Author Topic: Ok... belt speed for curing (I know this is SOOO subjective)  (Read 5297 times)

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Ok... belt speed for curing (I know this is SOOO subjective)
« on: September 14, 2011, 02:07:15 PM »
But help me out anyway.

I have that Chaparral 24" x 12' dryer with a 4' tunnel.  It has 3 12"x24" panels.  Only 2 are in operation (one is brand new) they are the first two panels.  They draw about 12.5 amps each at 220v.

I have the panels pretty low... Umm, 3 inches would be pushing it.  The temp prob is in the panel itself and it's set to 975 (that's where the guy had it).

What belt speed should I be looking at to get a cure?  I know it depends on lots of factors... but the best I can give you is... Wet on Wet, black and red ink on a white shirt.  My shop is probably at about 75 degrees (give or take a few 73 at the lowest... hey, if you got AC in your shop why not be comfortable. :) )

I have cracked open the door and pointed a infrared gun right after the 2nd panel and the shirt would show anywhere from 270 to 320  Don't know why it varied.  I watched from the end of the dryer and I saw smoke coming off the print.  BUT every shirt (all 5'ish) didn't really pass the stretch test.  I know that stretching isn't the end all be all... but as ignorant as I am I try everything.  I took one of the ones that messed up and washed it.  Once and it looked fine.  We threw it back in the was again but I haven't seen what it looked like this time.

Any guidance?

I'll take pics of all the "parameters" when I get home tonight but I'd like to be printing when I get home... so any direction would be most helpful.


Offline ebscreen

  • !!!
  • Gonzo Member
  • ******
  • Posts: 4281
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #1 on: September 14, 2011, 02:31:19 PM »
As you're looking for a ballpark anyways (with washing being the be-all end-all) get you a
non-contact thermometer from an auto place or a discount tool store or whatever. They've
really come down in price since I bought mine 5 years ago, should be $25-$30 or so.
Aim for ~380 at exit.

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #2 on: September 14, 2011, 02:32:58 PM »
I have cracked open the door and pointed an infrared gun right after the 2nd panel...

Offline ebscreen

  • !!!
  • Gonzo Member
  • ******
  • Posts: 4281
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #3 on: September 14, 2011, 02:35:38 PM »
Sorry, missed that part. Switch the wiring so that the last two panels are in operation. Much
easier to gauge temps that way.

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #4 on: September 14, 2011, 02:50:36 PM »
True!  BUT, I'm not just wiring it that way for fun.  The last panel is "burnt" and I would have to swap the panels physically.  I'm just not in the mood to do that.

Though I did pull apart the 2nd panel (the one I replaced) and I might be able to fix it... I'll post that on my other thread though.

Offline Frog

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 13980
  • Docendo discimus
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #5 on: September 14, 2011, 02:53:12 PM »
That 380, by the way, may be for just an instant, an instant before they exit. With your sert-up, that will be a little tougher unless you can reach in to the point just after the panel which is now the last panel.
Of course, remember it's only ballpark, and in ballparks, only the infield is close to standard, the rest varies greatly.
That rug really tied the room together, did it not?

Offline jsheridan

  • !!!
  • Gonzo Member
  • ******
  • Posts: 2130
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #6 on: September 14, 2011, 02:58:31 PM »
If you do not have or have access to a donut probe or something to read the ink film inside the dryer.. you'll have to wash test to be accurate.

Set up a black print, preferably something with detail and cut up some white shirts into squares, about 6-12 of them.

Set the belt speed a little over what you think is cure... print and run test #1.. write on it with permanent marker what the belt speed was.

Slow the belt and repeat until you've used all your squares.

Wash them on heavy duty with rough clothes like jeans and see where the ink stops washing off.


Blacktop Graphics Screenprinting and Consulting Services

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #7 on: September 14, 2011, 03:01:06 PM »
LOL... ok fellas I don't know how I can type any better... I know I do get long winded and I know I do wear you guys out with all my pestering questions but I just quoted myself saying that I can crack the door open and reach in with the gun and point down right after the 2nd panel. :p

I'm looking at buying another gun and pulling it apart to see if I can mount the sensor inside with the display/trigger outside and I wouldn't need to open the box up at all.  Could even wire it to a power supply and leave it running constantly if I wanted. :)

Offline Frog

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 13980
  • Docendo discimus
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #8 on: September 14, 2011, 03:04:52 PM »
You will still have to find that sweet spot in which the temp peaks for a split second. Also, does the temp drop at all when you open the door you quoted?
That rug really tied the room together, did it not?

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #9 on: September 14, 2011, 03:05:32 PM »
If you do not have or have access to a donut probe or something to read the ink film inside the dryer.. you'll have to wash test to be accurate.

Set up a black print, preferably something with detail and cut up some white shirts into squares, about 6-12 of them.

Set the belt speed a little over what you think is cure... print and run test #1.. write on it with permanent marker what the belt speed was.

Slow the belt and repeat until you've used all your squares.

Wash them on heavy duty with rough clothes like jeans and see where the ink stops washing off.

I will do this... sounds like a plan.

So I print then cut it... or do I cut it then print on each of the squares the same design?

I really need to learn emulsion. :D

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #10 on: September 14, 2011, 03:06:19 PM »
You will still have to find that sweet spot in which the temp peaks for a split second. Also, does the temp drop at all when you open the door you quoted?

Good question... I don't know though because I can't measure till I open the door. :D

I really am a pain in the ass aren't I? :D

Offline Frog

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 13980
  • Docendo discimus
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #11 on: September 14, 2011, 03:42:57 PM »
You could probably still measure at the same point (or another close to constant point) by reaching in a bit and aiming both with it closed, and with it open.

At any rate, almost certainly, your high reading of 320 on the surface is not sufficient.
That rug really tied the room together, did it not?

Offline Prosperi-Tees

  • !!!
  • Gonzo Member
  • ******
  • Posts: 4297
  • Common Sense - Get Some
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #12 on: September 14, 2011, 05:48:27 PM »
Ok I know this does not help any but I run a Ranar Curestar 4000, it has 1 large panel and I set the temp to 800 and belt speed to 25 and with dark shirts I slow the belt down to about 20

Offline Gilligan

  • !!!
  • Ludicrous Speed Member
  • *******
  • Posts: 6853
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #13 on: September 14, 2011, 07:13:18 PM »
What does 25 and 20 equate to in feet per minute?

I looked at my buddy's Brown which has 4 panels and his panels are about 5" or more up.  He has a probe IN the cabinet that reads 390.  His belt was doing about 1 foot every 10 seconds... so about 6'/minute.  They were curing White on Light Blue.  I don't think they adjust it often.

Offline jsheridan

  • !!!
  • Gonzo Member
  • ******
  • Posts: 2130
Re: Ok... belt speed for curing (I know this is SOOO subjective)
« Reply #14 on: September 14, 2011, 09:14:13 PM »
I cut it then print on each of the squares the same design?



Yes.. print, cure, write down speed.
Asjust speed, print again, write down speed.

Do this 6-12 times.

When the print starts smoking or the ink comes out looking bubbly, that's to hot and you're overcuring now.
Blacktop Graphics Screenprinting and Consulting Services