EFFECTS OF SUPERHEATED STEAM TREATMENT ON THE PHYSICAL AND MECHANICAL PROPERTIES OF LIGHT RED MERANTI AND KEDONDONG WOOD

Abstract

In this study, the effects of superheated steam treatment on physical and mechanical properties of light red meranti (Shorea spp.) and kedondong (Canarium spp.) wood were investigated. Wood samples with dimensions of 25 mm thickness × 25 mm width × 410 mm length were heat treated using superheated steam. Wood samples were heat treated at nine treatment levels ranging from 172 to 228 °C and 95 to 265 min. A set of untreated wood served as control. The physical properties such as mass loss, equilibrium moisture content (EMC) and moisture excluding efficiency (MEE) were determined. Bending strength, modulus of rupture and modulus of elasticity of the treated and untreated wood samples were determined. Mass loss was observed in the treated samples and its extent increased with increasing temperature and time. EMC of the treated samples was reduced and high MEE values were recorded, indicating decreased hygroscopicity of the treated wood. On the contrary, bending strength of the treated wood was negatively affected by the superheated steam treatment. Such reductions in mechanical properties became greater with increasing temperature and exposure time.