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Subject: Vacuum packing

Vacuum packing

From: Jerry Shiner <jshiner>
Date: Wednesday, June 9, 2004
David Kerr <d.kerr [at] nls__uk> writes

>I am experimenting with vacuum packing as a means of storing
>newspapers and I would like to find out more about other peoples
>experiences using vacuum packing technology as a means of storing
>library material.  I know the benefits of anoxic packaging to
>prevent chemical and biological reactions but there are a few areas
>in which I'd like find out more on ...

A few notes about Vacuum packaging. Vacuum packaging is not in
itself an anoxic process. Although much of the air surrounding the
objects is removed, the atmosphere in the bag remains normal (if
slightly reduced).

To make the bag truly anoxic, an oxygen absorber must be used. The
simple act of sealing the papers from external pollution and other
damaging factors may be adequate for your preservation purposes, but
oxygen absorbers are a small additional cost to go a little further.

Note that a very good barrier film should be used if you expect to
maintain long term oxygen free storage, as all barrier films are
permeable to some extent. An adequately sized oxygen absorber should
be used to trap any infiltrating oxygen. Shelf life of a barrier
film will be quite long- I have no actual numbers, but the materials
used in their manufacture are quite stable.

As for the shelf space saved, in my experience you can expect a
reduction to about two thirds (or less) of the original space
occupied. Adding in buffering paper will essentially double the
amount of paper stored, and you will likely end up using more shelf
space than the original collection did.

Note that under high vacuums/external pressure there may be some
offsetting of photocopied materials.

Jerry Shiner
Microclimate Technologies International

                  Conservation DistList Instance 18:1
                  Distributed: Thursday, June 17, 2004
                        Message Id: cdl-18-1-005
Received on Wednesday, 9 June, 2004

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