>This is a complicated matter. specifically, what are you trying to
>accomplish? In my database, I have 13,000 + different formulas for
>sensitized products. For the most part, Diazo materials are processed in
>ammonia fumes, and some sensitizers billed as diazo contain dicromates.
>dicromates can cause severe ulcers which take a long time to heal. Perhaps
>I can help if I know specifically what you are looking to achieve.
I do not know, if I find an answer, but the reason that I am looking for
healthy substitutes for dichromates is that it is not allowed to use them
at many institutions in Scandinavia, where the security health regulations
are very strict.
I have been experimenting a bit and found out, that I can do a lot, using
polymer silkscreen emulsions. I actually do get a tonal range, but I just
wanted to hear, if anybody else has discovered that.
I have been also experimenting with polymer plates, that is a lot of fun
too. My last class was for small kids (aged 5-15), who used them directly
in a pinhole box and then covered with paper pulp after the developement,
so we have got some beautifull white-on-white landscapes from the local
area. I do not dare to use dichromates with such small children, as they
tend to put everything into their mouth. But God knows, if polymer plates
are so much better than dichromates for that purpose.
That is what I hoped to hear more about from the experts on the list.
I am not working with Ulano products as Murakami screen products are at
least just as good,they tell me. That is the reason why the whole
silkscreen industry in Norway turned over to it.
Compositions are firms secrets, I understand.
Could someone tell more about the principals for photopolymers. Why can
they be just as harmfull as dichromates ? Now I am talking about
photopolymers, that are developed in water.