Treating wood

Claim 1

A PROCESS OF TREATING WOOD TO RENDER IT SUITABLE FOR RESIN IMPREGNATION, COMPRISING WETTING THE WOOD WITH A DILUTE SOLUTION OF MINERAL ACID, SUBJECTING THE WOOD IN A CLOSED CHAMBER TO THE ACTION OF LIVE STEAM AT A PRESSURE OF ABOUT 105135 POUNDS PER SQUARE INCH, CONTINUALLY REMOVING THE WOOD CONDENSATES AND REACTION PRODUCTS SOLUBLE THEREIN FROM SAID CHAMBER SO AS TO AVOID DEGRADATION THEREOF, MAINTAINING THE STEAM TREATMENT AT A TEMPERATURE OF ABOUT 340* F. TO 360* F. UNTIL A LIGNIN CONTENT OF ABOUT 40% TO 45% IN THE WOOD IS OBTAINED, WASHING THE THUS TREATED WOOD WITH HOT WATER TO REMOVE WATER SOLUBLES, REPEATING THIS WASHING TREATMENT A PLURALITY OF TIMES AND REMOVING THE WASH WATER FROM THE CHAMBER, AND THEN DRYING THE WASHED WOOD BY PASSING THROUGH THE CHAMBER A FLOW OF HIGHLY HEATED, INERT, ORGANIC DRYING VAPOR THAT REMOVES THE MOISTURE AND THE ORGANIC SOLVNT SOLUBLES FROM THE WOOD.