干燥温度对红锥树盘材色变化及干燥缺陷的影响  

Effects of temperature on color change and drying defects of Castanopsis hystrix wood

作　　者：刘光金[1,2] 贾宏炎 徐建民[2] LIU Guangjin;JIA Hongyan;XU Jianmin(The Experimental Centre of Tropical Forestry,Chinese Academy of Forestry,Pingxiang,Guangxi 532600,China;Research Institute of Tropical Forestry,Chinese Academy of Forestry,Guangzhou,Guangdong 510520,China)

机构地区：[1]中国林业科学研究院热带林业实验中心,广西凭祥532600 [2]中国林业科学研究院热带林业研究所,广东广州510520

出　　处：《西北农林科技大学学报（自然科学版）》2022年第4期83-92,共10页Journal of Northwest A&F University(Natural Science Edition)

基　　金：广西自然科学基金项目“珍贵树种红锥木材材色变异研究”(2018GXNSFBA294013)。

摘　　要：【目的】研究不同干燥温度条件下红锥树盘干燥过程中心材、边材材色变化及干燥缺陷,为红锥木材干燥工艺和高价值利用提供科学依据。【方法】在广西凭祥市中国林业科学研究院热带林业实验中心39年生红锥人工林内设置5块20 m×30 m的样地,每块样地选取1株优势木进行解析,截取主干0~2 m段树盘分别在60,80和120℃的恒温干燥箱内进行干燥处理,以室内常温条件下干燥为对照,每隔2 h测定不同处理树盘材色(心材材色变化指数ΔL_(ht)^(*)、Δa_(ht)^(*)、Δb_(ht)^(*)和ΔE_(ht)^(*),边材材色变化指数ΔL_(st)^(*)Δa_(st)^(*)、Δb_(st)^(*)和ΔE_(st)^(*))和心材、边材的裂纹数目、裂纹长度、裂纹宽度,采用三次曲线拟合干燥时间与材色变化的回归模型,应用单因素方差分析探究干燥温度对心材、边材的裂纹数目、裂纹长度和裂纹宽度等干燥缺陷的影响。【结果】3个干燥温度处理下,心材材色特征参数ΔL_(ht)^(*)、Δa_(ht)^(*)、Δb_(ht)^(*)和ΔE_(ht)^(*)分别为-10.59~2.85,-2.06~1.89,-4.33~-0.34和3.11~10.80,边材材色特征ΔL_(st)^(*),Δa_(st)^(*),Δb_(st)^(*)和ΔE_(st)^(*)分别为-6.99~17.32,-0.55~4.01,0.94~8.46和1.83~19.36;心材、边材均表现出亮度的热变化最大,总色差变异次之,色度变化幅度最小;单因素方差分析结果表明,常温阴干心材的裂纹数目、裂纹长度和裂纹宽度均显著低于120℃干燥处理;常温阴干与120℃干燥处理下边材的裂纹数目达到差异显著水平,而裂纹长度和裂纹宽度在常温阴干与80,120℃干燥处理下差异显著。随干燥温度增加,心材及边材裂纹数目和裂纹长度均呈增加趋势。在60,80和120℃3个干燥温度处理下,心材的裂纹数目分别为3.0,3.6和4.6条,裂纹长度分别为24.50,27.80和39.02 cm,裂纹宽度分别为2.85,2.36和4.00 mm;边材的裂纹数目分别为0.4,0.8和1.0条,裂纹长度分别为5.90,8.80和10.63 cm,裂纹宽度分别为1.26,4.09和4.47 mm【Objective】Color changes and drying defects of heartwood and sapwood areas of stem discs on Castanopsis hystrix different drying treatments were assessed to provide scientific evidences for kiln drying and utilization of C.hystrix.【Methods】Five 20 m×30 m plots were set in a 39-year-old pure C.hystrix plantation at the Experimental Centre of Tropical Forestry of Chinese Academy of Forestry in Ping-xiang,Guangxi.One dominant tree in each plot was sampled for stem analysis based on growth performance.Four discs from each dominant tree at the height of 0-2 m were collected.One disc from each sample tree was dried at room temperature as control and the other three were dried in electrically heated drying cabinet under 60,80 and 120℃,respectively.Wood color parameters(ΔL_(ht)^(*),Δa_(ht)^(*),Δb_(ht)^(*) andΔE_(ht)^(*) for heartwood andΔL_(st)^(*),Δa_(st)^(*),Δb_(st)^(*) andΔE_(st)^(*) for sapwood)and drying defects(number and size of cracks of discs)were measured and recorded every 2 hours.Cubic curve was applied to explore the relationship between drying time and color change,and one-way analysis of variance was adopted to study the effects of drying treatments on above drying defects.【Result】The heartwood color parameters ofΔL_(ht)^(*),Δa_(ht)^(*),Δb_(ht)^(*) andΔE_(ht)^(*) were-10.59―2.85,-2.06-1.89,-4.33--0.34 and 3.11-10.80 under drying temperature treatments.The corresponding values ofΔL_(st)^(*),Δa_(st)^(*),Δb_(st)^(*) andΔE_(st)^(*) of sapwood were-6.99-17.32,-0.55-4.01,0.94-8.46 and 1.83-19.36,respectively.The highest variation was observed in brightness both for sapwood and heartwood,followed by total color change.The color parameter redness and yellowness showed the lowest variations.The number and length of cracks for heartwood and sapwood showed an increasing trend with the increase of drying temperature.Under 60,80 and 120℃drying temperatures,the numbers of cracks in heartwood were 3.0,3.6 and 4.6 with length of 24.50,27.80 and 39.02 cm and widths of 2.85,2.36 and 4.00 m

关 键 词：红锥 心材 边材 干燥温度 木材材色 干燥缺陷 

分 类 号：S781.71[农业科学—木材科学与技术]