Too much heat

oh yea what about multiple prints on a shirt where you have to run the shirt through 2 or 3 times....
how does this effect the shirt strength

the shirt is ripping when you do the stretch test?

I have run the dryer hot before and never seen an issue like that.

Are you using quality shirts?

Holy lord BZ 412 is too high!Your t-shirt is ripping because its FRIED. If your using plastisol 320 for 30 seconds in the chamber is all you need.Waterbase 350 for 60-90 seconds.
As to the multiple prints everytime you run the shirt through it gets a little drier,so not to scorch the shirt you drop the temp a little because it doesn't take as much heat to get the ink up to temp the second and third time.
Alot of people do not take this into consideration but your blank t's have alot of moisture in them.Look at the tag and see where they are manufactured.Is it a tropical enviroment?Sitting on a loading dock in boxes made of paper soaking up the humidity?Little stuff like that effects your cure time and temp.
Also overcuring will crack the ink film just like its undercured.So you can have to much of a good thing.Do lots of tests.

Yeah you are using to much heat. I just recently bought a small VASTEX conveyor drier which is 4 ft long with one chamber. . . and this little dude only takes 30 secs and it is completely cured.

As mentioned before you have to take into condideration the environmental conditions as well. I live in humid SA TX which is adding moisture to the shirts which it affects the drying time. So compensate for this I bump the temp down a tad and add some chamber time.

With a little testing here and there you will know when to do this or not. Keep a spiral around and make notes of things you tweak in your shop. This has been a life saver for me.

yea i like that "FRIED SHIRTS"
i do cure at about 325 but i never thought about dropping the temp for 2nd and 3rd locations (thanks 4 thetip)

iwas just doing some tests to see how heat breaks down a shirt and it sure does ....i would say anything over 375 is a bad thing

oh Gildan Ultras made in honduras .
GET YOUR FRIED SHIRTS HERE!

Ha funny BZ, glad I could give you the tip.

BZ, get you an inferred heat gun and when the shirt comes out of the dryer check the ink temp. (as close to chamber of dryer as you can get) if its 325 its cured. Sometimes the dryer display is not a true temp. Maybe next year I'll sell Fried Tee Shirts at the State Fair...lol

yea i do use a gun

i was just testing around burnin shirts

This is how it goes.Front print 320 for 30 seconds. Back print lower the temp a little because the shirt will get hotter and the ink gets hotter faster.Sleeve print lower the temp a little more.Walaa-no scorched shirts.3 locations.Just to make it a little clearer.

standardgraphics said:

what do you know about?:

conveyor dryer final cure i was doing some tests
and like to make sure everything is cured for sure

so i bumped up the temp. (reading 412 on the temp. gun)

when i go to stretch the print ... the shirt rips easy

so what is the magic temp. ?

(does even the norm 320 deg weaken the shirt)

i run a tiny 6 foot (4' chamber )

Click to expand...

definately too much heat, the magic number is at least 320 on the print as the shirt exits the dryer, allow 90 seconds minimum for a good cure, that means only you will know what setting to use on your dryer after you do some experimentation.

Hey squeege, 90 sec for WB, 30 for plastisol.Otherwise you overcure and the ink will crack just like its never been cured.

INKFREAK said:

Hey squeege, 90 sec for WB, 30 for plastisol.Otherwise you overcure and the ink will crack just like its never been cured.

Click to expand...

if you say so INKFREAK, but i've been printing plastisol for 14 years and believe what you are saying is simply not true.

I cure at 320-350 on plastisol for no more than 30 seconds- need to go faster or get a bigger dryer, but I don't have any wash-off or fading issues.

If you use a thermoprope (ex. Atkins brand) and set it down on wet ink it will tell you at what point in your dryer the ink is reaching 320+ (for me at least 90 sec). Better to have ink reach 320 3/4 of the way through the dryer then at the very end because you know the day will come when a breeze or some other freak occurance will send your dryer's temp down unexpectedly.

It's just my opionion that 30 seconds as a guideline for cure time may not be the best advice. The correct time depends on your environment, your equipment and your given combination of ink and garmet.

See page 2 of this user guide from Rutland ink:

http://www.rutlandinc.com/screen/downloads/brochures/userguide.pdf

Sqeege,got 11 more years on you.I read my tech sheets all the time.They make me yawn after 25 years but I still read em.All depends on what plastisol your using .I'am talking about mine with NO additives.

Read page 2 on the link in the section called fusion.I understand that it takes the shirt a couple of seconds to reach 320 however the info says if you overcure it will crack and fail as if it were not cured.
So my standard rule of thumb is 320 for 30.I don't want to be right , just happy.And eating jobs gives me heartburn.

The user guide states that 1 minute is the required time for fusion + the time to achieve the proper temp, as shown in the graph. The guide also states you should not speed up your time for the sake of production speed. This would be particularly important for those with small dryers that suddenly get a large order requiring speed.

Just saying your 30 second rule may not be good advice for everyone...

Teeny tiny dryers yeah.But overcure is as bad as undercure.Please don't advocate adding additional production costs unless they are necessary.Time is cost,and its alot more expensive then ink.I've had large forced-air , small IR dryers and large IR dryers.Four-foot chamber,yeah,it goes really slow.
I do not sacrifice cure for the sake of speed I compensate by raising the temperature to account for the increased mass.Which in turn makes the first two of three shirts into sacrificial lambs ,but I usually just throw some test shirts in first to absorb the initial heat blast.
I have a four foot wide belt on my current dryer.I have a two foot wide short dryer for emergencys .In the past I've had 6 foot wide belts.The only thing that I cure a minute or more is WB. We do cure tests through-out the day because quality is extremely important.