压缩木研究现状与今后展望

压缩木技术研究历史很久。早在20世纪30年代,美国、德国的军用飞机上为防雷达发现就使用了压缩木。40年代日本京都大学木质研究所也以同样的目的,采用高温加压方式生产出山毛榉、桦木强化木材。近10年的压缩木研究目的是提高人工林软质材的强度、加工性能及扩大人工林木材的用途,研究内容主要分为“木材横向压缩变形”和“木材压缩变形的固定”两个方面。     

木材染色研究现状及功能化展望

通过功能化染色对木材提质增效,可以充分发挥我国丰富的人工林资源优势。本文综述了木材染色染料种类、染色机理、染色工艺和染色材性能等研究进展,简要分析了木材染色存在的主要问题,建议从功能拓展、染色智能化、专用染料研发和仿生结构染色等方面加强木材染色研究,推动现代木材染色向多功能化、智能化和生态化发展。     

第16届木材机械加工国际会议综述

第16届木材机械加工国际会议于2003年8月24日~27日在日本松江市举行。会议反映了国际木材机械加工领域的最新进展和研究动向。本文介绍了会议的概况和会议的主要内容。     

亚美马褂木与北美鹅掌楸木材的机械加工性能评价

本试验以亚美马褂木为主要研究对象,同时选取家具常用材北美鹅掌楸作为对照,参考LY/T 2054-2012《锯材机械加工性能评价方法》,对两种木材的刨削、砂削、铣削、钻削、开榫、车削性能进行测试。通过两者机械加工性能的对比分析,探究亚美马褂木作为家具常用材替代用材的可能性,达到增值利用的目的。试验结果表明:1)亚美马褂木与北美鹅掌楸的机械加工性能综合评分分别为47和48,均达到优秀等级。除钻削性能为良好等级外,两种木材在刨削、砂削、铣削、开榫和车削加工中表现优秀。2)当刨削深度为0.8 mm、进料速度为8 m/min时,两种木材的刨削性能最佳。3)树种对砂削性能的影响并不明显,120目砂纸的砂削效果优于80目砂纸。     

低质人工林木材家具关键连接部位接合方式研究

为了提高低质人工林木材家具关键连接部位接合强度,改善家具关键部位易松动、变形等质量缺陷。本文基于低质人工林木材材性,通过实验研究与实践经验相结合,对"T"型和"L"型部位的各种榫接合方式进行了研究分析。提出采用张紧木楔、多榫接合、胶黏剂强化以及局部补强等措施,优化现有接合方式,增强低质人工林木材家具关键连接部位的力学性能。     

林纸一体化与人工林培育的生物木材学研究

从发展林纸一体化的角度出发，阐述了林纸一体化将促进林业实现有序的良性生产。向规模化和产业化方向发展；介绍了林纸一体化与人工林培育的生物木材学的关系。纸浆用材生物木材学研究内容主要为不同高得率制浆技术纸浆性能对速生材最低的材性要求。化学组成与制浆性能的关系，材性与制浆性能的关系，纤维形态与制浆性能的关系。以及提出科学合理的定向培育纸浆材的制浆工艺技术对木材要求基准。     

拉脱维亚木材及制浆化学现状

拉脱维亚木材化学研究院的研究范围包括：木材化学、木材生物化学和木材的机械加工等方面的发展趋势。     

硅溶胶强化复合木材制备工艺研究

以硅溶胶为浸渍处理液,采用真空加压复合工艺制备强化杨树复合木材。集中研究了前真空时间、浸渍压力、浸渍时间、后真空处理时间4个浸渍工艺因子对复合木材性能的影响。结果表明,延长前真空处理时间和提高浸渍压力可以获得较高增重率的复合木材;经真空加压处理后的硅溶胶复合木材抗弯强度和抗弯弹性模量都得到提高,但为了获得较好的弯曲性能,不宜选用较高的浸渍压力和较长的浸渍时间。对于人工林杨树木材,在本研究条件下最适宜的浸渍处理工艺为：前真空时间20min,浸渍压力1.0MPa,浸渍时间30min,后真空时间为20min。     

密实型单板层积材研究现状与发展前景

介绍了人工林木材密实化改性研究现状与发展趋势,提出针对我国人工林材质特性,研究开发出合适的速生林高效利用技术,对生产密实型单板层积材的可行性和发展前景进行了探讨.     

木材树脂浸渍多功能改性的研究进展

树脂浸渍多功能改性是提高人工林木材性能及附加值,实现其高效利用的重要途径。本文综述了影响树脂增强改性的主要因素,包括树脂类型、分子量、固含量、树脂分布状态、木材材性和浸渍工艺等,重点阐述了增强-阻燃改性、增强-防腐改性以及增强-染色改性等树脂多效改性技术,并展望了树脂浸渍多功能改性的发展趋势,旨在为木材的浸渍改性研究提供参考。     

Physical properties of burnt timber, with special focus on the drying performance

Burnt wood has been found to perform different from sound (green) wood when dried together, but also with regards to other physical and mechanical properties. In this study the drying performance of wood burnt to different degrees in recent plantation fires was investigated, and the physical, chemical and wood anatomical properties of these different wood types were determined. Different cell structure and chemical composition due to thermal degradation could be observed as well as different drying performance and variation in mechanical properties. An explanation for the deviant drying performance was attempted with the observed structural changes.     

CT技术在木材工业中的应用

介绍了作者应用CT技术实现原木内部缺陷的无损检测、原木图象的三维重建和虚拟加工、以及木材内部密度和干燥过程中水分的分布等方面的初步研究成果,并对CT技术在木材科学研究中的一些问题和工业中的应用前景作了探讨.     

Properties of juvenile and mature woods of Hevea brasiliensis untapped and with tapping panels

This study was aimed at evaluating the properties of juvenile and mature wood from Hevea brasiliensis untapped and with tapping panels. Boards were taken from a 53-year-old Hevea brasiliensis plantation located in Tabapuã, São Paulo, Brazil. Half of the boards had the tapping panels region, and the other half had the untapped region. The results showed that: (1) there were increases of 6.6 % in the volumetric shrinkage of mature wood when compared with juvenile wood; (2) the densities and chemical properties of juvenile and mature woods are statistically equal; and (3) the tapping panel does not influence the properties of rubberwood.     

Influence of the manner of excitation of a machining system on the stability of the process of periodic circular cutting of wood tissue

The article deals with dynamic analysis of the influence of the manner of excitation of a machining system on the stability of the process of periodic circular cutting of wood tissue at an invariable frequency of cutting, taking into account dynamic properties of the machining system. For stability analysis we used a dynamic model developed for this purpose (Bu?ar and Kopa? 1996). The manner of excitation of the machining system has been defined by the radial immersion of the tool and the workpiece, taking into consideration, in modelling the process of cutting, both internal and external modulation of the cutting or exciting force. The internal modulation is the result of the effect of the properties of the machined material which are given by specific cutting pressurek _s, while the external modulation is the consequence of the varying material flux which is affected by relative displacements between the workpiece and the tool. Relative displacements, which are the result of the manner of excitation and dynamic properties of the machining system, are also the cause of self-excitation occurence. The results of analyses point to it that the manner of excitation of a machining system with known dynamic properties is of the essence for the stability of the process of periodic circular cutting of wood tissue.     

Dynamic model for the determination of instability of periodic circular cutting of wood tissue

Shown is a dynamic model of periodic circular cutting of oriented wood tissue in which both the properties of the material and the dynamic properties of the machining system have been considered. The cutting or exciting force is the result of internal and external modulation. The internal modulation is the result of the effect of the properties of the machined material which are given by specific cutting pressure k _s, while the external modulation is the consequence of the varying material flux which is affected by relative displacements between the workpiece and the tool. Relative displacements, which are the consequence of the manner of excitation and dynamic properties of the machining system, are also the cause of self-excitation occurrence. As in the process of cutting, the cutting or self-exciting force depends on relative displacements between the tool and the workpiece, the dynamic model developed is non-linear. By simulation of a dynamic model it is possible to analyse the process of cutting wood tissue in its entirety, and it can thus be employed to optimize the selection of tools and the processing parameters of machining.     

西南桦木材化学成分及其变异的研究

按照我国木材化学成分分析标准,对人工林西南桦木材化学成分进行了测定,结果表明含量分别为:纤维素47.31%,多戊糖23.99%,木质素24.57%,热水抽提物4.41%,1%NaOH抽提物15.15%,笨醇抽提物1.80%,pH值4.61;以上7个指标在树干不同高度的差异均未达到显著性水平;热水、1%NaOH抽提物含量和pH值在不同树龄间的差异达到了1%显著性水平;苯醇抽提物含量达到5%显著性水平.主要化学成分含量的差异不显著.比较分析认为,就木材化学成分而言,西南桦是比较理想的板材和造纸原料.     

马褂木人工林的生长和制浆造纸性能

基于优良种源筛选和人工林丰产特性研究，对8年生马褂木纤维形态、木材化学组分以及CTMP成浆物理性能进行测试分析，马褂木纤维细长，纤维形态与针叶树的幼龄材相似，其长度远大于其他阔叶树种。与速生桉木、杨木及四川桤木相比，马褂木综纤维素含量较高，戊聚糖含量中等，而木素和抽出物含量较低，CTMP成浆的抗张和撕裂强度较高，纤维分布均匀，浆料白度与四川桤木相近。     

Prediction of non-recoverable collapse in Eucalyptus globulus from near infrared scanning of radial wood samples

Near infrared (NIR) spectroscopy calibrations was used to predict radial profiles of cellulose content, wood density, cellulose microfibril angle (MFA) and modulus of elasticity (MOE) in 20-year-old plantation Eucalyptus globulus to identify non-recoverable collapse zones associated with tension wood. Radial (cambium-to-pith) wood cores were extracted at a height of 1.0 m from trees selected to represent a range of silvicultural treatments. NIR spectra were measured at 1 mm intervals along the radial-longitudinal face of each core after drying to 12 % equilibrium moisture content (EMC) at 40 °C. Tangential shrinkage was measured at eight points along each core, following steam reconditioning and re-drying to 12 % EMC. Additional cores from 20 of the sample trees were collected. Radial profiles of density, MFA and MOE were obtained for wood strips prepared from these cores, using the SilviScan 3 wood assessment system. Trait profiles were matched to radial NIR scans of these cores, enabling the development of NIR calibrations using partial least squares (PLS) regression. These, and an existing NIR calibration for cellulose content, were used to predict the radial profiles of the four wood properties for the first set of cores. Predicted wood properties were then related to actual tangential shrinkage measurements and the occurrence of visible bands of non-recoverable collapse. A regression model was developed to reliably predict regions of non-recoverable collapse from NIR-predicted cellulose content and MOE. Micrography of stained wood sections indicated that the collapse was caused by the presence of tension wood.     

Influence of mechanical properties and mineral salts in wood species on tool wear of high-speed steels and stellite-tipped tools – Consideration of tool wear of the newly developed tip-inserted band saw

This paper is the third in a series of work done on a novel technique for bandsawing, which uses a tip-inserted saw, and is gaining increasing popularity in Japan. It builds up on previous reports on the novel technique for bandsawing, which considered cutting tool hardness, tool wear, accuracy of kerf width, washboarding, and surface profiles of the workpiece. In this paper, ash content analysis and three-point static bending tests were conducted to clarify the influence of mineral salts and mechanical properties of wood samples of Elais guineensis (Oil palm), Strombosia glaucescens (Afina), and Cryptomeria japonica (Sugi) on cutting tool wear. The cutting tools were made from Stellite and High Speed Steels (HSS) of designations SUS420J2 and TiN coated SKH 51 according to the Japan Industrial Standards (JIS). Among the tested wood samples, the highest cutting tool edge recession when machining with SUS420J2 and TiN coated SKH 51 tools were recorded in Oil palm in spite of Afina possessing the highest mechanical strength properties. On the contrary, Stellite in spite of possessing the smallest hardness (HV580) among all the tested cutting tools recorded the lowest cutting tool edge recession when machining wood samples of Oil palm. However, Stellite recorded the highest edge recession when machining Afina, a high density species. Ash content analysis and a scanning electron micrograph of wood samples of the tested wood species show the presence of high proportions of mineral salts in the transverse, radial and tangential sections of Oil palm. This could perhaps account for the high cutting tool edge recessions recorded in wood samples of the Oil palm. The studies have demonstrated that silica accumulation species could have significant effect on tool wear of high speed steels.