GB881301A - Method of making consolidated lignocellulose boards - Google Patents

Abstract

881,301. Making wood fibre - board. BOWATER BOARD CO. Jan. 25, 1960 [March 3, 1959], No. 2607/60. Class 96. In the production of wood fibre-board, lignocellulose particles, e.g. of pine, cedar, hemlock, fir, hickory, oak, beech, birch, or maple are formed into a compact mat containing 6 to 16% of water, and 0.5 to 10% of resin, e.g. with 1 to 3.5% of wax, the mat is placed between smooth, imperforate platens of a press, and subjected to a temperature of 380‹ to 520‹ F. and to pressure greater than that of saturated steam at that temperature, such pressure being between 600 and 1200 lbs. per sq. in., until the mat is compressed to board of the desired density, the pressure being then reduced to below that of the saturated steam but not less than 100 lbs. per sq. in. to allow the steam to escape with a high-pitched noise, such reduced pressure being maintained until the noise ceases, and thereafter further reducing the pressure. The board thus made is stated to be of high strength, and resistant to moisture absorption and to abrasion, the hard, smooth surfaces having been undamaged by escaping steam. The board may be uniform, or it may have coarser fibres inside, and finer surface layers. Its specific gravity may be 0.8 to 1.2.