Curing Plastisol Ink with a Heat Press
Posted: Tue Nov 24, 2015 4:03 pm
It took a bit of tinkering, but it is working well. It is less than quick, but good for folks who don't have the cash or space for a conveyor.
I flash well enough to get a solid gel cure for handling. Then, in the press, do NOT just squash the shirt!
Turn the shirt over so heat has to migrate through a layer. That slows it down and makes the process more gentle. (Protect against ink getting on the press just in case.)
Here's the key:
I close the press with no clamping - just barely resting on the back of the shirt. Put a light weight on the press handle if you have to, but *no* pressure. *Any* pressure on the shirt will mess it up.
For my gear, I bake for two full minutes (!) with temp set at 330 - 350 (which is about how accurate my press is) and I go off and do something else, like make another shirt. This temp is same as my transfers, a big reason I have come back to using this setting.
With my gear and settings, this does not 100% cure the shirt, but it comes very close. Your shirt should now be set up like a transfer, with ink that will not squish. If you are NOT getting this result at this point you need to tinker with settings and times.
===> You may be able to speed this up with a higher temp and get a total cure, but I want the next finishing step - I want to press it and I like not having to change my settings for transfers.
I do not press immediately - I let it cool a bit by waving it around in the air. I don't want the ink to be tacky at all.
Now to finish, under a teflon or parchment I press for 15 sec at 350, medium-to-firm pressure. The results seem perfect.
+++
By coming as close as possible to 320 before pressure and starting to press with cool ink, my shirts are withstanding a medium pressure to get to a full cure.
Yes - it is slow, but you can multitask (print or paperwork, etc) during the bake stage.
I have tested in a few washes with perfect results, and I am still washing the test sample every day as harshly as I can.
I flash well enough to get a solid gel cure for handling. Then, in the press, do NOT just squash the shirt!
Turn the shirt over so heat has to migrate through a layer. That slows it down and makes the process more gentle. (Protect against ink getting on the press just in case.)
Here's the key:
I close the press with no clamping - just barely resting on the back of the shirt. Put a light weight on the press handle if you have to, but *no* pressure. *Any* pressure on the shirt will mess it up.
For my gear, I bake for two full minutes (!) with temp set at 330 - 350 (which is about how accurate my press is) and I go off and do something else, like make another shirt. This temp is same as my transfers, a big reason I have come back to using this setting.
With my gear and settings, this does not 100% cure the shirt, but it comes very close. Your shirt should now be set up like a transfer, with ink that will not squish. If you are NOT getting this result at this point you need to tinker with settings and times.
===> You may be able to speed this up with a higher temp and get a total cure, but I want the next finishing step - I want to press it and I like not having to change my settings for transfers.
I do not press immediately - I let it cool a bit by waving it around in the air. I don't want the ink to be tacky at all.
Now to finish, under a teflon or parchment I press for 15 sec at 350, medium-to-firm pressure. The results seem perfect.
+++
By coming as close as possible to 320 before pressure and starting to press with cool ink, my shirts are withstanding a medium pressure to get to a full cure.
Yes - it is slow, but you can multitask (print or paperwork, etc) during the bake stage.
I have tested in a few washes with perfect results, and I am still washing the test sample every day as harshly as I can.