IMPREGNATION EFFICIENCY OF FLAME RETARDANTS IN HINOKI CYPRESS (CHAMAECYPARIS OBTUSA) PLYWOOD USING THE VACUUM-PRESSURE METHOD. Short notes
This study aimed to investigate the effectiveness of vacuum-pressure impregnation for the flame-retardant treatment of hinoki cypress (Chamaecyparis obtusa) plywood. The effect of impregnation duration (50–75 min) on the solid content of flame-retardant impregnation (SCFI) was analyzed. The SCFI significantly increased with rising impregnation time, as demonstrated by analysis of variance and regression analysis. In addition, the outer regions of the plywood exhibited higher impregnation efficiency than the inner regions owing to directional permeability. These results emphasize the importance of impregnation time and fiber orientation in optimizing the flame-retardant treatment processes.