[Table of Contents] [Search]


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [BKARTS] Double-fan binding - Spine exposed by notching



I agree that the 3X figure is far too high for a double-fan-glued binding.
However, what am I missing from the calulations below? It seems to me that 3
notches, each .125 inches deep simply adds 3/4 of an inch to the length of the
spine. (.125"x6) The sides of the notch are glued, with the same or less
penetration of adhesive than the spine receives. The bottom of the notch
simply replaces the adhesion that would have occurred without the notches.
Thus the increase in glued area would be, at most 7 percent on a book with an
11 inch spine (.75/11), and 8 percent on a book with a 9 inch spine (.75/9).
    Of course the notches expose fibers to the adhesive, which should result
in a measurable increase in page pull strength, but the loss in openability is
substantial.
Rupert


>===== Original Message From "Book_Arts-L: READ THE FAQ at
http://www.philobiblon.com"              <BOOK_ARTS-L@LISTSERV.SYR.EDU> =====
>Great information Gregor:
>
>Would you mind however clarifying your statement that "many shallow notches
>effectively increase the
>(length) of the spine that is exposed to adhesive by X3." Isn't that
>statement a bit misleading?
>
>When double-fan gluing, isn't it the total glue area that is important? A
>simple sample calculation shows the following:
>
>   1. Non notched spine side area of page exposed to adhesive = 0.004 x 11
>inches = 0.044 sq inches
>   2. Notched spine side area of page exposed to adhesive = 0.044 x 3 =
>0.132 sq inches
>   3. Paper sides exposed to adhesive = 0.010 adhesive penetration x 2 sides
>x 11 inches = 0.22 sq inches
>
>   4. Total area non notched per page = 0.264 sq inches
>   5. Total area notched per page = 0.352 sq inches
>
>So it seems that notching only increases the total glue area slightly, it
>has 1.33 x the area and not 3 x the area as is often thought. One could
>increase the glue penetration only slightly on the side of each page and
>achieve the same total glue area. This would result in greater spine
>flexibility? Maybe notching is desirable in practice because it roughens up
>the paper fibers, but wouldn't just exposing the fibers be better?
>
>Ben Wiens...applied energy scientist
>Ben Wiens Energy Science Inc.
>8-1200 Brunette Ave. Coquitlam BC V3K1G3 Canada
>E-mail: ben@benwiens.com
>Energy Website: http://www.benwiens.com
>Read my popular web-booklet "The Future of Fuel Cells"
>
>-----Original Message-----
>Hi Ben and others:
>
>With regard to notching vs no notching when doing double-fan adhesive
>binding I must add that notching is not always necessary, and when it
>is done, it is not always done properly. As you have mentioned a deep
>notch (by this I mean 1/8 inch or more) may actually defeat the
>purpose of double-fanning by not allowing for an easy opening book. A
>deep notch allows adhesive to form cleats that resist the lay flat
>characteristics of the double-fan bound book. If you force open a
>book that has been deeply notched (pretend you are smashing it down
>on a flat plate photo copier) those little cleats may actually tear
>the paper.
>
>Very shallow notches of about 1/16 inch ( 2 mm) or less work very
>well. Especially when they are cut by a milling knife that clean,
>sharp and has many teeth. Our notching knives are cut in a
>trapezoidal shape. The many shallow notches effectively increase the
>(length) of the spine that is exposed to adhesive by X3 !!
>
>             ***********************************************
>            BOOK_ARTS-L: The listserv for all the book arts.
>      For subscription information, the Archive, and other related
>            resources and links go to the Book_Arts-L FAQ at:
>                      <http://www.philobiblon.com>
>
>        Archive maintained and suppported by Conservation OnLine
>                    <http://palimpsest.stanford.edu>
>             ***********************************************

Rupert N. Evans
May 1-October 31: 101 W Windsor Rd. #4107, Urbana, IL 61802-6697;
217-337-7833
November 1-April 30: 501-391 S LaPosada Circle, Green Valley, AZ 85614; 520-648-8365
Author of Book-On-Demand Publishing
I love to print and bind books

             ***********************************************
            BOOK_ARTS-L: The listserv for all the book arts.
      For subscription information, the Archive, and other related
            resources and links go to the Book_Arts-L FAQ at:
                      <http://www.philobiblon.com>

        Archive maintained and suppported by Conservation OnLine
                    <http://palimpsest.stanford.edu>
             ***********************************************


[Subject index] [Index for current month] [Table of Contents] [Search]