Heat Press marks

[nick001]

I need a little help but not sure who to ask. I have screen printed some shirts. I had received feedback from a few customers that have said the ink on the shirts was peeling off. After doing some research found that my shirts were not curing all the way. I had only used my Ryonet flash dryer to cure them. I believe the heat was hot enough, it was just not distributing the heat evenly across the design. So my back up alternative was to use a heat press. I use a heat press at 320 degrees for about 10 seconds with light press, not locking it down just holding it down. My problem now is that the shirts have a square heat mark where the press was. My kids shirts, I've washed them over and over and it eventually disappears, sometimes. But this is not something I want to present to the customer with a big square mark from the heat press. I've tried this with and without non-stick sheet and it still happens. And it happens on most fabric. How do I cure these shirts without the heat press mark? I'm using the Lava inks from Ryonet. And it could be any combination of white or white with colors. Most of the fabric I'm using are the A4 brand polyester, Bella+Canvas shirts, or Gildan brands. I've tried putting a teflon pillow inside the shirt with a non-stick teflon sheet, or non-stick fabric sheet, and even parchment paper on top of the shirt and I still get the marks. Maybe not as bad but they're still there. Any help or suggestions would be greatly appreciate.

[Chuggins]

Hi Nick!

Pressure marks on a shirts are always a hassle. It can also get worse when you are dealing with poly blends or 100% poly garments.

Under heat and pressure, the synthetic threads can get a little flattened, creating a glossy surface that you cannot get rid of, even with repeated washing. This is more pronounced when using a stampinator, iron, smoothing screen, etc. But worse when using an actual heat press. This does not happen 100% of the time, its mostly on the more inexpensive fabrics. Even going to very light pressure can create a light gloss on some of the synthetic fibers.

As for 100% cotton or more heat stable synthetic fibers, you can spritz the fabric with water and run it through your dryer. The steam will fluff up the natural fibers, removing the pressure marks. Conversely, you can also use a handheld steamer to remove the press marks. You have already seen these effects from when you washed garments that had the press marks.

[kimmiedp]

Hey chuggins will that tip with the spritzing or hand held heat steam also help with the polyester fabrics prior or post to pressing?

[Chuggins]

Kimiedp,

Polyester, with a couple of exceptions, does not fluff like cotton does. Also, during heat pressing, you can actually flatten the fabric/threads a tiny bit, causing a gloss.

So the short answer is no, it wont work, but you can always give it a try and see if you can diminish the effects. Typically you will put in a pillow to soften the pressure on the threads, but this still doesn't eliminate the core issue. Which is heat, time, and pressure on synthetic threads.

[beachgeek]

have dealt with some similar issues and have cut my temp down considerably for polyester while reducing the pressure on the press and adding 10 seconds to the time. . This is for sublimation only. I don't usually do plastisol transfers. I think you could get away with dropping to 300 degrees for curing and just add to the time.
I also have tried a trick I saw from one of my distributors and on sublimations I tear the paper so there isn't a hard edge which stops the outline of the paper. But you are mainly dealing with the press heat marks and cutting temp and pressure are the only two basic ways to stop that on polyester. the teflon sheets help too