Effect of Super High Temperature Pressure Treatment on Surface Color and Gloss of Cunninghamia lanceolata Wood

Sapwood of C. lanceolata was purchased from market in Hangzhou, Zhejiang province, and was cut into specimen with 20 mm×20 mm×20 mm. They were treated at 280℃, 300℃, 320℃ and 340℃ for 5 s and 10 s respectively for determination of various indicators of color and gloss. The results showed that the minimum luminance in tangential section of specimen treated by high temperature pressure was 45.21, 37.9% off of the control (no treatment), and that in radial section was 41.91, 38.8% off. The maximum chrominance in tangential section of specimen treated by high temperature pressure was 27.8 and 27.29 respectively. The luminance of treated specimen had negative relation with temperature and duration, but positive one with gloss. Change rate of luminance and chrominance of in tangential section of specimen was similar with that in radial section. The surface gloss (GZL) of specimen treated increased by 42.86% and that of GZT 35.42%. The experiment demonstrated that treated duration of pressure had more effect in gloss than temperature.