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Re: [BKARTS] The fairy dust of adhesive lay-flat bindings-Strength Testing?



Hi, Ben
Thanks for suggesting the "Corner Pull Test." My first knowledge of it came
from Werner Rebsamen's article, "Bookbinding Testing Laboratory Evaluates
Machinery, Materials, Techniques." Unfortunately, my copy of this is  not
dated, nor is a publication listed. (Werner was an Assistant Professor, so it
was several years ago). Of course we all use it when we tear a sheet off of a
pad. You are right that cold liquid adhesives do not fare well in this test,
nor do most sewn bindings, as you point out. Nor do wire bindings, plastic
comb bindings, saddle-stapled bindings, coil bindings, 3-hole punch, and many
others. The types of bindings which do well on this include Velobind,
AccoPress, Channel Bind, and most of the other mechanical clamp bindings.
Incidentally, most of the binding methods which score well on the corner pull
test score very poorly on tests of openability.
    Your list of tests is far from exhaustive. See www.tappi.com for full
descriptions of dozens of tests for paper, many of which have obvious
implications for book binding. Nor do you mention tests of adhesives, such as
viscosity, setting time, open time, etc. Nor do you mention tests for
openability (the reverse of mousetrapping). Nor do you mention any of the six
methods for testing grain direction (See Werner Rebsamen, New
    There is no single test which identifies the ideal book binding, in part
because no one method of book binding best serves all needs. However, you
would serve the field well if you were to identify and describe a standard
method for measuring the openability of a book. Presumably a coil binding
would rate a ten, and a cross-grained Velobound book might rate a two.
Rupert

    >===== Original Message From "Book_Arts-L: READ THE FAQ at
http://www.philobiblon.com"              <BOOK_ARTS-L@LISTSERV.SYR.EDU> =====
>OOPS I TORE OUT ONE OF YOUR PAGES!
>I went on a bicycling overnight outing to beautiful Gabriola Island BC
>Canada with a club I belong to and brought along the double-fan adhesive
>lay-flat test book I made. I passed it around to get some more impressions.
>Lot's of people said that they dislike typical mouse-trap books. One person
>described how he uses different fingers of one hand to keep the book open
>while he reads and eats supper. Most liked the idea of a lay-flat book. Then
>one of the really tall strong guys in the group tore out one of the pages
>unintentionally while playing with the book. I realized some more testing
>had to be done. I had not done a "Corner Pull Test". As soon as I got home,
>I did some Corner Pull Tests and found that my PVA adhesive bound lay-flat
>book only required 0.15 lbs force to tear out a page with the Corner Pull
>Test while the stapled, polyurethane, and thermal hot melt bound books all
>pulled 1.3 lbs. My PVA adhesive bound lay-flat book had scored well on a
>Page Pull Test  and other folding tests but was utterly weak on the Corner
>Pull Test.
>
>DESTRUCTIVE AND NON DESTRUCTIVE BOOK TESTS
>I decided to make a list of different book tests in case I had missed some.
>Some of these tests are destructive in which case a book will be destroyed
>while testing, which can be used to evaluate the binding design of books
>before producing them. Some tests are non destructive which can be used to
>evaluate books from the production line without destroying them. Probably
>only the minimum page pull test is non destructive:
>
>   1. Page Pull Test...leaf is pulled with uniform force along its entire
>length
>   2. Subway Test...book doubled back so covers touch
>   3. Page Flex Test...bending individual page in book 45 degrees repeatedly
>   4. Tumbling Drum Test...tumbling finished book in rotating drum
>   5. Corner Pull Test...pulling page at upper or lower corner only
>   6. Tearing Resistance Test...strength of paper with tear started
>   7. Folding Endurance Test...bending individual paper sheet repeatedly
>   8. Aging Test...determine breakdown of book materials
>   9. Whip Test*...book is whipped open and closed rapidly
>   10. Mull Strength Test*...open book is pulled at upper or lower edge till
>mull tears
>   11. Cover Hinge Test*...open book is pulled at upper or lower edge till
>hinge tears
>   12. Paper Tensile Strength...pulling necked down paper sample with and
>against the grain
>   13. Paper Stiffness Test...determining how easily paper bends and in
>different directions
>   14. Paper Crushing Test...see how well pages and cover stock can resist
>bending without creasing permanently
>
>*not typical presently
>
>PAGE PULL TESTS
>Here are some page pull tests I did recently which I listed in a previous
>message. I used a page pull tester made with a slot in the board and an
>inverted pant hanger. I only made the books marked with an asterisk*. The
>other books are commercially made. My PVA adhesive bound books did use
>fairly tight weave bookbinding mull.
>
>   1. Hot melt adhesive, Thermal Binding, noncoated paper, Page pull
>average=6.3 lbs/inch
>   2. Polyurethane adhesive, Clamped at spine single application, noncoated
>paper, Page pull average=3.2 lbs/inch
>   3. PVA adhesive, Double fan single application, nondiluted,  noncoated
>paper, Page pull average=2.54 lbs/inch*
>   4. PVA adhesive, Clamped at spine single application, nondiluted,
>noncoated paper, Page pull average=2.2 lbs/inch*
>   5. Polyurethane adhesive, Clamped at spine single application, coated
>paper, Page pull average=2.09 lbs/inch
>   6. Hot melt adhesive, Typical perfect bound, noncoated paper, Page pull
>average=1.9 lbs/inch
>
>PAPER TENSILE STRENGTH
>I made a test strip with necked down area of 0.25 inches wide. Stapled
>cardboard tabs with punched holes to each end. Paper is 0.004 inches thick.
>Applied force with jug filled with water till the paper tore. Calculated the
>combined mass of jug and water.
>
>   1. Office Depot multipurpose paper long grain=7400 psi=29.6 lbs/inch
>   2. Office Depot multipurpose paper cross grain=3557 psi=14.2 lbs/inch
>
>CORNER PULL TESTS
>In my corner pull tests I marked a 15 deg angle across one page. I stapled a
>cardboard tab with punched hole onto the upper corner of the preceding page
>which I pulled at the 15 degree angle till it tore visibly. Usually when the
>tear started it spread quickly. All the books had non coated paper in the
>20/50 lb range.
>
>   1. Hot melt adhesive, Thermal Binding, noncoated paper, Corner pull
>average=1.3 lbs
>   2. Polyurethane adhesive, Clamped at spine single application, noncoated
>paper, Corner pull average=1.3 lbs
>   3. Folded stapled sheets, noncoated paper, Corner pull average=1.3 lbs
>   4. Vinyl repair cold adhesive, Clamped at spine single application,
>nondiluted,
>noncoated paper, Page pull average=0.90 lbs
>   5. Sewn signatures, noncoated paper, Corner pull average=0.75 lbs
>   6. Hot melt adhesive, Typical perfect bound, noncoated paper, Corner pull
>average=0.67 lbs
>   7. PVA bookbinding adhesive, Double fan single application, nondiluted,
>noncoated
>paper, Corner pull average=0.15 lbs
>
>CONCLUSIONS
>   1. The PVA adhesive double-fanned lay-flat test book I made did well in
>the Subway Test, the Whip Test, the Page Pull Test, but failed miserably in
>the Corner Pull Test.
>   2. In a strong adhesive 8.5 x 11 inch size bound book, it would take 70
>lbs force to tear out a page with the Page Pull Test, but only 1.3 lbs in
>the Corner Pull Test. Any book is weakest in corner tearing.
>   3. Corner tearing strength does not seem to be related to the page pull
>strength.
>   4. In my opinion, corner tearing strength should be one of the most
>important tests in destructive testing at least.
>   5. The sewn binding is actually weaker in corner tearing strength than
>many of the better adhesive bound books as the load is placed on a single
>thread in a tiny hole which easily cuts into and tears a page.
>   6. Some adhesive bound books are 50% as strong in the Page Pull Test as
>the tensile strength of paper. Actually in tearing tests of these strong
>adhesive bound books, the paper does often tear as well as the adhesive used
>in binding due to the variable nature of the forces involved in a book
>compared to a test strip.
>   7. Either PVA is a very weak adhesive compared to other adhesives in
>terms of corner pull strength, or the PVA I received recently is very poor
>quality or defective. Either way it is what the bookbinder is using at the
>moment as well. A test strip of this PVA is very flexible and reasonably
>strong.
>
>QUESTIONS
>   1. If you have seen or done corner pull tests with PVA and other
>adhesives, I would appreciate seeing the results.
>   2. Corner Pull Tests are not mentioned very much or done it appears. Why
>is this? It appears to be an important test.
>
>Ben Wiens...applied energy scientist
>Ben Wiens Energy Science Inc.
>8-1200 Brunette Ave. Coquitlam BC Canada V3K1G3
>E-mail: ben@benwiens.com
>Energy Website: www.benwiens.com
>
>             ***********************************************
>            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>
>
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Rupert N. Evans
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>
             ***********************************************


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