Abstract: The present invention relates to the manufacture of a multilayered board having a stable, and moisture resistant surface. To accomplish this and other advantages of the invention, an improved binder system is used in the production of the surface layers of a multi-layered board which combines an excellent resin penetration inside the wood constituents of the board's surface layers, with a strength, durability and resitance to ambient water and moisture. The improved-binder system used in the production of the board surface layers accordinq to this invention involves contacting wood pieces with a binder composition comprised of a curable powdery aldehyde resin and a curable isocyanate resin in the substantial absence of free water to provide a composite mixture that can be formed into a surface layer for assembly and lamination together with other wood and resin composite layers.

Abstract: The present invention relates to the manufacture of a multi-layered board having a stable, and moisture-resistant surface. To accomplish this and other advantages of the invention, an improved binder system is used in the production of the surface layers of a multi-layered board which combines an. excellent resin penetration inside the wood constituents of the board's surface layers, with a strength, durability and resistance to ambient water and moisture. The improved binder system used in the production of the board surface layers according to this invention involves contacting wood pieces with a binder composition comprised of a curable powdery aldehyde resin and a curable isocyanate resin in the substantial absence of free water to provide a composite mixture that can be formed into a surface layer for assembly and lamination together with other wood and resin composite layers.