Re: silkscreen emulsion
Luis Nadeau (nadeaul@nbnet.nb.ca)
Fri, 09 Jan 1998 23:34:38 -0400
At 5:51 PM -0700 98/01/09, Bob_Maxey@mtn.3com.com wrote:
>Subject: Photopolymers
>
>
>>>>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 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.
>
>Every silkscreen emulsion and silkscreen emulsion sensitizer I am aware of
>DOES contain dicromate. I always suggest to others to use a premixed
>product rather than compound it themselves. Dicromates are potentially
>dangerious.
Traditionally, dichromates were used for silkscreen work. Ferric systems
were marketed by Autotype and others for some years but now I think they
pretty well have switched to diazo compounds. It is just a matter of
reading the labels.
Luis Nadeau
NADEAUL@NBNET.NB.CA
Fredericton, New Brunswick, Canada
http://www3.nbnet.nb.ca/nadeaul/