SHORT NOTE. THERMAL CHARACTERISTICS OF SENGON WOOD DRYING USING INFRARED AND COMBINED INFRARED-HOT AIR METHODS

This research aimed to determine the thermal characteristics of sengon wood due to drying at temperature of 70, 80, and 90oC with air velocity of 1 and 3 m/s using infrared (IR) and combined infrared-hot air (IR-HA) method. The thermal characteristics analyzed included temperature distribution, reduction in moisture content, and drying rate. The results of drying wood samples using IR method showed that the fastest drying time was obtained at 90oC with air velocity of 1 m/s. However, for combined IR-HA method, the optimal condition was achieved at air velocity of 3 m/s. The largest drying rate attained using combined IR-HA method was 0.27 g/min, while the smallest was recorded at 0.094 g/min with IR method. These results showed that combined IR-HA method produced a more evenly distributed temperature and faster drying time compared to the IR method

Dimensional stability and durability of hybrid sandwich panel made from oil palm lumber, sengon and gmelina with boron-alum impregnation

In this study, sandwich panels made from oil palm lumber, sengon, and gmelina wood were impregnated with a boron-alum solution to improve their water and termite resistance. Water resistance testing was evaluated using a thickness swelling test following the method in SNI 03-2105. The sandwich panel was also tested for its durability against dry wood termites, according to SNI 01-7207. The weight loss, mortality, and attack degree were used as the parameters for evaluating termite durability. The results showed that the treatment with a boron-alum solution can increase the stability, water resistance, and weight loss properties up to 73%, 41%, and 100%, respectively. The best properties of the sandwich panel were obtained by the sengon-isocyanate panel with 8% boric acid-borax and 5% alum treatment which has thickness swelling of 2.37%, water absorption of 49.04%, weight loss of 0.0124%, termite mortality of 100%, and attack degree of 0.