The manufacturing of medium density fiberboard (MDF) using dry forming process for interior purpose requires extensive amount of thermo-setting urea formaldehyde (UF) adhesive. Unfortunately, this adhesive brings about formaldehyde emission from the resulting MDF, which was potentially harmful to human beings. The use of activated charcoal can be effective to reduce such emission. As the relevance, this research aimed to investigate the effect of activated charcoal addition to the MDF pulp on formaldehyde emission from the MDF. The fibers for the MDF-mat forming were the pulp procured from the MDF factory, resulting from the thermo-mechanical pulping (TMP) conducted on the mixed mangium wood (Acacia mangium) and rubber wood (Hevea brasiliensis) in 3:1 (w/w) proportion, respectively. Such mixed TMP pulping was also done in the factory. The bonding between TMP pulp fiber during mat forming was assisted by the use of UF adhesive. Prior to the MDF mat forming, was added to the resulting TMP pulp-fibers activated charcoal in various amount, 2%, 4% and 6% based on fiber mass as well as based on UF adhesive mass. The activated charcoal was prepared by carbonizing candle nut shell into charcoal followed by activation process using phosphate solution. Meanwhile the forming of MDF mat employed air-dry process. As the control, MDF forming with UF adhesive was performed without addition of activated charcoal. It turned out that the activated charcoal-added MDF exhibited effective reduction in formaldehyde emission and significant improvement in physical and mechanical properties, i.e. lower thickness swelling, and greater MOR, MOE and internal bond, compared to the control MDF. The use of activated charcoal at 4% based on the adhesive mass seemed to be the optimum amount. Physical and mechanical properties of the activated charcoal added MDF could mostly meet the JIS specification.

Radiata pine (Pinus radiata) peeler cores are classified as a by-product of plywood manufacture and have the potential for development as value-added solid wood products. This article outlines technical and cost analyses of microwave surface modification of radiata pine peeler cores along with the methodology, including measurements of temperature distribution and of preservative uptake and distribution following microwave heating. After microwave treatment, the highest temperatures are observed on the surfaces of the peeler cores. A gradual decrease in temperature is noted with depth within the timber. Chromated copper arsenate uptake after pressure impregnation ranges between 94 and 314 liters/m 3 . This uptake is three to nine times higher than that of control timber (no microwave treatment). Cost analyses focus on the microwave treatment of peeler cores and indicate that microwave modification costs range from US$0.95 to US$1.23 for one peeler core (i.e., US$29 to US$37 per m 3 ), depending upon electricity charges and the number of working shifts employed.

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2Bamboo signifies as one of the fastest growing plants and it can be used for various products. In tropical countries such as Indonesia and Malaysia, bamboo is abundantly available at reasonable prices, therefore it is used for numerous purposes. However, as lignocellulosic material, bamboo is susceptible to fungal and insect attacks. Heat treatment is an option to improve bamboo's durability. The objective of this study was to improve the durability of bamboo using hot oil palm treatment. A Malaysian grown bamboo species, Buluh Semantan ( ), as a study material was soaked in hot oil palm for various temperatures and soaking time, before being inoculated with the basidiomycete in an agar block test. The results demonstrated that the longer the heating time, the more improved the durability of bamboo. Altering the temperature in the palm oil treatment produced varying results. Bamboo blocks that heated in hot oil palm at 100°C for 60 minutes shows considerably less weight reduction that indicates less fungal attack. Overall, the higher the temperature, the better the durability of bamboo. Please indicates what the meaning of heat treatment in this experiment, it is not clear.

The surface color of bamboo stem changes naturally due to surrounding conditions. This paper studies the changes in bamboo surfaces color due to room temperature drying (KU) and oven drying (KO) at 60±2 °C. The color changes of four bamboo species: mayan (Gigantochloa robusta Kurz.), ater (Gigantochloa atter (Hassk) Kurz. Ex. Munro), ampel kuning (Bambusa vulgaris var. striata), and wulung (Gigantochloa atroviolacea Widjaja) were studied together with their correlation to water loss. Color measurements were conducted based on CIE-Lab system, while water content related to weight loss and thickness shrinkage during KU and KO. The result showed that there was a close relationship between water loss and discolouration of bamboo culms. The water loss of mayan, ater, and wulung showed a positive linear correlation to change of bamboo surfaces color, where the higher water loss affect greater value of color change too. Oppositely, in ampel kuning, higher water loss, affect smaller color change value (negatively correlated). This was because the natural color of ampel kuning in fresh conditions is not much different from color after drying. KU treatments, biggest thickness shrinkage was mayan = 46.03%; biggest weight reduction was ampel kuning = 28.52%; and biggest color changes (ΔE*) was ater = 15.51%. KO treatments, biggest thickness shrinkage was mayan = 52.4%; biggest weight reduction was yellow ampel = 31.19%; and biggest color changes (ΔE*) was ater = 18.8%.