User login

Troubleshooting sandpaper-textured prints

Posted on Wed, 23 Aug 2006 at 23:24



I'm having an issue on our automatic that prints on certain brands of shirts are coming out with a rough finish. Some of them will even be smooth when it's flashed, and then rough when it comes off the conveyor. Other times texture is immediately evident while the garment is still on the press. Platens are clean, print isn't sticking to screen... This is most noticeable with white ink through a 110. Slower squeegee speed helps, but definitely does not eliminate the problem.

Any thoughts?

Location of Opportunity or Item

Comments

anthony-whalen says: There could be a couple of things that could cause this. It coul be your flash temp, time under flash, pressure, misleveled pallets, or a combo of all. If your temp is to low, as you know, can cause ...

There could be a couple of things that could cause this. It coul be your flash temp, time under flash, pressure, misleveled pallets, or a combo of all.
If your temp is to low, as you know, can cause the ink to stick under the next several screens. If your printing with a soft squeegee with hard pressure you may be sinking the base ink deep into the fabric. When the ink is flashed the very top will cure but because the large amount of ink under it will remain completely un-geled. The first couple of prints may print clean and feel cured but when it gets to the next screen small amount of ink may stick to following screens (this can also happen when a pallet(s) is out of level cuasing one peice to leave residue on following screens that redeposits on the next shirts causing bumps) It may not pop like a base that is very tacky. It may pull small balls of geled ink from deep spaces between the knuckles of the fabric exposing the uncured ink under it, then when it gets to the next screen that ink then pulls out and sticks causing a deeper hole. When the shirt is finished it may look pocked or the gloss may hide the rough texture till it's cured.
It could also be that textile companies reduce cost of fabric by producing fabric with loose threads that make it look thick but the density is low. If you use to much pressure or to little, when the base screen pulls away it can cause fibers that stick out from the thread to pull upwards and when flashed making it rough. When the next color goes down it has little points of base ink that don't push down because the get hot quickly and cure hard.
Another thing that I personaly had happen to me was the ink that the ink guy at our shop gave me had been reduced for quick halftone printing. Althogh I wasn't printing a base, when the peice went through the dryer it seemed like the plastisol colapsed down between the threads in the fabric. I'm still not sure if the viscosity reducer absorbed into the fabric or the ink became thinner in the curring process, but when I had him thicken it with thickening powder the problem went away.
If your using 110 mesh, find the tightest one available. I like to use 70/90/70 durometer sgueege at 20-25 degrees.
If it's none of this let me know.

posted on: Mon, 09/04/2006 - 2:49am

Did you enjoy this article? Click here to subscribe to the magazine.