Method of making hardboard

Claim 1

THE PROCESS OF MAKING A CELLULOSIC FIBER PRODUCT OF THE CHARACTER OF LUMBER WHICH COMPRISES PREPARING A PULP OF WOOD FIBERS; FORMING SAID PULP INTO AN AQUEOUS SLURRY; ADDING TO SAID AQUEOUS SLURRY A THERMOSETTING RESIN IN PROPORTIONS OF ABOUT 1% TO 5% BY WEIGHT OF THE DRY FIBER CONTENT; PRECIPITATING THE RESIN UPON SAID FIBERS WHILE IN SAID SLURRY BY REDUCING THE ACIDITY OF THE SLURRY TO A POINT WHERE THE RESIN PRECIPITATES THEREBY FIX THE SAME IN AND UPON SAID FIBERS; PREPARING A WET LAP OF SAID FIBERS ON A BOARD FORMING MACHINE; APPLYING TO THE SURFACES OF SAID WET LAP WHILE STILL IN WET CONDITION A LIQUID TREATING MIX CONTAINING A THERMOSETTING RESIN, SAID THERMOSETTING RESIN BEING UNIFORMLY DISPERSED AS FINE SOLID PARTICLES AS IMPREGNATED IN SAID WET LAP, SAID TREATING MIX BEING OF A CONCENTRATION AND BEING APPLIED AT A RATE SO AS TO PROVIDE ABOUT 10 TO 40 POUNDS OF TREATING SOLIDS PER THOUSAND SQUARD FEET OF WET LAP; AND THEREAFTER HOT PRESSING SAID WET LAP SIMULTANEOUSLY TO CAUSE THE FIBERS TO BECOME COALESCED AND CONSOLIDATED INTO A HARD, RIGID BOARD AND TO CURE THE THERMOSETTING RESIN.