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UV Printing on Mylar - Adhesion Promoters or Corona Treatment

feckmo

New Member
Hi All,

I'm new to the world of flatbed UV printing and I'm having a bit of trouble getting inks to stick properly to mylar films. Or, generically, polyethylene terephthalate (PET/BoPET). We have a new Mimaki JFX200-2513 which prints beautifully, but the inks don't stick well on these films.

I understand that this is an issue with surface energy and that UV inks have a hard time with this type of material so some sort of surface prep is usually necessary. We've tried a number of adhesion promoters with mixed success, but nothing I would call a solution yet. So, I'm wondering if (a) anyone has suggestions for effective PET adhesion promoters and (b) anyone has experience with flatbed or handheld corona treatment machines that I could run products through before printing? I would need something that could handle material up to 30" wide and 1" thick.

Any suggestions would be very much appreciated!

Thanks,

--Jim.
 

Robert Gruner

New Member
Jim,

There is a poster at this site who has previously posted that he has sold many Mimaki flatbed printers.

PDS Equipment
Steve Weist
615-812-3001

This gentleman might have an answer for you?

Let us know if you find a solution.
 

Nate1n22

New Member
Don't know much about the Mimaki's but there might be a different ink set with better adhesion on that material.
 

feckmo

New Member
Just wanted to bump this thread in hopes that more information might yield more information. We've done quite a bit more printing on the machine and have discovered that THE problem is the white ink. Or at least, printing with white ink in the workflow. When we print directly onto WHITE PET, all colors stick like glue. When we print to DARK PET with white underlayment, the ink cracks and flakes like crazy.

The material itself is essentially the same, so the issue seems to be that white ink in the workflow. Any ideas or suggestions on ways to get the performance to be similar? Is white inherently less "sticky" than color?

Also, Steve, thanks for the offer to help -- I'll give you a call tomorrow to discuss.

--Jim.
 

Pauly

Printrade.com.au
If the ink sticks to your the polyethylene but you're saying the white ink doesn't?

Do this test. Do a high density solid colour print. For example print a black patch, But in the RIP you'll need to edit the ink on the job to print 100% black instead of say 10/10/10/40 or what ever your profile does. Or even better, get it to go 100/100/100/100 and that will get you a thick layer of ink, similar to the amount of white that would be used.
See if that cracks and flakes off.
If it does, then you need an adhesion promotor regardless.
If it doesn't, then your white ink has different properties. It will still need an adhesion promoter but probably use less white ink.
 
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