Screen Printing Forum

I am a newbie to screen printing and I have been having many problems with washing out the image from the screen. I dont know if it is from me under/over exposing or what. I have been using DXP dual-cure emulsion on my 110 mesh screens and I have a Aluminum UV Exposure unit from ryonet. They have said that you need to expose it for 5 minutes. I do that and everytime I go to wash it out, it takes forever for the image to start to come thru but never all the emulsion leaves. Am I under exposing or over. I just dont know what to do anymore. Please help me.

How are you making your films?

Yeah Im printing them on my epson printer.

Sounds like it is either overexposed, too light a positive or both. Do a step wedge test.

Whats a step wedge tests. I just tried it again today and when I wash the emulsion out it comes partly out and I have to use a paper towel to wipe the rest of and the edges of the image Im trying to do come off in some parts. Whats a good film to use? maybe its that. How long should I actually put the frame in the light box?

http://www.screenprintingforum.com/foru ... test#p2789

there is a search feature at top of page where you can go back through old posts. that's how I dug this up.

How old is your emulsion and how long ago did you activate it? How long have your screens been coated with it? Duel crue has a shelf life. If its not the films being too light or that your over exposing them, then it could be your emulsion. Are you keeping tyour coated screens in the dark until it comes time to expose them?

I just bought new emulsion and mixed it last week. I coated the screens the day before I was going to print. Yeah the screens are on a drying rack covered.

Then it sounds like an exposure problem. Try decreasing your exposure time like the other poster suggested.

It could be three major factors:
1. The artwork is not a dark enough black. If you can hold it up to a light and still see light shine through then it is not dark enough.
2. Try decreasing the burn time by 30 seconds. If you notice the emulsion chips away easier but still have problems then decrease time more.
3. The emulsion you are using is not compatible with the exposure unit. Find out from the manufacturer what emulsion works best with the exposure unit. They should know since I'm sure they have done a lot of research on this.

Hope this helps!

It could be that your screens are getting exposed by daylight before exposing by lamp, where are you drying them, what lights are you using?