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排序方式: 共有2089条查询结果,搜索用时 15 毫秒
81.
Ragil Widyorini Jianying Xu Takashi Watanabe Shuichi Kawai 《Journal of Wood Science》2005,51(1):26-32
The effects of chemical changes in kenaf core binderless particleboards on the bonding performance and thickness swelling of boards were investigated by chemical and spectroscopic analyses. Mild steam-injection treatments (0.6–1.0MPa) caused significant degradation of hemicelluloses, lignin, and cellulose. Conventional hot pressing caused a lower degree of degradation of the chemical components. The hot-pressed kenaf core board without any binders showed poor bonding performance. Thus, it was found that partial degradation of the three major chemical components of the kenaf core by mild steam-injection treatment increased the bonding performance and dimensional stability of the binderless boards, and gave better quality binderless boards than those made by hot-pressing treatments.Part of this report was presented at the 4th International Wood Science Symposium, Serpong, Indonesia, September 2002; and at the 53rd Annual Meeting of The Japan Wood Research Society, Fukuoka, March 2003 相似文献
82.
原料表面碱液处理对稻草碎料板力学性能的影响 总被引:1,自引:0,他引:1
在实验室条件下探索了稻草原料表面碱液处理对稻草碎料板力学性能的影响.试验表明,处理后的稻草碎料板的内结合强度比处理前有大幅度提高,弯曲弹性模量和静曲强度比处理前则有所下降,但都达到了相关的国家标准;2h吸水厚度膨胀率升高,超过国家标准.因此稻草表面碱液处理提高了稻草原料表面润湿性和胶合强度,但对稻草碎料板的力学性能有影响. 相似文献
83.
刨花板用低毒改性脲醛树脂胶的研究与应用 总被引:2,自引:0,他引:2
本文描述了刨花板用低毒改性脲醛胶的性能。研究结果表明,用低毒生脲醛胶生产刨花板是可行的,不但可使各项质量指标达到国际一级标准,而且有量比原胶低10kg/m^3因此效益显著。 相似文献
84.
Koji?HayashiEmail author Masaharu?Ohmi Hiroshi?Tominaga Kiyoharu?Fukuda 《Journal of Wood Science》2003,49(5):398-404
We investigated the bending properties of composite boards produced by reinforcing both sides of corrugated particleboard with medium-density fiberboard (MDF). Thickness swelling and linear expansion (LE) were measured to assess the dimensional stabilities of the composite board. Although the apparent density of the composite board was 0.48g/cm3, its strength was found to be equivalent to that of 18-type particleboard as described in JIS A 5908. The boards parallel/perpendicular anisotropy in strength was 0.9. The modulus of rupture (MOR) of the composite board increased with board density only up to a certain density, beyond which the MOR was constant. On the other hand, the thickness swelling of both corrugated particleboard and the composite board was smaller than that of flat-type particleboard, satisfying the JIS A 5908 standard of 12%. Linear expansion (soaking in water of ordinary temperature for 24h) of corrugated particleboard was 0.7%–0.9% in the parallel direction and 2.1%–3.1% in the perpendicular direction; hence, anisotropy in linear expansion existed in the corrugated particleboard. The linear expansion of the composite board was 0.6%–0.9% in the parallel direction and 1.8%–2.5% in the perpendicular direction. Although the LE of the composite board was lower than that of corrugated particleboard, it is necessary to improve the LE of composite board for practical use. 相似文献
85.
CHEN Peng ZHAO Guangjie College of Material Science Technology Beijing Forestry University Beijing P.R.China 《中国林业科技(英文版)》2007,(2)
There are many advantages of bended wood,such as good-looking shape,simple process and low cost.The product,however,is easy to get recovery,which is urgent to be dealt with.This paper concludes the features of deformation and recovery of bended wood and wood-based composites and summarizes four treating methods to keep dimensional stability.Compared to bended solid wood,some elementary perspectives on the research of bended wood-based composites are presented.The purpose of this paper is to suggest:1)to investigate the optimum heating time and temperature that bended wood and wood-based composites need from the formation of deformation to the recovery and to the permanent fixation,according to its changes of dimensional stability such as curvature radius;2)to measure the composites comprised of wood and adhesives on the changes of stress relaxation,dynamic viscoelasticity and crystal1ization field;3)to quantitatively analyze changes of the major components in wood cell wall polymers as well as the composites under heat/steam treatment and untreated conditions.It will be helpful for subsequent research to clarify on the mechanisms of permanent fixation of bended wood and also contribute to that of wood-based composites. 相似文献
86.
Rashmi Kumari Hirokazu Ito Masahiro Takatani Miho Uchiyama Tadashi Okamoto 《Journal of Wood Science》2007,53(6):470-480
Although wood/cellulose-plastic composites (WPC) of low wood/cellulose content have been more accepted worldwide and are promoted
as low-maintenance, high-durability building products, composites containing high wood/cellulose content are not yet developed
on an industrial scale. In this study, flow properties, mechanical properties, and water absorption properties of the compounds
of cellulose microfiber/polypropylene (PP) and maleic anhydride-grafted polypropylene (MAPP) were investigated to understand
effects of the high cellulose content and the dimensions of the cellulose microfiber. The molding processes studied included
compression, injection, and extrusion. It was found that fluidity is not only dependent on resin content but also on the dimension
of the filler; fluidity of the compound declined with increased fiber length with the same resin content. Dispersion of the
composite was monitored by charge-coupled device (CCD) microscope. Increasing the plastic content in the cellulose-plastic
formulation improved the strength of mold in addition to the bond development between resin and filler, and the tangle of
fibers. The processing mode affected the physicomechanical properties of the cellulosic plastic. Compression-molded samples
exhibited the lowest modulus of rupture (MOR) and modulus of elasticity (MOE) and the highest water absorption, while samples
that were injection-molded exhibited the highest MOR (70 MPa) and MOE (7 GPa) and low water absorption (2%). 相似文献
87.
李军伟 《林业机械与木工设备》2015,(1)
阐述了三层实木复合地板的结构特点,对其产生弯曲变形的原因进行分析,并结合生产实际提出了三层实木复合地板的质量控制措施。 相似文献
88.
89.
介绍了一种单板条双向定向重组装饰木板的制造方法。采用该法制成的重组木板是由多条厚度为0.5~5mm、宽度为10~100mm、长度不限的单板条以宽面倾斜贴合并经施胶固化而成的板材;板材中单板条的长度方向与板材长度方向大致相同,单板条的宽度方向与板材的板面相交成15°~85°的夹角。该重组木板的制备工艺包括:1)单板制备;2)单板条制备;3)单板条端头加工;4)单板条干燥;5)单板条施胶;6)单板条陈化;7)双向定向组坯;8)压固成型;9)毛坯板材加工处理。采用该法制成的重组木板材表面具有类似于天然木材表面的条带状花纹,具有很好的装饰效果,可直接用于地板、家具面板和建筑装饰面材等领域。 相似文献
90.