Process of making board products

Claim 1

THE PROCESS OF FORMING BOARD PRODUCTS COMPRISING FORMING A PAIR OF LOOSELY FELTED WEBS FROM A THIN SLURRY OF CELLULOSIC FIBERS IN WATER, HEATING THE WEBS TO REDUCE THE FREE WATER CONTENT THEREOF TO AN AMOUNT NOT LESS THAN TWENTY PERCENT OF THE WEIGHT OF THE WEBS WITHOUT APPRECIABLE COMPRESSION THEREOF, IMMEDIATELY THEREAFTER COATING THE OUTER SURFACES OF THE HEATED WEBS WITH A DRYING OIL, INTERPOSING A LAYER OF COARSE WOODEN COMPONENTS BETWEEN SAID WEBS, SAID WOOD COMPONENTS BEING COATED WITH AN ADHESIVE MIXTURE OF ABOUT FIVE PERCENT BY WEIGHT OF SOYBEAN FLOUR AND ABOUT ONE PERCENT BY WEIGHT OF A SINGLE STAGE, POWDERED PHENOLIC RESIN WHICH IS SOLUBLE IN ALCOHOL OR ACETONE AND INSOLUBLE IN WATER, AND ALSO COATED WITH ABOUT ONE-HALF TO ONE PERCENT BY WEIGHT OF A PARAFFIN SIZING APPLIED AFTER APPLYING THE ADHESIVE MIXTURE, SAID WOOD COMPONENTS BEING MOIST TO THE EXTENT OF ABOUT TWENTY TO SIXTY PERCENT BY WEIGHT OF THE DRY WEIGHT OF THE WOOD COMPONENTS, THEN CONSOLIDATING THE WHOLE UNDER HEAT AND PRESSURE, THE HEAT BEING IN THE RANGE OF 275*F. TO 325*F., THE PRESSURE BEING ABOUT 50 P.S.I., WITH THE HEAT AND PRESSURE BEING MAINTAINED FOR SUFFICIENT TIME, IN THE RANGE OF ONEHALF TO TWO HOURS, TO RENDER THE PRODUCT SUBSTANTIALLY BONE DRY AND LIMITING THE EXTENT OF COMPRESSION, THEN COOLING THE PRODUCT WHILE EXPOSED TO FREELY CIRCULATING AIR UNTIL REHUMIDIFIED BACK TO THE NORMAL SIX OR SEVEN PERCENT, TO FORM A BOARD PRODUCT OF CONSOLIDATED WOOD COMPONENTS HAVING A DENSITY OF ABOUT 0.6 AND HAVING THIN, DENSE SKINS OF OIL-TEMPERED CONSOLIDATED FIBERS BONDED TO THE BROAD SURFACES THEREOF WITH THE FIBERS ON THE INNER SURFACES OF THE SKINS INTERLOCKED WITH THE ADJACENT SURFACE FIBERS OF THE CORE COMPONENTS AND BONDED THERETO BY THE ADHESIVE.