Factors affecting the strength and openability of tight backed, adhesive bound, hardcover volumes

The practice of tight backing adhesive bound, hard cover books has long been thought to enhance durability at the expense of openability. Tight backing is popular in a number of specialized binding markets, the most notable of which is textbook production. Yet despite their prevalence, there is a lack of information available about how the openability and durability characteristics of tight backed books are affected by variable factors in the production process. The purpose of this study was to evaluate three variables involved in the production of tight backed, adhesive bound, hardcover volumes. The three factors considered were bulk of the book block, surface area of adhesive application to the spine and paper stock. Analyses of durability was conducted using two pieces of testing apparatus, the Octagonal Tumbling Drum and the Universal Book Tester. Openability was measured using the Photocopy Openability Test. The statistical design utilized a blocked and replicated three way Analysis of Variance (ANOVA), conducted at the 0.05 alpha level. Where the data led to the rejection of the null hypothesis, a Duncan Multiple Range Test was employed to isolate the source of the variation. The procedures determined that bulk had no effect on openability, but became a factor in durability when the book was subjected to severe abuse. Paper stock was deemed to have no significant effect on either durability or openability. With regard to adhesive treatment, an inverted relationship was found to exist between durability and openability. As adhesive coating increased in surface area, durability was enhanced at the expense of openability. This was found to be a non-linear relationship. Finally, it was found that if the proper materials and construction techniques were employed in book production, then bindings with high durability could be created despite effects of other variable factors.