Storing plastic

Colin Williamson <smileplas [at] aol__com> writes

>We have several hundred plastic tokens dating from about 1900 to
>1985. ...
>
> ... Most are
>stored in transparent plasticised pvc folders which of course are
>not of archival quality. Furthermore, the PVC plasticisers might
>adversely affect the tokens if they migrate from the pvc, especially
>as and when the pvc starts to degrade, although there is currently
>no evidence of such interaction. Does anyone have any
>recommendations for an alternative storage solution whilst retaining
>visual access to both sides of the tokens?

PVC photo pockets and folders are being gradually replaced in museum
archives with polypropylene photo pockets and folders which are a
little stiffer than the PVC ones but transparent on both sides.

Polyester is also a very good alternative, being stiffer but more
expensive than polypropylene. We have experienced many problems with
PVC in contact with other plastics, especially low density
polyethylene which seems to 'suck' the plasticizer out of it
resulting in a stiff PVC pocket. Polystyrene achieves a chewing gum
consistency when stored in contact with plasticized PVC.

Yvonne Shashoua
Senior Researcher
National Museum of Denmark


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                  Conservation DistList Instance 20:31
                Distributed: Saturday, December 9, 2006
                       Message Id: cdl-20-31-009
                                  ***