热处理对毛竹竹材表面颜色的影响

为考察热处理对毛竹竹材表面颜色的影响,采用大豆油、固体石蜡、导热油、二甲基硅油、空气5种介质在200℃下对毛竹竹材热处理0.5~8 h,用国际照明委员会(CIE)制定的CIE 1976—L*a*b*颜色系统表征热处理前后竹材表面颜色,计算颜色总色差(ΔE*)、明度(L*)变化、红绿色品指数(a*)变化、黄绿色品指数(b*)变化,探讨热处理介质和处理时间对竹材颜色的影响。结果表明,不同热处理介质和处理时间均能显著改变热处理竹材表面的颜色,在相同的热处理时间下,不同介质改变毛竹竹材颜色的程度差异较大,大豆油、固体石蜡、导热油和二甲基硅油热处理竹材的ΔE*是空气的1.37~2.10倍。随着热处理时间的延长,热处理后竹材表面ΔL*、Δb*的绝对值逐渐增大;Δa*随时间的变化趋势与介质有关,空气与其他介质对Δa*的影响方向是相反的;ΔE*则随着热处理时间的延长而逐渐增大。

Effects of heat treatment on surface color of moso bamboo timber

In order to explore the effects of media and treatment time on surface color of moso bamboo timber, soybean oil, paraffin wax, heat conducting oil, polydimethylsiloxane and air were used as heating medium to treat moso bamboo timber under 200℃ for 0.5 to 8 hours, the surface color, including ΔL?,Δa?,Δb?,ΔE?, before and after heat treatment was characterized according to CIE 1976—L?a?b? system. It was found that both heat treatment media and time have significant effect on the surface color of bamboo timber, effects of different medium on surface color were different with the same treatment time, ΔE? of bamboo heat-treated with media of oybean oil, paraffin wax, heat conducting oil and polydimethylsiloxane were 1.37 to 2.10 times than that of hot air. As heat treatment time prolonged, the absolute value ofΔL?,Δb?andΔE?increased, however, the trend ofΔa?differed from hot air and other media.