Surfaced oriented strand board

Abstract

Wood particles are distributed in selected patterns and bonded together by an adhesive to form a multilayer wood particleboard. The board has a central core of three layers of wood strands sandwiched between two outer surface-forming layers of fine wood particles. The wood strands forming the central core have a length which is several times greater than their width, with their fiber elements substantially parallel to their length. The fine wood particles are irregularly contoured wood particles having a width and thickness less than the average width of the strands forming the central core layers. Each of the three central core layers has its wood strands distributed in a parallel orientation pattern, with the strands in the outer two layers of the core parallel and the strands of the center layer perpendicular to those of the outer two layers to form a layer-to-layer cross-oriented strand pattern. Both surface-forming layers are composed of fine wood particles of various sizes distributed in an unoriented graduated size pattern from the outer surface to the central core, with the progressively smaller or finer wood particles closer to the outer surface of the surface layers. The multilayer wood particleboard is made by forming a multilayer mat of adhesive coated wood particles, with each layer having the wood particle and pattern characteristics described above, and then compressing the adhesive coated wood particles forming the multilayer mat in a hot platen press.