TSB
screen printing => Waterbase and Discharge => Topic started by: TCT on April 28, 2014, 05:45:27 PM
-
We are going to run a job and I want to try to print it a little different- a discharge clear(80/20) underbase and then print 4 water based colors on top. Before everyone starts yelling at me, YES we would usually just print the colors as discharge with no UB. For this particular design I'm putting a distressed filter on the UB so the top colors should have a variation of opacity.
So my main question is: would you flash after the UB? My thought would be that if it was all done wet on wet, would there be a possibility that the DC may mix with some of the WB colors on top?
I can post a pic in a while when I'm back at my computer. That may make what I'm trying to do make mouse sense.
-
We do this all the time with plasticol on top and always flash. It is a very short flash (1.5-2 sec) just enough to steam the UB. If your pallets begin to get too hot it is going to cause issues with the top colors drying in the screens. If we run a straight D_Base we can get away with no flashing, on shorter runs, but with longer runs the pallet adhesive goes to crap. Hope this helps
Chris
-
We have to flash the DC UB here with plastisol top colors. Just like Parker does. The prints look fine doing it all wow but the DC UB is wet and it's ultimately going to contact the open areas of the color heads and will begin to clog their mesh openings, especially on higher mesh counts. After reading all the "don't flash the UB" type comments on here I had to learn the hard way that it does sometimes need flashed when we lost a grip of CMYK/DC UB prints due to the Magenta and then Yellow screens slowly clogging over the run. Couldn't see that chit until the back of the dryer and then we even tried to fight it and were heat gunning every 2 doz prints to check for it. In the end, just bump flash it and roll on.
WB over DC? I'd probably also bump flash the base. Contamination could become problematic. I've seen certain WB freak out when coming into contact with DC ink.
Again, the flash is brief and isn't necessary at all to get a good finished print but is necessary in most production situations that we've found.
-
Whatever you do don't print metallic water base over the discharge! :)
-
I tried a DC ub once on and order with yellow and blue wb on top. It did not work as expected. Once the ub is printed, there was much more saturation of the fabric left to get the top color opaque enough, so it came out light and pastel. If I triple printed the colors they would be passable, but still not right.
It might work with a super high pigment load top wb color, but I'm not sure I'll try it again.