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screen printing => Ink and Chemicals => Topic started by: IntegriTees on March 10, 2018, 10:00:36 AM
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the more and more triblends i print, the more I appreciate the 357 ink.
i'm finding though that after its flash, its transferring to the bottom of the next few screens.
it doesn't have any tack and we have a fan to cool it off after the flash, so why should it still be transferring?
I'm using a Red Chili D to flash it to 180 degrees/80% power (so once the pallets warm up, that only takes 2.5 seconds to reach) and then letting it cool down for one station.
Should i be flash it longer at lower power to reach the flash point? I'm trying to get this dialed in before the summer hits and any tips would be great.
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One of the filler components in ALL white inks is Calcium Carbonate - I.e. Chalk.
If you ever see white "build up" on another screen but its very dry and doesn't do anything.... its the chalk filler.
Its totally fine and shouldn't get in the way of your print. If you find it getting quite thick, think about putting in a smoothing screen - for the simple act of picking up most of the chalk on that screen.
I have a suspicion as to why some inks leave residue like that - pretty much every white I have used has done that at one - or more - times, but I am not certain.
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One of the filler components in ALL white inks is Calcium Carbonate - I.e. Chalk.
Boy, was this the case when I was first getting going back in the '80's!
Shirts printed with Union whites could have been used on blackboards for writing rather than wiping clean!
Seriously, young'uns have no idea how print-friendly whites have become (and they're still the most potentially troublesome)
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Lets get lead back in there to help with some of that opacity ;)
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Back on track with the poster's question, I bet that Robert from One Stroke will also weigh in on Monday.
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I would try flashing slightly longer time at a slightly reduced temp and see if that works. There is no Calcium Carbonate in the .357 white so that could not be the issue.
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I have learned some thing!
So, what would be the little bit of white transfer I am seeing on the .357 and the ELT-S inks be?
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Having never used a Red Chili D flash when testing new inks (we use black body infrared units), I am familiar with the intensity of the quartz units. Maybe the .357 white ink film is not gelled throughout the entire ink film thickness and when the squeegee of the following screen passes over the white it could force not quite gelled ink through the top skim gelled layer resulting in a slight transfer of the ink on every pass. The intensity of the flash unit could also be partially activating additives in the ink surface that would normally be fused within the fully cured ink leaving a dry feeling but slightly transferable on every pass Maybe a slightly less intense more thorough flash will solve either of these issues.
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Makes sense.
It does transfer over - most commonly - with bulb patterns. In between where the bulbs are, it transfers over more. Yea, never been a problem, just an observation. We also try to run our inks and pallets as cool as we can get away with...
Thanks Rocky!
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You're welcome!
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we were flashing to 180 and looked up the specs and it said 357 flash temp was 220. bumped up the flash and ran a job today and had no transfer at all.
Looks like we just weren't getting to the correct temp.
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we were flashing to 180 and looked up the specs and it said 357 flash temp was 220. bumped up the flash and ran a job today and had no transfer at all.
Looks like we just weren't getting to the correct temp.
Hey, I've heard that before. When in doubt, read the instructions! LOL!