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Re: [BKARTS] PVA;: what Elmer's is that?

I have Ph tested the Elmer's white glue.  It is quite acid.  While I don't know the composition of the glue, it can't be
PVA alone.  (I find this an excellent adhesive when used for things like leather to leather.  I wouldn't use it on paper.)

Alan Shalette wrote:
> PVA is an extraordinarily versatile adhesive used
> in a multitude of applications in a host of industries -
> bookbinding, printing, packaging, woodworking,
> electronics, and other types of manufacturing, as
> well as being packaged for retail customer use
> (e.g., Elmer's).
> As reported below, its development arose out of
> adhesive shortages during WW II.
> Also noted is that formulations of PVA-based
> adhesives include different types application-specific
> additives suited to the specific needs of those
> applications.
> Bookbinding is one such application, having particular
> requirements and requiring special types of additives
> and formulations.
> For hand bookbinding, we want an adhesive that :
> flows smoothly and can be applied in thin layers, can
> be thinned with water to adjust tack time, will bond
> pyroxlin-coated bookcloths (used to repel water, dirt,
> etc.), will dry within a reasonable time, is strong, won't
> age, is not affected by environmental factors (e.g.,
> won't absorb atmospheric humidity or pollutants), is
> flexible and transparent when dry, etc. We'd also like
> it to be reversible, but...
> Contrast these properties with woodworking formulations
> that are stronger than the wood they bond, include dyes to
> match wood colors, dry hard so they can be worked
> like wood, etc.
> Also contrast hand binding requirements with those
> specific to machine binding (see Tony Clark's
> "Bookbinding with Adhesives," McGraw-Hill (1988).
> Consequently, while there are many PVA-adhesives
> available, we use those that are specially formulated
> for bookbinding (e.g., check Talas's catalog online).
> In a pinch, something like Elmer's can be a satisfactory
> substitute, but woodworking adhesives usually can't.
> The same can be said for methyl-cellulose based
> adhesives (an important ingredient in Gummy Bears,
> laxatives, and pharmaceuticals).
> Alan Shalette
> -----------------------------
> Kantrowitz, Morris S.
> Miscellaneous Bookbinding Adhesives
> GPO-PIA Joint Research Bulletin,
> Bindery Series No. 4 (1953)
> Government Printing Office - Printing Industries Association
> Because of wartime restrictions placed on the quantities of animal glue
> available for use in the pro?duction of adhesives in the Government Printing
> Office, a study was made of various synthetic resins early in 1943 for the
> purpose of ascertaining whether or not some of these might prove satisfactory as
> substitutes for the glue compositions employed by the bindery.
> This investigation led to the development of several resinous adhesive formulas
> employing as the principal constituent a water emulsion of polyvinyl acetate
> resin. This compound, manufactured commercially as a heavy milky white emulsion
> similar in consistency to liquid glue, exhibits excellent adhesive qualities,
> drying out into a hard but brittle film. In view of its brittle nature when dry,
> it proved unsuitable in its manufac?tured form as a substitute for the flexible
> glue com?pounds employed for bookbinding operations such as gluing-off,
> lining-up, perfect binding, and padding.
> Experiments revealed that the addition of a soften?ing agent or plasticizer to
> the polyvinyl acetate emul?sion, in an amount equivalent to 8 percent of the
> total weight of emulsion, produced dry resinous films per?manently flexible and
> ideally suited for padding and notebook work. It was observed in the course of
> this research that the addition of varying amounts of a dibutyl phthalate
> plasticizer to polyvinyl acetate emul?sion increased the viscosity or thickened
> the padding compound in proportion to the quantity added. The increase in
> viscosity was so noticeable when 10 percent of the plasticizer was added that
> bookbinders who ap?plied the adhesive to the pads complained that the com?pound
> was too thick for easy application. The thick compound did not brush on readily
> and more time was consumed in working the thick mixture. Preliminary tests made
> with a padding compound of low viscosity demonstrated that a thin compound of
> uniform vis?cosity could be more readily applied than a viscous one.
> Small amounts of water were accordingly added to the plasticized polyvinyl
> acetate emulsion in order to thin out the mixture sufficiently for easy
> application by the bookbinder. A viscosity range lying between 5 and 7 poises
> was found to be best for padding work.
> A number of experiments were conducted using various chemical plasticizers in
> arriving at the present formulas used in this Office but only a few of these
> were found suitable in properties or of reasonable cost foruse as softening
> agents. Those which best met the requirements were dibutyl phthalate, glyceryl
> triacetate, sold under the trade name "Triacetin," and 2-methyl 2'4 pentanediol,
> sold under the trade name "Hexylene Glycol." The incorporation of small amounts
> of any of these chemicals into polyvinyl acetate emulsion pro?duces a very good
> bookbinding adhesive which remains flexible upon drying of the adhesive film.
> Some advan?tages of polyvinyl acetate emulsion over other resinous adhesives are
> that it is readily diluted with water as required by the bookbinder, it is easy
> to apply, and safe to use since it contains no flammable solvents. It is also
> easily washed out of brushes and containers with water while still moist. When
> this plastic sets, it becomes water resistant.
> The ordinary bindery glues and pastes are not satisfactory for adhering
> pyroxylin treated fabrics in some bindery operations and in many instances
> binders or cases glued with these adhesives pull loose or fail to remain glued
> after they have dried. The white resinous polyvinyl acetate adhesive has been
> found excellent for the pyroxylin treated fabrics and has been used in this
> Office with complete success. This adhesive can be used for many hand operations
> in?cluding gluing-off, lining-up, and the application of rides or labels. One of
> the uses found for this adhesive was that of affixing oil cloth linings to
> pyroxylin coated binders. The adhesive for this operation was applied by a
> machine to the back of an oil cloth strip, which was then applied to the inside
> of the binder. This ad?hesive produced a strong permanent bond between the
> tumed-in edges of the pyroxylin coated film and the oil cloth. Previous
> operations of this nature using hide glue as the adhesive were not satisfactory
> unless the turned-in edges of the coated fabric were first washed with alcohol,
> adding another operational cost to the production.
> There is no necessity for the use of preservatives with this adhesive since it
> does not deteriorate upon aging nor is it subject to molds or fungus growths,
> even though it may be exposed to the air for many months. How?ever, freezing
> destroys the emulsion, and therefore pre?caution must be taken to avoid exposing
> it to freezing temperatures before using.
> This formula produces an adhesive which will firmly fasten paper, leather, or
> such fabrics as pyroxylin treated, starch filled, rubberized, or plain muslin
> cloths to cellulose acetate surfaces. It has been used in this Office in the
> production of transparent cellulose ace?tate envelopes for the protection of
> maps and photo?graphs upon exhibition. The cloth binding used on this type of
> work is glued-off by hand, permitted to dry for about two minutes, and then
> applied to the cellulose acetate surfaces.  In preparing this adhesive add the
> water to the polyvinyl acetate emulsion and then follow with the dibutyl
> phthalate and gamma valerolactone with constant stirring. Either hexylene glycol
> or tri-acetin may be substituted for dibutyl phthalate as the plasticizer.
> ----------------------------------------------
>              ***********************************************
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J. J. Foncannon
Philadelphia, PA  19139

	The Belgian surrealist painter Renee Magritte entered a cheese store in Brussels to purchase a wheel of Swiss cheese. 
The owner pulled a wheel from the front window, but Magritte said he preferred the one on the back counter.
	?But they are identical,? the owner protested.
	?No,? Magritte insisted.  ?This one?s been stared at.?

Now Online - The Bonefolder, Vol. 2, No. 1 at <http://www.philobiblon.com/bonefolder>
             For all your subscription questions, go to the
                      Book_Arts-L FAQ and Archive.
          See <http://www.philobiblon.com> for full information

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