Exactly how long does plastisol have to remain at 330 degrees to cure?

[Mark @ Hurricane Printing]

I've never been 100% clear on this, and I never had any problems with images washing out. I've always wondered exactly how long plastisol has to remain at its cure point. I see these real little conveyor dryers and think there is no way a shirt can go thru there and reach 330 degress for no longer than a second or two. I have read things where it states that the second plasticol reaches 330 degrees plastisol is cured,,,then I read it has to reach 330 degrees and remain there for 30 seconds or more.

So whats the bottom line on this?

I have an 8ft drier and my heat chamber is about 42 inches long....images hit 330 about half way thru the chamber and max out to about 380-400 right before it exits....from the point it reaches 330 to the time it exits is about 10 to 13 seconds...like I said I never had one problem with an image washing out but it makes me wonder if I can speed up my belt a little bit.

[bimmridder]

To the best of my knowledge, the entire in thickness has to reach "320" for a full and proper cure.

[whitewater]

Roger Jennings gave me a tip..it should be under go through the dryer for about a minute.if i remember correctly...which for the small dryers i would have the shirts folded in half so as to fit more on the belt..so if its going in there slow it is baking the plastisol though..this would be good on an underbase print, but on a white tee or something it would probably go through quicker and the ink deposit would reach cure temp..

[Socalfmf]

it is suppose to get to 320?

[GaryG]

With Brim here - once the whole film thickness reaches 320, the ink has "cross linked"
and is fully cured. Past 350 (temp gun may read higher due to reflection, angle etc.) and starts to re-melt and weaken.
Gaging that temp is a whole other topic. Donut probe embedded in the ink is most accurate, but temp gun I think is most widely used. Wash, wash, wash...
 

[tonypep]

Thats right we have washers and dryers on site for this as well as for distessed applique. Retention time can vary between our dryers. We have pre-sets for pls and DC but still washtest

[prozyan]

The ink doesn't have to sit at its cure temp for any amount of time.  Once it reaches the cure temp, it is cured, period. 

The misconception comes from the fact that most people simply measure the surface ink temperature, which could very well be a higher temperature than the ink that is in intimate contact with the garment.  It is like cooking a large roast at high temperature.  The outside might get done or even burned, but the middle stays raw.   

[inkman996]

Roger Jennings gave me a tip..it should be under go through the dryer for about a minute.if i remember correctly...which for the small dryers i would have the shirts folded in half so as to fit more on the belt..so if its going in there slow it is baking the plastisol though..this would be good on an underbase print, but on a white tee or something it would probably go through quicker and the ink deposit would reach cure temp..

Rogers a good man but a minute? No way, if we had to wait a minute on our oven we would print as slow as manuals.

We print at full production speeds on a small electric 54" wide no problem. Wash test all the time for safety, we would do that even if we had a gargantuan oven as well.

[bimmridder]

And I'd guess manufacturers build in some "cover my a$$'' latitude as well. I doubt it would be admitted to, but it's there. Wash test is best. Document

[Frog]

When folks like Roger Jennings or QCM ink state a time like 30 seconds or a minute, I think that they are trying to cover for the folks who may not otherwise get the entire layer uniformly and consistently to cure temp.
I'm almost sure that it is merely insurance.

Though I'm sure that it happens, in my experience, I have rarely seen overcooked ink, but have seen plenty of undercured prints.

And of course, 330 is not the cure temp for all inks.

[alan802]

We set our dryer up so that the bottom of the ink deposit hits 320 with about 2' left in the heat chamber.  We have never had an undercured garment.  I do have the luxury of having a donut probe built into our dryer that helped us baseline everything which I know most people don't have that ability, but a $400 donut probe wouldn't be a bad investment for you guys who are way over-curing your garments.  Just the electricity or gas savings alone would pay for the probe within the first year.

[tpitman]

I shoot my laser gun up inside the tunnel, keeping the belt slow enough so the ink temp is at around 330 for 10 seconds or so before the temp starts to drop near the exit. Then a stretch test. I also try to keep the ink layer as thin as possible.
The only ink I've ever had trouble with was gold shimmer from Union. The first time I used it I watched temps as usual, did a wash test, and it washed out.

[Frog]

Ad of course, the tech sheets on metallics and shimmers do warn that the reflective nature of the inks will require an increase in either heat or dwell.

[abchung]

I think I have to agree with Roger Jennings, unless my donut probe is wrong.
It does take about a minute for the plastisol ink at normal thickness to reach 155 or 160C if you don't want your oven to be too hot. I tried to raise the oven temperature to make it rise quicker, but the ink temperature hits around 170 C towards the end of the tunnel.  By the way, I use an infrared oven.

We sometimes heat press wet plastisol, usually we press it for 30sec. Once we pressed it for 10sec for a thin layer of ink.

[inkman996]

I think I have to agree with Roger Jennings, unless my donut probe is wrong.
It does take about a minute for the plastisol ink at normal thickness to reach 155 or 160C if you don't want your oven to be too hot. I tried to raise the oven temperature to make it rise quicker, but the ink temperature hits around 170 C towards the end of the tunnel.  By the way, I use an infrared oven.

We sometimes heat press wet plastisol, usually we press it for 30sec. Once we pressed it for 10sec for a thin layer of ink.

Guess that means all the millions of shirts we printed for fifteen years are under cured.