Liquid photopolymer to make plates for Heidelberg “Windmill” 10x15

Most of the liquid photopolymer methods use a carrier sheet upon which steel bars are placed (which for the final thickness of the photopolymer layer, then a negative is placed on to pand covered with a piece of heavy glass. Pressure is applied with clamps to make certain the thickness is uniform across the sheet, and light is allowed to expose through the negative, crosslinking the photopolymer layer. After the negative is stripped off, and unexposed liquid is washed away, an image remains on the support sheet which can be mounted and used as a printing plate.

Generally the liquid systems I have seen have been softer durometer plates for rubber stamp replacement and for imprinting rough surfaces.

Hello Herny,
thanks for the reply.

Can you please tell me why the negative is placed in direct contact with the liquid photopolymer? Generally in the rubber stamps market I’ve read that a transparent film is used between negative and liquid photopolymer, to protect the negative.

For example I use inkjet films, and placing the negative in direct contact (emulsion side) to the liquid photopolymer, will ruin the totally the negative..

Should be possible to create sheets of photopolymer , from the liquid photopolymer, and then expose them like common photopolymers sheets, using vacuum?

Thanks.
Fabio

i have a cheapo poly machine for making rubber stamps. it is a light box with black lights for exposing and two pieces of glass one has magnetic strips on one side, the other has strips on both sides one side thicker than the other. you put the negative on the glass, then cover it with a clear film then pour the polymer, a thicker plastic covers the polymer, when the second glass is placed on top, the magnets squeeze the poly, you can use the thick magnets for thicker plates. Polymer can be bought for soft plates like rubber stamps or a harder duro. for plates. This works well for rubber stamps, the harder polymer is not so easy to use, i tried for a while to make plates for crash printing, very small plates worked ok, but any plate i made i could not get to come out even across the whole plate. Trying to make larger plates was a nightmare, the soft polymer would work well for rubber stamps, but the harder ploymer would hold the glass together so tight that i broke many pieces of glass trying to get them apart, now we just use soft polymer and only make signature stamps and a few art stamps with the machine. Let the guys that make poly plates for the trade make your plates, or use mag dies like i do. Good Luck Dick G.

Hello Dick G,
thanks for the reply.

What do you mean with “harder duro for plates”?

Does the rubber stamp liquid photopolymer is suitable for letterpress printing?

Does Anybody tried to use the liquid photopolymer used in flexography, to make plates for letterpress printing?

Thanks!
Fabio

you can buy the polymer resin that will be as hard as a mag die, but it is hard to work with. The softer liquid polymer resin for rubber stamps is too soft, you won’t get a deep impression with it, if you use too much impression it will distort, good luck Dick G.

Hello,
what’s a mag die?

thanks,
Fabio

mag is short for magnesium, that what plates are made of, liquid polymer used for flexography should work for letterpress, some larger companies that print forms have polymer plates they use on their forms presses to print small areas i think. Dick G.

Hello Dick G.
Thanks for the reply and for the suggestions.

Can you suggest me a brand of photopolymer resin?

I hope to have the time to find a solution for the liquid photopolymers in the letterpress printing.

Fabio

any place that supplies rubber stamp makers should carry polymer resin. i buy my supplies from millenimum marking, anderson veelin (don’t think spelling is correct on veelin) they also sell supplies, maybe check the yellow pages on this site. Good Luck Dick G.