Trying to understand my dryer (Radicure)

[Gilligan]

Ok.. so I've been trying to wrangle proper belt speed and such and we are struggling.

Donut probe isn't consistent and I want to trust it but sadly I've heard it's not good for infra red.

So we have been stretching and using non contact gun. Results stretch fine gun shows 430... we've sped up the belt for poly's. We've had bleed issues when running non poly inks on poly.

So I said f it I want this right and ordered a pile of thermal strips. 5 step and 8 step (8 goes to 390).

Threw a red cotton shirt on the belt and an 8 step, because I knew we were cooking them too hot.

Comes out the dryer untouched... 290 didn't register... had to run it through three times to get 330 to be black.

Pulled out a 5 step strip, thinking maybe these aren't good for this, same thing... photo to follow.

Ran it through the second time and got a few to go black. Pic following.

We've printed shirts for my wife's company and the girls wear them daily. Washed at least 4 times probably twice that. No signs of problems and not a single call.

Dryer is running at 1050, belt at 13 which equates to 30 seconds in the tunnel and panel height is 6".  3 panel 6' tunnel on the 2009 Radicure.

Shirts are streaming coming out the tunnel and even the cotton shirts are hard to handle. I bought gloves to handle the 50/50's and poly shirts as they are impossible to handle off the belt. Never had shirts that hot coming off the Chaparral and we never had under cure issues EVER.

[Gilligan]

Pictures as promised.

[Gilligan]

2nd time proof.

[Gilligan]

*crickets*

[blue moon]

slow down the dryer! Use the temp gun as it should be pretty close. try not to go over 350!

pierre

[GaryG]

Yes temp gun at consistent height and angle. Wash test, of course you know these.

*crickets*

These fry nicely well below 350. 

[Orion]

Maybe the labels are beyond their expiration date, I think 2 years is the max. Also the are to be stored in a cool dry place, preferably refrigerated.

[mimosatexas]

I'm also using an infrared dryer.  My shirts dwell for just over a minute in my tunnel, and I have the baffles pretty low.  I get my temp gun right up to the exit baffle and test about 8 inches from the baffle, on both sides and in the center of the belt.  Sides are always hotter by about 10 degrees in my dryer for whatever reason.  My exit temp is 330-335 on the shirt in the center.  Never had any curing issues and I only adjust on problem colors and low/no cotton stuff.  Discharge is a different story and I have forced air etc.

[Gilligan]

slow down the dryer! Use the temp gun as it should be pretty close. try not to go over 350!

pierre

P, we are temp gunning them at 430 now!  So slowing the belt down doesn't make sense if I'm trying to not go over 350. :/

Maybe the labels are beyond their expiration date, I think 2 years is the max. Also the are to be stored in a cool dry place, preferably refrigerated.

These were JUST purchased straight from the manufacture, not a supplier.

*crickets*

These fry nicely well below 350. 

LOL

[Frog]

A couple of things, though neither solves your problem:
1.Back when I cured with a four foot Scamp, I used these strips, except that I used them on the inside, to really assure me that the bottom of the ink layer was cured.

2. With you being a tightwad (like me lol!) I can't believe that you are using those things full width! I always cut them down the middle to double my stash.

[Gilligan]

I paid only $10 bucks a pack (16 to a pack)... I'll probably cut them later, thanks for the tip!  I just didn't want to introduce variables.

On Pierre's suggestion I fired up the heat press to test these strips.

So... didn't REALLY solve anything, just added more questions.

RESULTS:  At 320 on the press for 30 seconds the strip was showing a partial 320 (50% blackened) the digital read out had dropped to 316 as the platten/shirt was sucking the heat away from the platten in that 30 seconds.

ALSO: I ran two temp guns at the press the whole time it was heating up.  Showing fairly accurate temps (given the reflective nature of the element).  I would press it down for 30 seconds and shoot the platten as soon as the element would lift and it was almost on the nose temp wise there.  So I was pretty confident.

THEN: put a shirt on and did the same as above and it showed WAY lower (270)... but the strip still showed 320 underneath a teflon sheet with 30 seconds pressing.

SO: as I said, no real answers just more questions.  Yes the strips are activating at the right temp and yes my heat press is still rocking and rolling... furthermore yes my temp guns are both working (withing about 15 degrees of each other at the 300 mark)... BUT the questions are still, since EVERYTHING is still technically working why does my temp gun show 430 while the strips aren't being even lit up at 290.

*sigh*...I guess I will call the company tomorrow to see what they say about those strips.  They are meant for screen printing according to their site. 

Pierre is thinking that with the amount of air flow the Radicure moves that maybe the air in the chamber is getting up to temp as well.  I'm thinking about dropping in a oven thermometer that I have laying around if I can find a place to put it (I just figured out how I'm gonna do that!)... I'll also attache a temp strip to it as well.  This will be hanging down in the empty panel spot so it won't have any direct IR.  I don't expect this to hit actual temp that the garment will see... but I'm curious as to what it will see.

[nobrainsd]

The temp strips have more thermal mass than your t shirt material. They heat up at a different rate. The infrared temp gun also measures over a small area rather than just under that laser dot. So, unless you are aiming at a larger printed area with a relatively thick ink deposit the temp strip nor the infrared gun are a true indicator of ink layer temp and the test strip is definitely not going to indicate the shirt material temp (which will be higher than the test strip).

I'm generally printing thin layers of ink and a lot of the designs don't have large printed areas to shoot at, so I'm essentially monitoring the shirt material temp and inferring what the ink layer temp is. Printing poly sucks when you have to go as low in temp as you can. Slowing down your dryer and lowering the panel temp helps because the rate of change is slower and it gives you more latitude. It's easier to hit a sweet spot in temp and time but at a production cost.  I personally don't know how to set my dryer at it's lowest cure temp without wash testing.

[blue moon]

The temp strips have more thermal mass than your t shirt material. They heat up at a different rate. The infrared temp gun also measures over a small area rather than just under that laser dot. So, unless you are aiming at a larger printed area with a relatively thick ink deposit the temp strip nor the infrared gun are a true indicator of ink layer temp and the test strip is definitely not going to indicate the shirt material temp (which will be higher than the test strip).

I'm generally printing thin layers of ink and a lot of the designs don't have large printed areas to shoot at, so I'm essentially monitoring the shirt material temp and inferring what the ink layer temp is. Printing poly sucks when you have to go as low in temp as you can. Slowing down your dryer and lowering the panel temp helps because the rate of change is slower and it gives you more latitude. It's easier to hit a sweet spot in temp and time but at a production cost.  I personally don't know how to set my dryer at it's lowest cure temp without wash testing.

this! That is the reason I said to slow the dryer down. Try going back to 10" of height and longer dwell times. . .

pierre

[Gilligan]

I think it maxes out at 7.x" of height... I know it doesn't go much higher... maybe 8.x".

I can turn down the temps for sure, will probably save me some money.

[244]

I think it maxes out at 7.x" of height... I know it doesn't go much higher... maybe 8.x".

I can turn down the temps for sure, will probably save me some money.

set your panel height to 4" and adjust your temp to 950 with a 30 second retention time. That is a good starting point.