How to Remove Emulsion from Screen?
Hi, I was just trying to reclaim two screens. Both are wood frame 110 mesh. The only difference in the screens is that one is new and the other has been used many times. I cannot get the emulsion to wash off of the new screen. I made the screens at the same time, one being the design for the front of the shirt, the other for the back. I first used a diluted solution of the remover and when that didn't work I tried it at full strength. I will not come off. Do you have any suggestions and, can you tell me what I did wrong if anything. I have another new screen that I bought the same time as the "bad" one and am wondering if I'm going to have troubles with it too. Thanks in advance for any help you can give me.
This question is posed a lot so I am going to take some time to answer it.
There are a couple things that can go wrong when reclaiming screens. I think the majority of the problems come from these three roots. Not using enough water pressure to blow out the emulsion, applying too much emulsion originally to begin with, and not applying the emulsion remover properly. Let's start with the washout source. What are you using to wash your screens out with? A. garden hose with spray nozzle, b. garden hose w/ out spray nozzle, c. shower nozzle, d. sink, and e. small pressure washer. If you are using anything but(E)you are going to have a heard time blowing out the emulsion. All screen printing shops have a pressure washer, at least a small one. You need 1000-1500 PSI to properly blow the emulsion out after the emulsion remover has been applied to the product. Without the proper pressure you are going to have a hard time getting the thick spots and edges of the emulsion out. Pressure will blow out just about any tough spot. If you do not have a pressure washer I would suggest looking for a small electric one to start out with, between 1000-1500 PSI, I have seen them as low as $49.95.
If you don't have access to a pressure washer the garden hose with a strong nozzle is your next best bet, you cannot expect to get very good results with any of the other choices. Suggestion, if you have a screen that is being stubborn but do not have a pressure washer, take it down to a local car wash, put a quarter in the machine, and wash away.
How thick is your emulsion to begin with? If parts of your screen are washing out fine but thick spots want to stick, you are probably not coating your screen even enough. Try practicing using even pressure and a smooth but fairly fast coating stroke when coating the screens with emulsion. The edges will always be a little thicker because there is a slight overrun of emulsion on the end of the scoop coater. This may solve further problems in the future.
Application, how are you applying the emulsion remover? Emulsion remover (whether used concentrate or diluted) should NEVER be allowed to dry on the screen. This will PERMANENTLY lock the emulsion into the screen and make it virtually impossible to rinse even with high pressure. Spray on the emulsion remover to a slightly wet screen on both sides, let is soak in for about 15-30 seconds, then scrub with a scrub pad until you can see the emulsion break down and rinse with pressure. If the screen was ever exposed to water and then dried or any other type of chemical such as strong cleaning solvents (lacquer thinner) then that can also set the emulsion making it very hard to reclaim. Also, if your screens are under exposed to begin with and you then print through them and use cleaning chemicals on them this may set your emulsion in the screen. You need to make sure that you are getting the proper length of exposure.
Ideally you want to control your environment, have a dedicated washout sink with the proper pressure to spray out the screens, if you don't this right now; following the above steps should improve your results. One of the easiest ways to reclaim a screen is by using a dip tank. With a dip tank there is no scrubbing, waiting, or tough spots, simply dunk your screen in a micro wash solution, come back 4 minutes later, and spray out. Very simple!
Dip tank solution lasts for up to six months and can clean hundreds of screens. A small dip tank can be purchased with solution for a little over $200 and is a well added benefit to any small shop! http://www.silkscreeningsupplies.com/site/799934/product/EasiDSsm
There are always things to look forward to and shoot for in the future, for now I hope this has helped you out!
Screen exposure problems can be one of the most frustrating issues in the screen printing process. These videos cover most of the common issues with screen exposure. If you are having problems exposing your screen or with your image washing out, we highly recommend watching these videos that help trouble shoot screen exposure problems.
Help With Screen Exposure Problems, Part 1
Screen Exposure Trouble Shooting, Part 2