[microdocks]

We have a new LED light exposure unit and a new Epson printer
We are exposing between 20and 40 sec. And the screen will not wash out has anybody had this problem. NEED HELP

THANKS
L.A. Ray

 

[Dakent012]

Have you run a 21 step calculator?

 

[microdocks]

Yes we did We think it could be too much humidity in the room and the moisture is not getting out of the emulsion have you heard of this

 

[Dakent012]

Are you getting a solid 7? Yes, we just had our satti rep in on Thursdays and one of the test we ran in our screen room was the check the moisture in our screen room. Do you have a de-humidifier running with the door closed? Since two critical steps changed I would try and run each test individual. What I mean is use your old printer with your new exposure unit to determine if it's the printer and then vice versa your use your new printer with your old exposure set up.

 

[microdocks]

moved the screens to a different location with less humidity and results were better. Also got a dehumidifier hopefully this fixes our problems.

 

[sben763]

This won't fix your problem When you have humidity issues the screen will wash out or blow out as moist emulsion isn't as light sensitive as dry emulsion. If you not able to wash out its over exposure. Some of the photopolymer emulsions expose at 5-10 sec on LED units.

Rule of thumb. If you aren't able to wash out you have over exposure. This also includes pre exposure where UV is getting to emulsion before exposing screens or post exposure where UV hits screen before washout starts.

If it blows out(more then the image area) the under exposure including a humidity problem.

 

[microdocks]

here is a pic of was is happening, we have successfuly wash out a screen after this pic was taken ...moving screens to a less humid area helped a little. with dehumidifier things should be looking better

[media]https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-prn1/t1/16629_826779544016964_1842589051_n.jpg[/media]

this is the back side of the screen other side washed out fine

 

[microdocks]

Dehumidifier did the trick screens wash out wonderfully thanks for all the help figuring this out.
You guys are great !