TSB
screen printing => General Screen Printing => Topic started by: p_robertson_design on October 27, 2011, 01:28:21 PM
-
A while back we had an issue with some shirts discoloring after the customer received them. These were 100% polyester shirts, almost like the moisture wicking style. It seems that the image had left a "ghosted" impression on the opposite side of the shirt from the imprint. After some investigation, we concluded that the shirts had been reverse sublimated from where the print had made contact with the shirts after being folded into dozens and packed into the boxes. Apparently the heat transferring from shirt to shirt had lightened the ink used to dye the shirts from the manufacturer, causing the ghosted image on the opposite side..
Has anyone else had this issue?
-
I've never had it with poly, only 100% cotton...beefy tees nonetheless.
-
I haven't experienced it but I was warned of the very same issue by someone here just before I printed on 100% poly performance shirts.
-
We noticed it mainly on the Port Authority poly shirts. Seems that we just have to keep an eye on the way they are stacked when done, and not let them pile up at the end of the dryer. I was just curious if it was one of those things that only seem to happen to us, or if anyone else experiences this problem..
-
I saw it a few weeks ago with a friendly competitor shop. He brought one by to show me and ask my opinion of what happened. It had definitely sublimated from the print on another shirt after folded and boxed up. It was 100% poly, under armour type shirt, black with white and purple imprint. The purple wasn't a low bleed and the white wasn't low bleed enough for what he was doing.
-
Sublimating is a correct enough term, others refer to it as "ghosting". The poly is releasing a gas (you can usually smell this) and the gas is picking up traces of the pigment which can be picked up on the back of the garment on top. When dozens of garments are stacked high upon eachother the pressure on the bottom pieces increases the chance of this happening. Rick Roth has a good article on this on the M&R board or you can find it in Printwear last issue.
-
I know the process of sublimation from when I used to design plaques for my last employer, but this was the first I have seen it happen to shirts. I hadn't realized that they could actually do recolor the shirt simply by having a heat source applied to it..
-
Tony explained it..
Link to Ricks Blog and article.
http://theinkkitchen.com/2011/08/mysteries-and-ghosts/ (http://theinkkitchen.com/2011/08/mysteries-and-ghosts/)
-
I read Rick's blog and it is interesting but this particular quote I would call the "Survivalist Man's Fix" rather than "poor man's fix". Because, when it comes to poly garments and their high cost and high tendency to cause problems, I don't see this step as wasted time even with the correct ink, but rather as covering your own ass.
"Poor man’s fix: you can also set up a million fans stack the shirts all over the place and cool off the shirts before stacking them. This is a desperate move (you are printing at night and don’t have any other ink) or a dumb move (time is money too, don’t cheap out on buying the ink.)"
-
We have had this problem as well, the only sure cure is what has already been said, cool them before stacking. I have noticed that the poly shirt hold their heat for hours.
-
One of the biggest issues that printers face in working with synthetic blend shirts and performance wear garments is the narrow processing window between hitting the correct temperature to fully cure the ink, and avoiding the maximum temperature that the garments can take before they bleed. Couple this with the temperature variations that occur in most of the drying equipment that we use for either flashing between colors, or the oven to fully cure the ink and you can see the tightrope that screen-printers need to walk.
A standard plastisol ink needs approximately 320 degree F all of the way through the ink layer to the garment interface to achieve a full cure, which is just about the same temperature that some of the dyes used on these synthetic garments become unstable. You didn’t mention what type of ink that you’re using, but you might consider looking at a purpose designed ink system that cures at a lower temperature as an option to help build in a safety margin between achieving effective cure, while avoiding heat induced bleeding / sublimation.
-
I just did some nike dri fit tees with rutland super poly white. It was a breeze to print and there were no issues. I think it is very important to have the right supplies. Sure you can plow a field with a pool cue but do you really want to?
Now that said, the super poly white is AWESOME!!!!!! I printed it through a 156 and it was truly a one hit white. I called rutland to see if I could use the same white on my cotton tees. I tested and it printed just as well on 100% cotton. I was told that the ink could gas into the 100% cotton tees the same as in the discussion. Has anyone ever tried/experienced this on cotton?
Matt
-
Interestingly, the first ever heard of this ghosting on shirts stacked above, was when certain 50/50 low bleed inks were used on cotton.
-
Everyone is on the right track. :) A low cure ink is a good option to fix the issue, as is changing to a peroxide based white. The bleed resistant chemistry in the white is reacting with a yellow dye in the garment. If you change the bleed resistant chemistry to peroxide based, then you can eliminate this from happening. So, if you ever fear ghosting may occur that is the full proof answer. Of course, you can use the fans, alternate stacking, etc.