探求小径落叶松集成材经济效益新途径

针对大径级优质木材资源供应日趋紧张的现实,一些科研单位和木材加工企业陆续进行了落叶松小径木集成材的试验和开发,对扩展落叶松材的加工利用范围、提高利用价值做了有益探索.立足于国内集成材生产实践,着眼于中小径落叶松材质特性的适应性,着力于落叶松小径木集成材生产问题的破解,对于提升集成材的发展力,提高落叶松小径材利用效率均具有重要意义.     

采用微机控制制材的出材率

目前,在北海道的森林资源中,绝大多数为3～4等中、大径低质材,平均径级为28～36厘米。今后将有大量的落叶松,云杉等人工林中、小径级材。这些低质原木的制材,不仅要靠目测定下锯法,更应通过机械自动选择最适宜的下锯法。在林产试验场使用了     

小径材制材工艺

分析了小径材制材现状,总结了小径材制材常规下锯法和国内新型制材方法-六棱柱体下锯法制材特点和各下锯法工艺路线,并且分析了各下锯法的优缺点,以期为小径材的高出材率、高附加值利用以及实现小径材在结构工程和家具等领域的拓展应用提供途径和方法。     

小径材制材工艺

分析了小径材制材现状,总结了小径材制材常规下锯法和国内新型制材方法-六棱柱体下锯法制材特点和各下锯法工艺路线,并且分析了各下锯法的优缺点,以期为小径材的高出材率、高附加值利用以及实现小径材在结构工程和家具等领域的拓展应用提供途径和方法。     

落叶松木材细胞年轮内生长模型的研究

以黑龙江省帽儿山的落叶松为试材,利用显微镜测定年轮内细胞面积从早材到晚材变化的数据并对细胞面积从早材到晚材的生长变化进行了研究归纳,利用最小二乘法对数据进行曲线拟合得出:年轮内细胞面积从早材到晚材成复合函数变化趋势,由此得出落叶松细胞在年轮内生长的经验模型,此研究对落叶松的生长规律研究具有一定的价值。     

小径级果木材的家具设计

木材以其优越的环境特性,一直是家具材料的最佳选择,然而面对大径级木材资源的日益紧缺,充分利用小径材越来越受到人们的重视。通过分析小径级果木材料的形态和纹理等特征,提出利用小径果木材开发制作朴实、自然、环保的个性化风格家具,分析小径果木材在家具上的应用方式、设计优点和设计方向,为小径级果木材料的利用提供思路和方法。     

中小径级珍贵材新中式卧室家具增值设计研究

为提高中小径级的珍贵材在家具生产中的利用率以及家具产品的增值率,开展如何有效利用中小径级的珍贵材在新中式家具设计中的应用。针对木材供需不平衡的资源现状,以中小径级的珍贵材为家具材料,分析其定义、材质特性以及在家具设计中的利用方式,进而以产品增值为导向,新中式风格家具为例,综合考虑市场、用户和企业的需求,提炼出基于中小径级珍贵材的新中式卧室家具增值设计策略。并将理论应用于设计实践,在"三川"系列的基础上进一步运用弯曲构件、优化结构以及简化接口等现代工艺技术设计优化为Q系列。通过有效利用中小径级的珍贵材,综合视觉美感、功能需求、生产工艺等多维度实现新中式家具产品的增值,为家具企业开发生产新产品提供参考。     

杨木小径材化机浆漂白技术的研究

扬木小径材在国内多用于制造人造板,在造纸上应用较少。开发利用小径材原料对于增加原材料来源,提高木材利用率有重要意义。使用杨木小径材制得的化机浆具有良好的可漂性能,本实验对杨木小径材化机浆的漂白工艺进行研究,发现氧化＋还原性的H2O2＋Na2S2O4两段组合漂白效果显著。其中一段浆浓10％,H2O2用量1．5％,二段浆浓6％,Na2S2O4用量1．5％时,浆料白度便能够达到80％ISO以上。     

利用马尾松小径材和枝桠材制造硫酸盐法漂白浆的研究

利用马尾松原木生产漂白浆,已经有了十多年历史。但是,马尾松原木的供应已经非常紧张。为了满足漂白浆不断增长的需要,必须充分利用现有的马尾松小径材(间伐材)和枝桠材。 本研究的目的在于了解小径材木片和枝桠材木片以及它们与原木木片混合后的漂白浆的物理性能及其使用价值。     

日本开发落叶松多层结构胶合板与干燥锯材的复合结构材

据日刊木材新闻2003年9月19日报道,以生产建筑框架材、落叶松LVL为主的高桥林产公司,新近开发出以胶合板为芯板两侧胶贴上锯材的干燥复合结构材。 干燥复合结构材是用针叶材(日本落叶松、CSP)     

短周期落叶松漂白化学浆的打浆性能探讨

对短周期及成熟兴安落叶松漂白化学进行了打浆特性的研究，观察了打浆后的纤维细结构，并测定了手抄片的性能，探索了短周期兴安落叶松材漂白化学浆的打浆性能和抄造高级纸张的可行性。     

落叶松木材力学性质及应用研究进展

阐述了近年来落叶松力学性能研究的进展;对落叶松力学性能在制浆造纸和木结构用材上的应用进行详尽描述;提出了落叶松木材力学性能的研究方向,为落叶松木材资源高值化利用提供借鉴。     

Rapid prediction of surface characteristics of European and Siberian larch wood by FT-NIRS

Application of coatings on larch wood surfaces with high concentrations of arabinogalactan and wood resins and/or low pH-values can pose problems regarding film formation and service life of coatings. In the present feasibility study, FT-NIR spectroscopy as a method for the quantification of the abovementioned wood characteristics on the surface of heartwood of European and Siberian larch (Larix decidua, Larix sibirica) was investigated. Predictions by FT-NIRS were accurate and reliable for the actual arabinogalactan content on the wood surface with R² (CV) of 0.75–0.89 and RMSEP of 18.82–29.14 mg g^?1. Prediction of the pH-value of the larch wood surface was also possible, although less reliable than for the arabinogalactan content (R² CV: 0.60–0.70; RMSE: 0.34–0.37). The prediction of the wood resin content allowed only a rough estimation of the actual resin concentration, which might be due to the uneven distribution of the wood resin across the wood surface. It was concluded that the quantification and finding of extreme values of arabinogalactan content and surface pH-value can be predicted accurately, while the prediction of the wood resin content gives only indicative values.     

The use of wood in practice – a hygienic risk?

The survival of bacteria on wood was investigated in laboratory experiments using naturally occurring and hygienically relevant bacteria and in a trial performed in a meat factory. Different types of wood dust (pine, larch, maple) and polyethylene chips were inoculated with chicken manure to study the interactions of bacteria and wood. The survival of the different bacteria from chicken manure was followed by plating on selective media. In addition, denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments from directly extracted DNA was used to precisely analyze changes in the relative abundance and composition of the manure-derived bacterial community on wood and plastic. Bands of DGGE-community profiles which reflected changes in the composition of the bacterial community on wood and plastic were excised, re-amplified, cloned and analyzed by sequencing. A rapid decrease of CFU of manure-derived bacteria was observed on pine-wood which correlated with the decreased amount of DNA extracted from pine-wood. Bacteria applied on larch, maple and plastic survived longer than on pine. Investigations have shown that some bacterial groups, e.g. enterobacteria, are more affected by wood and plastic than other bacteria. Furthermore, our results indicated that extractives from different wood types influenced the survival of bacterial species differently. Better hygienic characteristics of pine-wood compared to plastic as a material for transportation pallets were also observed in preliminary tests under practice conditions during a 4-week test in a meat processing factory.     

Sterols and Triterpenyl alcohols in common pulpwoods and black liquor soaps

The amount and composition of lipophilic extractives, and especially of sterols and triterpenyl alcohols, were analysed for six important pulpwood species, i.e., Scots pine, Loblolly and Longleaf pine, Norway spruce, Siberian larch and Silver birch. Sulphate soaps (tall oil soaps) derived from these species were also analysed. Scots pine and Loblolly pine contained the highest amounts and Siberian larch the lowest amounts of lipophilic extractives. The highest amounts of sterols were found in birch. The sterols in wood occurred mainly as esters. Sitosterol was the main sterol in all species. Isolation and analysis of the steryl esters confirmed the natural occurrence of sitostanol esters in wood. Considering the use of sitosterol or sitostanol as cholesterol-lowering component in food products, a high ratio of sitosterol to campesterol is beneficial. This ratio was high in birch and pines but clearly lower in spruce and larch. The highest ratios of sitosterol to campesterol were found in soaps from pines and birch.     

On the modelling of colour changes of wood surfaces

Colour has an influence on the aesthetic properties of wood surfaces, and changes in colour have an impact on each individual’s perception of wood construction materials. This study examines an approach to model the discolouration of wood during natural weathering. A novel mathematical model was used to estimate colour changes of two softwoods during natural weathering. The surface colour of fir and larch samples was determined according to the CIEL*a*b* system during natural weathering over a period of one year. In order to demonstrate the value of the model, two different weathering sites were chosen. The data collected from each site was smoothed using a local regression method, and the corresponding parameters were used to generate the confidence intervals around the smoothed curves. The results show that all three colour parameters exhibit varying differences during the weathering trial. The locally weighted regression method seems to be an appropriate approach for modelling weathering effects and could be used to simulate colour change in wood in exterior applications in the future.     

Scherfestigkeits-Test zur Eignungsprüfung verschiedener Holzarten für gipsgebundene Holzwerkstoffe und REM-Betrachtung der Scherflächen

A shear strength testing method is introduced for gypsum wood test specimens. The morphology of dihydrate crystals was investigated immedately after shar lesting by means of SEM-mieroscopy. Spruce, birch, larch and poplar were used for shear specimens. The shape of the interfacial crystals and the thickness of the interfacial layer were taken as characteristics for inhibitors present in the wood. Shear strength values decreased with decreasing size of DH-crystals formed in the interfacial surface. An impregnation of the cell walls, similar to that in magnesia-bound or cement-bound wood composites was not observed. The adhesion between gypsum and wood was effected by mechanic anchorage of DH-crystals in the cell wall. A penetration of the cell wall did not occur.     

The effects of acetylation on the extractives of Sitka Spruce (Picea sitchensis) and Larch (Larix leptoleptis) wood

The extractives of acetylated spruce and larch wood were investigated and compared with their respective control counterparts using Fourier transform infrared to determine the effects of acetylation on extractives. Significant differences were observed among the spectra of organic solvents extractives in the control and modified wood, but no such differences were found in water-soluble extracts. It is postulated that the relatively bulky extract substances resident in the gross capillary structure were modified during the acetylation of wood and subsequently recovered by organic solvents, but the hot water extractives were possibly sugars from hydrolysis of less ordered polysaccharides. The mechanism of extractives action during acetylation is that of a scavenger mopping up unreacted anhydride and by-product acetic acid.     

The use of a microtensile strength bench for testing the strength of growth rings of softwoods and hardwoods parallel to the grain

A self-developed microtensile strength bench was used to detect possible differences in tensile strength between early wood and late wood of Scots pine and beech. The difference in tensile strength parallel to the grain between early wood and late wood in Scots pine is more obvious than that of beech. The use of a gelglue (ethylcyanoacrylate) for fastening the small specimens to the testing bench was very promising. The tests showed that the method is very useful, because of a very small number of failures.     

落叶松新浆种的开发——第二部分 落叶松与黑云杉混合制备预热化学机械浆和化学机械浆

对落叶松—云杉混合预热化学机械法(CTMP)和化学机械法(CMP)制浆的研究结果表明,在云杉中配加少比例量的落叶松、能降低磨浆能耗,提高所得浆的强度性能。在落叶松—云杉混合木片的磨浆过程中,两种木片之间有相互促进作用。