webygail13

I'm in a tight spot, I just opened up a screen printing shop, I've being doing heat transfers for a few years and decided to print my own shirts. I have an exposure unit from Logos Screen Printing, brand new. I have accurip software printing with an epson R1400. I am using Ryonets DXP Dual Cure Emulsion. I mixed the diazo and everything, followed instructions, using a dark room. I've tried 12 screens so far, exposing anywhere from 1 minutes to 2 and half minutes. The emulsion recommends 90-120 seconds. Here is the problem, First I was washing it all out, under exposed. Then as I expose it for longer, some of the screen that doesn't need to wash out does and some of the screen that should wash out doesn't. So how in the world do you know if you are underexposing or overexposing? I have an order of 75 shirts that I need to have done in the next few days. But I can't even make a screen to print! Please help!!

 

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misterbigal

Hi
Are you using the right strength exposure to tie in with the recommended time?
You should set up a test screen with strips of mask that you can remove at certain intervals during the exposure. How long are you washing out for? You need to soak some emulsions for a few minutes and then blast them - even some over exposed screens give up sometimes!!
Keep at it though - it can be very frustrating I know!
(are you washing out in dark/subdued light)

 

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amp267

try this post. it might help

lost

 

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studog79

Aru you using a 1500 PSI powerwasher to wash out your screens? Is your vaccum working so light is exposing OK. 95% of all people under expose the screens. What color is your mesh? Yellow should be exposed about 80% longer than white?

A step test is what you need to use to properly determine your exposure times.

 

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chuckh

Contact your supplier and get an exposure calculator. All the emulsion companies have their own but anyone's will work. It is the only logical way to go.

 

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webygail13

Well, here is what I've figured out. After all of my frustrations this weekend, I sat down and starting thinking all of this through. When I installed my accurip, I had some problems. So a tech guy from accurip did a remote connection to my computer to fix the problem. Why he was on there, he set up my printer as well in the software. So I assumed all was well. So while being frustrated, I read the instructions again to my printer. I noticed that my dpi was supposed to be set at 1440x720, it was set at 720x720. Also the standard ink box was checked, rather than the "more ink" box. The instructions said to try both and use what works better. So I changed dpi, and checked more ink, printed a new positive. Exposed for 2 minutes, perfect image! I still had a few tiny tiny dots not wash out, but when I printed my shirts, they printed perfectly, it was not a detailed image. So, I'm guessing that was my problem, not having an opaque enough positive. That is the only screen that I've had a chance to burn, so hopefully in the next week or so I can really experiment and make sure that I can produce a screen on a regular basis! Thanks for the help guys. Any other advice is appreciated!

 

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