共查询到19条相似文献，搜索用时 187 毫秒
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阐述了单板层积材产品的优点,介绍了以落叶松为原料,利用胶合板生产设备加工制造单板层积材的工艺技术及产品性能. 相似文献
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根据美国ASTM D5456《结构复合木材产品评价规范》评价方法标准及美国工程木材协会PRL-501《单板层积材性能标准》,对国产杨木单板层积材力学性能进行了检测和评价分析。通过拟合优度检验,发现杨木单板层积材力学性能与对数正态分布拟合得较好。杨木单板层积材力学性能特征值的研究可为我国结构用单板层积材特征值确定方法提供参考。 相似文献
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对当前国内外的单板层积材的生产工艺、技术水平、产量规模、产品应用、市场和产业发展前景进行了全面分析,为我国单板层积材产业的发展提供参考。阐述了我国现有的单板层积材生产存在规模小、技术落后、产品的质量比较低、应用市场有待进一步开发等问题。指出了相关科研院所和高等院校相关学科需要进一步加强单板层积材的生产工艺技术和应用市场开拓的研究。 相似文献
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单板层积材的应用和发展前景 总被引：17，自引：0，他引：17
介绍了单板层积材在建筑构件中和在其他领域中的应用情况和主要特点；ＬＶＬ在全世界的生产量，销售价格和生产成本。简述了我国胶合板企业通过技术改造，生产ＬＶＬ的可能性和技术方案。 相似文献
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单板层积材的生产工艺及发展前景 总被引：2，自引：0，他引：2
吴立农 《林业机械与木工设备》2000,28(11):30-30
介绍了单板层积材的生产工艺及产品特点，并对国内单板层积材的发展前景提出个人看法。 相似文献
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探讨了利用速生杨木单板层积材及科技木生产实木门的可行性,介绍了杨木单板实木门的制造工艺。速生杨木单板层积材压缩率、硬度、抗弯强度、尺寸稳定性等指标均远高于普通板材,是一种很好的结构用材,可用其替代高档硬质实木使用,以提升杨木产品的科技含量和附加值。 相似文献
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Zephyr strand board (ZSB) and zephyr strand lumber (ZSL) were produced using zephyr made from poplar veneer to investigate the greater utilization of low-density poplar as a structural material. These materials were then compared to ordinary plywood, laminated veneer lumber (LVL) from poplar veneer, lauan plywood, and particleboard. The bending properties (moduli of rupture and elasticity) of ZSB proved superior to those of poplar plywood: and ZSL produced from poplar veneer zephyr had bending properties greater than ordinary LVL from poplar veneer. Apparently, the conversion of the poplar veneer into zephyr material had a positive effect on bending properties. Additionally, poplar ZSB had bending properties superior to those of lauan particleboard and equal to those of lauan plywood. The internal bond strength of poplar veneer ZSB was nearly two times greater than that of lauan particleboard.Parts of this report were presented at the international symposium on the utilization of fast-growing trees, Nanjing, China, October 1994. Report IV appeared inMokuzai Kogyo 49:599, 1994 相似文献
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竹片覆面胶合板的初步研究 总被引：2，自引：0，他引：2
本文研究了以竹片为外层材料、多层杨木单板为芯层材料的复合胶合板的结构和力学性能，分析了板坯结构形式、纵向纵片厚度、单板层数及板坯压缩率与产品机械强度之间的关系。初步研究结果表明，板坯结构形式对产品的静载荷抗弯曲性能影响显著；在试验范围内，纵向竹片厚度为３．５－５．０ｍｍ、板坯压缩率在２３％左右时，竹片覆盖面杨木胶合板的综合力学性能比较理想。 相似文献
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Fracture toughness of wood and wood composites has traditionally been characterized by a stress intensity factor, an initiation strain energy release rate (G init) or a total energy to fracture (G f). These parameters provide incomplete fracture characterization for these materials because the toughness changes as the crack propagates. Thus, for materials such as wood, oriented strand board (OSB), plywood and laminated veneer lumber (LVL), it is essential to characterize the fracture properties during crack propagation by measuring a full crack resistant or R curve. This study used energy methods during crack propagation to measure full R curves and then compared the fracture properties of wood and various wood-based composites such as, OSB, LVL and plywood. The effect of exposure to elevated temperature on fracture properties of these materials was also studied. The steady-state energy release rate (G SS) of wood was lower than that of wood composites such as LVL, plywood and OSB. The resin in wood composites provides them with a higher fracture toughness compared to solid lumber. Depending upon the internal structure of the material, the mode of failure also varied. With exposure to elevated temperatures, G SS for all materials decreased while the failure mode remained the same. The scatter associated with conventional bond strength tests, such as internal bond and bond classification tests, renders any statistical comparison using those tests difficult. In contrast, fracture tests with R curve analysis may provide an improved tool for characterization of bond quality in wood composites. 相似文献
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Laminated products, such as laminated veneer lumber (LVL) or plywood (PW), have become important recently. The objective of
this study was to determine and compare properties of panels fabricated with veneers of Gmelina arborea trees in a fast-growth plantation and glued with phenol formaldehyde resin. The results showed that LVL and PW physical and
mechanical properties are comparable to those of solid wood with a specify gravity of 0.60. Moreover, these panels can be
cataloged into group 2 of PS 1–95 of the Voluntary Products Standard of the United States. The difference in physical properties
was not statistically significant between LVL and PW panels, except for water absorption. Some mechanical properties, such
as hardness and glue-line shear, modulus of rupture in perpendicular flexure, nail and screw withdrawal parallel, and perpendicular
strength, were statistically different between LVL and PW. However, no differences were established for the modulus of elasticity,
tensile strength parallel to the surface, or tensile strength perpendicular to the surface. The differences were attributed
to the venners’ orientation in the panels studied. 相似文献
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Robert B. Currie Gary B. Byrom Alexander Bruce Robert G. Schmidt 《Wood material science & engineering》2020,15(4):190-197
ABSTRACT A glycerol-borate complex has been developed and demonstrated as a new glue line treatment for engineered wood products such as laminated veneer lumber (LVL) and plywood. This allows the entire billet or panel to be evenly penetrated with boron to elevated levels, which increases the level in the central ninth and ensures the panel is significantly higher in boron throughout the panel compared with traditional envelope treatments. These external treatment systems often result in envelope treatments as it is difficult to get the treatment chemical evenly into the central ninth of the panel. The glycerol-borate complex reported herein is compatible with phenol formaldehyde resins typically used for plywood and LVL. These resins systems are not typically compatible with boron as the boron binds to the phenolic hydroxyl groups resulting in a range of undesirable side effects, such as premature gelation of the resin system. Boron is less toxic than alternative treatment chemicals and is very effective due to its broad spectrum of fungicidal and insecticidal activity. Boron does not break down into ineffective compounds and thus does not require high treatment dose levels. Additionally, the amount added can be directly measured using ICP-MS to ensure a suitable level of treatment chemical has been added. 相似文献
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B. Ozarska 《Wood Science and Technology》1999,33(4):341-351
This review on the use of hardwoods for the production of LVL revealed that a large number of research studies have been
carried out, particularly in North America and three Asian countries (Japan, Malaysia and China). However, the studies have
been restricted to species of low to medium density, i.e. 290 to 693 kg/m3. Two major potential uses of hardwood LVL have been investigated in these studies: domestic and industrial structures, and
various furniture components. The production of structural LVL in North America and Asia was based predominantly on low density
hardwoods. A study currently carried out in Europe aims at using medium density hardwoods for structural LVL. The LVL used
for furniture components was produced from medium density hardwoods. No work has been undertaken outside Australia on the
use of high density species for LVL. In Australia, studies undertaken on the production of LVL and hardwood plywood from eucalypts
revealed that there were significant problems in gluing the dense raw material which often had a high level of extractives.
Peeling low quality, small diameter eucalypt logs also created problems when the traditional plywood processing techniques
were used.
Received 7 July 1997 相似文献
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提出一种单板层积材力学强度分级系统的设计方案。该方案利用高精度数字时间转换芯片TDC-GP1测试超声波在单板层积材中的传播速度,从而评估单板层积材的力学强度并对其进行在线分级。试验表明,该系统工作稳定、抗干扰能力强,精度高,适合工业推广。 相似文献