文献类型：期刊文献

中文题名：竹节对集成材胶合性能的影响

英文题名：Influence of node on the bonding properties of glued laminated bamboo

作者：李振瑞[1,2] 初石民[1] 秦理哲[3] 林兰英[1]

第一作者：李振瑞

机构：[1]中国林业科学研究院木材工业研究所,北京100091;[2]国际竹藤中心,国家林业和草原局/北京市共建竹藤科学与技术重点实验室,北京100102;[3]广西民族大学化学化工学院,南宁530008

年份：2022

卷号：7

期号：6

起止页码：80-85

中文期刊名：林业工程学报

外文期刊名：Journal of Forestry Engineering

收录：CSTPCD;;北大核心:【北大核心2020】；CSCD:【CSCD_E2021_2022】；

基金：国家自然科学基金(31370012)。

语种：中文

中文关键词：竹节;集成材;胶合性能;理化性质;解剖构造

外文关键词：node;glued laminated bamboo;bonding property;physicochemical property;anatomical structure

分类号：S781.9

摘要：竹节的分布规律使其在竹集成材生产过程中成为不可忽视的重要部位,对产品的胶合性能会产生一定的影响。为探讨竹节对竹集成材产品胶合性能的影响机制,选用毛竹(Phyllostachys)为试验对象、竹节组坯方式为变量因子,对比3种竹节组坯方式(“竹节-竹节”“竹节-节间”和“节间-节间”)胶合试样的剪切强度和木破率,主要从竹节的理化性质(密度、热水抽提物含量、pH)和解剖构造两方面分析其对胶合性能的影响。结果表明,竹节的存在能够显著提高竹集成材的胶合性能。从理化性质角度分析,竹节中热水抽提物含量低于节间,表面极性较弱,竹节与节间的pH基本一致,对胶黏剂固化时间的影响差异不明显,因此其化学特性不是竹节胶合性能优于节间的主要原因。竹节密度大于节间,是竹节胶合性能较优的主要原因之一。从解剖构造角度分析,除裸露在胶合表面的基本组织薄壁细胞和纤维细胞外,胶黏剂还可以通过竹节特有的横向维管束渗透进入竹材内部组织中,竹节较优的渗透性能是其胶合性能优于节间的重要原因。
Bamboo is one of the fast-growing, high-strength and resource-rich materials and is commonly used for structural laminated bamboo timber. However, bamboo is hollow, anisotropic, and has nodes, which makes it difficult for bamboo products obtained by directly assembling bamboo chips to meet the requirements for structural materials. The distribution law of bamboo nodes makes it an unavoidable part of the production of glued laminated products, and the nodes have a significant influence on the gluing performance of the product. Moso bamboo was chosen as the experimental object with the combination of nodes as a variable factor to study the influence mechanism of nodes on the bonding properties of the glued laminated bamboo in this study. The shear strength and wood failure percentage for three laminating types of the node(“node-node”, “node-internode”, and “node-internode”) were investigated, and two primary influencing factors, including physicochemical properties and anatomical structure, were analyzed in detail. The maximum shear strength and wood failure percentage of laminates were found in “node-node”(11.78 MPa, 88%), which was higher than that of “node-internode”(10.73 MPa, 87%) and “internode-internode”(10.20 MPa, 85%). The results indicated that the nodes could significantly improve the bonding properties of glued laminated bamboo. From the perspective of physicochemical properties, the node(16.66%) presented lower content of hot water extractive than that of the internode(20.51%), leading to a weaker surface polarity, and the pH value of the node(5.41) was almost the same as that of the internode(5.6), and the node(61 s) performed effects on the curing time of urea-formaldehyde resin similar with the internode(64 s). Hence the chemical features would not contribute to the better bonding properties of the node. The significant improvement of bonding properties could be attributed to the higher density of nodes(0.81 g/cm~3) than the internode(0.69 g/cm~3). As for the anatomical structure, the nodes contained both longitudinal and transversal vascular bundles, but the internodes only had cells arranged in the axial direction. The adhesive could penetrate the internal tissues of the bamboo through the unique transversal vascular bundle of nodes except for the parenchyma cells and fiber cells exposed to the bonded surfaces, which mainly contributed to the better permeability and bonding performance than that of internodes. In addition, vessels were tubular molecules with the largest cross-sectional dimension in bamboo vascular bundles, and the pits on their walls played a significant role in the penetration and diffusion of adhesives.