EFFECTS OF ANATOMICAL CHARACTERISTICS AND WOOD DENSITY ON SURFACE ROUGHNESS AND THEIR RELATION TO SURFACE WETTABILITY OF HARDWOOD

Adhesion capability of timbers varies greatly depending on anatomical structure and origin of the species. Unlike temperate hardwood, tropical hardwood has slightly different anatomical structure due to the influence of growing season. This study evaluates the anatomical structure of three tropical hardwood species of different densities, namely, batai, sesendok and kedondong and their effects on surface roughness and wettability. Rubberwood was used as control. The fibre length, wall thickness, lumen diameter, fibre diameter, vessel diameter, density, surface roughness and wettability were determined according to the relevant standards. The study showed that the strength of the relationship varied according to species and anatomical structure. Very good correlations (r(2) > 0.8) were obtained between the anatomical characteristics and density, surface roughness and surface wettability for batai, sesendok, kedondong and rubberwood. Rubberwood behaved differently than the three species while batai and sesendok were quite similar. Density and surface roughness were highly influenced by fibre wall and cell wall thicknesses while contact angle, by fibre length, fibre diameter, fibre wall thickness and lumen diameter. Surface wettability of the wood was influenced mainly by fibre wall thickness and surface roughness.