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

[Sbrem]

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.

This will depend on the size of your dryer. A bigger dryer will let your shirts stay in longer. I've always felt that a dryer shorter than 8 ft. is an invitation to trouble, you have less latitude. Like with a microwave, your food will thank you if you heat it a little slower than full blast... and for those wanting to try out the water based stuff, a larger dryer with convection (gas) is very helpful.

Steve

Steve

[Colin]

Bottom Line on Plastisol Cure temps and time:

Entire!!!!  Ink layer needs to reach 320 degrees, which is the common cure point for plastisol ink.  If that takes 2 minutes, it takes two minutes... if it takes 30 seconds, it takes 30 seconds.

Once the resins have fully absorbed the plastisizers in the ink, it is cured.  Science is pretty dependable this way.  Yes you can get the plastisol to hot.... but it takes a lot of heat to do that and if you are doing that, your shirts are scorching first.  Heat stabilizers are added to all inks.

HOWEVER!!!!

The longer plastisol ink is at it's cure temp, the better it's ADHESION is.  This really should only be applied (possibly) to athletic garments since they go through a beating during play. 

Just something to think about.

Edited for typos lol

[Homer]

is it possible to over cure plastisol?

[inkman996]

Thanks Colin spot on.

My issue with Rogers statement of one minute is its irresponsible to tell anyone how long any ink in,an oven needs to be period. All ovens are different and all settings are set up different. Everyone's shop has different air flows from one another.

The responsible thing to say is test test test! Find the set up and settings that works for your particular environment and oven. Then document everything and always be diligent and test often.

Steve is correct with a less than eight footer we have to be more than precise on our heat and belt speeds, the latitude is quite small. A tiny adjustment on our belt speed can make a huge difference.

Like I've said before we wash test often, I take strike offs home all the time and rotate them in my washer. Always concerned some day a bad wash will show up but so far our latest oven is rocking.


P.S. if I ran a thirst through my oven for one minute I would have a smoking mess.

[3Deep]

Yes!!!!!! I've did it before on a spot heater, that stuff will bubble up like crazy, and your shirt is just about burn, kinda hard to do but it can happen.

Darryl

[whitewater]

The dryer i used for my manual, yes it was small jennings..so he probably did mean for that particular dryer..

Now i have a Fusion 4 panel and the shirt is in there for like 20-30 seconds, but is twice as long..

but  there is different airflow in my shop all the time, if we have a window open or the door open and we always have to check for curing all the time , we dont assume..so we have to adjust...

we dont speed it up to much because we want it in there to get the whole deposit cured..

[Admiral]

I use 19 belt speed for plastisol on tees 12 feet heat sprint 2000

which means about 38 seconds dwell, temp is at 363 on the dryer

if I wasn't using gas I would aim for a longer dwell for sure though

[hilljob]

i just recently bought a vastex d-100 and this lil thing is awesome,, i have it set to take about 1 min 3 seconds for the shirt to go from one end to the other,,it reaches 330-340 no problem...for someone that is just starting out and i was using a flash cure to cure,, this was the best investment i made so far

[Dottonedan]

Ught oh, sounds like he's hooked. 


Don't worry, if you keep at it, you will be amazed at all of the growth and fun new toys you will be buying. Upgrading will seem to never stop.

[Prosperi-Tees]

Yup that's the fun and bad part of this business. Buying what suits you now, upgrading when you outgrow that to something you need then and then do it all over again. Its a vicious cycle.

[alan802]

instantaneously once the entire deposit reaches it's cure temp.  Plastisol doesn't have to be at a certain temperature for a length of time, just has to reach that temp that it was made to cure at.  Most plastisol inks these days cure at a lower temp than 330.

[JBLUE]

Alan that is not 100% true. For Example Quick White from Wilflex does require a longer dwell at the curing temp of 320. Just getting there is not enough.

[GKitson]

instantaneously once the entire deposit reaches it's cure temp.  Plastisol doesn't have to be at a certain temperature for a length of time, just has to reach that temp that it was made to cure at.  Most plastisol inks these days cure at a lower temp than 330.

That blanket statement is kind of like saying all screenprinters are aging, ponytailed, balding, wanna be hippies, who bootleg tye-dyed Deadhead shirts in the parking lot before they get stoned at a GD concert.  While it may be true in many instances, there are exceptions.

The plastisol ink guys should chime in here but some of the 'newer' plasticizers require being "held at cure temp" to allow complete conversion to washfast solids.

Ink guys where are you.....

[alan802]

Alan that is not 100% true. For Example Quick White from Wilflex does require a longer dwell at the curing temp of 320. Just getting there is not enough.

From what I understand about how plastisol inks work, once they reach the "magic" temp, the cure process is finished and there is no need for an extended dwell.  The ink goes through 5 stages and the final stage is when the resins completely absorb the plastisizers at the proper temp for that to take place and viola, ink cured.  I'm sure there is a given amount of time for that absorption to take place but the absorption process is happening at the same time the ink film is being heated and the final stage and all the plasticizer is absorbed at the right temperature, the cure temp of that specific ink.  So I guess it depends on what your definition of dwell is.  I'm not suggesting that we find the exact time an ink deposit reaches it's cure temp and then yank it out of the dryer.  For example we set our dryer temp and belt speed so that our ink reaches 320 with about 2-3 feet left in the chamber for the shirt to remain under that heat to insure proper cure.  Now it could be argued that we are in fact submitting this garment to a "dwell" but again, we're splitting hairs.  What Wilflex is saying sounds like the absorption of the plasticizers takes longer and requires a more significant dwell time to insure proper cure, ink has changed chemistry so I'm not really arguing against anything but again, probably a matter of opinion like what "is" really "is".

This is from a Richard Greaves article from years back, so it could be outdated with the new ink requirements:  "As plastisol ink is heated, its resin particles simultaneously expand and absorb plasticizer. Full fusion is reached at approximately 320F."  And from Union and International Coatings: "Once the entire ink film thickness reaches the proper temperature, the ink is fully cured."  Perhaps Wilflex is providing a "cover our ass" with the additional dwell, or the new chemistry of their inks require a longer time at a certain temp for the resins to absorb all the plastisizers...I don't know.  Things change, the chemistry of plastisol inks has really changed the last 5 years so perhaps there is something to the need for plastisol inks to dwell at the cure temperature now but I haven't read anything that goes into specifics about the need for a dwell so maybe an expert can chime in and clear up any misinformation.

[alan802]

instantaneously once the entire deposit reaches it's cure temp.  Plastisol doesn't have to be at a certain temperature for a length of time, just has to reach that temp that it was made to cure at.  Most plastisol inks these days cure at a lower temp than 330.

That blanket statement is kind of like saying all screenprinters are aging, ponytailed, balding, wanna be hippies, who bootleg tye-dyed Deadhead shirts in the parking lot before they get stoned at a GD concert.  While it may be true in many instances, there are exceptions.

The plastisol ink guys should chime in here but some of the 'newer' plasticizers require being "held at cure temp" to allow complete conversion to washfast solids.

Ink guys where are you.....

I guess my use of "instantaneously" was not in the right context, and perhaps my understanding of what I've read from the ink guys is not entirely correct, but when I read what Richard wrote many years ago that's what I took out of it.  And again, we all know how the ink manufacturers do like to cover their ass since we know that their recommended cure temps are quite a bit higher than what they actually cure at, so perhaps this new dwell recommendation is a product of that as well.  Again, like you Mr. Kitson, I'm awaiting a more clear statement from someone who knows more about it than I.