Hello, George and Bev,
While all archivists know this is a bad thing, I have seen several
"delamination" where the adhesive paper label has pulled the lacquer
and reflective layers off the disc. I have also seen one disc (CDR)
that suffered this kind of damage in shipping (years ago).
Even the pieces of a Mitsui will exhibit this when it is snapped for
security reasons, but I've never seen it in a properly stored disc.
Part of my informal testing has been to give my kids (ages 10 and 11)
silver CD-R copies of albums in the family collection to protect the
originals from kid-handling (and also letting them know that these
are not to be traded, sold, etc., as these are backup copies of
originals and not additional licenses to the material).
None of these silver CD-Rs have failed with kid-handling in
plastic/tyvek sleeved portable cases. Not scientific, just comforting.
I have had some non-physical failures in similar copies kept in the
car when I was in So. California, but the Mitsuis seem to have held
up while the "Klone" brand exhibited failures. Again, unscientific.
At 03:49 AM 7/7/2005, you wrote:
>From: Patent Tactics, George Brock-Nannestad
>----- several persons responded - apparently correctly - that there are no
>adhesives used in the lamination process for CDs. However, for the CD-R to be
>able to tolerate handling, there has to be adhesion between the various
>layers. If the strength in the interface between layers (adhesion) or in the
>material internally (cohesion) is not sufficient for the purpose, then the
>laminate separates. That could potentially be the case in the phthalocyanine
>layer that separates the polycarbonate from the metallization. I have no
>reports of such a thing happening, but on the other hand, very few people
>have first-hand experience of phthalocyanine as a house building material. I
>have myself _unsuccessfully_ tried the Scotch-tape test (using a high-grade
>tape) to separate the polycarbonate sheet from the deposits.
Richard L. Hess email: [log in to unmask]
Media web: http://www.richardhess.com/tape/
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
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