[Flatlander24]

Been working on my first screen print order but have ran into some issues. I am printing some martial art uniforms that are of a ribbed material that is flat on the top of the ribs. The first problem was about 10 days after printing them the black of the uniform bled threw. I responded to this by adding more white undercoat which seems to have cured this problem. The logo is red with white outline so I have used the white undercoat as the outline and just added 2 coats of red for the center of lettering and logo. Now the black is not bleeding but during test washing the white is cracking after 4 to 5 washes. I am thinking that I should add the white outline as another screen to balance the ink coats. I have been using a flash dryer for final cure but I am also getting a little buddy conveyor dryer which should help make final cure more consistant. Is there any other ideas that may help as these uniforms are a bit spendy and I am going to stand behind what I sell so this project is a loss but but the learning curve is good and it has opened other doors for t shirts. Thanks for any ideas.

 

[ole Jobe]

What material is the uniform? Bleeding is normally a polyester issue. Are you using plastisol inks? If you are only doing one coat of white, the cracking would be the result of undercuring. God Bless.

 

[Flatlander24]

They are 65% poly and 35% cotton and the white has 3 coats they bled threw at 2 coats. It could be from under curing.

 

[ole Jobe]

Another possibility is heat build-up from flashing to the point that the bottom layer of white is reaching cure temp before the last coat is laid down. When this happens the layers of white do not mix and cure together, thus it cracks.

 

[Flatlander24]

Heat build up is a real possibility. I have ordered a higher opacity white ink so hopefully this will stop the need for so many coats. Thanks for the advice.

 

[Celtic]

With that high a level of poly, I would DEFINITELY add the poly additive to your ink.
That's why you're experiencing the bleed through.
Also, you mention that the material is ribbed. With ribbed material, you can definitely have problems with the ink cracking...of course, undercuring will do that too.
Definitely get some poly additive and add to your inks.

 

[Flatlander24]

I started to test today with low temp additive for polyester in my ink and using a conveyor dryer (just received). Seems to be doing the trick so far 4 washes into the test and no cracking or bleeding. Took 10 days for them to bleed last time so will have to just sit and wait. Thanks for the info.