Title: News from the Preservation Office
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00083040/00019
 Material Information
Title: News from the Preservation Office
Physical Description: Book
Creator: University of Florida Libraries. Preservation Office.
Publisher: University of Florida Libraries
 Record Information
Bibliographic ID: UF00083040
Volume ID: VID00019
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Full Text

Their Love is Chemical, or, the Case of the Sticking Books
The question of the month comes from the Price Library of Judaica where
certain books have begun to exchange bodily fluids, gases and chemicals.
The question is simple: "What is causing our books to stick together?"
First thoughts on the culprit in this case of the sticking books is Rela-
tive Humidity (RH) and its detrimental effects. RH is a more probable
cause than the only other thing which immediately jumps to mind:
"maybe the books have fallen in love and have simply grown attached to
one another." Theoretically, pockets of humid air trapped between books
might result in sticking. Oxygen and hydrogen molecules in this humid air
could cause chemicals in book-covering materials to change chemically
and, therefore, stick in a process called hydrolysiss." However, the-
chances of air being trapped between the tightly shelved books of the
Price Library are unlikely, though RH in the Library currently fluctuates

continued on next page 0

between 60% and 80+% (remember: books should be stored at 50% RH if pos-
sible, and mold bloom begins at 65+% RH).
Examination of sticking books reveals that only two types of books are in-
volved. One of the types is covered in vinyl. The other is covered in pyroxy-
lin- coated bookcloth. Vinyl, the covering used on most three-ring binders, is
often used on books orginating in Israel. It is a relatively inexpensive cover-
ing material which can easily be molded and welded around the case of
book. Pyroxylin-coated bookcloth is the major form of bookcloth used in the
United States, and has been used since 1931. In every case, books covered in
vinyl were found to be sticking to books covered in pyroxylin-coated book-
In truth, vinyl and pyroxylin are the worst of neighbors. To greatly sim-
plify the chemistry, vinyl often contains unstable plasticizerss" which "vol-
atilize" out of or escape from the vinyl in the form of gases. (The loss of
plasticizers, by the way, causes the vinyl to embrittle over time.) Pyroxylin,
a form of "Nitrocellulose," is normally a very stable compound of nitrogen
and cellulose. Pyroxylin-coated bookcloth also includes vegetable oils as
plasticizers. These plasticizers make the pyroxylin all the more stable and
do not tend to volatilize. As gases escape from the vinyl-covered book, they
migrate to the adjacent pyroxylin-coated bookcloth where the gaseous chem-
icals interact with the nitrogen and cellulose in pyroxylin to create a highly
sticky substance.
What can be done? It would be nice to re-case all vinyl-covered books, but
too expensive. It might be nice to use other kinds of coated bookcloth, like
starch-coated or acrylic-impregnated bookcloth. But, starch-coated cloths
are yummy for insects. (Pyroxylin is not. Would you eat dynamite, an unsta-
ble nitrocellulose compound?) Acrylic-impregnated cloths are already used
in the Libraries, but only on those books which can make do with a light-
weight cloth. (Heavier cloth, such as that pyroxylin is used in, would be
stiff and unworkable if it were acrylic impregnated.) The solution, other-
wise, would entail separating the two types of books by one of the following
methods: 1) shelving vinyl books together; 2) intentionally mis-shelving an-
other type of book between the vinyl and pyroxylin books; or, 3) slipping a
piece of cardboard between the vinyl and pyroxylin books. These methods
confuse users.
Because this battle of the books' cases does not harm the textblock, the
simplest solution seems to be to do nothing to prevent sticking until the books
stick together. Nothing else is cost effective or wise. Vinyl books do not al-
ways come in contact with pyroxylin books; and if they do, another type of
book may quickly come between them. After books stick and the sticky sub-
stance is deposited on the case, there is little else we can do but re-case.
Luckily, the cases of the sticking book case are few.
Erich Kesse

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