Razak Wahab, Ros Syazmini M Ghani, Hashim W Samsi and Mohd Sukhairi M Rasat
Keywords: Cultivated timber, oil heat treatment, colour changes, strength reduction, chemical changes
Abstract: Investigations carried out to determine alteration that occurred in the oil heat treated 18-years old cultivated Acacia mangium. Harvested logs of A. mangium segregated into the bottom, middle and top portions containing heartwood and sapwood were oil heat treated in a stainless tank with palm crude oil as a heating medium at temperatures of 180, 200 and 220oC for 30, 60 and 90 minutes respectively. The evaluation of the changes in the wood performed by using BS and TAPPI standards. The relationship between the changes in the colour, strength and chemical composition, were made using correlation analysis. The result showed oil-heat treatment reduced the lightness of the wood and darkened the both parts of the wood. The strength of the wood reduced slightly after the oil-heat treatment. In the chemical compositions, the percentages of the holocellulose, ?-cellulose, hemicellulose and extractive contents decrease with the increase in treatment temperature and duration. The oil heat treatment process at 200°C for duration 60 minutes is recommended for A. mangium wood as it improved the colour of the A. mangium and uniformised the colour appearances of the sap- and heartwood. The loss in strength at this temperature and duration is acceptable as the treated wood only experiences strength loss of less than 15% in MOR.
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