LED Bulbs Already Failing

[markvas]

Hello Alan,
This is Mark Vasilantone, sorry for the slow response we honestly don't monitor the forums enough. I actually had to re-register my self to login. Please give us a call and we will ship a replacement light bar to you, today. The install is easy, two screws and a quick disconnect is all that is needed. The biggest pain will be sliding out the glass. My tech guy, Steve, can offer any advice if needed.

Also, I may be wrong but I don't think you ever took my offer for an upgraded vacuum pump. That offer still stands, we changed out the pumps a while ago and will upgrade you, just mention that when you call.

regards Mark

Hello Again Alan,
We have another chance to get a new light bar out to you today. I know you are a busy man but I promise a quick call to us, or the TX dealer River City, and we can make this happen fast.

Mark Vasilantone

[DouglasGrigar]

ALL of the other manufacturers, if you ask, will share that info.

Out in the wild - no they do not, clearly not all.

[DouglasGrigar]

To get the detailed images, you expose for a very short time but then the screen breaks down after 100 shirts even if you're using 22 psi on the print heads.  If you shoot the screens so that they can hold up on press you won't get any of the detail.  It's a double edged sword.

It always is a double edged sword...

Part of it comes from the fact that you can’t get two industry companies or printers to agree on simple definitions of what they talk about.

Fudging detail by exposing for lower time ends up with softness you have to deal with - this brings up the entire issue of “post exposure” and the physical/chemical issues of each emulsion (note just emulsion).

Then - mesh choice, EOM, and positives (because we all know ink-jet positives will not spit out 2% dots from the file as we deal with splatter and absorption).

[DouglasGrigar]

I heard that Vastex have a policy on not engaging in any online banter/complaints/etc. I can't decide if it's smart to stay off that slippery slope, or if it's stupid to ignore this part of modern business and networking.

Actually that would be me, and not Vastex in particular, as you see some responses.

Most of you know that I work with the Vastex folks the most out of the industry and they have ended up as a second family to me over the years (and yes you will always have arguments with your brothers from time to time - just ask me about press configurations sometime at a show).

Two things here, in the past (and thankfully the far past now) we have had to deal in our industry with some particular problems - Solipsistic narcissism and the grandiose flow of arrogance and BS that flows, and a good share of predatory individuals and companies.

I was warned years ago that “Crusading” for the industry on-line was similar to “casting pearls” and was told in exact terms by three very respected compatriots in the industry “get the hell off the internet and stop trying to whack-a-troll with the creeps and armchair commanders and giving away time” - so I did.

I may well regret even getting in on things, but I’ve never been one to avoid risky behavior.

I do want to bring up two ideas: confirmation and selection bias...

How many LED units (from any of the top makers) are out there and how many “issues” with them are there and how out of the numbers do we see problems?

[alan802]

To get the detailed images, you expose for a very short time but then the screen breaks down after 100 shirts even if you're using 22 psi on the print heads.  If you shoot the screens so that they can hold up on press you won't get any of the detail.  It's a double edged sword.

It always is a double edged sword...

Part of it comes from the fact that you can’t get two industry companies or printers to agree on simple definitions of what they talk about.

Fudging detail by exposing for lower time ends up with softness you have to deal with - this brings up the entire issue of “post exposure” and the physical/chemical issues of each emulsion (note just emulsion).

Then - mesh choice, EOM, and positives (because we all know ink-jet positives will not spit out 2% dots from the file as we deal with splatter and absorption).

Over the last year with the exposure unit we've been able to find ways to squeeze out additional performance but I won't lie and say it's just a part of the process, it's sucked.  And even though I've been told our Richmond really wasn't THAT good of an exposure unit, that doesn't bode well for the ones that can't hold a candle to it in performance.  A huge perception problem for us was the fact that even when we didn't really know what we were doing, we rarely had any stencil issues.  Screens didn't break down on press and getting acceptable halftones in the outer ranges wasn't difficult.  And having been humbled now it's made more of an impression on how good (or not so good depending on who I talk to) the old metal halide unit was.

I finally got to call Vastex this morning and have a new strip coming along with a new vacuum pump.  I'm very pleased with the Vastex crew in the way they treated me this morning.  When it comes to whether or not manufacturers should have an active role on the forums...it can be done, but not many can do it right.

I don't expect much to change with our exposures with the new strip but I hope we'll see our vacuum times drop from 65-70 seconds to at least half of that.  And 30 screens per day average that time savings will add up over the week.

[DannyGruninger]

Alan, sorry if it's been mentioned but what emulsion are you using? I've tested close to 200 emulsions on LED and I will say that some worked exceptional on our MH prior to going led but on led they were absolutely horrible. We've had some big name/popular emulsions that we couldn't hold a 20% dot on to save our asses after using led. So I would be curious to know what emulsion your using.

[Rockers]

To get the detailed images, you expose for a very short time but then the screen breaks down after 100 shirts even if you're using 22 psi on the print heads.  If you shoot the screens so that they can hold up on press you won't get any of the detail.  It's a double edged sword.

It always is a double edged sword...

Part of it comes from the fact that you can’t get two industry companies or printers to agree on simple definitions of what they talk about.


Fudging detail by exposing for lower time ends up with softness you have to deal with - this brings up the entire issue of “post exposure” and the physical/chemical issues of each emulsion (note just emulsion).

Then - mesh choice, EOM, and positives (because we all know ink-jet positives will not spit out 2% dots from the file as we deal with splatter and absorption).

But fact is that screens that have been coated the same way for years and exposed on a MH unit  come out just fine while burning the same screens on the LED unit you get not as good results. How often we found ourselves in the situation of having the remake screens because the fine lines are just gone but the screen itself is still not exposed completely. Using a exposure calculator from Saati gave us shocking results. Exposure times would have been above the recommended ones by the emulsion manufacturer but I can promise you there would be no useable fine details left on a screen. All I`m saying is I can hold a lot more fine lines on a 150-s by exposing it on a MSP3140 then on the LED unit. And believe me we have not changed the way we make film positives over the last few years.

[Rockers]

Alan, sorry if it's been mentioned but what emulsion are you using? I've tested close to 200 emulsions on LED and I will say that some worked exceptional on our MH prior to going led but on led they were absolutely horrible. We've had some big name/popular emulsions that we couldn't hold a 20% dot on to save our asses after using led. So I would be curious to know what emulsion your using.

I can tell you what we use or used to use.
ChromaBlue
Murakami SP-1400
Murakami Aquasol TS
Now we use ChromaLime which is made for LEDs apparently.
There were some other emulsions too but they made just short "guest appearances" at our shop.
Next week we have some Kiwo emulsions coming in that are as well formulated for LEDs

[alan802]

Alan, sorry if it's been mentioned but what emulsion are you using? I've tested close to 200 emulsions on LED and I will say that some worked exceptional on our MH prior to going led but on led they were absolutely horrible. We've had some big name/popular emulsions that we couldn't hold a 20% dot on to save our asses after using led. So I would be curious to know what emulsion your using.

I feel like I've tested hundreds but it's really only been about a dozen.  All of the usual suspects, but the best overall emulsion has been Chromaline's Prototype 16-17i(2).  I know we could squeeze some smaller halftones (under 200 microns) out of a dual cure and in the past I've been absolutely against going in that direction but I understand I don't need to be so close-minded on these types of things.  Depending on how much faster the new vacuum drawdown time is, and the burn times for the dual cures we might be able to use them without losing that much time versus what we're doing now.  I've got a part timer handling the reclaiming, coating and burning of our screens and the addition of 30-45 seconds per shoot isn't a total deal-breaker if it means more detail and durability of the stencil.

To be totally honest, I haven't seen a huge difference between the different photopolymer emulsions.  Sure, some are a little better than others here and there, but overall we haven't been able to get near as much out of the stencils as I expected.  When I tested I tried to use a gallon at least but I've found that unless an emulsion is total junk, sometimes a gallon just wasn't enough to get a solid assessment. 

[markvas]

Gentlemen, admittedly I am no artist so I may not be able to debate this, but here are test images we have done. This one is a Chromaline DZ dual cure, 2/1 coat-round side, on a 305 mesh, at one minute exposure. More images to follow. FYI, all positives were pressure washed aggressively from shirt side. So I can't say how many prints these positives will hold up to because they were test screens, but we also did post curing in the sun. Then we did a point high velocity pressure wash test and found no difference in breakdown time.

Mark Vasilantone

[markvas]

Here is another test image.

MVas

[jvanick]

mark -- how thick was the emulsion (measured) on those?

It looks quite thin?

just curious as we've seen major differences depending on emulsion thickness in how well any LED unit works.

[Vastex]

mark -- how thick was the emulsion (measured) on those?

It looks quite thin?

just curious as we've seen major differences depending on emulsion thickness in how well any LED unit works.

All of those tests were coated twice on the shirt side and then once on the print side with the round edge of the scoop coater. We've played around with some crazy thick coats like the attached image which is a 3/5 coat with Ulano Orange at 30 seconds. They aren't too practical but it was more because a lot of people said that LEd can't expose a thicker stencil.

-Paul

[DouglasGrigar]

Exposure times would have been above the recommended ones by the emulsion manufacturer but I can promise you there would be no useable fine details left on a screen. All I`m saying is I can hold a lot more fine lines on a 150-s by exposing it on a MSP3140 then on the LED unit. And believe me we have not changed the way we make film positives over the last few years.

Is not the point right there? You are apples and orange-ing this...

I have a brand new truck and it is the same brand (UV exposure) but one has dual back wheels and and a big block and the newer less expensive one is small block standard - but I don’t get why they won’t do the same job...

Tubes 15-17% loss (but I can still get more and better halftone imaging than 60% of the industry with base level equipment)

LED - 7-8% loss

MH - 3-5% loss

Then the size, features, active life, maintenance, price, energy use....

All different - not bad just different.

I cannot expect my Jeep to be able to keep up with a Mustang now can I? Does that make my trashy Jeep bad?

[DouglasGrigar]

I know we could squeeze some smaller halftones (under 200 microns) out of a dual cure and in the past I've been absolutely against going in that direction but I understand I don't need to be so close-minded on these types of things....

To be totally honest, I haven't seen a huge difference between the different photopolymer emulsions.  Sure, some are a little better than others here and there, but overall we haven't been able to get near as much out of the stencils as I expected.

Is this not again trying to race a pickup truck (SBQ) where a corvette is more proper (Diazo Dual-Cure - and we are talking about detail imaging BTW)?