Marking plastics

Alan Hawk comments on marking plastics objects by barrier coating
before marking. Care must be taken as this may well cause
degradation problems if the plastic is cellulose nitrate or acetate.
I have seen examples where degradation of imitation tortoise shell
made from cellulose nitrate is initiated by a barrier coat used to
mark the item. Pamela Langdow's original request referred to
Melaware which is a urea-formaldehyde thermoset material and
applying a barrier layer will not harm this material.

Colin Williamson
Plastics Historical Society


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                  Conservation DistList Instance 15:66
                 Distributed: Thursday, March 28, 2002
                       Message Id: cdl-15-66-004
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