Justification of the choice of gluing mode for plywood from hardwoods

Plywood is a wood-based board material made of thin sheets of veneer. Plywood is the most demanded material in construction and industry not only in Russia, but also abroad. The sphere of its application is diverse: furniture, interior and decorative items, construction, packaging, beekeeping, aircraft and machine building, shipbuilding, arms industry, rocket building, manufacture of musical instruments, advertising industry. All researches conducted to date, both world and Russian scientists are aimed at finding ways to improve the strength characteristics of plywood, to develop a popular range to meet the needs of modern society. The purpose of the present work is to substantiate the choice of gluing mode of hardwood plywood, to study the specifics of the processes occurring during the pressing of plywood, to substantiate them from the theoretical and practical point of view. The application of the method of forming the package with the displacement of the middle layer by 450 will allow to achieve an increase in the shear strength of the glue layer by 46% for birch plywood, by 17% for aspen plywood and by 44% for beech plywood. In case of production applications, it is recommended to form such sheets from lump veneer. The recommended modes of pressing of hardwood plywood will provide the value of the shear strength on the glue layer, corresponding to GOST 3916.1- 2018 [22]. At the same time, the use of increased pressure is justified only in the production of plywood from aspen veneer; for other species, changing the value of pressing and pressing pressure is not reasonable.