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家具和地板用浸渍改性杉木研究进展 总被引:2,自引:0,他引:2
《林业工程学报》2016,(5)
杉木是我国南方重要的速生林树种之一,但其木材存在诸多缺陷,极大地限制了其在家具、地板中的进一步开发利用。将杉木进行浸渍改性以提高综合利用率是解决全球木材的供需矛盾和家具、地板用材短缺的重要手段之一。浸渍改性目前主要应用的树脂有UF树脂、PF树脂、聚乙烯醇缩甲醛、MF树脂等,其中以PF应用较常见,其改性效果较为显著。浸渍改性过程中,主要有真空处理、真空加压、抽提后常压浸渍或真空浸渍等浸注方法,辊压浸注作为常温常压条件下高效快速浸注处理木材的方法也可用于杉木的浸渍改性,真空-叠压法既能保证改性药剂完全渗入杉木木材,也能防止杉木试材在压力下被压溃。不同的浸渍工艺参数和树脂固化条件对改性后杉木性能影响不同:浸渍时间对浸渍材的吸水率及吸水厚度膨胀率影响较大,热压温度、热压时间与压缩变形恢复率、静曲强度密切相关,各工艺因素间存在一定的相互关系和影响。最后讨论了浸渍改性杉木在家具、地板业中的发展方向与应用前景,为杉木浸渍改性的进一步研究和应用提供参考。 相似文献
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思茅松3种密实化改性材物理性质比较 总被引:1,自引:0,他引:1
密实化是提升低密度人工林材品质、拓展其用途的重要途径之一。以思茅松为研究对象,在考察水抽提处理对其可浸渍性影响的基础上,分析比较了糠醇化、机械压缩以及两者联合等3种密实化改性方式对其剖面密度、吸湿性、24 h吸水性和吸水厚度膨胀率的影响。结果表明:1)水抽提处理有助于提高思茅松材的可浸渍性,质量增加率可以提高11.35%,而且剖面密度分布存在显著差异;2)浸渍可均匀提高木材厚度上的密度,机械压缩促使思茅松材形成了内高外低的密度分布,联合改性材剖面密度的分布特征类似于压缩密实化材,但内外层间的过渡更为平缓;3)糠醇浸渍可以显著降低木材的吸水性和吸湿性,机械压缩对木材吸湿性的影响不明显,但其吸水率稍高,因糠醇树脂的原因,联合改性材的吸湿吸水性均显著下降;4)糠醇浸渍可以显著降低木材的吸水厚度膨胀率,对压缩密实化材具有较好的定型作用,联合改性材的24 h吸水厚度膨胀率为3.3%,接近于对照材的4.1%,而压缩材为24.7%,糠醇浸渍材只有0.4%。同时,水溶液的酸碱性对木材的吸水行为也有影响。综上,糠醇化与压缩密实化的联合改性非常有潜力用于速生低密度松木材的增值加工,而热水抽提处理可以作为提高松木糠醇浸渍的预处理手段。 相似文献
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《中南林业科技大学学报(自然科学版)》2020,(10)
【目的】竹材内含丰富的淀粉和糖类物质,易遭霉菌侵蚀,耐候耐久性差,探讨糠醇树脂改性对重组竹物理力学性能和防霉性能的影响,为重组竹糠醇树脂改性技术提供参考和借鉴。【方法】利用10%、20%、30%质量浓度的糠醇树脂加压浸渍竹束单元,对其进行改性处理,并采用"热进冷出"工艺制备重组竹板材,测量不同质量浓度糠醇树脂改性处理竹束的颜色和增重率,比较不同质量浓度糠醇改性重组竹材的吸水率、吸水厚度膨胀率、弹性模量、静曲强度、热稳定性、防霉性能和微观结构,检测了糠醇树脂在竹材样品中的显微分布,系统研究了糠醇树脂质量浓度对重组竹物理力学性能、热性能和防霉性能的影响规律。【结果】糠醇树脂改性处理使竹材颜色明显加深,尺寸稳定性、热稳定性和防霉性能显著提高,与对照材相比,改性竹材的色差可提高30.92%,吸水率可降低41.03%,吸水厚度膨胀率可降低46.34%,热失重率可降低75.38%,防霉等级可提高3个等级;糠醇树脂改性处理对重组竹的弹性模量影响不显著,但使其静曲强度最大可降低20.21%;随着糠醇树脂质量浓度的增加,改性竹材的颜色、尺寸稳定性、热稳定性、防霉性能均呈显著增加趋势,其静曲强度呈逐渐降低趋势。【结论】糠醇树脂改性重组竹具有优异的物理力学性能和防霉性能,20%糠醇树脂改性重组竹对霉菌的防治效力达到100%,可广泛应用于室外竹制品的制造。 相似文献
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试验引入聚乙二醇改性体系以补偿五硼酸铵处理结构刨花板时造成物理力学性能的降低,并研究了处理后结构刨花板的吸水性能。结果表明:24h吸水厚度膨胀率和24h吸水率这两项指标与五硼酸铵添加量的相关性最大,该两项结果均随五硼酸铵添加量的增加而增大。聚乙二醇种类对结构刨花板吸水性的影响大于添加量的作用。尤其是24h吸水率,4个添加量水平下的结果均无显著性差异。 相似文献
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对毛白杨木材浸注脲醛树脂胶制备压缩改性木材中的主要影响因素及相关工艺参数进行初步探索与试验,并在实验结果基础上讨论了各因素对制作工艺及其性能的影响。结果表明:①影响板材性能由主到次因素的顺序为压缩率-热压时间-热压温度;②在试验参数范围内较好的工艺参数为热压温度140℃、热压时间20min、压缩率50%;③在试验参数范围内热压时间对试件增重率、含水率、树脂留存率影响显著,而热压温度对试件增重率影响显著,压缩率对试件密度、变形回复率、吸水厚度膨胀率影响显著。 相似文献
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Ayoub Salari Taghi Tabarsa Abolghasem Khazaeian Ahmadreza Saraeian 《Journal of Wood Science》2012,58(6):513-524
In this study, the effect of nanoclay on some applied properties of oriented strand board (OSB) made from underutilized low quality paulownia wood was investigated. Organo-modified montmorillonite (MMT) at four levels (0, 1, 3 and 5?%) was added to urea formaldehyde (UF) resin. Some chemical properties of paulownia wood (holocellulose, cellulose, lignin and ash contents, pH value and hot and cold water solubility), mechanical [modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength, screw and nail withdrawal strengths], physical (water absorption and thickness swelling) properties and formaldehyde emission of the strand boards were evaluated. Mechanical properties of all panels complied with the general-purpose OSB minimum property requirements of European Norm. With increasing 5?% nanoclay to UF resin, mechanical and physical properties of the resulting panels improved and formaldehyde emission decreased. However, none of the panels satisfied the thickness swelling and water absorption requirement. The results of X-ray diffraction and transmission electron microscope analysis confirmed the good dispersion of nanoclay in the resulting OSBs. Using paulownia as a fast-growing underutilized species not only can sustain the forests but also can supply raw material to countries facing shortage of wood. 相似文献
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广宁县竹香骨下脚料制备竹碎料刨花板及其复合改性研究 总被引:1,自引:0,他引:1
采用竹香骨下脚料为原料,以脲醛树脂和三聚氰胺改性脲醛树脂胶粘剂制备竹碎料刨花板,并与木纤维复合改性,检测并分析了内结合强度、静曲强度、弹性模量和吸水性。结果表明,在热压温度为160℃时,竹碎料板和竹木复合碎料板的物理力学性能均满足国标规定在干燥状态下使用的普通用板要求。当木纤维与竹碎料复合后,复合板材的静曲强度和弹性模量有一定程度提高,但内结合强度降低。 相似文献
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Abstract Binderless boards were prepared from kenaf core under various manufacturing conditions and their water resistance
properties were evaluated. The board properties evaluated were retention ratios of modulus of rupture (MOR) and modulus of
elasticity (MOE), internal bonding strength after water treatment (IB), thickness swelling (TS), water absorption (WA), and
linear expansion (LE). These values were then compared with those of boards bonded with urea-formaldehyde (UF), urea melamine
formaldehyde (UMF), and phenol-formaldehyde (PF) resins, and their water resistance properties were assessed. We found that
pressing temperature was one of the most important conditions for the improvement of water resistance properties. The retention
ratios of MOR, MOE, and IB of kenaf core chip binderless boards (pressing temperature 200°C, target density 0.8g/cm3, and the three-step pressing of 6MPa for 10min, then 4MPa for 3min, and 2MPa for 3min) were 37.1%, 49.9%, and 55.7%, respectively,
compared with values for UMF-bonded boards of 22.5%, 27.1%, and 40.7%, and values for PF-bonded boards of 42.8%, 41.8%, and
54.1%, respectively. The results showed that the water resistance properties of binderless boards were higher than those of
UMF-bonded boards and almost as high as those of PF-bonded boards.
Part of this article was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003 相似文献
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初步探讨了实验室条件下烟秆/木材刨花板的生产工艺,研究了热压时间、施胶量、密度、木刨花加入量等因素对板材的静曲强度、内结合强度、吸水厚度膨胀率的影响.实验结果表明,烟秆/木材刨花板的静曲强度和吸水厚度膨胀率较纯烟秆刨花板有所提高,内结合强度相差不大. 相似文献
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Ee Ding Wong Min Zhang Guangping Han Shuichi Kawai Qian Wang 《Journal of Wood Science》2000,46(3):202-209
Two main types of fiberboards were produced using lauan (Shorea spp.) fibers with an isocyanate resin as the binder; fiberboard with a flat, homogeneous (homoprofile), and typical U-shaped (conventional) density profile along the board thickness. The processing parameters included manipulation of mat moisture content distribution, press closing speed, and hot pressing method. The results are summarized as follows: (1) A larger variation was observed in the peak density (PD) and core density (CD) of fiberboards at 0.5g/cm3 mean density (MD) level than in those at 0.7 g/cm3. Generally, PD showed a greater variation than CD, irrespective of MD level. (2) Boards produced using two-step hot pressing recorded substantially higher PD with reduced CD. (3) Multiple regression analysis showed that CD and PD could be calculated based on the other profile defining factors, and a rough estimation for peak distance and gradient factor was possible. (4) Based on static bending, conventional fiberboard had a higher modulus of rupture (MOR) than the homo-profile board but a similar modulus of elasticity (MOE). (5) At 0.5 g/cm3 the MOR and dynamic MOE of fiberboard increased by up to 67% and 62%, respectively, when the PD increased from 0.5 to 1.07 g/cm3. Similarly, an increase of PD from 0.7 to 1.1 g/cm3 resulted in corresponding increases of 55% and 34% in the MOR and dynamic MOE of 0.7 g/cm3 boards. (6) The internal bond strength and screw withdrawal resistance were almost entirely dependent on the CD and MD, respectively. (7) Homo-profile fiberboards registered higher thickness swelling and water absorption than conventional fiberboards throughout the dry/wet conditioning cycle. 相似文献
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We investigated the properties of composite board formed using base sheets of aluminum foil-laminated and polyethylene (PE)
plastic-laminated liquid packaging paperboard (LP) as an alternative to recycling these items in wastepaper stream. Boards
of different specific gravities ranging from 0.55 to 0.75 were made by pressing shredded LP blended with urea resin having
resin content of 6%–10% at 180°C. Subsequently, we also prepared mixed particleboard [wood (WD) particles and LP mixed], three-layered
particleboard (LP as the middle layer, WD in the upper and lower layers), and wood particleboard all having resin content
of 10% and various specific gravities. Static bending and internal bonding strengths and thickness swelling of the specimens
were determined to examine their properties. At the same specific gravity, the properties of LP particleboards were affected
by their resin content. The modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond strength of the LP particleboards
increased with increasing specific gravity of the boards at the same resin content, but thickness swelling of the LP particleboards
showed the reverse trend. The average MOR of the LP particleboards approximated that of the mixed particleboards and was greater
than those of the three-layered particleboards and wood particleboards. Internal bond strength and thickness swelling of the
LP particleboards were smaller than those of the other particleboards. Based on the above observations, we deemed that LP
can be made into composite boards with adequate properties either alone or mixed with wood particles. 相似文献