No abstract

Smoke treatment can be used to enhance wood resistance to subterranean termite attack. In this study, kesambi (Schleichera oleosa) wood was pyrolyzed to produce charcoal. The smoke produced as a by-product of pyrolysis was used to treat sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), mangium (Acacia mangium), and pine (Pinus merkusii) wood samples for 1, 2, or 3 weeks. Following the smoke treatment, the wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) according to the Indonesian standard 7207-2014 in a laboratory. The color change caused by smoke treatment was observed, and chemical analysis of smoke was also done. The results showed that chemical compounds of kesambi smoke predominantly consisted of acetic acid, phenol, ketones, amines, and benzene. The color of smoked wood became darker, less yellow, and a little redder, while a longer smoking period produced a darker color which was more resistant to termite attack. Smoke treatment enhanced the resistance of wood to subterranean termite attack, and the resistance levels were not significantly different based on the duration of the smoke treatment.

The objective of this work was to evaluate some of the properties of experimental wood plastic composite (WPC) panels manufactured from a low percentage of rubberwood (Hevea brasiliensis Muell. Arg), waste polyethylene terephthalate (PET) and silica at three different ratios. It was determined that water absorption values of the samples decreased with the increasing amount of PET in the panels. The lowest absorption value of 0.34% was determined for the samples having 40% PET in their content as a result of 24-h soaking. The highest hardness value of 4492 N was found for the samples made with the combination of rubberwood, PET and silica at 10%, 40% and 50%, respectively. The compressive strength of WPC specimens also followed a similar trend with the hardness characteristics of the panel and improved with increasing PET percentage. Statistical analyses revealed that values of compression strength, hardness, 2-h and 24-h water absorption of the specimens made with 20, 30, and 40% PET content resulted in significant difference from each other (p ≤ 0.0001). Based on the findings in this study it appears that increasing silica content in the samples adversely influenced their mechanical properties while creating a certain level of enhancement of water absorption of the specimens. It seems that using a combination of waste PET and a limited amount of silica with a low percentage of wood particles could have the potential to produce value-added environmentally friendly composites to be used for different applications.

Timber utilization is mostly affected by wood chemical composition and its natural durability in certain condition. This paper studies chemical composition and under shade natural durability of eight wood species originated from Banten and West Java Provinces. Chemical composition was tested based on Norman and Jenkins' methods, SNI 14-0492-1989 and SNI 14-1032-1989 and the wood natural durability test was conducted outdoor under the shade. Result shows that in general wood chemical composition of eight wood species tested is approximately in average of those in broad leaf trees. Among the wood samples studied, the highest holocellulose content was recorded from baros wood (Michelia champaca L.) which was about 75.64% and the lowest holocellulose content was recorded from pasang taritih wood (Lithocarpus elegans Blume Hatus ex Supadmo) which was about 60.19%. In term of lignin content, the highest percentage was recorded from pasang taritih wood, which was about 35.14% and it is comparable with those of ki hiyang (Albizia procera (Roxb.) Benth.) wood, which was about 25.35%. The greatest extractive content was recorded from tarisi wood (Albizia lebbeck (L) Benth), which was about 7.9%, while extractive content nemely tangkalang wood (Litsea roxburghii Hassk) falled into 1.54%. Under the shade durability test showed pasang taritih wood performed second class durability (class II), while the other seven wood species of tarisi, ki hiyang, hanja, cerei, tangkalang, baros, and kapinango were extremly non durable (class V).

Indonesian log production is dominated by young trees harvested from plantation forests. The timber contains of sapwood and juvenile wood, which are not resistant to termite attack. Smoking treatment can enhance wood resistance to termite attack, but it also changes the color. Specimens of mangium (Acacia mangium) and sengon (Falcataria moluccana) wood were exposed for 1, 2, and 3 weeks to smoke produced from the pyrolysis of salam (Syzygium polyanthum) wood. The color change of the wood was measured using the CIELab method. In addition, wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) under laboratory conditions. Untreated and imidacloprid-preserved wood samples were also prepared for comparison purposes. The results showed that the color of smoked wood differed from that of untreated wood, and the color change for sengon was greater than for mangium. In addition, the 1-week smoking period changed the wood color less than the 2-and 3-week periods, which did not differ. Imidacloprid-preserved wood had distinctive color changes compared to untreated wood. Untreated mangium wood had moderate resistance to subterranean termite attack (resistance class III), while sengon had very poor resistance (resistance class V). Salam wood smoke enhanced wood resistance to termite attack, and smoke treatment of 1 week for mangium and 2 weeks for sengon resulted in the wood becoming very resistant (resistance class I). Both types of smoked wood were more resistant to subterranean termite attack than imidacloprid-preserved wood (average class II resistance).