Solvent resistant plates

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Solvent resistant plates

Postby SknyRussianHillbilly » Thu Sep 03, 2009 7:30 am

Can anybody make a recommendation of a plate material to use with an ink that contains 40% heptane?

Thanks
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Re: Solvent resistant plates

Postby cheapthrills » Tue Sep 08, 2009 7:35 pm

Sounds like food contact ink. Last time I ran this ink was with rubber and no affect. I suggest the swell test, place a piece of finished polymer in the ink for 24 hours. Measure caliper before and after. Also check durometer, does it fell "mushy"? I clean polymer plates with FilmKleen with contains heptane with no adverse results.
If the plates swells more than .002, probably a problem. Short run go for it.
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Re: Solvent resistant plates

Postby Frank Burgos » Thu Sep 10, 2009 4:27 pm

Great tips. Thanks
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Re: Solvent resistant plates

Postby SknyRussianHillbilly » Tue Sep 22, 2009 1:20 pm

by cheapthrills on Tue Sep 08, 2009 7:35 pm

Sounds like food contact ink. Last time I ran this ink was with rubber and no affect. I suggest the swell test, place a piece of finished polymer in the ink for 24 hours. Measure caliper before and after. Also check durometer, does it fell "mushy"? I clean polymer plates with FilmKleen with contains heptane with no adverse results.
If the plates swells more than .002, probably a problem. Short run go for it.

---------------------------------------------------------------------------------------------------------------

Thank you but actually no, it is not for food contact. It is a print primer consisting of almost 40% heptane, almost 40% vm&P naptha, almost 20% nP acetate, and about 5% of an unknown resin.

Rubber is out of the question, because I will need spot application of the primer with registration to a solvent ink system printed with a conventional sheet photopolymer. I did the swell test with a couple of the plate systems we use from commercial platemakers and the swell effect in about 12 hours was so much that the strips just curled up around themselves making it virtually impossible to mic. them out. The plates were definately softer, but I am a little at a loss to define "mushy". I do not have a durometer to check plate hardness. Interesting thing was that caliper dropped .001-.002 and the plates flattened out somewhat in a couple of days. I am not exactly sure what would happen in my press with a plate that puffed up the way it did, but I imagine that it would not be too pretty.

I did find a plate made from a liquid photopolymer system that stood up very well overnight, but I am looking to make sure that I have alternatives in getting this project into production.

Any other information from anyone would be greatly appreciated.

Bill
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Re: Solvent resistant plates

Postby cheapthrills » Tue Sep 22, 2009 6:26 pm

Co-solvent varnish. I like that you tried liquid, water wash is also an option. If these don't work you may look into laser engraved rubber roll for register. Good luck, these are the type of projects I use to call "career enders"!
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