SURFACE ROUGHNESS AND WETTABILITY PERFORMANCE OF THERMALLY MODIFIED ROWAN WOOD AS A FAST-GROWING SPECIES

Abstract

This study aims to examine the effect of the thermal modification process on the surface roughness properties of the wood of rowan (Sorbus aucuparia L.) as a fast-growing species. Four thermal modification processes were applied, with temperatures of 160 and 180 degrees C and durations of 2 and 4 hours. In total five groups were compared, including the untreated group. Arithmetical mean roughness, maximum height, ten-spot average roughness, and root-mean-square deviation were measured using a stylus-type profilometer, both parallel and perpendicular to the grain, according to the JIS B 0601 standard. Wettability was determined by measuring the contact angle of a droplet of distilled water. After dripping, the camera captured several images to measure the contact angle. The results showed that thermal modification decreases the wettability of the samples. Moreover, increments in temperature and duration may further decrease wettability. On the other hand, there are no significant differences between groups in terms of the surface roughness values, measured both parallel and perpendicular to the grain, except for two groups. It is concluded that these process conditions did not substantially change the surface roughness properties of rowan wood panels. However; the decrease in wettability may provide new possibilities for the use of less-known wood species.