LED Exposure Units - Emulsions

[Prōdigium]

Not that I want to get into a "whats better", "this sucks" or my exposure unit is better...or whatever debate. But after reading a painfully long thread about the issues of LED exposure units, I thought it would be interesting and helpful to gather some basic data from real shop users. Compiling some basic real world data may even help existing users resolve some complaints or address some performance issues with their own units. I believe it would be helpful, to many people to have some feedback on emulsion. As with ANY exposure unit emulsion choices will play a huge part in perceived and real performance of an exposure unit.

There are tons of emulsions on the market every shop will pick one or more based on THEIR needs alone and there is no wrong or right choice....its about what works for your shop, ultimately that is all that matters. This is not a contest, there is no need to embellish results or try to make a case for faster is better because for some shops, clearly too fast IS the problem.

Now we all know, or should know that there are a gazillion variables at play when it comes to "proper" exposure of a screen but for the sake of making this an easy thread to reply too ans assimilate lets keep it down to the basics. Giving members some real data here will prove a huge resource for future members as well so lets keep it on topic. Each member can take what they want from it later and use it...for whatever reason in a new thread where the merits of any brand of whatever can be debated.

For now, lets just compile some data.

• What Brand Name Of Exposure Unit - Model
• What Brand Name Of Emulsion, and version
• Average number of screens burned per day
• What is your coating method (1x1 ~ 2x1..etc)
• Is your screen room climate controlled? (Yes , No)
• Exposure Times for the following mesh. (please indicate mesh colors)
• 110 , 155, 195, 255
• Average production runs

Lastly any foot notes about what you believe is the quality of the stencil such as breakdown issues, poor halftone resolution or even problems with reclaiming..which may indicate improper/under exposure.

[jvanick]

I think a few additional fields should be added for those know/can provide the data.

- EOM
- "Positive type" CTS or Film or Velum (does anyone still use that here?)
- Stouffer Strip results.
- Ink type (plastisol, waterbase, discharge, hsa?)


For us:

M&R Starlight 2331 with the glass removed
positive source - I-Image (epson based unit)
Saati PHU + diazo11 (To slow it down)
20 screens per day
coating method 1/0 on Thin-thread mesh
screen room is climate controlled at 72-76 degrees, 25-30% RH 24x7.
all screens exposed to a solid '7' on the stouffer strip.

exposure times:
150/48Y - 30 sec
160/48W - 24 sec
225/48Y - 18 sec

Approximate EOM across the board is 17%.

production run can be anywhere from 12 pieces to 20,000 pieces.

[Gilligan]

You could just use/hi-jack this google docs sheet I started a long time ago.

https://drive.google.com/open?id=1DQahuQ2WivbJJ9aGp7zyIxmMSWJitNNvipFsX4ajaFE

[screenprintguy]

I think a few additional fields should be added for those know/can provide the data.

- EOM
- "Positive type" CTS or Film or Velum (does anyone still use that here?)
- Stouffer Strip results.
- Ink type (plastisol, waterbase, discharge, hsa?)


For us:

M&R Starlight 2331 with the glass removed
positive source - I-Image (epson based unit)
Saati PHU + diazo11 (To slow it down)
20 screens per day
coating method 1/0 on Thin-thread mesh
screen room is climate controlled at 72-76 degrees, 25-30% RH 24x7.
all screens exposed to a solid '7' on the stouffer strip.

exposure times:
150/48Y - 30 sec
160/48W - 24 sec
225/48Y - 18 sec

Approximate EOM across the board is 17%.

production run can be anywhere from 12 pieces to 20,000 pieces.

Jason, only 1 swipe of emulsion one only 1 side of the mesh?

[jvanick]

I think a few additional fields should be added for those know/can provide the data.

- EOM
- "Positive type" CTS or Film or Velum (does anyone still use that here?)
- Stouffer Strip results.
- Ink type (plastisol, waterbase, discharge, hsa?)


For us:

M&R Starlight 2331 with the glass removed
positive source - I-Image (epson based unit)
Saati PHU + diazo11 (To slow it down)
20 screens per day
coating method 1/0 on Thin-thread mesh
screen room is climate controlled at 72-76 degrees, 25-30% RH 24x7.
all screens exposed to a solid '7' on the stouffer strip.

exposure times:
150/48Y - 30 sec
160/48W - 24 sec
225/48Y - 18 sec

Approximate EOM across the board is 17%.

production run can be anywhere from 12 pieces to 20,000 pieces.

Jason, only 1 swipe of emulsion one only 1 side of the mesh?

That's correct .. a 1/1 builds 50% eom

[screenprintguy]

So you use this method for both wb, and plastisol? Just curious man. I always thought you had to have the coat on both sides for a true crosslink. I'm not using phu but I wonder if I'm hurting our printing with a 2/1

[jvanick]

So you use this method for both wb, and plastisol? Just curious man. I always thought you had to have the coat on both sides for a true crosslink. I'm not using phu but I wonder if I'm hurting our printing with a 2/1

We've looked with microscopes with Ross Balfour from saati and confirmed that the emulsion is completely encapsulating the mesh.

A 1/0 from the print side actually results in a perfect glisten method as well.

[Frog]

It's not always as easy as just counting strokes, or even which side of the coater is used.
As pointed out, some can apparently lay down enough emulsion with one stroke while others may need more.
Pressure, speed, viscosity, mesh count, and maybe even how the stars are aligned seem to all affect the end result.

[Dottonedan]

The perfect coating all depends on the technique.  J Vanic may be very slow but sure or evenly coated (while going slow).  Thats extremely hard but he may have a knack for it. Most need several coats and need to coat semi faster to eliminate any studders. That's why for him, a 1/1 would be too much.

The trick to getting the correct thickness is using a gauge to measure EOM.  Doesn't matter how you get there.

[jvanick]

The perfect coating all depends on the technique.  J Vanic may be very slow but sure or evenly coated (while going slow).  Thats extremely hard but he may have a knack for it. Most need several coats and need to coat semi faster to eliminate any studders. That's why for him, a 1/1 would be too much.

The trick to getting the correct thickness is using a gauge to measure EOM.  Doesn't matter how you get there.

We are installing an auto coater in a few weeks hwre, it's going to be interesting to dial it in and see what a 1/1 delivers.   To be honest I'd much rather be coating 1/1, but it is what it is for now.

A thickness gauge, to me, is as important as a stouffer strip of tension meter.

If you can't measure it, you can't track it, if you can't track it, you can't improve it.

[rusty]

We just got a starlight unit and haven't dialed in all the numbers yet but we have also been doing mainly spot colors as of late.

     - starlight 2331
    - emulsion we are currently using is Chromalime
   - 5 screens a day on average
   - Coating method is a bit different. I coat once with an oversized coater to cover complete screen and the use a smaller coater to scoop up excess and give an even coat. I do this to eliminate using tape and quicken    setup and reclaim. it would probably qualify as a 1/0 coating method
    - room is not climate controlled yet.
    - as of now my exposure time is 15 seconds across the board. We are mainly using S-mesh except when doing flatstock then we are using 230 mesh only. We are currently a manual shop  for t-shirts (we have an automatic for glass printing) and are not doing any sim process at the moment.
     - average production runs are about 100 shirts (anywhere from 48 to 144)

Sorry this isnt as detailed and specific but figured you might want to know what some smaller shops are doing and as we grow and dial everything in I will add in more specific numbers.

[Prōdigium]

We just got a starlight unit and haven't dialed in all the numbers yet but we have also been doing mainly spot colors as of late.

    - emulsion we are currently using is Chromalime
   - 5 screens a day on average


It might be enough to help others figure out how to get a better exposure, or make them think about changing emulsion for a better exposure. Speaking of emulsion, what product name from Chromaline...they have lots of versions of emulsion.

[Prōdigium]

I think a few additional fields should be added for those know/can provide the data.

- EOM
- "Positive type" CTS or Film or Velum (does anyone still use that here?)
- Stouffer Strip results.
- Ink type (plastisol, waterbase, discharge, hsa?)

Well, to be honest I think that in the majority of shops...even ones that do good printing, they do not have a clue what EOM they have. As for film types, well again way to many variables and ink types are actually not relevant. The idea of this thread is to get some data that would allow people who are using, or considering LED exposure units to see if maybe the emulsion choice they have is appropriate and if they are getting satisfactory exposures. 

[rusty]

We just got a starlight unit and haven't dialed in all the numbers yet but we have also been doing mainly spot colors as of late.

    - emulsion we are currently using is Chromalime
   - 5 screens a day on average


It might be enough to help others figure out how to get a better exposure, or make them think about changing emulsion for a better exposure. Speaking of emulsion, what product name from Chromaline...they have lots of versions of emulsion.

the emulsion from chromaline is called chromaLIME.

https://www.chromaline.com/product/chromalime/

[Frog]

Speaking of emulsion, what product name from Chromaline...they have lots of versions of emulsion.

Lance, the Chomalime is Chromaline's new emulsion tuned for use with LED

http://www.ikonics.com/pdf/user-guide/chromaline/ChromaLime_140904.pdf