Plywood is a wood based panel material laminated of veneers with grain direction perpendicular in adjacent layers. The usage of plywood can be expanded in cause of possibility to use special lay-up schemes tending to improve mechanical properties which depend on grain direction in outer plies. Also the presence of phenol film and thickness reducing of outer ply may influence plywood strength properties. That’s why the research purpose was to determinate the bending strength and modulus of elasticity of foiled birch plywood types with special veneer lay-up schemes, bending flatwise and edgewise. Two special plywood types produced at JSC “Latvijas Finieris”, 28 mm thick Spec1 and 30 mm thick Spec3, with different veneer lay-up schemes were chosen for bending properties determination tests according to the European standard EN 789. Specimens were tested with face veneer direction parallel and perpendicular to longitude. As well moisture content and density of a specimen were determined. Report contains bending strength properties comparison of special plywood specimen with different width and load direction. The results are bending strength is significantly higher for less wide special plywood specimens. And the bending strength of special plywood loaded edgewise are 4 % lower for Spec1 type and 9.5 % lower for Spec3 type than loaded flatwise for a specimen with same cross-sectional dimensions.
Keywords: foiled plywood, veneer lay-up schemes, bending strength, modulus of elasticity
Authors
Lipinskis I.
Department of Wood Processing, Latvia University of Agriculture, Latvia
Spulle U.
Department of Wood Processing, Latvia University of Agriculture, Latvia
Forest and Wood Products Research and Development Institute, Latvia
Tuherm H.
Department of Wood Processing, Latvia University of Agriculture, Latvia
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