UV filtering materials

Joachim Huber <joachim.huber [at] prevart__ch> writes

>... Many museums use their UV protection films on windows
>for more than 10 or even 20 years believing that there is still full
>optimum uv protection. Has somebody actually measured UV levels of
>"old" UV protection films after 10 or more years of use? What would
>ba a safe timeframe for the use of such a product considering that
>UV absorption should still be effective (e.g. in Europe). ...

In recent postings concerning the performance of coatings, several
attempts have been made to come up with a ballpark figure as to
their useful life.  I'm interested in knowing if anyone has data on
how these materials behave as they fail.  Do they age "gracefully"
(that is, does their decreased ability to reduce UV transmission
follow a gentle curve when plotted against time), or does the rate
of their inability to reduce UV transmission increase drastically as
they degrade?

Will Jeffers
Collections Care Scientific Research Assistant
Scientific Research Laboratory
Museum of Fine Arts
465 Huntington Avenue
Boston MA 02115


                                  ***
                  Conservation DistList Instance 19:10
                Distributed: Wednesday, August 17, 2005
                       Message Id: cdl-19-10-005
                                  ***