METHOD FOR PRODUCTION OF WALLBOARDS Russian patent published in 2000 - IPC

FIELD: forest and wood-working industries, in particular, production of low-toxic wallboards. SUBSTANCE: preparation of urea-formaldehyde resin in production of chip wood boards is accomplished at a carbamide-to-formaldehyde ratio equal to 1 to 1.10-1.15 mole with selection of optimum adhesiveness, the formaldehyde acceptor is selected with due account for preservation of the strength of the boards. Used as an acceptor is diphenyl propane or melamine, or carbamide - with an increase of the dry residue of resin, diphenyl propane and carbamide are introduced in resins at temperature of 15 to 40 C, and melamine, at 80 to 100 C. Binder with diphenyl propane or melamine is used in external layers, and binder with carbamide - on external layers of the briquet. EFFECT: enhanced quality of wallboards. 7 cl, 2 dwg, 4 tbl