Janka hardness of plywood reinforced with pre-impregnated cotton fabrics

Abstract

Higher properties of plywood can be achieved trough applying different non-wood materials in their structure. Тhe aim of this research is to study the Janka hardness of experimental plywood reinforced with cotton fabrics pre-impregnated with alcohol-soluble phenol-formaldehyde resin. Plywood models were made 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 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. Tests for plywood hardness according to Janka were done on each plywood model. The research results showed that the values of Janka hardness are affected by the use of pre-impregnated fabrics as reinforcements in plywood structure.