MATERIAL OF CONSTRUCTION BOARDS AND METHOD OF THEIR PRODUCTION Russian patent published in 1995 - IPC

FIELD: wood-working industry. SUBSTANCE: raw material is ground up to the particle size not more than 3 mm. After that the raw material is dried up to the humidity of 12-14 per cent at the temperature of the heat-carrier 170-180 C. The carpet is shaped with the density deviation not more than 10 per cent, the cold premolding is carried out at the unit pressure of 2-2.5 MPa and the duration of 1-5 min. The hot premolding is exercised at the unit pressure of 9-10 MPa and the duration of 1 min/mm of the thickness of the ready-made board with the consequent cooling and conditioning during 15-30 days. The obtained material of the board has wt. lingo-carbohydrate compounds 28.5-33.5, polysaccharides 14.58-16.58, water in the fixed state - 12-14, hardwood raw material the rest. EFFECT: facilitated manufacture of the pressed boards of the hardwood raw material. 2 cl, 5 tbl