Binder's board

Ursula Kolmstetter <ukolmstetter [at] ima-art__org> writes:

>... assumed that they are acid-free. But they are not.  Our conservator
>for works on paper did a test and found that they are not acid-free.

I received a copy of Ursula Kolmstetter's inquiry requesting
feedback regarding acid free board.  As the distributor listed in
her inquiry, I wanted to make sure I addressed her concerns.

I called the manufacturer of our acid-free board, Rock-Tenn Company.
They maintain that their board is acid-free. "Our acid-phree board
will almost always show a presence of lignin because we use recycled
paper.  We manufacture an acid-free board that contains a buffering
solution to control pH.  We do not claim to be a lignin free board."

If the tests that were performed found lignin, that does not mean
that the board is not acid free.  They explained to me that lignin
free board is a different board than acid phree board and more
expensive to manufacture.

Here is a copy of an article regarding the acid content of binders
board...

   "During recent years there has been increased interest
    developing, among libraries in general and
    archivists/conservator in particular, in regards to the effect
    of acidic cover-board in the long range (100/200 year)
    preservation of books.  The Davey Company has been asked
    numerous times what the pH factor of our board is and whether or
    not the slight acidity will present a destructive influence over
    the long term.  The first part of that question has to be
    answered by evasion.  We do not know the pH of individual
    sheets, bundles or toms of board shipped to our customers.  We
    do know the pH of the water extracted from this board, a figure
    that is monitored continuously in our plants.  Bear in mind that
    water (of neutral pH) is used in the production of board as a
    vehicle to carry the recycled cellulose fibers from separation
    of the fibers (beating) through cleaning and refining to the
    paper  machine where the fibers are then reassembled in board
    form, after which the water vehicle is then removed by pressing
    and drying.  The pH of this water vehicle varies, during the
    course of any week, from a pH of 5.5 to 7.0.  However, there has
    not been established a proven correlation between the vehicle
    and the cellulose fibers carried by it; so that if the water
    extract is 6.5 pH at any given moment we cannot say with
    certainty that the board produced at that moment is 6.5 pH,
    though, we would suspect it to be close."

I hope that this information has helped to clarify any issues
regarding acid-free binders board. Regards,

Chris Paxson
Customer Service Manager
LBS
1801 Thompson Ave.
Des Moines, IA 50316
800-247-5323 x-309
Fax: 800-262-4091

                                  ***
                  Conservation DistList Instance 13:10
                   Distributed: Monday, July 26, 1999
                       Message Id: cdl-13-10-009
                                  ***