【作者】 高喜桃；

【导师】 韩健；

【作者基本信息】 中南林业科技大学 ， 木材科学与技术， 2010， 硕士

【摘要】 单板层积材(Laminated Veneer Lumber,简称LVL)具有轻质高强、力学性能稳定、尺寸规格灵活等特点,是一种高性能、生态环保的新型建筑复合材料。近年来,国内单板层积材发展迅猛。利用改性处理的速生人工林木单板,制造强度高、纹理美观的强化单板层积材,不仅能有效利用我国林木资源,而且大大提高了速生木材的产品附加值。本论文是在前人对杨木及单板层积材研究的基础上进行总结,结合实际情况对速生杨木单板增强来制造杨木单板层积材,并对其物理性质和力学强度进行了一系列的研究。研究是以速生杨木为主要原材料,用水溶性低分子量脲醛树脂、水溶性低分子量酚醛树脂浸渍处理,来制备强化杨木单板层积材。在制备强化杨木单板层积材的过程中,探讨了最佳的浸渍工艺,并通过讨论抽真空时间、树脂固体含量、浸渍温度、常压浸渍时间4个变量因子,建立材料的性能与工艺因子的关系,找出制备的最佳工艺参数。根据生产设备条件和产品的最终用途、最终性能要求,建议脲醛树脂浸渍生产工艺参数为：抽真空时间为30min、树脂固体含量为30%、浸渍温度为30-35℃、常压浸渍时间为3h；酚醛树脂浸渍生产工艺参数为：抽真空时间为30min、浸渍固体含量为25%、浸渍温度为35-40℃、常压浸渍时间为9h。通过试验方法的改进,结果表明试件的物理力学等性能,完全可以达到结构单板层积材E1标准,酚醛树脂增强杨木单板层积材达到室内外装饰结构木的要求、脲醛树脂增强杨木单板层积材达到了室内非结构用装饰木的要求。此外,通过红外光谱分析,发现浸渍增强杨木单板层积材的红外光谱与树脂的红外光谱相差并不大,对比树脂的合成工艺,可以知道树脂只是机械的填充在杨木中。透过电镜观察,发现酚醛树脂浸渍的杨木单板层积材的浸渍效果比脲醛树脂的好,树脂浸入杨木单板中时,主要是从细胞间隙浸入木材内部,其次才是透过细胞壁进入木材；通过观察发现导管的横向渗透性能比管胞细胞差很多。更多还原

【Abstract】 LVL (Laminated Veneer Lumber, referred to as LVL) which has high strength, stable mechanical properties, flexible sizes features, is a new-construction composite materials of high performance and eco-environmental characteristics. In recent years, Chinese LVL was developing rapidly. Using fast-growing artificial wood veneer which had been modified manufacture high strength and beautiful texture enhanced laminated veneer lumber, which not only can be used efficiently our forest resources, but also the fast-growing wood products’added value improved greatly.This paper is based on the summary of predecessor’s research on Poplar and LVL, to create an enhanced poplar LVL in accordance with the actual situation on the poplar wood veneer, and to conduct a series of studies on its physical properties and mechanical strength. This research use Poplar veneer as the main raw materials, use low molecular weight water-soluble PF and UF resin as dipping liquid, to manufacture intensified Poplar LVL. In the process of manufacturing intensified Poplar LVL, explore the best impregnation process, to establish the relationship between material properties and Process Factors by discussing the soaking time in the vacuum, the resin solid content, soaking temperature, soaking time at room temperature, and then identify the optimal process parameters. According to the conditions of production equipment and the product end-uses of the final performance requirements, recommending the best urea-formaldehyde resin impregnated technology parameters are:the soaking time in the vacuum is 30min,25%solid resin content, soaking temperature of 30-35℃, atmospheric pressure impregnation time is 3h; The best process parameters of PF resin impregnated production were:the soaking time in the vacuum is 30min,25%solid resin content, dipping temperature is 35-40℃, atmospheric pressure soaking time is 9h.Through the improvement of test methods, the results show that the physical mechanics properties of the specimen can completely meet the Japanese JAS standards FC1 laminated veneer lumber, Poplar LVL enhanced by PF resin can used indoor and outdoor decorative wooden structure requirements, UF Resin enhanced Poplar LVL reached interior non-structural decorative wood requirements.In addition, through infrared spectroscopy can find that there is not significant difference between the infrared spectra of soaking enhanced poplar LVL and the IR spectra of resins, and can know that the resin only filled mechanically in the poplar veneer compared to the resin’s synthesis process; Through the electron microscope can found that the result of PF resin impregnated Poplar LVL is better than urea-formaldehyde resin impregnated. When resin immersed in poplar veneer, the main gap is immersed in wood from the cells inside, then followed by cell wall into the timber; at the same time, observed that the lateral permeability of the ducal cells is much worse than the tracheid cells.更多还原