13317Re: [PPLetterpress] Photopolymer with 'moving' parts
- Dec 3, 2012
At Otis we recently had a similar problem after changing the bulbs out on platemaker, the Anderson Vreeland Rep suggested warming up the bulbs for 5:00 cycles before making plates for a month or so until there is even burn on the bulbs. He checked and found uneven bulb strength when exposing. We have had no problem since, warming up the bulbs up first. We do not back expose... after a couple of months after the bulbs have an even burn it should not be necessary. Perhaps you need to warm up the bulbs? Also check temp on the wash out.
--- On Mon, 12/3/12, tinglado_letterpress <doloresj3@...> wrote:
From: tinglado_letterpress <doloresj3@...>
Subject: [PPLetterpress] Photopolymer with 'moving' parts
Date: Monday, December 3, 2012, 9:58 PM
Dear list members,
I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ÂºC, dry out: 10 min at 80 ÂºC and post exposure 300 s.
The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean (http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?
The problem only happens with the '1' and the 'l' characters.
I am in trouble, because it happens every time I try to process this work.
Please, help!!!! :-)
Thank you in advance and regards,
- << Previous post in topic Next post in topic >>