Screen Printers Open - A Forum for Screen Printing and Embroidery

What are y'alls thoughts about this? I am looking for a way to print on darker shirts. Ok lets be honest. Black shirts. I was thinking about a discharge underbase and have ordered the union pre-print discharge kit which is for underbasing for experimentation.
Here is what I think some of my pitfalls are:
1. short dryer chamber (I know...genetics) it is 4 feet long. It has 2 1800 watt ir panels so it is capable of generating the heat. (i could run twice through the dryer?).
2. dealing with a water-based product in a low speed production environment.
3. the smell ( never smelled it, but I can imagine) My dryer has an exhaust but I'm not sure how effecient it will be with the fumes.

What are other issues with discharge? I have never used it.
 I am trying to avoid using a flash dryer as space and time is limited. I only have 1 platen on my 6 color press in the trailer and I'm already stretching the time with a full color print and dryer time. (with darks I would not do front and back I dont think...)

Thanks
Darryl

I agree. I do not think it will work. Maybe in the middle of the winter on a wet day.

When i tested printing process color over a discharge base on a black shirt, i was unhappy with the loss of vibrancy of the process colors printed on top of the discharge underbase.

Process color is translucent inks requires the white under the ink to act as a reflector to make the color ink visible. The exact same screens an ink printed over a white underbase and the discharge underbase were like night and day. The white underbase print had very vivid color, where the discharge ink was dull.

I aslo wondered if the discharge was effecting the process colors themselves, but since the color didn't disappear i figured it was a reflection issue and not a discharge issue, but i could be wrong. I did my testing with union process color inks, so another ink might have better results.

fred

I think that after you add the plasitcharge to a plastisol, it has a shelf life. I've used the water based discharge for an underbase and printed the spot colors with plastisol through a 280 or higher. Nice soft hand. However, without convection in your dryer, and the short length, and doing in an event trailer, it's probably a recipe for a bad day in the trailer... you really need to get the water out of the underbase, and convection helps a lot with that issue.

Steve

i know this is a stretch and I do value the input.

I called back and switched it to the plastisol based additive. I

If the discharge is added to plastisol, why not just print a white underbase?

 I am trying to avoid using a flash dryer as space and time is limited. I only have 1 platen on my 6 color press in the trailer and I'm already stretching the time with a full color print and dryer time. (with darks I would not do front and back I dont think...)

Your beating your head against a wall here.
Only way I see it working is to pre-print some to have on hand and use a heat gun in the trailer.
How many colors is it and can you post a pict?

Maybe even the best case is to make transfers and heatpress on site.

Use a fast flash grey for the base unless you need white in the design. Clamp the flash panel in one of the print heads and hang the cord down from the ceiling in the center of the press. Set the off contact to about 1/2 or 3/4 inch. Just don't keep going around and around with the print heads. This will be 10 times faster than discharge as you will only be adding a few seconds to the printing time for flashing. When you are not printing just point the head with the flash towards the back of the trailer and have the rear door open if possible.