[urbanpirate]

I’ve been printing using Permaset Supercover inks for the past 3 years. No major problems, but a customer has just been in touch because the T-shirt he bought has the ink staining the other part of the design.
It’s a two colour design, white and blue. Printed and head pressed, 2 x 20sec at 180°C. No problems with design washing out etc. But this guy put his t in the washer at 30° and noticed that some of the blue as stained the white.

It looks like in the wash it’s folded onto itself and some blue has transferred to the white. Is there anything I can do to stop this from happening again??

 

[TABOB]

I’ve been printing using Permaset Supercover inks for the past 3 years.

Printed and head pressed, 2 x 20sec at 180°C

Have you read the instructions?

With 180°C for 40 seconds the print may look OK, but it isn't, especially when you are using retarder.
The retarder is Glycerol and does not evaporate, so you have to give it time to cross-link and become part of the ink.

Many people cure water based inks for 60 seconds or so, but it's not the right way.
I also cure water-based inks for 60 seconds, BUT I use a catalyst.
For some reason Permaset inks do not not have a catalyst option.

Low and slow is much better.
I would suggest 160°C for at least 3 minutes, even if it feels that it is not required.

 

[urbanpirate]

Yes.... I read the instructions. You'll note that 180C isn't listed and they are guidelines not rules. You'll see that the time gets shorter the hotter the source....hence 40 secs at 180.

160 for 3 minutes on a heat press would most likely burn the shirt....so I don't think I'll try that. After all, this is the first, and only, issue I've been informed of regarding this issue and no design washes out with my process, so why change it that radically?

I don't use any retarder, only water.

I guess what you're saying though, is that it's not been cured long enough??

 

[TABOB]

160 for 3 minutes on a heat press would most likely burn the shirt....so I don't think I'll try that.

It will not.

I don't use any retarder, only water.

The ink does contain retarder already.
Additional retarder would increase the curing time by 20% .

I guess what you're saying though, is that it's not been cured long enough??

That's what I think.
You are of course free to do your own tests.

 

[NoXid]

I cure Permaset for 60 seconds at 340 with a heat press, all one pressing, no lifting. I used to do two 45 second presses with a lift inbetween. The instrcutions assume a conveyor dryer, not a contact heat source. For other inks with much greater resistence to drying in screen (like Green Galaxy), I cure for 2 minutes.

That said, 180C (356F) seems a bit on the high side. I'd cure longer and well away from 360F.

And all that said, my prints are flashed on press before ever getting to the heat press.