Method of making a grooved, fiber-clad plywood panel

The method of making a plywood panel having a grooved, fiber-clad surface including the steps:

• rough machining a metal caul plate so as to produce a rough, jagged, textured surface on the upper side of said plate,
• forming a plurality of parallel ridges comprising weld beads on said upper surface of said caul plate about one-eighth inch high with converging, rough-surfaced opposite said walls adjacent said upper side of said plate,
• vacuum-forming a spongy, cellulosic, fibrous, pulp web from a slurry of cellulosic fibrous pulp and including a thermo-setting resinous material,
• juxtapositioning said web and a plywood assembly,
• assembling said caul plate and said web and the plywood assembly with said ridged surface of the caul plate next adjacent said web,
• and compressing said caul plate in a hot press under sufficient heat and pressure against said web and plywood assembly to cause steam to be formed due to the moisture from said web for softening the layer of plywood assembly next adjacent said web whereby said ridges and the jagged textured surface of said caul plate will emboss a complementary surface pattern on the outer surface of said web, with said ridges becoming releasably embedded in said plywood assembly, and will securely bond said web and the plywood assembly together.

The method of making a plywood panel having a grooved, fiber-clad surface including the steps:

• forming relatively wide and deep, spaced apart, parallel grooves in one surface of a preformed plywood panel,
• forming a caul plate with spaced apart ridges projecting from the surface of said caul plate, said ridges being located for alignment with the parallel grooves in said one surface of said preformed plywood panel, said ridges being generally complementary to said grooves in said one surface of said preformed plywood panel, but being larger in width and depth than said parallel grooves in said plywood panel,
• forming a spongy, cellulosic, fibrous, pulp web from a slurry of cellulosic, fibrous pulp, said web having a moisture content of from fifty to seventy percent, and including a thermo-setting resinous material,
• juxtaposing said web and said plywood panel with said web being disposed over said one surface of said plywood panel,
• assembling said caul plate and the assembly of the plywood panel and web in a hot press with the ridged surface of said caul plate next adjacent said web and with said ridge in alignment with said parallel grooves,
• and compressing said caul plate in said hot press against said web and plywood panel including bringing said ridges of said caul plate to bear into said parallel grooves under sufficient heat and pressure to cause steam to be formed due to the moisture from said web for softening the layer of the plywood panel next adjacent said web and producing a permanent deformation in at least said next adjacent layer by permanent movement of wooden components thereof enlarging said grooves and compressing said web between said ridges and said grooves for thorough bonding of said web into said grooves, said web being compressed against said panel by said caul plate to form a continuous protective coating over said panel, said moisture being driven out by said heat and pressure,
• wherein the side edges of said ridges of said caul plate are roughened so as to frictionally engage and stretch corresponding portions of said web and carry the same into said grooves for compression thereof without tearing of said web for causing said web to provide a non-ruptured dense overlay.