INFLUENCE OF DRYING TEMPERATURE ON THE PHYSICAL AND MECHANICAL PROPERTIES OF RUBBERWOOD

Commercial drying of rubberwood at high temperature is still unknown. This study investigated the influence of high temperature on the physical and mechanical properties of rubberwood. Experiments were carried out at 60 °C (conventional temperature) and at high temperatures, namely, 100, 120, 130, 140 and 150 °C. Both quarter and flatsawn showed average thickness shrinkage of less than 7% ( 2 mm) and average width shrinkage of less than 5% ( 5 mm) after drying at conventional and high temperatures. Rubberwood exhibited greater shrinkage in thickness than in width for both radially and tangentially oriented specimens that were dried at temperatures above 100 °C. The incidence of serious collapse and/or honeycombing was not observed at all the high temperatures tested. Improvement of various mechanical properties was observed in all high temperature-dried samples up to 130 °C compared with conventionally dried material. The enhancement of specific strength properties such as hardness, compression parallel to grain and shear strength could be observed up to 150 °C.