Change of Color and Wettability of Heat-treated Hard Maple Lumber

In order to investigate change of wood color and wettability of hard maple after heated at the temperature of 165°C, 180°C and 195°C, L∗a∗b∗ was measured using a color-difference meter, the anti-absorption efficiency, anti-swelling efficiency and anti-volume efficiency of specimens were calculated in this study. The results of this study were as followings: Chrominance was lowest (17.5) for 165°C and highest (43.5) for 195°C treated specimen. As heat temperature was increasing, the whiteness index and yellowness index of the surface layer of treated specimens were reduced but redness index was increased while the whiteness index of the inner layer of specimens presented higher value, however, the yellowness index and redness index presented lower value compared to surface layer of specimens. Anti-absorption efficiency and anti-swelling efficiency of treated specimens were significantly increased as heat temperature being increasing. Anti-absorption efficiency was high when specimens were subjects to high temperature and low relative humidity and that was low when specimens were subjects to low temperature and high relative humidity.