Research of the influence of the adhesive layer thickness on the plane of deltoid parts of the root part of book blocks

Studies of the effect of changes in the thickness of the adhesive layer on the change in the cross-sectional area of the deltoid sections of the root part of the book blocks, sewn with threads, have found that in the process of opening the book, efforts are made leading to destructive processes, with a gap in the duration of use of the book. It has been proved that the increase in the thickness of the adhesive layer leads to an increase in efforts to overcome the elastic properties of polymer plates obtained after polymerization of the applied adhesive, and which are applied with different intensity depending on the geometric inhomogeneity of the W-shaped plate. The surface tension of the concave part of the adhesive layer tangent to the folds of the notebooks increases, which leads to a decrease in the relative elongation. When performing technological calculations of the thickness of the adhesive layer, and, accordingly, the cost of glue for edging book blocks sewn with threads, it is advisable to take into account the necessary and sufficient conditions to ensure the strength and operational stability of the adhesive plate. With prolonged bending, the thickness of the adhesive plate directly affects the ability to minimize the effort applied to open the blocks. Therefore, the profile application of glue to the root of the book block, sewn with threads prevents the alignment of the outer part of the adhesive layer in the plane, which leads to overuse of glue and increase the bending force of the root of the block during reading or scanning information. Actuators of profile application of glue can be used to replace the mechanisms of modern book lines, which form a consumable adhesive geometry. Experimental studies have confirmed that the location of the points of application of forces to open the book block and bend the root adhesive plate, are accompanied by heterogeneity of deformation of semicircular and deltoid areas. This suggests that the obtained data on the impact and disproportionate deviations of changes in the thickness of the adhesive layer and the cross-sectional area of the deltoid areas, in the most obvious form, are observed in the area between the notebook space.

Keywords: adhesive composition, deltoid section, profile shaft, points of effort ap­plication.

doi: 10.32403/0554-4866-2020-1-79-89-102