Dryer Settings

[ericheartsu]

I'm planning on cracking open my donut probe today, and testing different inks and garments through our two dryers.

Obviously each dryer is different, but what is the best retention temp. and time for standard plastisol and discharge inks?

I thought we had both nailed down, but I want to be 100% concrete, and create a log book for my employees to be able to set up the dryer based on the project they are printing! I was always under the impression that most plastisol (and discharge for that matter) needed to cure in the oven for 2 mins, at around 325 degrees.

If we bump our temp up, can we cure for less time in the chamber?

[Frog]

My understanding is that plastisol merely needs to reach a certain temperature, while waterbased and discharge ink also have to evaporate water.
Hence, there is no definite dwell time per se with plastisol, merely the 290-320 required for different plastisol inks needs to be met throughout the entire layer, however long a particular dryer and setting requires. Dwell times may be suggested to help assure that those conditions are met. I seem to remember QMC being the company that did give a time.

The waterbased and discharge inks I've seen usually require a dwell time of 90 seconds at 320.

[Croft]

get ready to pull your hair out with that donut probe

It will cause more questions than answers.

[Frog]

get ready to pull your hair out with that donut probe

.

[dirkdiggler]

pretty sure curing plastisol is a FUSION process, once the fusion happens its cured.  I believe most ink manufacturers say that's at 325 degrees, but its actually probably just a little less than that.

[Doug S]

get ready to pull your hair out with that donut probe

It will cause more questions than answers.

Agreed, I've used the probe and it shows a 20 to 30 degree difference then the temp gun.  The probe had me wondering if I had been undercuring all along.  It is good for finding out if you have cold spots in the chamber however. 

[Frog]

I can assure you that a probe, with its crosshairs embedded in the ink, is very likely reading 20-30 degrees different than the reflective nature of the non contact gun and its surface-only reading.

We learn to just use guns just as a relative reading, as it's not uncommon to see a momentary reading of 380 or more with a gun, just before exit to assure that the whole layer reached 320

[Gilligan]

I'd trust the donut probe.  That means you might have issues if you are on the edge.

[alan802]

What kind of issues are you guys having with the donut probe?  I had never used one until a couple years ago, but I can't remember there ever being any hair-pulling moments so maybe I can help?  Maybe there are some issues with trusting the probe reading?  There have been times when the probe didn't read hot enough for the ink to be cured but using the stretch and wash tests it was cured but there are a few variables that can affect the readings.  I do know that I don't have to worry if ink is cured or not when the probe temp reaches 315-320.  But with the temp gun I'm not near as confident.  We do use the temp gun as a spot checker because I've got the donut probe to cross-reference with but I regularly check them both against each other.

And there is usually a 30-50 degree temp difference between our probe reading and our laser gun reading.

[Printficient]

You should use the probe if you have one at every season change to map your dryer.  I used mine once every 90 days or so.  Also by once I mean a minimum of 3 times.  Once down the right side of the dryer, once down the middle and once down the left side.  I also would use it periodically when the belt was full of shirts.

[bimmridder]

Wilflex has a nice little pdf chart to map and log dryer temperatures.