FIRE-RESISTANT WOOD-PARTICLE COMPOSITION Russian patent published in 1995 - IPC

FIELD: wood-particle compositions. SUBSTANCE: fire-resistant wood-particle composition contains, mas.%: urea formaldehyde resin 6,9-10.8; ammonium chloride 0.1-0.2; phosphogypsum 5-15; the balance, wood chips. Wood chips are mixed with phosphogypsum and resinified with binder. Wood mass is pressed at 75 C and pressure of 2.2 MPa for 0.3 mm per millimeter of thickness. Board characteristics thickness 10 mm; ultimate strength: at static bending 17.9-22.6 MPa; swelling for 24 h 16-23.1% content of formaldehyde 7.2-9.7 mg per 100 g of board; mass loss by method of fire tube 3.8-8.8. EFFECT: higher efficiency. 2 tbl