Cure problem all the way. After you cure a shirt, do the 'stretch test'. Grab the design on either side and reaf on it.
Is it rubbery? Good.
Did the ink separate from itself (split)? Undercured.
Did the shirt rip? You either pulled really darn hard, or it was overcured and burned the substrate.
That's right Richard...I almost forgot that one...I always rub a small part of the inside of the shirt on the print to see if it is cured. Even after all these years.
So there you go Steve...if the ink dosen't rub off, your good to go. And that is one of the first "Rules of thumb" that a screen printer learns...
.
__________________ At the edge of our dreams lay the ideals of true creation.
I'm afraid not. From the information I've gathered, once you've started the chemical reaction and concluded it, it can't be re-initiated.
Quote:
Originally Posted by Union Ink
Curing plastisol inks is a matter of exposing them to the proper amount of heat for the correct length of time. Correct curing of plastisol ink is extremely important. The most common problem encountered with plastisol inks is poor washability. In almost every case, this is due to incomplete ink cure.
When plastisol is heated, the resin particles absorb the surrounding liquid (plasticizer) and swell, merge with each other and form a tough, elastic film. It is generally impossible to overcure direct prints because the overcure temperature is above the scorching point of the garment. However, it is not recommended that you heat the ink layer above 350º F (176º C). Above this temperature puff inks fall like a cake when you slam the oven door, and problems with dye migration are greatly increased. If the entire thickness of the ink is not brought to the correct curing temperature the ink will be under-cured (the resin has not absorbed all of the plasticizer) and the ink will crack and flake off the garment when washed.
Plastisol will start to become dry to the touch or gelled (also called semi-cured) between 180-250º F (82-121º C). It becomes fully cured between 280-320º F (138-160º C), depending on the type of plastisol. The temperature at which the ink becomes fully cured is called the fusion temperature.
I beg to differ....you sure can run them through the drying cycle again. I've done it many times for over twenty years and plastisol is the same now as it was then. If it has not cured all the way....it can still yeild the same chemical reaction with heat to fully cure it.
And I have never heard of "Pulling the ink off" when trying to cure the ink a second time. That might happen with a heat press, but not a flash or conveyor dryer.
.
__________________ At the edge of our dreams lay the ideals of true creation.
Last edited by Greg Hamrick; March 22nd, 2007 at 03:47 PM.
Let me not recind my previous statement, but add to it based on information provided by a Wilflex representative:
"In general, undercured inks can be fully cured at proper temperatures within a couple of weeks of the original processing date provided the garments have not been washed. The best thing to do is to attempt re-curing and wash testing on a few of the suspect garments to confirm good results. Then process the entire run under the same conditions."
So basically it's possible, but time-sensitive. This could explain why it never worked for me, but worked for Greg. I'm willing to bet the time-frame is more like a week, rather than two...
As for 'pulling the ink off' you are being too literal Greg, but it's nice to know you are reading everything. My reference was that it aided in ruining the quality of the previous cure. My experience has been that it causes cracking and deviations in the ink, a separation from the substrate.
i have re-cured them again. it was that or buying more and re-printing. it may be a half measure but the punter already has them now. i will replace any dodgy ones.
i noticed that the ink was a bit powdery to the touch before the re-curing but didn't seem to be afterward. i rubbed the t against the print and stretched it a bit and it seemed better.
i also washed one and that seemed better. maybe it's a selective perception problem. anyway i'll soon find out.
for future reference i spoke to someone in the know about the sericol super opaque white; and they said that 90% of people have problems with that particular product. apparently it has to be cured longer at a lower temperature for best results.
experience is a great teacher. many thanks. interesting quotes above. i think i'll try curing for longer with this next time.
plasticol white on black probs uk 
