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screen printing => General Screen Printing => Topic started by: Shanarchy on September 06, 2012, 08:07:08 PM
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I just ran a batch of shirts yesterday. White ink on black 50/50 tees (G5000). I'm folding them up and noticing the prints all are cracking if you slightly pull on them. Not sure what I got going on here.
I know that typically this would be under cured garments. Being 50/50 I did tap the dryer temp down a hair.
But I am also wondering, what if I fully cured the underbase? Would this cause this? Is it even an issue if you cure your underbase? I've heard people say they've printed new prints over misprints.
I am also using a new ink for the first time. Excalibur TKO pf white.
Thoughts on what may be the cause and how I can trouble shoot this? I am going to run them through the dryer again and see if this makes a difference, but as of now I am thinking I am going to reprint them and not give this batch to the customer.
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Also, could heat pressing them possibly save me here?
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Run through dryer first, sounds like classic undercure.
I've heard of the "fully cured underbase" theory, but in 7 years
of putting ink on shirts I've not had this happen.
IMO, it's either undercure (likely) or a problem with the ink.
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I think that the classic fully cured base story is more about giving your top prints not only a better "toothed" base like a primer, but less shine on the top coat as well. I also have printed fulll designs over old prints successfully.
I'd crank up the heat, or slow down the belt a whisker, and run 'em through again and check 'em out before re-running.
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Run through dryer first, sounds like classic undercure.
I've heard of the "fully cured underbase" theory, but in 7 years
of putting ink on shirts I've not had this happen.
IMO, it's either undercure (likely) or a problem with the ink.
I had the fully cure thing happened to me a few weeks ago. The customer complained that the top layer ink just pills off after several washes.
Thus I bit the bullet and got myself a donut probe. It saved me a lot of guess work.
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Normally if it cracks or peels off you have gone past cross linking. Over cured. Could be a bad batch or unbalanced batch of ink. If the print fades then that is undercured. A lot of 50/50 inks have a very low cross link temp and do not react well to going that far past it.
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Follow up:
I ran them all back through the dryer and they all seem fine if I stretch them. Definitely was a little scare. Probably a good reminder that I need to check my cure temps at the beginning of the run a little better.
Thanks for all the super fast responses!
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Normally if it cracks or peels off you have gone past cross linking. Over cured. Could be a bad batch or unbalanced batch of ink. If the print fades then that is undercured. A lot of 50/50 inks have a very low cross link temp and do not react well to going that far past it.
When I over cure I see bubbles come on the ink indicating it is tooo hot... I think under cure
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Normally if it cracks or peels off you have gone past cross linking. Over cured. Could be a bad batch or unbalanced batch of ink. If the print fades then that is undercured. A lot of 50/50 inks have a very low cross link temp and do not react well to going that far past it.
When I over cure I see bubbles come on the ink indicating it is tooo hot... I think under cure
Seeing bubbles can also be a cheaper ink, usually white , years ago we had this problem with all the NEW bright whites coming out , It ended up there was puff being added that caused whiter white but caused problems with over printed inks.
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I would allso check my dryer for cold spots...temp gun never hurts, I check our dryer thru our runs not just the shirt but the IR panels as well. Oh or it could been some ink you got from SONNY LOL sorry Sonny couldn't help myself
Darryl
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I would allso check my dryer for cold spots...temp gun never hurts, I check our dryer thru our runs not just the shirt but the IR panels as well. Oh or it could been some ink you got from SONNY LOL sorry Sonny couldn't help myself
Darryl
Not a bad idea to check the dryer for cold spots. I'm pretty sure it's because they were coming out very hot and I tapped the temp down (being 50/50's) without checking the ink temp coming out the dryer. Dumb decision on my behalf, especially using a new ink for the first time. Luckily I noticed it.
Darryl, can you set your Anatol to flood while the press indexes? Right now mine doesn't index until the print arm reached the next print head, it starts to flood as the table rises. (hope that makes sense). I'm pretty slow printing so it's not really slowing me down, but would be nice to change for when you send white ink around twice.
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Check your settings you may have it on a flood delay or something.
Darryl