Cellulose acetate

Does anyone have any experience in dealing with
deteriorated/deteriorating Cellulose Acetate objects?

We have a metal (Fe) corkscrew with the handle and outer case/sleeve
made of cellulose acetate (identified by FTIR and vinegar smell). It
comes from about the 1950's or very early 60's.  We had it stored in
an acid free cardboard box, lined with Microwrap, for about a year,
at ca 20 degrees C and < 50% RH. Before storage it had little
globules of liquid inside the case/sleeve.  The metal corkscrew
could not be removed from the CA case/sleeve as the case/sleeve had
shrunken and distorted.  We opened the storage box up yesterday for
an inspection and found that it was covered with needle shaped
crystals which we have ID'd by FTIR as being Triphenyl Phosphate
which you would know is the plasticizer.

We are considering our options and would like to hear your opinions.
Do you think we should remove the Triphenyl phosphate crystals?  Do
you think we should return the object to the acid free cardboard box
lined with Microwrap?  Do you think cold storage is appropriate, if
so what parameters?  We have a cold room where we store cellulose
acetate negatives (10 degrees C, 35% RH) and Freezers (-10 degrees)
Would either of these be appropriate?

If you have been successful or unsuccessful in dealing with
deteriorated/ing Cellulose Acetate objects, I'd appreciate hearing
your experiences.

Ellie McFadyen
Supervising Conservator (Preventive)
Preservation
National Archives of Australia
+61 2 6212 3422
Fax: +61 2 6212 3469


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                  Conservation DistList Instance 18:13
                 Distributed: Tuesday, August 17, 2004
                       Message Id: cdl-18-13-014
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