dialed in for the 3140 so changes in the RIP can be made to compensate for it. I am certain that with proper tools LED unit will expose 3%.
For anybody trying to see the calibrated 2% dot on a 305, it is not going to happen with ANY unit!!! As I understand, the physical limitation of the mesh is 3%. At that point the dots become too small to hold on. It would be possible to calculate the dot size and compare it to the opening size, but I'll take the expert's word on it. Anybody printing a 2% at 55lpi on a 305 and holding it is either not calibrated, on the wrong mesh or wrong lpi.
pierre
It's all relative to your specific device and setups. I'd guess that 90-95% of the industry produces printed apparel without a densitometer calibrated halftone LPI because of the cost to get one and the fact that they have been selling printed apparel without one for years. That doesn't mean what they print for halftone dots is truly correct, just well enough apparently.
Also, note that even with a densitometer, those calibrate (tone) accuracy and not size of dot accuracy. For example, an accurate calibrated 2% tone can still have a huge dot such as in a 20lpi. One mans 2% in a 55lpi is not the same as another. There will be people who can hold a 2% dot in a 55lpi on a 305 mesh (with their device). Of those, their dot is larger or closer to a 3% in another device.
RE: Abuffington on the digital Dmax (as it pertains to DIGITAL from DTS from what Iv'e seen). Our picoliters laid down over top each other to form that 2% dot can be made with varying options.
* 1, 2 or 3 head that contributes to Dmax
* You have the ink/output resolution 1200x1200, 1200x900, 1200x600 etc. that contribute to Dmax.
* print speed.
* Uni or Bi direction.
* INK TYPE. Ours is already very solid/opaque despite the other contributing factors above.
All of those contribute to an excellent Dmax. At the same time, some of those can also contribute to additional gain at output. Therefore, we already build in a standard 80/60 curve at install for basic prints. Think 45lpi. As you go up in line count, you want to open those shadow tones up a little in your curve to compensate for gain in the shadow tones. as line counts go up, shadow tones get smaller and (closer) together. Someone who has a 1 head that likes to print 65lpi, will have one curve adjustment while someone who has 3 heads printing 65lpi will have another gain adjustment. This is yet one other reason why one curve for one shop does not work best for another shop.
These curves (without calibration) using a transmissive densitomotor are all just a (hypothesis) until you have them calibrated on press. We do not calibrate (using a transmissive densitomotor). We calibrate our machine for various print speeds/heads and confirm alignment etc.. Everything after that is up to the customers as each customers shop and gain is different.
Each imaging device (Wet film imagestter, Digital film, Laserwriter, DTS) comes with some form of image adjustment options internally but many printers are not designed or intended for single color B/W (solid) output with halftone conversions in mind. For those, you must get a RIP to do halftones. Those various rips output on their own a halftone dot sized by line count. They do not compensate by default for the TYPE of printer device it is coming out of.
The sharp sides (smoothness) of each dot or edge of the curve on the letter S, is determined by the devises output resolution. 300, 600, 1200, 2400 dpi etc. While early on, for myself I had always preferred the Wet film imagestter at the highest rez I could get, it was not needed for apparel. 600-1200 dpi (output) rez is fine.
A very high line count (in the mid tones or 20-80%) is very beneficial. The finer you can hold the small dots, the better but there is a point where it is not feasible such as trying to hold 1,2 and 3% dots in production as some such as Pierre has indicated. Still, you should have a goal of holding the smallest as best you can and then the most important part is to (know what that is) so that you can prepare your art accordingly. High LPI produces a beautiful tone and blends verses chunky dots. The higher the lpi, the thinner the ink should be up to a point. Blends are easier to achieve but so should the other needed elements be in place such as mesh tension, high mesh, thinner EOM, proper printing methods etc. This is why some may not be able to hold the 2% dot even if they had a machine that could give it to them. Many factors must fall in line.
As a theoretical comparison, back in the day, I was holding a 3% dot on 55lpi (using wet imagesetter film) at 2400dpi on a 305 mesh. The mesh brand was SATTI but I don't remember thread diameter. Compare that size to something of today from the typical digital film and that dot size might be similar to your 3% in a 70lpi and many would not be able to output it let alone hold it in the screen nor print it with your average inks. Comparing again, the hardest case scenario considering 3 head and heavier ink coverage for fast production using DTS at it's average dpi output, the 3% 55lpi dot might fall close to your typical results of a digital film printer if not 4% without some form of compensation. This is why the need for a densitomotor exist.
It should be said, that the (size) of the 2-3% dot (based on output device) is not as important as can you hold it on press with your other variables. Having a goal of shooting for the smaller 2-3-4-5% dots and learning what is needed/how to get there to increase your ability to hold smaller dots (no matter the lpi) can only make you better than proving you are comfortable with the 7-10% dot. You are losing more art information somewhere on some of your jobs if not.
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We've successfully held the calibrated 4-5% dot at 55lpi on 330S mesh on the Vastex unit. Same thing with 3140 was holding 3%. BUT . . . . the exposure system was dialed in for the 3140 so changes in the RIP can be made to compensate for it. I am certain that with proper tools LED unit will expose 3%.
For anybody trying to see the calibrated 2% dot on a 305, it is not going to happen with ANY unit!!! As I understand, the physical limitation of the mesh is 3%. At that point the dots become too small to hold on. It would be possible to calculate the dot size and compare it to the opening size, but I'll take the expert's word on it. Anybody printing a 2% at 55lpi on a 305 and holding it is either not calibrated, on the wrong mesh or wrong lpi.
pierre
It's all relative to your specific device and setups. I'd guess that 90-95% of the industry produces printed apparel without a densitometer calibrated halftone LPI because of the cost to get one and the fact that they have been selling printed apparel without one for years. That doesn't mean what they print for halftone dots is truly correct, just well enough apparently.
Also, note that even with a densitometer, those calibrate (tone) accuracy and not size of dot accuracy. For example, an accurate calibrated 2% tone can still have a huge dot such as in a 20lpi. One mans 2% in a 55lpi is not the same as another. There will be people who can hold a 2% dot in a 55lpi on a 305 mesh (with their device). Of those, their dot is larger or closer to a 3% in another device.
the 20lpi was never part of this conversation!
if you take a look, you'll see that I SPECIFIED 55lpi and 2%. This creates a dot that has to be very specific in size and can be recreated anywhere in the world, by any piece of equipment and if it is 2% and 55lpi it will ALWAYS look the same!
Anybody can print any size they want and as long as the print and the printing works out OK, nobody needs a densitometer. Some ppl have a 2% dot in their art file, but when they actually develop the screens, it's 7%! They just held a 7% dot, not a 2% dot. BUT as soon as you start saying that you can hold a 2% dot at 55lpi, that means only one thing.
Also, holding a dot means (at least in my book based on what I was told) all the dots in that range have opened or cleared. By that definition, it is not possible to hold a 2% dot on the 305 as it is thinner then the mesh and will be lost when it lands on it.
pierre
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We've successfully held the calibrated 4-5% dot at 55lpi on 330S mesh on the Vastex unit. Same thing with 3140 was holding 3%. BUT . . . . the exposure system was dialed in for the 3140 so changes in the RIP can be made to compensate for it. I am certain that with proper tools LED unit will expose 3%.
For anybody trying to see the calibrated 2% dot on a 305, it is not going to happen with ANY unit!!! As I understand, the physical limitation of the mesh is 3%. At that point the dots become too small to hold on. It would be possible to calculate the dot size and compare it to the opening size, but I'll take the expert's word on it. Anybody printing a 2% at 55lpi on a 305 and holding it is either not calibrated, on the wrong mesh or wrong lpi.
pierre
Still, you should have a goal of holding the smallest as best you can and then the most important part is to (know what that is) so that you can prepare your art accordingly. High LPI produces a beautiful tone and blends verses chunky dots. The higher the lpi, the thinner the ink should be up to a point. Blends are easier to achieve but so should the other needed elements be in place such as mesh tension, high mesh, thinner EOM, proper printing methods etc. This is why some may not be able to hold the 2% dot even if they had a machine that could give it to them. Many factors must fall in line.
THIS! Get your stuff calibrated and test to see what you can hold. With that knowledge, as Dan preaches, you will know exactly what you can and can not print and what will be the issues on the press. Calibration helps to have an intelligent conversation with another person allowing the dots to be compared (or we might be comparing apples to oranges). If you don't care to compare, work of your own system, but in the end it is much better to measure properly.
And the example I often cite is the need for 4% magenta in 4CP in order to print gold jewlery or medals. If you can't hold a 4% dot, your gold will be all yellow and not look right. So learn what your limitations are, drop down to 45lpi if you need to hold a 4% dot and print the gold medal order!
pierre
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Getting a densitometer, using it, calibrating our curves to our press, and learning what variables affect that curve during printing (which we're still learning, to be honest), has been huge to my quality of printing, and quality of knowing what it's going to look like at output vs on the screen.
We've done some single-screen discharge printing here recently that I would have said that I couldn't print done just 6 months ago... and now, while I wouldn't say easy-peasy, is certainly not only do-able, but makes some of our more cost-sensitive customers VEYR happy.
It's amazing what you learn when you start looking at the dots and realize that you don't really have to adjust the art to make it look great on press...
*staying out of the LED discussion, as when it really comes down to it, all I care about is solidly exposed screens... 18 seconds, 60 seconds or 75 seconds... it's still faster than I can image a screen, or rinse it out... if you can image a screen faster than you can expose it, I guess then it might mater.
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Got 3 more screens with Chromablue'ish emulsion, results aren't as good as I was hoping. 305's again, 15%EOM/R on the 30 & 7 second screen, 14% for the 15 second. 8 microns on two and 9 microns for the other.
30 SECONDS: 15 SECONDS: 7 SECONDS:
Imagesetter-65lpi=31-97% Imagesetter-65lpi=28-97% Imagesetter-65lpi=15-93%
85lpi=53-96% 85lpi=48-90% 85lpi=18-90%
100lpi=71-94% 100lpi=62-87% 100lpi=40-83%
Epson-65lpi=28-90% Epson-65lpi=23-90% Epson-65lpi=washout
85lpi=44-85% 85lpi=36-81% 85lpi=washout
I finally got to see MAJOR differences (there were many already but this was not so subtle) between the imagesetter film (great D-max, very good D-min) and our Epson film. The 7 second exposure really showed how really good film can make the difference. The Epson section didn't hold up and half of it washed out without much effort. I guess I could have babied it and held a lot of the detail but I'm trying to not do that with this test and spray them out just like it's any other screen. I sure wish I had a Techstyler the last few years. But I can't wait to get even better exposures with CTS.
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We've successfully held the calibrated 4-5% dot at 55lpi on 330S mesh on the Vastex unit. Same thing with 3140 was holding 3%. BUT . . . . the exposure system was dialed in for the 3140 so changes in the RIP can be made to compensate for it. I am certain that with proper tools LED unit will expose 3%.
For anybody trying to see the calibrated 2% dot on a 305, it is not going to happen with ANY unit!!! As I understand, the physical limitation of the mesh is 3%. At that point the dots become too small to hold on. It would be possible to calculate the dot size and compare it to the opening size, but I'll take the expert's word on it. Anybody printing a 2% at 55lpi on a 305 and holding it is either not calibrated, on the wrong mesh or wrong lpi.
pierre
It's all relative to your specific device and setups. I'd guess that 90-95% of the industry produces printed apparel without a densitometer calibrated halftone LPI because of the cost to get one and the fact that they have been selling printed apparel without one for years. That doesn't mean what they print for halftone dots is truly correct, just well enough apparently.
Also, note that even with a densitometer, those calibrate (tone) accuracy and not size of dot accuracy. For example, an accurate calibrated 2% tone can still have a huge dot such as in a 20lpi. One mans 2% in a 55lpi is not the same as another. There will be people who can hold a 2% dot in a 55lpi on a 305 mesh (with their device). Of those, their dot is larger or closer to a 3% in another device.
From P,
the 20lpi was never part of this conversation!
If you take a look, you'll see that I SPECIFIED 55lpi and 2%. This creates a dot that has to be very specific in size and can be recreated anywhere in the world, by any piece of equipment and if it is 2% and 55lpi it will ALWAYS look the same!
(if it is compared to another 2% 55lpi that has also been calibrated, yes it should look the same). Also, even yours, Your 2% 55lpi is not going to looks the exact same size as a 2400 dpi wet film processing imagesetter. Close, but not exact.
Anybody can print any size they want and as long as the print and the printing works out OK, nobody needs a densitometer.
I would prefer everyone have and use one, but thats not the norm. I'm not saying they don't need one. They do. Everyone needs one. Getting them to get one is a different story.
Some ppl have a 2% dot in their art file, but when they actually develop the screens, it's 7%! They just held a 7% dot, not a 2% dot. Well, that seems a bit extreme but ok. Could be.[/size]
[/size]BUT as soon as you start saying that you can hold a 2% dot at 55lpi, that means only one thing.[/size]
No. That means (someone printed a 2% dot in their process). It is their 2% dot. It is their norm (unless it gets calibrated), that is their gauge. They have nothing else to assign that areas except for where they started out being (2%). It's a 55lpi, It's 2% in the art so this (THIS) is our reference point...unless you have a densitomotor, It's held in the screen, it's printed on the shirt, it's presenting a nice award winning print (proven). For that person, thats the norm. That is the 2% in a 55lpi. Is it correct and truly a 2%. I don't think it matters since (something), some image data representing another color tone (was there). Will the customer ask for a refund if he finds out it was really a 3.5 or 4%?
[/size]Also, holding a dot means (at least in my book based on what I was told) all the dots in that range have opened or cleared. By that definition, it is not possible to hold a 2% dot on the 305 as it is thinner then the mesh and will be lost when it lands on it.
pierre
[/size]
There's your problem. You restrict yourself to "definitions". You ever heard of impressionism? How about Pointilisim? How about faking it? As you indicated, you need 4% dots. Using 2% dots (I would safely try to make use of 3% dots) during production) but obtaining 50% or half of the 2% dots, combined with 3 -5 other colors of the same example, makes or represents a tone of another color. Correct? Yes. So, sprinkles of 2% (lets say you hit and miss 50% of the dots on a color) CAN and does make an image representation. It's all about resolution. These 2% areas broke up, hitting and missing, doesn't look great (when isolated and reviewed/compared to a given area of pretty solid squares, BUT, don't hate the fat people. We are people too. Everything has a purpose. Put those 2% dots in the art and you can make something.
[/size]I'm going to show you something here shortly. I have a bad memory for most things but for some things, (screen printing in particular), I have a good memory. So I will show you all something here as soon as he replies.
Re: the 20lpi. Yes, (I said that). People do that now and then. They may say something (you didn't) ;) and put it in a post and reply (adding in various other things that other people have said in 2-4 more previous post combining them into one post. Is that so strange? I put it in the equations because earlier, prior to your reply, someone was talking about the size of a 2% dot being bigger or not accurate across the board. (There was a lot of that said). Then even you mentioned "size" of a dot. The fact that you specified 55lpi or not doesn't pertain justifiably to make an argument here. What I said, applies to every line screen (when you compare a 55 to a 55 or a 62 to a 62 etc. to another device). This is before you even get to burn it, wash it out and print it. Again, if you want to have them equal, then yes, someone else's device would have to be calibrated...and the one being compared would also have to be calibrated...and only then would you be sure that they are as accurate a possible...and the 2% would be a 2% (but only on all machines calibrated) across the world. Like I said. Most don't get theirs calibrated and if you calibrate for someone, that doesn't mean it will be true 6 months later and you must calibrate (to the printed dot on the shirt), not the film results from a machine.
I agree. As I stated, some peoples devices put out a slightly thicker/bigger dot (even tho it's the same line screen) than another device. So yes, thats due to it not being calibrated with a densitomotor.
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Sorry.. couldn't resist.
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Sorry.. couldn't resist.
This is me. Been fighting exposure for way too long. Read through this thread and others on LED many times now. Starlight should be on the way next week.
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His Premier