new to the screen printing industry. i am having trouble with burning my screen and the image coming out right. i have heard about under-exposing and over-exposing. how long do you usually let your emulsion cure before burning your image?
Many factors come into play on this end. Humidity is a big deal. I can dry a freshly coated frame in about 3-5 min in my dark room yet others take a full 24 hours.
How are you storing and drying your frames? may need to get a dehumidifier.
It depends on the temperature. In the summer we can dry a screen in 20 minutes. In the winter it can take 2 or 3 hours. We use little space heaters to dry them quickly. What sort of problems are you having? It may be your exposure time. Or the amount of emulsion your putting on the screen.
Many factors come into play on this end. Humidity is a big deal. I can dry a freshly coated frame in about 3-5 min in my dark room yet others take a full 24 hours.
How are you storing and drying your frames? may need to get a dehumidifier.
How are you getting them to dry in 3-5 minutes Richard? That's extremely fast.
We have a dark room (old office converted) with racks built on the walls. In the center of the room we have a dehumidifier. After reclaiming a screen we shade to remove as much water as possible and just set on the rack to dry. Coated screens are the same. Coat and place on rack. We will move the dehumidifier closer to the coated frames for quicker drying.
1st thing in the morning we turn the dehumidifier on and leave on all day. dumping the collected water when necessary
It depends on the temperature. In the summer we can dry a screen in 20 minutes. In the winter it can take 2 or 3 hours. We use little space heaters to dry them quickly. What sort of problems are you having? It may be your exposure time. Or the amount of emulsion your putting on the screen.
i am just having trouble burning the image to my screen. i wash my screen with the degreaser, let it dry, apply the emulsion with one of those metal trough, place the screen in the box to dry, i waited like a day for it to dry. take my screen out of the box and line my image up, then i expose the screen in our light box, go to wash out and it takes a while for the image to wash out, then it just all starts to fall out. i have tried to expose for 15 sec. to about a 1 1/2 min. i am using saatichem textil pv emulsion.
I know it's frustrating. Is the image extremely difficult to open? If this is the case you are giving it to much time in the exposure unit.
If it is opening very quickly and falling apart then you are not giving it enough time in the exposure unit.
Also, how much pressure are you using with your pressure washer? You shouldn't need to much.
Also make sure that when your carrying your screen from your exposure unit to your spray out station you are not exposing the screen to the sun. Get a little spray bottle and spray both sides of the screen before carrying out into the light.
Hope this helps. let me know how it goes.
Good luck
i exposed my image for 25 sec. and washed it out of the light and it still didnt work. my image just came out real fuzzy looking. some of the edges of the image look kind of stringy, if that makes any sense.
Did the emulsion come out really easy or was it difficult to get out. If it was really easy you need more time in the light. If it was very difficult you need less time. It sounds to me like you may not be putting enough time in the light. We usually go for 2 minutes. But all exposure units are different.
Keep me posted.
Cleaning the screen is critical. If you do not get all of the contaminants off of the screen - the emulsion will not adhere to the screen. What brand of degreaser are you using? You may also need to use an abrader on the screen. When you clean the emulsion out of the screen are you using a high pressure spray? If so, you need to make sure you thoroughly wash out the screen between each step. First emulsion remover, high pressure wash, degreaser, high pressure wash. Let the screen dry thoroughly. Coat emulsion upstroke on one side, flip screen and coat upstroke on the other side. Nice even thin coatings on both sides. Lay screen with the side that will be next to the garment down. Ink side up. This helps keep the emulsion where you want it. Make sure you have the artwork tight against the screen when you burn the image. Get the water to it quick after burning the image to stop the process. Nice light pressure rinse on both sides. Different emulsions work differently. We use a very fast exposure emulsion, that is extremely tough. It's not cheap, but we do production runs and fast is best.
We have an exposure unit. How does the light box work? Does it have suction?
its probably the same thing that you have. its a box with probably six lights with glass over them. it does have suction, but the screens are too small to use the suction so we have one of those foam blocks with a handle that you set in the ink side of the screen when exposing.
emulsion dry time? 
