METHOD FOR PRODUCTION OF FIREPROOF PLYWOOD AND PLYWOOD BOARDS Russian patent published in 1998 - IPC

FIELD: wood-working industry, in particular, methods of production of plywood and plywood boards. SUBSTANCE: method provides for production of ecologically clean fireproof high-strength plywood and large-size plywood from small-size veneer sheet without cementing and joining of sheets of finished plywood of small size. Used as adhesive is powdery mixture of solid phenolphormaldehyde resin, urotropin, hydrolyzed lignin and carbamide. Veneer sheet is impregnated in solution of diammonium phosphate with standard content of dry matter of up to 300 kg in dense cubic meter of veneer sheet. EFFECT: reduced toxicity of plywood and increased strength. 6 cl, 1 dwg