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screen printing => Ink and Chemicals => Topic started by: XG Print on June 01, 2016, 10:56:01 AM
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I've only been at this for 7 years but you would think I would have come across most issues but this one I have not. I use HVP emulsion and on the last run of screens we used at the end of the week I had 1 screen that my screen guy could not get the emulsion to come out of on about 1/4 of the screen. We use ER 188 for our emulsion remover and it normally works with ease but this stuff acts like it is baked on?? Any ideas on what I can use to get it off and save my screen. The emulsion was on maybe 2-3 days tops. That is about the norm here. It was some of the last emulsion from a gallon but it seemed to burn fine. I thought maybe the ER 188 had lost its juice or something but it is only a week or so old and he washed out about 10 screens after that one just fine. I am all ears??? :(
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Sounds like he let the emulsion remover dry on that portion of the screen. Once that happens, a jackhammer isn't gonna get the emulsion off.
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Also, if underexposed, it is much more susceptible to hardening by contact with inks and cleaning chemicals.
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Frog hit the nail on the head
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if underexposed, and then hit with something like screen opener during printing, you can lock the emulsion as well...
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Id try some of the nasty dehazer to get that off.
We've had luck with underexposed photopolymer being removed with it. It takes almost as long to clean the screen as to cut the mesh out and re stretch it however haha!
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I would try the nasty dehazer, but if it's really locked in, you'll just be wasting time and chemistry. It's probably faster to take the mesh off and restretch, sorry to say...
Steve
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All comments here are correct. SBQ emulsions remain sensitive after exposure. As mentioned screen openers can hit underexposed screens and lock in the emulsion. Same for emulsion remover, once it's dried on the screen which this sounds like, it is impossible to remove. Caustic haze remover can be applied to the area and let sit for 3-4 minutes. Rinse off gently to avoid splashing it back on the worker. Then apply emulsion remover to get reclaim. To prevent lock in from screen openers or chemistry just post expose the squeegee side at 2x exposure time, or put it out in the sun.
Al
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Been where your at, what I did was spray remover on it and brushed it in let it sit for a few sec then power wash and repeated it until it all blew out, brushing the remover into the screen is key.
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CCI GR70 works for me every time.
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Once I thought I was smart for adding water to thick old emulsion.
It exposed with no problem and was happy with myself.
When it came to reclaiming, I was crying for wasting several new screens.
You can reclaim it with chemicals and high water pressure, but at what cost.
It took me ages to reclaim those screens.
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Thanks guys...Looking at it now it could be a number of things...Our bulb on the MSP3140 is getting a little older so I bumped my exposure times a little. I was able to finally get the screen back with the de-haze technique. Brushed it on and let it sit for about 5 mins then rinsed....Went back with the Emulsion remover and it started to come off. Repeated the process and it finally came off. Thanks as always for everyone's help!! I'm still puzzled as to why only 1 screen did this but I guess stranger things have happened!! :D
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One screen?
For us, it is on which row on the drying rack. If our cabinet is full, some screens dry faster than others because of the fan inside the cabinet.
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One screen?
For us, it is on which row on the drying rack. If our cabinet is full, some screens dry faster than others because of the fan inside the cabinet.
I hope that you are not talking about the same thing as may have caused XG's problem of possibly letting the reclaim liquid dry on the screen.
One should never commit to more screens than they can handle with this stuff on hot days especially. Whether pulled from a dip tank, or applying emulsion remover manually in a stack, only apply to as many screens as can be blown out while they are still wet.
But you know that. ;)