Effect of Air Heat Treatment on the Color Change and Weight and Density Loss of Six Korean Oak Woods

Abstract

The effects of air heat treatment were evaluated on six Korean oak woods: Quercus serrata (Qs), Quercus mongolica (Qm), Quercus acutissima (Qac), Quercus aliena (Qal), Quercus dentata (Qd), and Quercus variabilis (Qv). Color change (ΔE*), weight loss, and density loss were examined using flat-sawn heartwood boards before and after treatment at 160 °C, 180 °C, 200 °C, and 220 °C for 2 h. Overall, the ΔE*, weight loss, and density loss increased with temperature. The properties between temperature and species showed distinct differences. A change to a darker color was observed in all species after treatment at 200 °C. Qm and Qd exhibited the highest and lowest L*, a*, and b* values after treatment at 220 °C, respectively. The highest ΔE* values were obtained in Qd at 160 °C, Qs at 180 °C and 200 °C, and Qv at 220 °C. Qd and Qv exhibited the highest and lowest weight losses at 160 °C, respectively. Qac and Qal showed the highest and lowest weight losses at 220 °C, respectively. Qm showed the highest density loss at all temperatures, whereas Qs had the lowest at 160 °C, and Qac had the lowest values at 180 °C, 200 °C, and 220 °C.

Keywords

• air heat treatment
• color change
• oak wood
• quercus spp.
• weight and density loss