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screen printing => Waterbase and Discharge => Topic started by: ericheartsu on October 28, 2014, 01:11:20 PM
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Whenever i'm running my dryer for discharge, is it going to hot or to slow if i'm getting curled up tags? is the heat damaging or shrinking the garment if it's doing this?
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Are they the tear-out type of tags? Those curl on us no matter what. It's the material they are made of.
Gildan style doesn't though.
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some are, but even on gildan 5000s they curl so bad
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gas dryer.. 350 degrees for 3 minutes in the heat chamber.
flip the edge of the shirt with the tag under and it won't shrink.
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Ditto. Tuck them if needed.
We have a Sprint 2000 HO. The circ blower is always at it's highest setting which is a pretty serious amount of air flow. We set the temp to 320˚F for plasti and HSA (long retention on the HSA, shorter on plasti) and 350˚F for WB and DC with as long as a retention as production will allow.
I think everyone should have their ideal dryer settings for perfect curing and then a second set of settings that represent the limit of how fast/hot it can be ran so you aren't adding even more stress/worry to those busy times when two presses are spinning full tilt.
In the end you also need to find a magic number that you can run multiple ink types on. Weekly, I ponder why I didn't push harder for a split belt.
I think it's hard to get "too hot" for wb/dc and I've noticed it really likes hitting 350 at some point. I can't scientifically validate that though, still need to do some hard core cure + wash tests to get exact figures on everything through the Sprint. Rutland recommends taking a little Blue PS in whatever base you are testing and curing at a bunch of different settings then wash testing to find the optimal range you can cure in. Sounds like a good approach to me. I'm curious to see what I find, to see how low or high a temp wb/dc can effectively cure at.
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We have two dryers and typically run them like this:
Sprint International:
380 degrees
Poly shirts-26 belt speed (typically in the chamber for about 25 seconds)
100%-20 belt speed (typically in the chamber for about 30 seconds)
Discharge/wb- 08 belt speed (typically in the chamber for about 1min 10secs)
Mini Sprint
405 degrees:
Poly shirts- 28 belt speed
100% cotton-18-22 belt speed
Discharge/WB-08 belt speed
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Or spritz with water. About the same time as a tuck. We don't do either though.
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So, how long is a drying chamber that a shirt is in for 3 minutes? Because that would be about 3 feet per minute in our dryers with 10 foot boxes, incredibly slow it seems... even with a 60" belt, we'd have to run the press slow. Always something...
Steve
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incredibly slow it seems... even with a 60" belt, we'd have to run the press slow. Always something...
yes it is slow.. that is why so many printers thinks it's OK to just crank up the heat and run it through... if it doesn't cure then send it back through!
then they complain about WB not working for them ::)
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our dryer isn't that long, and we don't really have issues with inks not curing, obv. i'd like for it to be longer, but both our dryers work fine
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wow that seems hot. Even on the little Heatwave I have the temp at 360 for 100% cottons, and 340 for heathers for discharge prints, belt slowed down to hold them in there for at least 2 mins. I have a mark on the speed dial to repeat, it's like 1.2 on the speed, lol, very slow, but we have never had a complaint from washed out waterbased or discharge prints. I can't wait to get a bigger dryer to speed things up at least by having a larger belt to stage shirts, more heat chamber and slightly faster belt speed for wb prints. Bigger dryer is obviously awesome for plastisol, but when we get a nice sized order of discharge prints we are turtle speed depending on the image size. So we "creatively" lay the shirts on the belt to get as many in there as we can, but it's still slow. All the reps I've talked to say don't rush it with discharge and wb prints or you may not "fix" the pigments into the fibers properly. Tuck those tags for sure!! Tultex and Nextlevel like to shrivel up big time.
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check out the Sprint 3000, no more belt speed, that's a thing of the past! now you set time and everything is touch panel. SUPER COOL!
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We're way on the low side, 340 @ 1:20 for all discharge & WB in the Heatwave. Every once in a while we may have to run something through twice (usually the result of a shirt not laying flat), but its few and far between and we haven't run into any issues otherwise.
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So, how long is a drying chamber that a shirt is in for 3 minutes? Because that would be about 3 feet per minute in our dryers with 10 foot boxes, incredibly slow it seems... even with a 60" belt, we'd have to run the press slow. Always something...
Steve
That would be a belt speed of about "4" on our 16' Sprint. I agree, not realistic for most production even with the 60" belt and I would consider our dryer fairly large and beefed up.
But that 3 minute figure is likely a cover thine ass when you see it in tech sheets as 3 minutes means a lot of different things in a lot of different dryers curing a lot of different print sizes with all sorts of different levels of penetration and ink deposit. If it's referring to the fact that 3 full minutes at a certain temp does something for the print in terms of heat setting the ink than I stand corrected. However I think that number is given to cover a wide variety of curing environments. Our dryer has more BTU and airflow/exchange than standard models so maybe our ideal retention time is actually lower, IR panel dryers with no airflow or adequate air exchange are on the complete other end of the spectrum.
You just have to carefully test in the end. There is likely a point of diminishing returns for retention time and temp after which the print does not cure any better. Find it and I imagine you can up production and/or save on the utilities.
Another interesting variable is the amount of binder in the wb ink mix. Rutland offers a wb base that's crazy cheap, something like $18 a gallon, but needs a serious cure. We skip it and go for the "quick cure" to keep things safe and ensure we can run as fast as we need but if you had an insane amount of curing capacity you could purchase or make wb and dc inks and run for half the price. Not sure where the trade off would be there with utilities v. ink cost.
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So, how long is a drying chamber that a shirt is in for 3 minutes? Because that would be about 3 feet per minute in our dryers with 10 foot boxes, incredibly slow it seems... even with a 60" belt, we'd have to run the press slow. Always something...
Steve
That would be a belt speed of about "4" on our 16' Sprint. I agree, not realistic for most production even with the 60" belt and I would consider our dryer fairly large and beefed up.
But that 3 minute figure is likely a cover thine ass when you see it in tech sheets as 3 minutes means a lot of different things in a lot of different dryers curing a lot of different print sizes with all sorts of different levels of penetration and ink deposit. If it's referring to the fact that 3 full minutes at a certain temp does something for the print in terms of heat setting the ink than I stand corrected. However I think that number is given to cover a wide variety of curing environments. Our dryer has more BTU and airflow/exchange than standard models so maybe our ideal retention time is actually lower, IR panel dryers with no airflow or adequate air exchange are on the complete other end of the spectrum.
You just have to carefully test in the end. There is likely a point of diminishing returns for retention time and temp after which the print does not cure any better. Find it and I imagine you can up production and/or save on the utilities.
Another interesting variable is the amount of binder in the wb ink mix. Rutland offers a wb base that's crazy cheap, something like $18 a gallon, but needs a serious cure. We skip it and go for the "quick cure" to keep things safe and ensure we can run as fast as we need but if you had an insane amount of curing capacity you could purchase or make wb and dc inks and run for half the price. Not sure where the trade off would be there with utilities v. ink cost.
We have 2 older Advance dryers, electric in, gas in the middle, electric on the way out. When we do discharge, they go through twice. I think I'd rather have the catcher send them down a second time while the pressman does his changeover to the next job. When John mentioned the 3 minutes, I think he meant that's what they do there, not just the manufacturers "cya". The guys in the shop are liking discharge more and more, but we had a major fail the other day when the colors did not come out the way they should; so we made a new white screen and underbased the colors and printed plastisol on top so we could get the job out the door. I was explaining that we need to do some serious testing, that not all colors use the same amount of ZFS, that there are many brands to consider, inks and shirts, and they seem to want to get into it. Now, if I can just get them to come here and read the exploits of those of you doing some serious work to get an idea of the thought processes they need to have in mind...
Steve
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With our Sprint International, we set our temp to 330 and belt speed at 10 for about a 85 second dwell time. I've ran them as fast as 12 and got a good cure with DC. Our chamber length is 12'. I've played a lot with these settings and have gotten cures at some very extreme settings that I wouldn't have thought would work well.
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We just ran an 1,100pc order with CCI D-base ink on PC54 heather navy shirts. 1 color straight base no pigment in a HeatWave dryer. Set the dryer @ 375* print was in the chamber for 50 sec. Print discharged fine. If it dischages good is there any reason to leave it in any longer. I'm still fairly new to WB/ discharge prints so we are doing lots of research and testing. This is our largest job, but we've ran a few other with great results and have done wash tests and everything seems fine.
Any info/tips would be appreciated.