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Re: PU coating
Posted: 12 Feb 2015, 14:28
by tracyreed
Thought I would experiment with some PU coatings from paint shop, first on ply, then mdf.

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- DSC01266.jpg (91.76 KiB) Viewed 30 times

- vB_ID:3303
- DSC01266.jpg (91.76 KiB) Viewed 30 times
Re: PU coating
Posted: 12 Feb 2015, 23:29
by Greybeard
Can you give any details of what you used, spray or film, to do the coating with ?
Many thanks,
John
EDIT
Just found your earlier thread. Is this the ' Rasmart' you mentioned there ?
Re: PU coating
Posted: 13 Feb 2015, 11:20
by tracyreed
Hi, no the earlier thread was Rasmarts coatings, this is a specialised pu coating, the clear one works a treat, the white has a milky appearance which works with some prints but not others. I am working with a local chemist to try and find a way to sort it. My problem is I need a cost effective way to coat large (over 2 metre items). But Im getting there.
Re: PU coating
Posted: 13 Feb 2015, 11:30
by ArferMo
Thats the key Tracey..... cost effective, tends to be the downfall of too many products. Following your exploits with great interest.
Re: PU coating
Posted: 13 Feb 2015, 12:20
by JMugs
Interesting, cost effective depends on what you can charge, so I will also be following with interest.
Janners
Re: PU coating
Posted: 13 Feb 2015, 17:11
by Greybeard
tracyreed;97643 wrote:............this is a specialised pu coating.......
I like the brilliance of the print. This is onto a pu coating on the ply ? I thought only polyester was possible, due to its chemical structure.
I can see I'm well down the learning curve yet.
I'm looking at a way to print onto small areas, typically 2cm x 10cm, so much less of a problem than you face, >2m, yipes !
John
Re: PU coating
Posted: 13 Feb 2015, 20:57
by pisquee
synthetic polymers work, but some better than others.
as the ink turns to a gas with heat, the 'pores' of the polymer open up allowing the gassed ink in. the cooling down closes the pores and the ink resolidifies.
pressure from the heat press makes the gass go deeper into the surface in a more concentrated way, rather than spreading out.
more natural materials which are porous will obviously also accept the ink, but their pores are unaffected by the heat, they are always open/porous, so when the heat is taken away and things cool down, the pores don't close trapping the solidified ink, so the print isn't as permanent - it will wash out, rub off or just fade quicker.
Re: PU coating
Posted: 13 Feb 2015, 21:26
by Greybeard
Hi pisquee
I've started another thread about the chemistry of dye-sub and possible materials, so that it doesn't divert from Tracy's work.
John