节子的性质及其对木材材性的影响  

Nature of the Knot and Its Impact on Wood Properties

作　　者：李明月 陈东升[2] 王雪玉[1] 任海青[1] LI Ming-yue;CHEN Dong-sheng;WANG Xue-yu;REN Hai-qing(Research Institute of Wood Industry,CAF,Beijing 100091,China;Institute of Forestry,CAF,Beijing 100091,China)

机构地区：[1]中国林业科学研究院木材工业研究所,北京100091 [2]中国林业科学研究院林业研究所,北京100091

出　　处：《西北林学院学报》2020年第4期197-204,共8页Journal of Northwest Forestry University

基　　金：中央级公益性科研院所基本科研业务费专项。

摘　　要：树节是指树干内部的枝条基部或枯死枝条形成的结疤,在用材中称为节子。在树木生长过程中节子独特的理化性能对树木的生长有良好的作用。但是在木材加工利用过程中节子的存在严重影响木材性能和加工利用。本研究对节子的构造、物理力学性质、化学性质和检测方法等5个方面研究现状进行了总结。节子的存在对于树木的生长过程中枝条与树干之间最佳连接方式,无论在应力作用还是外部细菌等因素的影响下,节子在树木生长过程中所体现的物理性能和化学性能都有着良好的作用。但是在木材的利用中,节子对于木材力学性能和加工性能的影响巨大,不仅对于刀具损伤较大,在一定程度上降低木材的抗拉、抗压、抗弯性能,同时对于木结构连接部位的力学性能也有一定影响。目前国内外对于板材节子检测的研究较充分,但是对于原木的节子检测研究较少。在有节材力学性能预测方向,得到了较为精准的预测模型。并且通过节子特征、林木密度、树龄、树干特征等对节子进行预测,帮助在树木生长过程中对木材进行改良。现阶段对节子的研究主要集中在力学性能和检测等方向,对于节子部位的超微观构造和构造智能性利用等方面相对薄弱,对于节子如何影响木材力学性能的机理并未深入。Branch knot,which is called knot when it is in timber,refers the base of the branch within the trunk or the left branch base after the branch is removed from the trunk.In tree growth,the unique physical and chemical properties of knot have a good effect on the growth of trees.However,in wood processing and utilization,the existence of knot seriously affects the wood properties and processing and utilization of wood.In this paper,the research status of knot was summarized from five aspects:knot structure,physical and mechanical properties,chemical properties,and detection methods.The existence of knot plays very beneficial roles in the best connection between tree trunk and branches and in tree growth,no matter under the influence of stress or external bacteria and other factors.However,in the use of timber,knot presents huge negative impacts on wood mechanical properties and processing properties.It causes great damage to the wood processing tools,reduces the tensile,compressive,bending properties of wood to a certain extent.In addition,it also imposes destructive effects on mechanical properties of the wood structure connection parts.At present,there are many researches on the detection of plank knot at home and abroad,but few on the detection of log knot.In the aspect of predicting mechanical properties of the woods with knots,some more accurate models were obtained.The knots can be predicted by their characteristics,tree density,tree age and trunk characteristics,so as to improve the wood quality during tree growth.The current knot research interests mainly focused on wood mechanical properties and knot detection.Few are on knot supermicroscopic structure and utilization of structural intelligence,as well as the mechanism that how knot affects wood mechanical properties.

关 键 词：节子构造 木材材性 节子检测 

分 类 号：S781.5[农业科学—木材科学与技术]