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screen printing => Ink and Chemicals => Topic started by: Rocky Bihl on March 15, 2018, 01:59:10 PM
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Low cure plastisols have been manufactured for many years now and most of the applications have had to do with vinyl floor tiles or carpet backing. These types of plastisol formulations have a very short shelf life which isn't a problem in the flooring industry since most of this stuff is manufactured and used right away. These "low cure" type formulations have been adapted several times over the last 10 years or so to be used as screen printing plastisols all aimed at lowering dryer temps to eliminate bleeding problems when printing on 100% polyester garments. The initial results were always promising, the white ink printed great and the shirts showed no signs of bleeding coming out of the dryer. The prints would then be set aside for a few weeks or ran through several warm water/warm dryer wash cycles and the initial favorable results were long gone. Not only did the white prints on the polyester shirts bleed, but the ink itself would become thick and sticky almost impossible to print with. The chemistry involved in making a very good low bleed ink let alone one that will cure at 270F or below and also not turn to a thick sticky paste in the bucket is very difficult. So if you are thinking about using or switching to a different brand of low cure ink do a few warm water/medium dryer wash test to make sure your nice looking polyester print jobs remain nice looking as long as possible!
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Rocky, you got me confused here, almost sounds like your bashing your own ink company LOL, but then I read the last part, so your saying One Stroke is the best for low cure inks? I'm just a printer so this might be over my head ;D
darryl
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Just because something will cure at 250* does not mean it has any bleed blocking properties.
Traditional low cure formulas will start to "flash" or cross link at room temps. This specifically, is what he is referring to above.
We have also seen this lately with other "low Cure" ink companies out there. Give the ink a few months and it looks like its turning into a door stop.
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When formulating the ELT series of inks the long term bleed resistance of these formulas had to at least be as good as our regular 320F degree curing inks before being released since that is what One Stroke Inks is best known for. As I stated above this was no easy task but I did get there and the ELT and ELT-S series of inks were ready to sell. I read and hear on the phone all the time that if the print looks good sitting on the shelf for 3 or 4 days and doesn't bleed, it is good to go! Not trying to bash the competition here, they tend to get their feathers ruffled very easy! I just want screen printers who try other companies low cure inks to do a few warm or hot water wash/dryer test. Don't let that right out of the dryer nice bright white print fool you. It could very well bleed far worse over time than if you would have used a conventional 320F cure ink. And yes we do have the most bleed resistant/ high or low cure/ easiest to print inks on the planet!
FYI We just released the ELT-X series of inks. The print softness is very close to the ELT-S series but with much better opacity!
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Just because something will cure at 250* does not mean it has any bleed blocking properties.
Traditional low cure formulas will start to "flash" or cross link at room temps. This specifically, is what he is referring to above.
We have also seen this lately with other "low Cure" ink companies out there. Give the ink a few months and it looks like its turning into a door stop.
A random thought occurs:
If an ink does cure at 250 isn't it possible you won't need any bleed blocking properties?
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Yes it would need to have bleed blocking ability. If it did not, all you would achieve by the 250F cure would be delaying the dye migration until it eventually worked its way through to the top of the ink film over a few weeks time, or when your customer throws the print in a hot clothes dryer like I do when I do laundry.
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Ok that cleared that up for me, my rep from One Stroke is awesome! love the inks just hate the price, but you get what you pay for, so I'll be paying for more. ;)
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Some of our larger customers who are using the ELT/ ELT-S series exclusively on everything they print on tell us they are seeing 25-30% savings on their utility bills by allowing them to lower all of their dryer temps to 270F or so. This really helps offset the higher cost of the ELT ink.
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Yes it would need to have bleed blocking ability. If it did not, all you would achieve by the 250F cure would be delaying the dye migration until it eventually worked its way through to the top of the ink film over a few weeks time, or when your customer throws the print in a hot clothes dryer like I do when I do laundry.
Interesting. Used to do a lot of retail on fleece, only time I ever saw delayed migration.
Never used low bleed, never had them come back besides that one run (that I assumed I'd torched.)
Dye houses pull a major change in the last ten years?
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Thats standard garment response for the 20+ years I have been in the biz.
Poly is not created equal.
Favorite example:
I had a customer when I was at QCM. He has a gas dryer he ran juuuuust above cure temp. Used one of our great low bleed whites. He used 3 screens to make a bullet proof looking white. They started printing the 50/50 shirts... first half they ran were from one country of origin - A... the second half from another country of origin - B.
Shirt group A ran great no bleed or anything. Shirt group B instantly started to color shift. Switched out to a poly white and the print was deemed acceptable. Same brand - same "shirt".
Sometimes its immediate, other times you go to grab a misprint to test on and notice the white ink is... no longer white...