EVALUATION OF FLAME RETARDANT IMPREGNATION IN PERFORATED HINOKI (CHAMAECYPARIS OBTUSA) PLYWOOD

Recently, perforated plywood has been widely used as an indoor sound absorber. Flame retardant treatment is essential for the utilization of wood materials as indoor building materials. Among the various flame retardant treatment methods, we focused on pressure impregnation of water-soluble phosphate flame retardant in commercial Hinoki (Chamaecyparis obtusa) plywood. Experimental perforation rates were 0.06%, 0.1%, 0.3%, and 1.7%, and impregnation times were 30, 60, and 90 min. Then, we evaluated the impregnation as a function of plywood perforation frequency and impregnation time using Pearson's coefficient correlation analysis and multilinear regression analysis. The greater the perforation frequency and impregnation time, the greater the impregnation. Increasing impregnation correspondingly improved the performance of the flame retardant.