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为探索不同平衡处理条件对刨花板物理力学性能测试结果的影响规律,以16 mm厚刨花板为试验对象,以标准平衡处理条件(20℃,相对湿度65%)为基础,以2种温度条件(5℃和35℃)和2种相对湿度条件(30%和90%)作为对比,测试不同平衡条件下试件的各项物理力学性能。从结果来看,在本试验范围内平衡处理条件对刨花板物理力学性能测试结果有影响,其中湿度对测试结果的影响显著,而温度的影响较小。对比平衡处理后的试验结果可知,温度一定时,随着湿度的增加刨花板试件的含水率明显增加,其静曲强度、弹性模量、握螺钉力、内胶合强度、吸水厚度膨胀率的测试值随着含水率的增加而降低。 相似文献
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分析比较了中密度纤维板试件在检测时所用万向节数量对表面结合强度测试结果的影响。经过试验,结果表明:使用万向节对表面结合强度的测试值有一定的影响,使用两个万向节的表面结合强度测试值比用一个和不用要大。 相似文献
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以过硫酸铵(简称APS)为引发剂,以醋酸乙烯酯为接枝单体,在水相介质中制备了蜡质玉米淀粉胶粘剂。研究了APS的添加量、接枝温度、pH、接枝共聚时间、单体滴加速度、单体与淀粉的质量比、糊化热处理程度等因素对接枝共聚反应的影响,并研究了接枝参数与胶粘剂压缩剪切强度之间的关系。结果表明:当APS的添加质量为淀粉干基质量的1.16%、接枝温度为70℃、接枝共聚时间为3.5 h、滴加速度为0.105 8 mL/(kg.s)、单体与淀粉的质量比6∶5、糊化条件85℃、30 min时,接枝百分率最高(50.83%);接枝百分率和支链相对分子质量均对淀粉胶粘剂的压缩剪切强度有一定的影响,且接枝百分率对蜡质玉米淀粉胶粘剂压缩剪切强度的影响比支链淀粉相对分子质量对蜡质玉米淀粉胶粘剂压缩剪切强度的影响大。 相似文献
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G. Tondi S. Wieland T. Wimmer T. Schnabel A. Petutschnigg 《Holz als Roh- und Werkstoff》2012,19(2):271-278
Synergic properties between starch and sugar were discovered. 100% crop-based starch and sugar formulations were studied.
Classical preliminary tests such as curing temperature and gel time were measured for different starch-sucrose water suspensions.
More significant information was deducted with applied tests such as plywood gluing tests and particleboard production. Wood-to-wood
bonding properties were analysed applying NaOH and high temperature (180°C) as catalysts for starch gelification. Comparable
strength to commercial urea-formaldehyde and polyvinyl acetate adhesives was achieved in plywood tests. Consequently, the
knowledge acquired in wood bonding of flat surfaces was applied to particleboard production. These derived particleboards
showed that it is possible to obtain a panel with only carbohydrates as gluing agent. Starch-sugar synergy in alkaline environment
increases the internal bond (IB) of the natural panels up to 0.25 N/mm2. Possible mechanisms of synergy between these saccharides were proposed. Finally, a blended formulation with Mimosa tannin
allows for achieving an internal bond of 0.40 N/mm2, which is the required value for interior grade particleboards (DIN EN 312). Starch-sugar-tannin adhesives are 100% environmentally-friendly
formulations. 相似文献
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以碱木质素为原料,通过胶体磨的作用,合成碱木质素脲醛树脂。结果表明:随着木质素加入量增加胶合强度降低,甲醛释放量也随之降低。当反应温度90℃,缩合pH5.5,碱木质素用量为50%时,胶粘剂具有较高的胶合强度,甲醛释放量达到国家E2标准。 相似文献
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木材影响其胶合强度的诸因素分析 总被引:2,自引:0,他引:2
论述了木材与其胶合强度有关的因素,诸如木材的密度、纤维方向、含水率、收缩膨胀率、粘接面特性、抽提物和pH值等对木材胶合强度的影响。 相似文献
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Michiel J. Boonstra Antonio Pizzi Martin Ohlmeyer Wulf Paul 《Holz als Roh- und Werkstoff》2006,64(2):157-164
Steam pre-treatment can effectively improve the dimensional stability of panel products such as particleboard and fiberboard. At temperatures above 200–210 °C steam pre-treatment might result in a significant reduction of the bond strength of the panel product. The results of an effective two stage heat pre-treatment process, in which treatment temperatures below 200 °C are used, are given in this paper. The variations in process conditions which affect the particleboard properties are described in detail. A two- stage heat pre-treatment with temperatures below 200 °C appears to improve the dimensional stability of panel products. The process conditions used have an effect on thickness swelling and internal bond properties of the particleboard prepared, especially during the first process stage (hydrothermolysis). The best results were obtained with wood particles which were only thermolysed (without curing). 相似文献
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1.Key Laboratory of Advanced Textile Materials and Manufacturing Technology;Ministry of Education;Zhejiang University of Science and Technology;Hangzhou;Zhejiang 310033;China; 2.Hangzhou College of Vacation Technology;Hangzhou;Zhejiang 310018;China 相似文献