Effects of heating temperature and time on the mechanical properties of heat-treated woods

Abstract

This study was performed to investigate the effects of heat treatment the on mechanical properties of two species of wood under different heating conditions including at 180°C for 12 h and 24 h, and at 210°C for 3 h and 6 h. Two species of wood, Pinus densiflora and Larix kaempferi, were exposed to different heat treatments to assess the effects on the volume change, bending properties in static and dynamic mode and compressive strength. The results showed heat treatment caused significant changes in mechanical properties such as the static and dynamic moduli of elasticity (MOEd and MOEs), and the modulus of rupture (MOR). The volume of the wood after heat treatment decreased as the heating temperature and time were increased. The bending strength performance of the wood after heat treatment decreased as the heating temperature and time were increased. The effect of heat treatment at a high temperature on the bending MOR was greater in both species than that for a long time. However, the compressive strengths of all the heat-treated samples were higher than the control sample. Furthermore, highly significant correlations between MOEd and MOR, and MOEs and MOR were found for all heating conditions.