How do I make sure I am getting a proper cure?

[im_mcguire]

NOOB Question I know.

I have been printing a bunch of shirts and sweatshirts, with no issue, and now, I just saw a test shirt a pressman of mine took home, and it is cracked, faded, and uncured fully.

I have a older American Tex Air 30, and do strech tests on all of my shirts, but I obviously am missing something.  I have a heat gun, and temp reads a little over 320.

My fear is that the way this dryer is designed, 6' chamber with hot air circulating for 4', and 2' worth of infrared panel.

Is there a good way to really test my dryer or infrared panel?  Maybe the panel is losing power or going out (it is almost 30 years old)

[Frog]

NOOB Question I know.

I have been printing a bunch of shirts and sweatshirts, with no issue, and now, I just saw a test shirt a pressman of mine took home, and it is cracked, faded, and uncured fully.

I have a older American Tex Air 30, and do strech tests on all of my shirts, but I obviously am missing something. I have a heat gun, and temp reads a little over 320.

My fear is that the way this dryer is designed, 6' chamber with hot air circulating for 4', and 2' worth of infrared panel.

Is there a good way to really test my dryer or infrared panel?  Maybe the panel is losing power or going out (it is almost 30 years old)

The one time, some years back, that I ran a job with a high failure rate, it was due to a draft from an un-noticed partially opened door. I learned my lesson. btw, I also run an older American dryer. Fact is, when I ran a four foot Ranar Scamp, which was nothing more than a flash panel suspended over a small conveyor, I was able to get full cure.
You mention using a gun and getting a reading of 320 (I assume a non-contact thermometer). What are you reading and where? With my "gun", I get a  peak reading of 375-400 for an instant just before a shirt leaves the tunnel. Your reading may be only measuring the surface of the ink layer, while the bottom remains uncured.
Most experts will remind you that only a donut probe with the wires embedded in the ink layer will give an accurate reading, but be warned that many also report that they have issues with these devices as well. They take a little practice.

[ScreenFoo]

Wash test.

Even better, print for hockey players.

[Stinkhorn Press]

my opinion, IR panels+conveyor=bad dryer.

not really addressing the issue advice: toss you IR dryer as soon as you can. GET a gas dryer. (bonus: it's cheaper to run at the moment).

If you're handy you can buy a gas dryer cheap.
If you're not as handy/don't have the time, you can still get a decent dryer in the building, installed, gone-over, vetted, for 10K.

[mooseman]

In my uneducated dumb thumb opinion 320 out isn't penetrating all thye ink you are putting down. Just like any problem you have to get to the bottom of things so i am thinking 320 out temps are leaving you a little short of a full through the ink cure.
Our tunnel out temps are in the 360 - 380 range, we print mostly 100 cotton and 50/50 blends . On 100% poly we drop to 340 right at the out throat of the IR dryer. We temp gun the first item through on ever job and catch another one every now and then jusy to be sure the heat is on so to speak.
I know this will get comments but we don't seem to have any problems
mooseman

[Prince Art]

I have a heat gun, and temp reads a little over 320.

How long is it hitting 320? If it's only for a few seconds, then mooseman is probably correct that you're not curing all the way through on some prints.

We have short IR 2-panel dryer. I try to hit about 20 degrees above the target temp under each panel. There's a temp dip between the panels, but by overshooting, it means we keep the whole print at cure temp or higher for probably about 30 seconds or more. I'm not sure how that translates to your setup; but it sounds like you've got to adjust in some way to make sure you're getting ink hot enough all the way through & sustaining it long enough.

Side note, re Frog's Scamp: We started with a tiny Black Body Lil Buddy, with a target temp of 350-380. We were safe even on triblend (no scorching), as long as we stayed below 380. Downside was that we had to run shirts through twice, 2nd time backward, to make sure we got a full cure all the way across all shirts. Now, we've got a somewhat bigger dryer, and we have to watch cure temps way more carefully to avoid both scorching & undercuring. Not sure I have a point in that tidbit, except that there doesn't seem to be much room for set it & forget it with curing. You've got to keep monitoring it. (At least with small dryers.)

[kingscreen]

Off-contact temperature guns are only reading the surface temperature.  So if it's only hitting 320 you're not getting a full cure.
Also, it should be noted that those guns, especially the cheap ones, are rarely very accurate.  If you're over-reading by even 5 degrees you're even worse off.

In your arsenal, you should have or look at getting:

- Off-contact temperature gun.
- Paper thermometer strips.
- Donut-style Thermocouple probe.

Do regular stretch and wash tests.

[ScreenFoo]

Off-contact temperature guns are only reading the surface temperature.  So if it's only hitting 320 you're not getting a full cure.
Also, it should be noted that those guns, especially the cheap ones, are rarely very accurate.  If you're over-reading by even 5 degrees you're even worse off.

In your arsenal, you should have or look at getting:

- Off-contact temperature gun.
- Paper thermometer strips.
- Donut-style Thermocouple probe.

Do regular stretch and wash tests.

I don't mean to imply I'm disagreeing 100%, but you could get a surface temp of 320 and be curing.  Low temp cure ink and a very long dwell in a lower temp dryer can surprise you.

I'd also point out that one of the downfalls of many inexpensive IR temp guns is the spot size.  At a decently long throw, the cheaper units have a huge sampling area which makes accurate measurements even more difficult.

[mooseman]

.
Yes this seldom gets mentioned, we tend to think the temp zone is the little dot we see whan we aim,  but the actual measurement footprint is highly influnced by distance and angle of contact.

To be consistant we always try to shoot the target at the tunnel exit  gun pointed straight  down  at a 90 degree angle directly at the ink deposit on the shirt and lastly try to keep the gun at tunnel exit altitude so we have a constant parameter reading for the out temp. whatever the temo it actually is at least it is REVIEWED if not actually reported in a constant way.
Lastly we started with a Fluke brand temp gun which some will agree is a better quality tool.
mooseman

[RICK STEFANICK]

I know that dryer well.. Turn the circulating air off and that will help you out.

[heray11]

 If there is a blower on the unit with a squrel cage, make sure its free of lint buildup. Poor air circulation can cause goofy stuff.
  Check the amp draw on the elem, The interioor wiring might be going bad.