Poplar (Populus) wood was subjected in this work to thermo-hydro-mechanical treatment. The influence of the treatment parameters on the physical and mechanical properties were investigated. The wood samples were densified under three compression ratios (0%, 30%, and 50%), and thermally treated at three temperatures (180 °C, 200 °C, and 220 °C), at three thermal treatment durations (3 h, 4 h, and 5 h). The density, modulus of elasticity, modulus of rupture, radial hardness, and thickness swelling were measured. The results showed that the densities of the samples increased by 36.6% to 49.7%. As the compression rate increased, the temperature, duration, modulus of elasticity, modulus of rupture, and hardness increased. However, the dimensions of the densified samples were less stable. Compared to the densified samples, the maximum thickness swelling could be reduced by 74% (from 29.7% to 7.8%) when subjected to a thermal treatment at 220 °C for 3 h.
The effect of thermal treatment on physical and mechanical properties of Luehea divaricata hardwood
