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screen printing => General Screen Printing => Topic started by: Inkworks on September 05, 2014, 02:14:31 PM
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Here is what I can tell you:
Base coat is a 156LX, we've tried two different whites and various states of flashed, no difference. We even thrie 2 coats of base white, no difference. one white was QCM fast flash, which is our normal cotton white, not a new bucket. the other was a sample of Triangle cotton white. no difference.
Top coat (maroon) is QCM W.O.W Bright Red with a bit of QCM W.O.W Black. 320 grams to 20 grams if that helps. neither are new buckets, both have had lots of use. it was printed through a 230, but then switched to a 156, both showed the same problem.
When pulling the Gildan 2000 Black shirt from the platen, the maroon fractures and ends up looking like a distressed print. flashing the maroon cures this problem.
we've tried all sorts of different squeegee pressures and angles too.
picture shows flashed and unflashed samples after pulling
wtf?
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In my experience, this is typically the result of too much tack along with over flashing.
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I agree. This can also happen with a DC UB
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In my experience, this is typically the result of too much tack along with over flashing.
agreed, over flashing on the base...
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Well we're at about 2 seconds flash, nothing different ink or flash-wise than we've done for the last 3 years, hundreds and hundreds of jobs.
It was a somewhat new bucket of QCM Fast Flash, but we have run several jobs with it without issue, but QCM quality has gone to complete poop after the Rutland buy-out.
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I thought too much tack too for a while,because we had just run tech shirts, but now we've tried platens with almost no tack left on them.
I'm running atest with 1.2 seconds of flash (quartz flash on auto) if I can get it to cure, but like I said, these aren't seeing any more flash than normal, and less than many jobs.
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Okay, actually turned the flash down to the point where it wasn't flashing fully and base white ink was transferred to the maroon screen and still seeing a bit of cracking.
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try running the shirts around again so the last color has been flashed as well
So, when pulling shirts all ink colors have been gelled. Not what you want to hear on a big job,
but thats what we've done when this happened to us..
V/r - John
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or if you have an extra flash, flash at the unload station... probably be faster than running them around the press a 2nd time.
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yeah, it's not a huge job, but I don't even want to tear it down until I lick the problem. We'll try switching to a different top color before tear-down. This shouldn't be related to using 156LX as a base coat mesh right? We've run 230 T mesh base whites without this issue.
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Your maroon is the problem. The orange is not fracturing. I don't remember what it was but I had this happen on a job also. I hate printing maroon on PFPF under base. I don't remember what I did to fix it for sure. I didn't change my flash much so I don't think that was it. Try running the maroon with less pressure so you lay down more ink. That should fix it.
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We've done that, we actually went from a 230 maroon screen to a 156 for just that purpose.
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We've done that, we actually went from a 230 maroon screen to a 156 for just that purpose.
Well then I have nothing. I do remember this happening, like yours only with the maroon. Are you PFPF the underbase for the maroon? That I think is the problem that started this for us. I only remember it happening for the first 20 or so. Then our changes on press fixed it. You know it may have not been the changes we made but the fact that our boards got hot. Where your boards hot when printing this job?
This can easily be fixed with adding a flash before the unload station like some have said. Like you I want to know why it happened not just make it go away.
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Almost looks like the underbase is rejecting the top coat of maroon. Did you get them to shake hands before starting? j/k
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Well after a phone call to Sonny/Printficient (Thank-you!) we seem to have found the culprit!
Pallets were sporting a coat of Sprayway Fast Tack 384 Super flash mist from the previous run of tech shirts. not a ton, and not enough to cause a problem with pulling the shirts off, but basically may have been causing some sort of chemical/offgassing thing. Fresh pallet tape and a change to Sprayway 83 Web adhesive cured the problem, even though overall tack wasn't reduced, in fact it was probably increased.
We ran the job (96pcs.) and flashed after the maroon, but after that I left it set up and started to eliminate potential causes as I sure didn't want to run into this under a tight deadline.
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Well after a phone call to Sonny/Printficient (Thank-you!) we seem to have found the culprit!
Pallets were sporting a coat of Sprayway Fast Tack 384 Super flash mist from the previous run of tech shirts. not a ton, and not enough to cause a problem with pulling the shirts off, but basically may have been causing some sort of chemical/offgassing thing. Fresh pallet tape and a change to Sprayway 83 Web adhesive cured the problem, even though overall tack wasn't reduced, in fact it was probably increased.
We ran the job (96pcs.) and flashed after the maroon, but after that I left it set up and started to eliminate potential causes as I sure didn't want to run into this under a tight deadline.
Glad I could help. Just one of the many wacky things I have had happen over the course of my printing career.
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Dare I ask if the problem resurfaces using a water based tac like Textac?
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I have had the same thing happen a few times and it does seem to alway be red ink for some reason.
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Dare I ask if the problem resurfaces using a water based tac like Textac?
I can't tell you, I had some and was going to use it, but went with the web-tack instead. We often switch up cotton/fleece/triblend and tech shirts all day long and I've found water based tacks don't perform as well as we'd like on broad varieties of fabric.
We did throw some Cool Grey 11C on the maroon screen to see what happened, and it printed and pulled just fine. It seemed to be the red/maroon ink and flash/mist adhesive combo that was the problem. Sonny did predict that due to the difference in pigment properties between red and black/white.
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Just wanted to chime in on this since I just had this issue a few days ago. Was running about 280 units on a 5 color print, last color down was dallas green. The first few I had the "cracking" just on the Dallas section of the graphic. After a little bit of trial and error decided to double pass the green and that solved the problem right up, shirts still looked perfect with the double pass, but for some odd reason the issue disappeared.