杨木刨花模压平面工业托盘的研究

探讨了自行研制的利用杨木废木屑模压而成平面工业托盘产品的主要技术特点和生产工艺特点,并通过实验测定了模压刨花托盘的吸水膨胀率、抗弯性能及托盘支脚和加强筋的抗压特性,结果表明该产品具有一定的创新之处。     

氮源用量对杨木白腐菌降解效率的影响

通过调整培养基中氮源的含量,利用白腐菌Phanerochaete chryscoporium和Trametes versicolor对杨木木片处理28 d,分析了木片的质量得率及化学成分的变化.结果表明:当酵母浸出粉的用量为1 g.L-1时白腐菌对原料中的木素降解率最高,在氮源用量相同的情况下,白腐菌Phanerochaete chryscoporium比Tranetes versicolor降解木素的速率更快.     

硅酸钠/聚乙二醇浸渍改性杨木工艺及性能研究

目的 为了提高速生杨木的物理力学性能、尺寸稳定性、热稳定性等性能，以硅酸钠(Na2SiO3)溶液和聚乙二醇(PEG)溶液为改性剂，旨在提高杨木的力学性能、尺寸稳定性以及耐热性能，并探究硅酸钠质量分数、聚乙二醇质量分数以及分子量对改性杨木性能的影响，获得最佳浸渍工艺。方法 运用单因素试验法探究硅酸钠质量分数、聚乙二醇质量分数、聚乙二醇分子量3个因素对改性杨木浸渍效果的影响。通过最佳浸渍工艺制备硅酸钠/聚乙二醇改性杨木与硅酸钠改性杨木，并测定其顺纹抗压强度、表面硬度、吸湿体积膨胀率等性能和结构表征，探究其与未改性杨木的差异。结果 通过单因素试验结果可知，以质量分数为10%的Na2SiO3、PEG-400以及质量分数为5%的PEG-400的浸渍工艺制备出改性杨木性能较佳。硅酸钠/聚乙二醇杨木改性材的顺纹抗压强度、抗弯强度、端面硬度、径面硬度和弦面硬度较未改性杨木的分别提高了69.4%、19.1%、42.2%、39.5%、19.2%，吸湿体积膨胀率较硅酸钠改性材降低了40.0%。结论 速生杨木经过硅酸钠/聚乙二醇改性后的力学强度，相较于单独硅酸钠改性杨木的力学强度有所提升，尺寸稳定性能增强，因此在性能及应用方面，硅酸钠/聚乙二醇改性杨木更具优势。     

单板层积材的应用和发展

单板层积材可分为结构用和非结构用2类。文章阐述了2类单板层积材应用现状和研究进展，并探讨了生产单板层积材的新工艺、新方法以及市场前景和发展趋势.     

工艺参数对硬枫薄木贴面杨木多层板表面质量的影响

以硬枫薄木和杨木多层板为材料,根据影响薄木饰面家具表面质量的工艺因素,对添加剂、涂胶量、热压压力、热压温度、热压时间5因素进行4水平的L16(45)正交试验,用平衡分析法对透胶率和翘曲度进行分析,得出最佳的贴面工艺。研究表明,单位压力与涂胶量是影响透胶率和翘曲度的最重要的因素,添加剂对透胶率影响较大而对翘曲度影响最小,热压温度和热压时间对透胶率和翘曲度的影响不明显。     

杨木浆和苇浆混合洗选漂

介绍了新疆地区的杨木浆与芦苇浆混合洗选漂的实验室结果和生产实践,讨论了苇浆和杨木浆的配比对成浆质量的影响,并总结了生产过程中应注意的问题。     

挤压疏解对化学蒸煮的影响

本文研究了挤压疏解作用对化学蒸煮的影响.结果表明,挤压疏解可以显著改善木片对液体的吸收性,在相同的蒸煮条件下,使卡伯值降低7.6个单位,在粗浆得率仅降低1.72%情况下,细浆得率提高11.5%.     

Farm wood fuel and energy project

This paper describes the findings of the Farm Wood Fuel and Energy Project. It began in 1991 and ended in 1997 and was undertaken to provide a commercial demonstration for the establishment of 50 hectares of short rotation coppice (SRC) on six farms in southern England and the development of associated marketing activities. The Project:

• — taught farmers how best to grow the crop and will enable them to teach others;

• — determined that winter conditions in the UK are unsuitable for most harvesting equipment trialled and that both harvesting and chip storage need to be re-examined;

• — demonstrated that SRC has the potential to be competitive with fossil fuels;

• — gave confidence to Government to include a Band for energy crops under the NFFO electricity generating procedures

     

Combustion properties of laminated veneer lumbers bonded with PVAc,PF adhesives and impregnated with some fire retardants

In this study, the effects of impregnation materials di‐ammonium phosphate, aluminium sulphate, potassium carbonate, calcium chloride, zinc chloride on combustion properties of 3 ply laminated veneer lumbers (LVL) produced from Walnut (Juglans regia L.) using phenol–formaldehyde (PF), poly (vinyl acetate) have been investigated. The pressure‐vacuum method was used for impregnation process. Combustion test was performed according to the procedure of ASTM‐E 69 standards. During the test, mass reduction, temperature and released gas (CO, NO_X, SO₂, O₂) were determined every 30 s. As a result, zinc chloride was found to be the most successful fire‐retardant chemical in LVL at PF adhesive. Since it diminishes combustion, the fire retardant of LVL produced from walnut using PF adhesive can be advised. Copyright © 2009 John Wiley & Sons, Ltd.     

Connections for composite concrete slab and LVL flooring systems

Composite concrete slab and timber flooring systems are commonly used in many parts of the world to exploit the high strength-to-weight ratio of timber and the good acoustic separation provided by concrete floor slabs. This paper describes the results of an experimental programme that investigated the suitability of a range of connectors to transfer shear between a concrete slab and a laminated veneer lumber (LVL) beam. Shear tests on reduced scale specimens were performed with the aim of comparing the strength, stiffness, and post-peak performance of different connectors such as round and rectangular concrete plugs with and without screw and steel pipe reinforcement, proprietary (SFS) screws, coach screws with different diameters, sheet brace anchors, and framing brackets. The rectangular concrete plug reinforced with a coach screw was found to provide the greatest stiffness and strength, as well as favourable post-peak behaviour. Such a system can be used for cost-effective composite floor systems due to its efficient cost-to-capacity ratio, which reduces the number of connectors needed along the beam axis to achieve the composite action.