sublimation white spot issue on white polyester shirts

[paul 44]

HI Folks, quick question..

I have recently come across this issue where i'm getting a blank spot on the printed t shirt after sublimating. I have recently swapped out the old heat platen for a new one that I had stored (chinese press)

You can see the white 3/4 of the way down on the E, I can also see the ink still on the paper.
I did a previous test print to this one and it was much worse as the pressure was crap really so i raised the base plate of the press to compensate, the images here are not as bad as the first but this was printed at pretty firm pressure.
I checked the platen yesterday as i had swapped it out and the temp in the middle of the platen was bang on (within a few degrees)

I'm using sublisure inks printed on the trusty Ricoh 3110, 60 seconds press time, firm pressure at 374 f (190 c) Chinese press (old platen swapped out for a hardly used one)
I'm gonna test again later with the old platen to see if i get the same

Anybody else had this?

[socialgiraffe]

It is most likely to do with uneven pressure.

Dye Sub is all about getting even pressure across the area you are printing.

I would take a look at the base plate to see if there are any imperfections in that or the top platen or teflon sheet (if using one)

[paul 44]

thanks for the response, I have a base of silicon rubber on the base plate , the heat plate has a teflon sheet attached, dosent seem to bad, slight ripple right in the center which is on the old plate which I swapped out, the new plate which also has a teflon sheet has no ripples and it was worse, old plate seemed better strangely enough. I may do another print tonight with yet more pressure to see how that goes.

[paul 44]

well a few prints later and same problem but only on some shirts, very slight but I know its there and can be seen.

Later prints were done at a higher pressure, everything prints ok apart from the center of the print, base plate and rubber mat are fine so im thinking its a heat problem but I find this a bit hard to fathom as i've used 2 different plates, one is brand new.

The only thing I can see is on the heat platen where the teflon sheet is attached, slight ripples but would have thought the high pressure would have dealt with that issue.

[webtrekker]

Try removing the teflon sheet from the heat platen and using a loose teflon sheet instead.