Creep behaviour of commercial wood based boards under long-term loading at room conditions in Taiwan

The purpose of this study was to investigate the creep behaviour of commercial wood based boards (sanded and laminated) under long-term loading at room conditions in Taiwan. Ten types of commercial wood based boards were used to test their physical and mechanical properties in this study. Four types of these boards were used for the same test after laminating with red oak (Quercus spp.) veneer or balanced paper. The bending creep was measured at room conditions with central concentrated loading. The values for creep deflection of commercial wood based boards 18 mm thick decreased from 1.06-1.19 mm to 1.00-1.12 mm after laminating veneer or balanced paper. The relative creep (120 days) of those specimens decreased from 1.71-3.17 to 1.43-2.04 after laminating with veneer or balanced paper in four months' loading. The creep deflections of specimens increased with increasing loading time. The linear regression function is t/y = a + bt, where t is time, y is deflection. When the b value is larger, the boards displayed good creep resistance. The residual bending strength of wood based boards after creep test would be retained at about 80-95%, and the residual bending strength between particleboard proved more significant than between fiberboard.