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screen printing => General Screen Printing => Topic started by: Nation03 on December 12, 2016, 07:57:08 PM
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So for the last 10ish years I had the pleasure of using my old boss's Maxi-Cure (6ft of heat/2 functional panels). She was old, but we basically had it on one setting that worked for almost everything we printed, and it spoiled me. So now I'm starting fresh and I have a new Curestar 6000. It's a smaller dryer than what I'm used to.
Can anyone using/used to use an 8ft dryer shed some light on best settings to get an optimal cure? My white prints aren't passing the pull test like they use to on the Maxi-Cure. Granted, I pull pretty hard, but I never had any cracking issues before. I bought a temp gun and was hitting anywhere from 350-390 on the surface. My only guess is that the dwell time in the chamber isn't enough. Shirts were spending about 35 seconds in the actual chamber, but probably only spent 10ish seconds in the chamber at 320+.
Also, I don't really know how high or low to put the actual IR panels. I started with them really low and was getting too many scorched shirts. Now I raised them quite a bit. advice on panel height would be great as well.
Any insight would be appreciated. I know settings can and will vary shop to shop, but I'm just looking for some rough estimates.
Thanks!
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We have an older EconoMax and I'm thinking the IR panels are at 4 inches high and we run heat around 950 to 1000 degrees and the belt speed is set at 1 which gives us about a minute in the tunnel. I can give you exact numbers once I get back in the shop tomorrow, but even at the same numbers I use you might need to check your panels and see what heat they are putting out, just point your temp gun at them and look at your temps.
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Okay cool, thanks. I'll make some adjustments tomorrow.
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try to increase time in oven even if you have to drop temp and belt speed.
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We keep our panels at the lowest height going in and higher going out. This allows the prints to get up to temp faster and then even out as it goes through. Not sure if you can do that with yours, or if the panels have to stay level?
We also try to keep the belt as slow as production will allow, but our chamber is only about 4'
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We have a similar setup, w/ a 4' chamber, 2 panels. Panels are about 6" above the belt, and we aim to keep garments in the chamber for about a minute. We set the first panel hotter than the 2nd, to boost up to temp then sustain it. I make sure we're hitting cure temp under each panel. (There is a bit of a drop in the middle.)
With this dryer, we haven't found temp settings that work for everything. We have to check for every run, as many variables can come in to play. (Biggest 3: fabric type, whether garment was flashed or not, & ambient room temp). With this short of a chamber, I generally shoot for a hitting peak temp of about 30 degrees higher than ink cure temp, per the heat gun reading.
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Thanks for the info so far. Both panels are connected so I cant really put one lower then the other. I guess I can slant it down a little in the front and raise it in the back. I'm going to check my panel height today and adjust accordingly. I'll adjust the dwell time so the shirts are in there for about a minute. Thanks again.
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Just a quick update. I ended up setting my panels to 5" off the belt. Dryer temp was set to 750 degrees and dwell time in the dryer was around 70 seconds. That seemed to do the trick just fine.
Yesterday I was doing a 1 color white on 29M royal shirts, 177 pieces. Tested the first shirt, stretched fine and I proceeded with the job. After we finished up I went to check a few of the shirts to make sure they were still stretching okay and most of them cracked when stretched. I find it hard to believe I'm under curing with that kind of dwell time and the temp gun was reading a little over 400 degrees on the ink surface.
I've washed a bunch of test prints I've done the last few weeks and I haven't had anything washout yet, but the cracking is a little unsettling. Traditionally I use to be able to pull the shirt to the point where I thought it was going to rip, and the ink wouldn't crack. I'm wondering if this is just the case with the Wilflex Lava LB white?
On the flip side, I also printed some polyester basketball tops with a slightly faster belt speed, and they stretch just fine.
We have a bunch of ceiling fans that we had running, I'm wondering if the little air movement actually effected the results? Nothing is really blowing through the chamber, but since it's only 4 feet long I'm wondering if we should just keep the fans off to play it safe.
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I was told by a highly skilled printer here on the board that if it stretched to 30% w/o cracking that was enough to ensure it was cured as far as a stretch test goes.
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This is all good stuff but every shop should have a temperature gun or better yet Thermocouple with screen print donut probe. I have both and used one of them on every order. I think this is a must have in every screen printing shop.
Thermocouple infrared gun
http://www.cooper-atkins.com/Products/Infrareds/ (http://www.cooper-atkins.com/Products/Infrareds/)
Thermocouple with screen print donut probe
http://www.cooper-atkins.com/Products/Thermocouples/AquaTuff_35100_K_Screen_Print_Kit_93816-K/ (http://www.cooper-atkins.com/Products/Thermocouples/AquaTuff_35100_K_Screen_Print_Kit_93816-K/)
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This is all good stuff but every shop should have a temperature gun or better yet Thermocouple with screen print donut probe. I have both and used one of them on every order. I think this is a must have in every screen printing shop.
Thermocouple infrared gun
[url]http://www.cooper-atkins.com/Products/Infrareds/[/url] ([url]http://www.cooper-atkins.com/Products/Infrareds/[/url])
Thermocouple with screen print donut probe
[url]http://www.cooper-atkins.com/Products/Thermocouples/AquaTuff_35100_K_Screen_Print_Kit_93816-K/[/url] ([url]http://www.cooper-atkins.com/Products/Thermocouples/AquaTuff_35100_K_Screen_Print_Kit_93816-K/[/url])
This ^^^^^^^^^^^^ Makes Life a whole lot easier!
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He said he has a temp gun and it's reading 400 on the print.
I think if they aren't coming out or cracking in the wash, you are probably just over stretching the ink when testing. I know in my experience I stretch test by maybe elongation the print 20% or so and if it fails that it is undercured. If it passes it will not crack or wash out later. Never had an undercured shirt come back to me...
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Thanks for all the feedback everyone. 20/30% stretch the print seems to be fine. I must be muscling these guys a little too much lol. For safe measure I bumped the temp to 775 and slightly slowed down the belt speed. I'm just going to give todays test prints 5-10 washes and hope for the best.
Thanks again for the input.
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We have multple temp guns, a donut probe and a couple of different temp strips.
All still feels like a crap shoot in the end. :(
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I found some old temp strips we use to use back in the day, so I ran one thru the dryer and got total black from 290 to 330 with a dwell time of about 52 seconds and was checking it with the temp gun as well, temp gun was about 370 or a little more aimed at the ink.