Експлуатаційні дослідження показників кутового зсуву клейової полімерної пластини корінцевої частини книжкового блоку

Abstract

The purpose of the work is to study the deformation of the adhesive layer of the root portion of the book block, stitched threads, the influence of the bending angles of the polymeric adhesive plate during the exploitation of book products, which contribute to the creation of zones of variable concentration of destructive stresses of the internal structure of the plate, as well as the influence of the time of the load on these areas, that proportionally influence on the reduction of the elastic properties of the plate and the development of residual plastic deformation phenomena. The amount of deformation of individual sections of a radial adhesive polymer plate, during operational loads when using book blocks stitched together, depends not only on the elastic material properties of the adhesive composition, its isotropy, the thickness of the applied layer, but also on the angles of the plate kinks that contribute to creating variable zones concentration of destructive stresses of the internal structure. Stresses occur at the edges of the joints of the glue plate with the paper of the folds of the backs of the notebooks on the one hand, and the edging paper, on the other hand, in the form of sections of compression and tension in places of discrete kinks. The duration of the loads in these areas, in proportion to the decrease in the elastic properties of the plate and the increase in the phenomena of residual deformation. Taking into account the negative influence of discrete angular bends of rooted glue polymeric plates in any part of it and the heterogeneity of the duration of loads during the exploitation of book products lead to deformation formed during bending of the plate and promotes the accelerated transformation of processes of elastic deformation into residual processes of plastic deformation. The use of high strength and high elastic adhesive compositions, which do not have a negative effect on the stiffness and bending stability of the glued system, can minimize the disadvantages of the angular displacement, which in turn will provide a prolonged operating period and a favorable competitive appearance of book products.