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screen printing => Equipment => Topic started by: TCT on October 30, 2014, 09:40:25 AM
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Looking for some advice here guys.
Looks like it's about time for us to make a move with the new exposure unit. Our current Workhorse PhotoSharp(1000 watt metal halide) has served us well for 10 years but now the shutter is not working and it looks like its about a $350+ upgrade to get it working like new. At the same time we've got a large Halux(can't find a model number on it to save my life) metal halide exposure unit that we got in a bundle deal about 2 years ago. The Halux unit I don't know much about, it does have a Olix AI 111 integrator with it. It came with a a rotating Millington Machine screen holder and a vacuum pump. All I really need for this unit is just a new bulb and a small electrical run. The bulb it came with is a Phillips HPM 15, which looks to be about a 2000 watt metal halide.
So here's my crossroads: do I buy a new LED unit? Do I buy a retrofit led unit to put inside of our PhotoSharp to convert it to an LED unit? Or do I stick with a powerful single point metal halide exposure unit with the Halux we have? The way I look at it the Halux unit will probably cost us $450 for a new bulb and wiring. The main problem is I know very little about this Halux unit, it came with a 2000 watt bulb, but can I put a 5000 watt bulb in it? Our biggest drawback right now aside from the shutter not closing on the PhotoSharp is exposure times, I need to get that cut down I know that a LED unit will cut it down to mere seconds. At the same time I know that with a powerful enough metal halide single point light source we can also get cut down to seconds. Currently we use Murakami SP-1400 but are thinking about making the switch back to Murakami HV/P.
So do I drop the $450 or so to get the Halux up and working? Knowing that I'll have to continue to buy new balls for it. Do I buy the retrofit LED unit about $2,500? Or do I go all out and buy a nice new LED unit? I like the LED units because I know that they are going to save a lot of electricity and at the same time I won't have to replace the bulbs. I also know the advantages of the single point metal halide units offer. Ideally I'd get a STE-II in here and call it a day, but unless there is a black friday deal on those for say $10K, I'll have to wait ;D
What would you guys do?
Also does anybody know anything about this Halux unit? Can I get say a 5000 watt bulb for it?
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if you can afford it, STARLIGHT! my opinion.
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i'd go LED, the bulbs for standard units are pricey...and so is the power to run it...it was about $900 cost to run electrical to wire our 7500w unit in a few years back.
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I know the bulbs are pricey for MH units, but I am just wondering if it is worth it to get a LED unit when I have 2 decent MH units here already. $350 to fix one and $450ish to wire up and get a bulb for the other.
I have still yet to receive a "solid" price on a Starlight unit, but in my head I'm assuming $8K-$10K. Vastex retrofit is like $2500 and that is with adding a hefty cushion for freight.
So lets call it a $2K difference between getting a nice MH unit up and working and a LED unit..... I am just torn!
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get the LED, it will save you a ton in power...and it's plug and play...no wiring unless you don't have a 110v outlet where you want it.
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You could also sell your MH units to offset the cost since the LED will basically last forever.
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i'd go LED, the bulbs for standard units are pricey...and so is the power to run it...it was about $900 cost to run electrical to wire our 7500w unit in a few years back.
Our unit is $7,800 solid! you should sell what you have and get the Starlight. Sure I am biased, but I am also right!!Try one and if you feel I am wrong send it back and I will pay the freight both ways!!!!!!!!!!
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Hard to beat that offer
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Get the starlight and don't look back. Best piece of equipment I have (the 23x31 version.) It's amazing.
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Get the starlight and don't look back. Best piece of equipment I have (the 23x31 version.) It's amazing.
agree. the starlight made our busy season a breeze.
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buy a starlight and never have this conversation again. If you stick with MH, there will be a day you are in this same exact spot....for once, money can buy time...
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I agree, buy an LED unit and never worry about it again
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I agree, buy an LED unit and never worry about it again
That is not necessarily true. Just like all cars are not alike neither are LED units. Time will tell.
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Thats true some cars from every single car manufacturer will have issues sooner or later
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I have been meaning to start a thread on our latest purchase but haven't had the time to devote to doing it right. Our Richmond finally bit the dust a few weeks ago when our control panel buttons stopped working. I knew it was coming but was hoping to get as much out of it as possible and usually when the buttons stopped firing they would only fail for 15 minutes to an hour or so at a time and then would suddenly start working again. I'll save many of the details for my thread but I knew Kevin at River City had the big Vastex unit and although my research had told me the Starlight was probably the best unit on the market we pulled the trigger on the Vastex. I won't get into the argument on who makes the best units or who uses the best bulbs but on my thread I'll lay all the facts of our experience with the Vastex, good and bad. The good far outweighs the bad but it's worth noting everything so that people can use that info to make better decisions.
I've tried like hell to compare the detail between our old MH and new LED unit and after looking at dozens of stencils at 60X magnification I can say that our MH gives slightly better detail but honestly it's so damn close that depending on my mood I could go either way on the winner and because I don't like ambiguity in this type of comparison I declare the 10K MH unit the winner.
Our times are slightly faster than a new MH bulb and the best part is it will always stay at this speed. I wish the control panel was a little more technologically advanced than it is but oh well, it is what it is and it works fine. My sausage fingers have a tough time setting the correct times and I have to use what little of a fingernail I have to set the time because no way my finger is going to press that button without touching both buttons on either side of the one I want to push.
I've ran a few hundred screens with HVP and 75-100 of the SP1400 and I much prefer the pure photopolymer because it's extremely fast and the 1400 is not, 45-65 seconds for the 1400 versus 6-20 seconds with the HVP. I shot a 120/54 with a decent stencil yesterday at 15 seconds and it showed no signs of underexposure. It was much easier to get underexposed screens with the 1400 and overall I didn't like it versus the HVP and I think we'll stick with the PP emulsions from here on out. Reclaiming is also much faster with the HVP and it's very noticeable.
I'll go into more detail in the other thread and copy/paste most of what I've typed here. I'll do my best to get that up today but no promises.
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Get a Starlight. We love ours!
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We are still in the evaluation process of LED exposure units. Our first tests were very promising and no doubt about it LED's are the future of curing. One point to note is that most LED systems are wavelength specific. They output at the same nanometer wavelength whereas a Metal Halide will have multiple spikes in the important wavelengths to cure all emulsions. Diazo emulsions tend to like 360nm whereas Pure Photopolymers like HVP fall in the 390-420nm range. For this reason Pure Photopolymers and Dual Cures expose well on the LED systems.
There are some new players that popped up at SGIA. Light Speed which is repped by North West Graphics in MN has a patented multi-spectral light source with good focused lenses. The concept sounds great to an emulsion manufacturer since we know multi-spectral metal halides simply create stronger stencils. However in the US we don't see the 80k-90k print runs in water base and discharge that exist in large production shops off shore. For us the light has to be able to create a very strong screen for these longer runs. In the US however LEd's will work very well since we are lucky to see 10k runs here. The Starlight is incredible and exposure time is so short we worry a little about the lattitude of exposure, but initial tests show very strong positives. For us only very long runs will be needed to compare to MH lamps. The other new exposure unit is from Douthitt and designed by Olec. Their LED lights are quite strong by comparison to other units and need to be water cooled and we will test these as well, but for plastisol the LED systems are very good and the lamp life and 110V is a huge cost savings.
Not to be overlooked, Sign Tronics and others have scanning laser exposure with incredible details, CST as well, and we will be testing these on long run wb, discharge for evaluation.
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We are still in the evaluation process of LED exposure units. Our first tests were very promising and no doubt about it LED's are the future of curing. One point to note is that most LED systems are wavelength specific. They output at the same nanometer wavelength whereas a Metal Halide will have multiple spikes in the important wavelengths to cure all emulsions. Diazo emulsions tend to like 360nm whereas Pure Photopolymers like HVP fall in the 390-420nm range. For this reason Pure Photopolymers and Dual Cures expose well on the LED systems.
There are some new players that popped up at SGIA. Light Speed which is repped by North West Graphics in MN has a patented multi-spectral light source with good focused lenses. The concept sounds great to an emulsion manufacturer since we know multi-spectral metal halides simply create stronger stencils. However in the US we don't see the 80k-90k print runs in water base and discharge that exist in large production shops off shore. For us the light has to be able to create a very strong screen for these longer runs. In the US however LEd's will work very well since we are lucky to see 10k runs here. The Starlight is incredible and exposure time is so short we worry a little about the lattitude of exposure, but initial tests show very strong positives. For us only very long runs will be needed to compare to MH lamps. The other new exposure unit is from Douthitt and designed by Olec. Their LED lights are quite strong by comparison to other units and need to be water cooled and we will test these as well, but for plastisol the LED systems are very good and the lamp life and 110V is a huge cost savings.
Not to be overlooked, Sign Tronics and others have scanning laser exposure with incredible details, CST as well, and we will be testing these on long run wb, discharge for evaluation.
Light Speed is not new and has been around for years. Just a FYI. Also we have customers who do very long water based runs and the results of the screens life are very similar to mercury vapor curing.
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I was in the exact same spot as TCT.
We have two complete Olec 5k systems, total redundancy save for our integrator and photocell. Just purchased a new photocell to boot and we have a 3 different reflector options. It seemed silly to move to anything else but what pushed me over was space and electrical.
The Starlight we ordered takes up nothing compared to the giant Millington frame and lamphead on a cart setup. Most importantly I dropped 29a of draw from our electrical situation. The 5k Olec draws almost exactly 30a when running and we shoot a lot of diazo added, high EOM screens which means it's running a lot.
Would I have done it if space/power were not an issue? Hard telling. I guess I'll let you know when the Starlight gets into production.
I like buying anything we can from M&R. Only knock I have on the Starlight is it needs just 6 more inches of expo area to do (2) 23x31 screens at a time. Given the expo time reduction we'll see from shooting 2up with the halide 63" away from the glass I reckon it will be a non issue but it seems like a no brainer to add that additional space. Must be something to do with the parts that prevents it.
We did run over 10k pc runs of discharge, wet on wet (which was the lone cause of breakdown for us), earlier in the year and we needed 2 sets of screens if I recall correctly, all hardened with "permanent" 2 part hardener, so if that job swings back around next Spring I can put the LEDs to that ultimate test.
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I was in the exact same spot as TCT.
We have two complete Olec 5k systems, total redundancy save for our integrator and photocell. Just purchased a new photocell to boot and we have a 3 different reflector options. It seemed silly to move to anything else but what pushed me over was space and electrical.
The Starlight we ordered takes up nothing compared to the giant Millington frame and lamphead on a cart setup. Most importantly I dropped 29a of draw from our electrical situation. The 5k Olec draws almost exactly 30a when running and we shoot a lot of diazo added, high EOM screens which means it's running a lot.
Would I have done it if space/power were not an issue? Hard telling. I guess I'll let you know when the Starlight gets into production.
I like buying anything we can from M&R. Only knock I have on the Starlight is it needs just 6 more inches of expo area to do (2) 23x31 screens at a time. Given the expo time reduction we'll see from shooting 2up with the halide 63" away from the glass I reckon it will be a non issue but it seems like a no brainer to add that additional space. Must be something to do with the parts that prevents it.
We did run over 10k pc runs of discharge, wet on wet (which was the lone cause of breakdown for us), earlier in the year and we needed 2 sets of screens if I recall correctly, all hardened with "permanent" 2 part hardener, so if that job swings back around next Spring I can put the LEDs to that ultimate test.
I think you will be pleasantly surprised how fast burning one screen at a time will be. Your screens should work just as good or better on the long water base runs.
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You selling either 5k light zoo? :D my 1k is starting to wear on me as my screen volume increases...
definitely don't have the funds for led right now unfortunately, not until I at least get an auto.
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You selling either 5k light zoo? :D my 1k is starting to wear on me as my screen volume increases...
definitely don't have the funds for led right now unfortunately, not until I at least get an auto.
Both actually and the vac frame as well though I doubt that's worth shipping. Would like to keep the Olecs on hand for a few weeks while we ensure that LED is going to work for us but email me and we can set something up.
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I already got a killer deal on a huge vacuum frame locally. Been using it for flag frames, but with my 1k light and proper exposure distance it is taking like 12 minutes to expose...which sucks. PM me how much you're asking for the 5k lights whenever you're thinking of selling.
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I am new to this place and only been printing for a few years full time. I built an exposure unit and I get times of 30 seconds on 230 mesh screens. I have not noticed any undercutting. That's with unfiltered black fluorescent lights. I wanted to build a led table but was scared of the results
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A lot of factors determine exposure time and quality. I used the unfiltered black light bulbs for a few years, and they are indeed faster than a 1k MH at the proper distance away from the glass, but speed means little when it comes to quality. I experienced massive detail loss when doing 55 LPI halftones using the black lights, to the point that I finally transitioned to the MH. I also print lots of 200+ runs of discharge, and I was seeing both detail loss and screen breakdown with the black lights, but have not had those issues with the MH. If you are just doing plastisol and just doing spot colors, the black lights are fine.
The 12 minute time I mentioned above is on a MASSIVE frame coated in a diazo emulsion and being exposed from 5+ feet away for proper/even exposure. Lots of variables that determine the time :D
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We are still in the evaluation process of LED exposure units. Our first tests were very promising and no doubt about it LED's are the future of curing. One point to note is that most LED systems are wavelength specific. They output at the same nanometer wavelength whereas a Metal Halide will have multiple spikes in the important wavelengths to cure all emulsions. Diazo emulsions tend to like 360nm whereas Pure Photopolymers like HVP fall in the 390-420nm range. For this reason Pure Photopolymers and Dual Cures expose well on the LED systems.
There are some new players that popped up at SGIA. Light Speed which is repped by North West Graphics in MN has a patented multi-spectral light source with good focused lenses. The concept sounds great to an emulsion manufacturer since we know multi-spectral metal halides simply create stronger stencils. However in the US we don't see the 80k-90k print runs in water base and discharge that exist in large production shops off shore. For us the light has to be able to create a very strong screen for these longer runs. In the US however LEd's will work very well since we are lucky to see 10k runs here. The Starlight is incredible and exposure time is so short we worry a little about the lattitude of exposure, but initial tests show very strong positives. For us only very long runs will be needed to compare to MH lamps. The other new exposure unit is from Douthitt and designed by Olec. Their LED lights are quite strong by comparison to other units and need to be water cooled and we will test these as well, but for plastisol the LED systems are very good and the lamp life and 110V is a huge cost savings.
Not to be overlooked, Sign Tronics and others have scanning laser exposure with incredible details, CST as well, and we will be testing these on long run wb, discharge for evaluation.
Thanks for the input! I actually know the guy behind the Light Speed, good guy he is my go to tech when I have problems with my old equipment. He has been working on and selling the Light Speed for maybe 7 years now.
I use Murakami emulsion and don't really plan on switching so it is great to get info from you about the multi-spectral LED's. I know he was just up at Chromaline with the new unit and they had rave reviews for him.
If we stay using the SP-1400 do you think the multi-spectrum LED would be a great benefit?
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We are exposing Sp1400 with a 156 mesh with a Starlight. .. 40 seconds with the glass, 22 seconds with the glass removed.
These screens have seen 2000 pc discharge runs with no post hardening or breakdowns, and even after rinsing them with a pressure washer at the end of the run, they're good to go for another run.
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As noted in previous posts, you can get a strong screen with the new LED units out there. Our preference for multi spectral light stems from the need our offshore clients have when printing 80-120K runs. For runs under 10k the LED's are producing great screens when exposed well. We have shops testing on longer runs currently and will post the results. Emulsion is only part of the solution to avoiding breakdown on press with wb, discharge and HSA inks. Press set up, operator knowledge of how these inks print better, and how a wb and plastisol press set up differs from plastisol is also crucial to long runs with wb inks.
My biggest tech challenge is getting customers to realize just obtaining an image may not be a good screen exposure. Durability of the stencil is directly related to how much light energy you are able to give the emulsion before it is over exposed. An image obtained by under exposure will never match the durability of a good exposure using as much time as possible.
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As noted in previous posts, you can get a strong screen with the new LED units out there. Our preference for multi spectral light stems from the need our offshore clients have when printing 80-120K runs. For runs under 10k the LED's are producing great screens when exposed well. We have shops testing on longer runs currently and will post the results. Emulsion is only part of the solution to avoiding breakdown on press with wb, discharge and HSA inks. Press set up, operator knowledge of how these inks print better, and how a wb and plastisol press set up differs from plastisol is also crucial to long runs with wb inks.
My biggest tech challenge is getting customers to realize just obtaining an image may not be a good screen exposure. Durability of the stencil is directly related to how much light energy you are able to give the emulsion before it is over exposed. An image obtained by under exposure will never match the durability of a good exposure using as much time as possible.
Al,
can you please define the overexposure of the emulsion as you use the term?
thanx,
pierre
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I was looking to pull the trigger on one of these by the end of the year but not sure if we will make it. I heard today that Workhorse will be introducing an LED unit at ISS Long Beach in Janruary.
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Hello Pierre,
It was great to see you and other forum members at the show.
About overexposure.
Here is one way to look at it.
With a 50-100x microscope we examine a 40-50% halftone. We look specifically at the side wall of the halftone to see if there is a dark halo, or a light halo around the dot, or whatever dot shape you use, and we view the dot from the print side of the screen. A light halo inside the halftone dot shows overexposure. The dot has been undercut with too much light and the emulsion opening on the squeegee side is smaller than the print side. The sidewall is angling inward to create the smaller halftone opening on the squeegee side. With a dark circle the opening on the squeegee side is wider due to the developing water washing away soft emulsion and we are seeing the shadow and emulsion when viewing from the print side. The more the halftone dot shape has no dark or light halos around them the more vertical the halftone sidewall. A halftone like this will not dot gain as easily (underexposure) or require more pressure to clear <20% dots, (overexposure). Helps keep sim process sharp and tonal values accurate, although some dot gain is to be expected, thats why halftone outputs to film should be linearized to compensate for dot gain of 10-20%
This all assumes you have a well functioning lamp. If your lamp is old you can both overexpose and underexpose a screen, huh? OK I did have band practice last night but I've sobered up by now, so this can happen. What is going on is the exposure time in light units may be long due to a weak MH lamp or if you use weak chaotic fluorescent lamps. The time needed to get the emulsion film exposed to avoid slime on the inside may be so long that undercutting is occuring, and an older lamp's light may have lost UV power and is not cross linking the emulsion completely. Typically discharge or HSA inks will cause premature breakdown on what was supposed to be adequate or more than adequate time. The strength of the light in the 360-420 nanometer wavelengths is key. If the bulb has aged it may still shoot a screen well for plastisol, but for discharge it can breakdown in hundreds of prints once the lamp has lost strength. So yes you can over expose and under expose on the same screen but it just won't be visible until it breaks down.
However there are times where overexposing can help simple spot art for discharge. Bumping exposure 10-20% isn't going to hurt solid spot art and will give it a little more durability when shot with a fresh MH, or LED.
Al
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I got a phone call while exposing a 2/1 coated SP-1400 on 280 yellow mesh yesterday and ended up exposing it for almost 12 minutes, which is about 3 times as long as my standard exposure for that mesh/emulsion on my current unit. It washed out more or less perfectly which shocked the hell out of me. No halftones though so a little undercutting isn't a big deal.
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We purchased a starlight a few months back and it has been great, Very comparable to detail of Metal Halide, I Wish the starlight was 3 inches wider so I could shoot 2 screen at a time, To me it doesn't make sense why M&R did not just make the frame 3 inches bigger but leave the LED strips the same size. Might add $500 in material but we would be able to shoot 2 screens at a time. I have a feeling this will be something they come out with in the next year and we will all upgrade. LOL
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We purchased a starlight a few months back and it has been great, Very comparable to detail of Metal Halide, I Wish the starlight was 3 inches wider so I could shoot 2 screen at a time, To me it doesn't make sense why M&R did not just make the frame 3 inches bigger but leave the LED strips the same size. Might add $500 in material but we would be able to shoot 2 screens at a time. I have a feeling this will be something they come out with in the next year and we will all upgrade. LOL
Most of the benefit is lost though with such fast exposure times. Our pure photo-polymer emulsion is done exposing before you can walk out of the door of the dark room that is only 6 feet away...
With diazo I suppose it might almost be worth it but those times are still pretty low for us. Work flow wise it doesn't help though too because you grab the imaged screen, load new screen to be imaged, expose screen you took off CTS....etc, the imaging and washing out are the slower parts now...