摘 要
多层板又称为胶合板,是由木段旋切成单板或由木方刨切成薄木，再用胶粘剂胶合而成的三层或多层的板状材料，通常用奇数层单板。然而，由于单板材质软、尺寸稳定性差，制成的多层板易吸湿变形，影响其使用性能。针对多层板尺寸稳定性差的问题，需对单板进行物理改性和化学改性处理。物理改性方法中较为常用是炭化改性，炭化改性通过高温热处理手段减少木材组分中吸水羟基的含量，可以降低木材的吸湿性和内应力，提高木材的尺寸稳定性。目前，国内外对炭化木质材料的物理力学性能研究主要集中在炭化木材上，对炭化单板的研究较少，对炭化单板所制多层板的物理力学性能以及炭化层分布位置对多层板力学性能的影响的研究更是较少。炭化层分布位置对多层板力学性能有着十分重要的影响。通过改变炭化层在多层板中的放置位置实验以及检测多层板的抗弯强度、弹性模量、冲击韧性等一系列指标从而确定最佳的炭化层在多层板中的放置位置。
关键词：多层板 力学性能 炭化层
Abstract
Multilayer plywood, also known as plywood, is a kind of three or more layers of laminated material, which is made up of wood segments cut into veneers by rotary cutting or thin wood planing and then bonded with adhesives. Odd layers of veneers are usually used. However, due to the soft material and poor dimensional stability of veneer, the multi-layer laminates are easy to absorb moisture and deform, which affects their performance. In order to solve the problem of poor dimensional stability of multilayer board, physical and chemical modification of veneer is needed. Carbonization modification is commonly used in physical modification methods. Carbonization modification can reduce the content of absorbent hydroxyl in wood components by means of high temperature heat treatment, reduce the moisture absorption and internal stress of wood, and improve the dimensional stability of wood. At present, the research on physical and mechanical properties of carbonized wood materials at home and abroad is mainly concentrated on carbonized wood. The research on carbonized veneer is less. The research on the physical and mechanical properties of multi-layer board made of carbonized veneer and the influence of the distribution of carbonized layer on the mechanical properties of multi-layer board is even less. The distribution of carbonization layer has a very important effect on the mechanical properties of multilayer plates. The optimum position of carbonized layer in multilayer board is determined by changing the position of carbonized layer in multilayer board and testing a series of indexes such as bending strength, elastic modulus and impact toughness of multilayer board.
Keywords：multilayer board mechanical property Carbonization layer
1.前言
随着绿色设计的理念深入人心，越来越多的人更加注重新材料的研究。关于多层板的研究国内外都涉及，将炭化后的单板制成多层板,一方面提高多层板的耐腐性,延长多层板的使用寿命,炭化后的多层板用途更加广泛。另一方面,炭化后的单板的颜色更加的均匀,色度变深,可作为良好的表面装饰材料。在木材的炭化生产过程中不添加任何化学药剂,污染问题少、处理工艺简单。并且炭化木在使用过程中不会对环境和人体造成任何损害,这不仅改善了环境、减少了污染，并且能够使人类获得更好的使用体验。
但就目前的国内外研究现状而言，将炭化板与素板（未炭化板）组合成为复合型多层板，其力学性能实际表现尚未有相关研究。炭化板对多层板的力学性能的影响规律，目前也并未有研究证明其表现的具体影响。所以对“炭化层分布位置对多层板力学性能的影响”这一课题进行具体研究。将炭化层放置于多层板的表层、中间层分别进行实验并检验其指标，这对促进多层板的生产以及满足多层板市场日新月异的需求有着十分深远的意义。
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