Evaluation of Color Changes, Wettability, and Moisture Sorption of Heat-Treated Blue-Stained Radiata Pine Lumber

To improve the color and surface properties of blue-stained radiata pine, heat treatment was carried out at different temperatures and times. The color change, wettability, and dynamic moisture sorption of the wood were investigated. The results showed that, as the treatment temperature and duration time increased, the surface brightness of specimens gradually decreased, and the surface color became more reddish and blueish. In addition, the contact angle of distilled water at 0 s and 18 s gradually increased as the treatment temperature and time increased, which indicated a decrease in the surface wettability. The color of the blue -stained wood became more uniform with reduced surface wettability and hygroscopicity but increased sorption hysteresis after the treatment.