UV filters

I am writing in response to the discussion on UV-protection films.

Roger Wullf and Michael Maggen have already summarized some major
considerations but there seem to be in fact various manufacturers of
films with greatly varying qualities.

One of them is 3M who has been developing a protective film for many
years and just recently launched a new product under the name of
GlassSafe by 3M. GlassSafe comes as a clear or tinted film and is
made of 58 layers. 52 polyester layers which are laminated in
alternating (90 degree) direction of their production and 6 layers
with special functions such as UV and IR absorption. The actual
chemical make-up of the 6 special function layers is not being
disclosed. The adhesive is as for many other such films, a water
activated acrylic resin.

GlassSafe claims to be the most technically sophisticated product of
its kind on the market and is being exclusively distributed by
GlassSafe International, Inc. in Hollywood Florida. Their poor
web site <URL:http://www.glasssafe.com/> does unfortunately not
provide any scientific data but I have recently measured its UV-VIS
spectroscopic and other properties and be happy to share this
information.

Visible light transmission is claimed and was measured to be more
than 94% for the clear GlassSafe film while UV transmission (200 -
400 nm) is max. 4 - 8%. It has a good acid/base resistance as well
as a scratch resistant finish. One of its greatest advantages lies
in the considerable protection against glass break or intrusion
which is achieved by the 52 polyester layers. Total film thickness
is 0.008 mm. Some additional information can be found within our
web site: <URL:http://www.visualbyte.com.br/ArtCare/glasssafe.htm>

Stephan Schaefer
ArtCare & Consulting
Rua Oscar Freire 715/81
01426-001 Sao Paulo, SP
Brazil
+55 11 8819282
fax: +55 11 2809519

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                  Conservation DistList Instance 11:16
                 Distributed: Thursday, August 14, 1997
                       Message Id: cdl-11-16-006
                                  ***