EFFECT OF THERMAL MODIFICATION ON DECAY RESISTANCE OF <em>CORYMBIA CITRIODORA</em> AND <em>PINUS TAEDA</em> WOOD

Abstract

Alternative and eco-friendly technologies such as thermal modification can improve durability and dimensional stability of wood. This study evaluated the effect of thermal modification on resistance improvement of Corymbia citriodora and Pinus taeda wood against brown and white-rot fungi under laboratory conditions. Wood samples were subjected to treatment temperatures of 160, 180, 200, 220 and 240 °C in a laboratory electric furnace, under dynamic nitrogen atmosphere. A treatment temperature of 260 °C was additionally used for P. taeda. Seven planks, with dimensions of 6 cm × 16 cm × 56 cm (thickness × width × length), were used for each temperature. The thermally modified planks were transformed into prismatic test samples with dimensions of 1.9 cm × 1.9 cm × 1.9 cm. Inoculated culture bottles containing test blocks were kept in an incubation room for 12 weeks. Thermal modification temperatures at 160 and 180 °C decreased the biological resistance of C. citriodora wood. Treatment temperatures of 200, 220 and 240 °C showed satisfactory decay resistance gains for both species. Rhodonia placenta was the most degrading fungus at temperatures lower than 200 °C.