Polypropylene bags

I was recently asked about polypropylene/polyethylene bags used by a
comic collector who had heard that some manufacturers use a chloride as
a surface  preparation for bonding the edges.  This doesn't make sense
to me (why not just use heat and save money?).  However, has anyone
heard of this sort of preparation and know what problems such a
preparation might cause?  Are these safe materials to use with paper
materials like comic books? Thanks for any help.

Paul Romaine
Gilder Lehrman Library Foundation
New York, NY

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                  Conservation DistList Instance 7:28
                Distributed: Tuesday, September 28, 1993
                        Message Id: cdl-7-28-007
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