Impact of Heat Treatment on Physico-Mechanical Properties of Thermally Modified Anthocleistha djalonensis Wood

摘要

Thermal modification at relatively high temperatures is an effective method of improving the dimensional stability and mechanical properties of wood. This study was carried out to investigate the impact of heat treatment on the physico-mechanical properties of thermally modified Anthocleistha djalonensis wood. Thirty nine defect-free specimens of dimensions 20 mm × 20 mm × 60 mm were prepared for dimensional stability and compression tests. For the evaluation of static bending strength, thirty nine specimens of dimensions 20 mm × 20 mm x 300 mm were also prepared. After drying to a constant moisture content of 12%, samples were thermally treated at temperatures of 120, 140, 160 and 180°C for 60, 90 and 120 minutes duration respectively in the furnace. The mean values of the density showed a significant reduction as a function of treatment condition while an increase of the modulus of elasticity during the bending test was noticed. The minimum MOE value of samples was 3266 N/mm2 at 120°C for 1h while the maximum MOE of samples was 3908 N/mm2 at 160°C for 2h, whereas the compressive strength parallel to the fibre increased after heat treatment. It was observed that thermal modification improved dimensional stability and mechanical properties of the wood. Physical properties generally decreased with increasing temperature intensity.