Physical and mechanical properties of composites made from bamboo and woody wastes in Taiwan

This study investigated the physical and mechanical properties of six groups of bamboo–wood composites (BWC) made from bamboo and wood wastes, which are produced from the industry processing in Taiwan. Results obtained from non-destructive testing (NDT) indicated that the boards made with 100% bamboo residues (Group B) revealed higher ultrasonic-wave velocity (Vu) and tap tone sound velocity (Vt) than other BWC boards. Both Vu and Vt of composite boards were proportional to the ratio of bamboo residues contains. Three-layer composites made with bamboo/wood/bamboo residues at 1:2:1 ratio (Group B/2W/B) had the highest specific strength as well as modulus of elasticity (MOE) and modulus of rupture (MOR) among all the composites. B/2W/B composite board had structural characteristics similar to those of medium-density fiberboards (MDF) and particleboards; thus, it might have better compression resistance than other types of boards. B/2W/B composite board also had the highest screw holding strength (SHS); next was the boards composed entirely of woody wastes (Group W). The results obtained from analysis of water absorption rate (WA%) show a positive correlation with porous bamboo contents; meanwhile, wood chips have higher water-absorption swelling rate than bamboo residues. Hence, it showed greater change in thickness swelling coefficient (TS%) and volume swelling coefficient (S%)