南京林业大学学报(自然科学版) ›› 2007, Vol. 31 ›› Issue (04): 6-10.doi: 10.3969/j.jssn.1000-2006.2007.04.002

• 研究论文 • 上一篇    下一篇

柔化辊和光滑压辊对单板质量及旋切参数的影响

蒋身学1,戴春平2,王建和2   

  1. 1. 南京林业大学竹材工程研究中心, 江苏 南京 210037; 2. 加拿大Forintek研究所, 温哥华V6T 1W5, 加拿大
  • 出版日期:2007-08-18 发布日期:2007-08-18

Veneer Quality and Lathe Parameter Setting Comparison Between Peeling with Incisor Bar and Smooth Roller Bar

JIANG Shen-xue1, DAI Chun-ping2, WANG Jian-he2   

  1. 1. Bamboo Engineering Research Center Nanjing Forestry University, Nanjing 210037, China; 2. Forintek Canada Corp. Vancouver V6T 1W5 B. C. Canada
  • Online:2007-08-18 Published:2007-08-18

摘要: <正>利用电镜技术研究美洲黑杨次生韧皮部筛管和伴胞发育过程中细胞超微结构的动态变化,观察到筛管和伴胞由同一个次生韧皮部衍生细胞分裂分化形成。筛管的发育历经未成熟期、成熟期和衰退期的变化。未成熟期筛管分子表现为细胞的径向扩展、壁的增厚、筛管质体和P-蛋白质的产生;成熟期筛管分子细胞组分发生选择性自溶,细胞核核质弥散状,核膜不清晰,或核膜清晰而核物质降解,最后细胞核完全解体转化为P-蛋白质类的物质;衰退期筛管分子细胞质完全解体消失,失去功能。在筛管成熟期间,伴胞的细胞质较浓,内含丰富的核糖核蛋白体、线粒体等细胞器,与筛管相连的细胞壁上具有胞间连丝。随着筛管功能的衰退,伴胞表现出典型的细胞程序性死亡特征,细胞质内质网库槽膨大,细胞核核周腔出现,染色质凝聚边缘化,最后细胞完全解体消失。总之,美洲黑杨次生韧皮部筛管发育首先经历了细胞去核化的过程,在维持一段时间的生理功能后细胞质逐渐解体消失,与此同时伴胞细胞核、细胞质降解。笔者推测筛管与伴胞一起作为功能复合体共同完成各自的细胞程序性死亡过程。

Abstract: In order to compare the effect of peeling with incisor bar and with smooth roller bar on veneer quality, a mini-lathe in Forintek’s laboratory was significantly upgraded by installing digit control system and two kinds of bars. Forty-five spruce blocks were peeled with incisor bar and smooth roller bar respectively so as to investigate the effect of three controllable variables, pitch angle (PA), vertical gap (VG), and horizontal gap (HG), with three level configurations and duplication twice for each controllable peeling parameters setting, on veneer quality while other parameters were fixed. The effect of bar type on veneer curl-up and thickness variation was compared. The test results demonstrated that the peeling with incisor bar could reduce green veneer curl-up ratio over 60% compared with the smooth roller bar, and generate more even veneer thickness and less veneer thickness variation than the smooth roller bar. The optimum lathe settings for incisor bar and for smooth roller bar were quite different, which indicate that the lathe settings have to be adjusted after changing bar from one to another. The optimum lathe settings for incisor bar were PA 90.5°, VG 9.84mm, and HG 2.79mm. In contrast, the optimum lathe settings for smooth roller bar were PA 88.5°, VG 11.75mm, and HG 2.54mm in this experiment.

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