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screen printing => Screen Making => Topic started by: balloonguy on June 25, 2024, 05:31:09 PM
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I have some screens for a long time (years). All of a sudden 8 out 10 screens that I am reclaiming are getting totally locked up. The only thing that changed is my film. I went from a thermal film from oyo to epson inkjet. The emulsion and reclaimer are the same. I emailed the emulsion company to see if they had a bad batch or any other complaints. I have 2.5 gallons here but they are all teh same batch. I am not sure if the last gallon was the same batch or another. I am starting to stress. I have messed up about 40 screens in the last 10 days.
On a side note- who do you guys use for remeshing? Anyone in north FL or south GA?
Thanks.
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Spot color supply in GA Brannon and his guys do a great job
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While mesh can get "brittle" after many many years, if your emulsion is locking up it's something else going on.
The only time I've seen it happen is when you spray emulsion remover (or put the screen in a dip tank) and then let
the screen dry. Number one killer.
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I have some screens for a long time (years). All of a sudden 8 out 10 screens that I am reclaiming are getting totally locked up. The only thing that changed is my film. I went from a thermal film from oyo to epson inkjet. The emulsion and reclaimer are the same. I emailed the emulsion company to see if they had a bad batch or any other complaints. I have 2.5 gallons here but they are all teh same batch. I am not sure if the last gallon was the same batch or another. I am starting to stress. I have messed up about 40 screens in the last 10 days.
On a side note- who do you guys use for remeshing? Anyone in north FL or south GA?
Thanks.
Is your exposure unit still working as it should?
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That is a good question. I will have to check when the last bulb change was but it is a least a couple of years… I will get a new bulb in and see if that makes a difference. Thanks for the thought.
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Review every step.
Degreasing
Drying
Coating
Drying
Exposure
Post exposure
Press use
Reclaim process
I've seen stupid simple things such as a swift change in humidity throw a screen room into a tailspin.
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I went from a thermal film from oyo to epson inkjet.
Did you carefully re-calibrate your exposure times? Some films can have an big effect on exposure. The clarity and transmissivity of films can vary wildly and there is ink receptive coatings on inkjet film. It's possible you need a much longer exposure to have the proper amount of UV energy to punch through the new film. The detail you want might still be there and the screens are holding up ok on press, (for now) but inadequate exposure might be locking the emulsion up.
I would do a thorough step-wedge test once the new lamp is installed.
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What exposure unit do you have ? Has your times changed ? If emulsion is not exposed correctly and chemicals hit the emulsion it can lock it in.
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Sorry to take so long getting back to this…
I checked a lot factors. After getting a new bulb I tried to do a step wedge test ranging from 5% of expected time to 400% of expected time. I never got a good exposure and still had issues with the emulsion locking. I emailed the manufacturer and the reply was pretty worthless. About a week after emailing they replied with my batch number was the last of 2023 and that they had no other complaints or issues. I tried a few other brands and all the results were pretty good. I ended up with ulano orange. The step wedge came in just slightly over what I calculated from the spec sheet. I am fairly certain that the issue was a bad batch of emulsion. I damaged a lot of screens including 4 more while testing with the new bulb. Sometimes the obvious answer is the correct answer.
As always I appreciate the response and help I get from you guys.
THANK YOU ALL!