Process of making fiberboard from groundwood

Claim 1

IN A PROCESS OF MAKING FIBERBOARD CONSISTING ESSENTIALLY OF A MAT OF FIBERS OF WOOD, THE STEPS WHICH COMPRISE PRODUCING IN A SINGLE GRINGING OPERATING FIBERS OF SUCH COARSENESS THAT FROM 7% TO 20% WILL BE RETAINED ON A 103 MESH SCREEN AND THE RATIO OF TOTAL SHORT FIBER TO TOTAL LONG FIBER GREATER THAN 65 MESH IN SIZE WILL BE BETWEEN 2 TO 1 AND 1 TO 3 BY SUBJECTING PIECES OF WOOD TO LONGITUDINAL GRINDING BY PRESSING THE WOOD AGAINST THE CURVED PERIPHERAL GRINDING SURFACE OF A ROTATING GRINDING STONE THE DIAMETER OF WHICH IS GREATER THAN THE LENGTH OF THE PIECES OF WOOD AND THE AVERAGE GRIT OF WHICH IS AT LEAST AS COARSE AS 27, WITH THE DIRECTION OF THE GRAIN OF THE WOOD LYING SUBSTANTIALLY NORMAL TO THE AXIS OF ROTATION OF THE GRINDING STONE, AND WITH A LINE DRAWN PERPENDICULARLY TO THE LONGITUDINAL AXIS OF THE WOOD AND PASSIGN THROUGH THE AXIS OF THE GRINDING STONE SUBSTANTIALLY BISECTING THE LENGTH OF THE PIECES OF WOOD AND LYING SUBSTANTIALLY PARALLEL TO THE DIRECTION OF PRESSURE APPLICATION, SAID RELATIONSHIP BEING MAINTAINED SUBSTANTIALLY THROUGHOUT THE GRINDING OPERATION, REMOVING ANY GROSS PARTICLES SUCH AS KNOTS BUT RETAINING SUBSTANTIALLY ALL OF THE GROUND MATERIAL, AND FORMING A FIBERBOARD DIREACTLY FROM AN AQUEOUS SLURRY THE FIBER FRACTION OF WHICH CONSISTS SUBSTANTIALLY WHOLLY OF THE FIBERS SO FORMED.