Bending properties of reinforced plywood with fiberglass pre-impregnated fabrics

Abstract

One of the methods for achieving higher plywood properties is reinforcing the plywood structure trough applying different non-wood materials in it that will contribute in achieving higher physical and mechanical properties of the end product. The aim of the research presented in this paper is to study the bending properties of plywood reinforced with fiberglass fabrics pre-impregnated with alcohol-soluble phenol-formaldehyde resin. The pre-impregnated fabrics were incorporated as layers in the structure of the plywood panel. Different models of reinforced plywood were made through a change of the position of the reinforcing layers in the structure of the panel. One additional model was made without reinforcements as comparing plywood model. Plywood composition was consisted of eleven layers of peeled beech veneers with thickness of 1.5 mm and 1.85 mm. Alcohol-soluble phenol-formaldehyde resin was used as plywood binder. The bending strength and modulus of elasticity in bending of the plywood panels were tested in two directions: parallel and perpendicular to the face grain. The research results showed that the values of bending strength and modulus of elasticity in bending are significantly affected by the use of pre-impregnated fiberglass fabrics as reinforcements in plywood structure.