Aluminium barrier foils

Martina Griesser <martina.griesser [at] khm__at> writes

>...To prevent the objects from further
>corrosion the conservator and I discussed the possibility of
>applying barrier foils between the metal boards and the objects.
>Unfortunately we do not know any further details about either
>suppliers of such barrier foils (especially suppliers within Europe)
>or crucial properties of the foils one has to look at. Therefore any
>information about your experience using such barrier foils as well
>as supplier information would be very helpful.

You can consider a number of options. You may seal the objects
completely in barrier film "bags", or you may cover the metal
shelving with some material that will isolate the objects from
direct contact only.

In both cases you have a wide choice of materials: some function as
physical barriers (such as metal foil, EVOH, ACLAR, or
glass-laminate type barrier films.) Note that each of these barrier
films offers different advantages (permeability to various gases,
transparency, and so on).

Other materials function as "active" barriers, and react with (or
trap) the dangerous gases. Two examples are Corrosion Intercept film
(a polyethylene film "doped" with molecular copper), or the boards
which contain zeolites / molecular-traps and activated carbon
(MicroChamber, available from Conservation Resources). They can also
be made into sealed containers/envelopes.

Also available is "Optimum" barrier film, which combines a double
foil outer layer with an inner layer of Corrosion Intercept film.
This film provides an excellent barrier properties and an "active"
inner layer.

I don't believe that any  suppliers have insurmountable problems
shipping anywhere in the world today, so I would not limit yourself
to a European supplier, unless you have need of very quick service
and frequent orders.

Jerry Shiner
Keepsafe Systems &
Forever Yours Bridal Gown Preservation
Toronto, Ontario

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                  Conservation DistList Instance 12:66
                Distributed: Thursday, February 11, 1999
                       Message Id: cdl-12-66-004
                                  ***