共查询到19条相似文献，搜索用时 703 毫秒
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透明涂饰刺槐木材的色度学参数及其漆膜性能 总被引：1，自引：0，他引：1
《木材工业》2016,(1)
为开发刺槐木材涂饰工艺,分别采用聚氨酯漆、丙烯酸水性漆和合成大漆,对刺槐木材漆膜色度学参数和漆膜性能进行了评价。结果表明,这三种涂料对刺槐木材均表现出良好的涂饰效果,漆膜明度均存在下降趋势(其中合成大漆下降最明显),漆膜色饱和度均增加;总体色差变幅最大为合成大漆,聚氨酯漆最小;漆膜性能均达到GB/T4893《家具表面理化性能测定法》和GB/T 15036-2009《实木地板》一级或二级要求,聚氨酯漆耐磨性、硬度最高。 相似文献
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软质木材的表面密实化 总被引：3，自引：0，他引：3
探讨软质木材表面密实化的理想状态和途径,研究用酚醛树脂浸渍、再进行不同程度压缩木材的表面密实化效果.试验结果表明,浸渍压缩后木材密度从表层到内层的分布呈现一定的梯度,表面密度均高于内层密度和平均密度;试件的表面硬度、耐磨性和尺寸稳定性均有不同程度的提高. 相似文献
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《林业工程学报》2016,(1)
针对防滑防振型结构胶合板的开发,探索采用阻尼涂料对意杨胶合板进行表面涂饰处理,以构建新型木基阻尼结构体系。试验了自由型和约束型两种阻尼结构,全面分析了阻尼涂饰意杨胶合板的涂层附着力、涂层界面、摩擦系数、耐磨性、硬度和耐冲击等性能。研究结果表明:总体而言,阻尼涂饰能在确保良好界面结合的基础上,赋予胶合板优异的表面性能。阻尼涂料能有效渗透入意杨木材,形成紧密的结合界面。阻尼涂饰胶合板的表面防滑性能和耐磨性能均优于常规MF浸渍纸饰面板,表面布氏硬度和抗冲击性能优于意杨胶合板素板,其中布氏硬度达到44.02~51.97 MPa,冲击强度最高达到30.71 k J/m~2。综合考虑,建议采用自由型阻尼结构,阻尼涂料厚度控制在约1.5~2.0 mm。以上研究结果对于开发功能型胶合板新产品具有显著的参考价值。 相似文献
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水热-微波处理对榆木软化和顺纹压缩及弯曲的影响 总被引：3，自引：1，他引：2
采用水热-微波处理方法对榆木成熟材进行软化处理,通过顺纹压缩率、单维和多维弯曲最小曲率半径表征木材软化效果;以XRD,FYIR等方法测定木材表面组成、结晶度变化,分析软化处理对木材顺纹压缩的影响.结果表明:水热-微波处理可显著增强木材的软化性能,处理后木材中的抽提物几乎完全抽出(1.73%～0.47%),半纤维素发生明显降解,使木质素相对含量得到增加,木材表面羟基数量显著增加;非结晶区微纤丝趋于有序,相对结晶度提高,结晶区表面微纤丝羟基裸露,氢键键合增强,结晶区宽度增加.当采用处理方案为B时,顺纹压缩率最大,单维和多维弯曲时的曲率半径最小.较高的结晶度和适宜的羟基数量是试样B表现出较高软化性能的主要原因. 相似文献
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采用氮气射流对热处理材落叶松进行等离子体处理,研究了不同处理高度、不同处理时间对热处理材漆膜性能的影响,通过仪器测定,分析了不同等离子体处理条件下被处理材的漆膜性能变化机理,并得出本实验中改善热处理材落叶松漆膜性能的最佳等离子体处理工艺参数。结果表明:随着等离子体处理高度的降低和处理时间的延长,热处理材漆膜质量损失率降低,漆膜性能逐渐提升;等离子体处理改善热处理材漆膜性能的最佳工艺时间为20 s、高度为15 mm;等离子体处理过程中引入的大量氨基、羟基、羰基、羧基等亲水性基团是被处理材漆膜性能提升的根本原因。X射线光电子能谱分析显示,经过等离子处理后的落叶松,C元素含量降幅为12.63%,O元素和N元素增幅分别为14.32%,83.87%。FT-IR结果表明,处理后的木材表面—OH、C—H、C=O的峰的强度明显加强。因此,对热处理之后的木材进行等离子体处理,可大幅度提升其漆膜性能,从而改善产品缺陷、提高附加值。 相似文献
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Surface modification of wood using friction 总被引：1，自引：1，他引：0
Lauri Rautkari Milena Properzi Frédéric Pichelin Mark Hughes 《Wood Science and Technology》2009,43(3-4):291-299
The potential of linear vibration friction as an innovative means of producing increases in both surface density and surface hardness was explored. The influence of processing pressure and time on the degree of surface densification, surface hardness and surface elasticity was investigated. It was found that surface hardness (measured as Brinell hardness) was positively correlated with densification ratio. Furthermore, surface elasticity, that is the ability of the surface to recover elastically after indentation during the Brinell hardness test, could be increased by up to 33% depending on the degree of surface densification. The temperature rise due to friction was also studied. During processing, it was found that the temperature rise on both the radial and tangential surfaces was positively correlated with the processing pressure and time. 相似文献
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Effects of semi-isostatic densification of wood on the variation in strength properties with density
The variation in strength properties with density was compared between semi-isostatically densified and non-densified wood.
Strength properties were compared with published data from earlier studies using other methods for densification. Small clear
specimens of eight species were analysed for compression strength in axial, radial and tangential direction, three-point bending
and Brinell hardness. After densification, all tested strength properties increased with density, but especially strength
perpendicular to grain became lower than expected from the density of non-densified wood. Strength of densified wood relative
to what could be expected for non-densified wood of similar density was denoted as ‘strength potential index’. For axial compression
strength and bending strength, strength potential index of individual wood species varied between 0.7 and 1.0, i.e. densified
wood is slightly weaker than what could be expected from its density. Strength potential index was lower for properties much
determined by strength perpendicular to grain. In radial direction, densified wood was rubbery with low modulus of elasticity
and nearly no proportional limit or modulus of rupture. Generally, wood was apparently weakened in proportion to the degree
of compression in respective direction. Strength potential index also increased with increasing original density of the species. 相似文献
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Matthew Schwarzkopf Michael Burnard Guillermo Martínez Pastur Lucas Monelos Andreja Kutnar 《Wood material science & engineering》2018,13(5):305-315
Nothofagus pumilio and N. antarctica forests of Southern Patagonia, Argentina are currently being managed for production of saw logs with fast growing conditions. The result of these management strategies is faster growing forests, but also an increase in the percentage of low-density wood. The motivation for this study was to find a way to valorise this low-density wood. Surface and bulk densification treatments were applied these wood species and were then applied as face layers in three-layer composites. The mechanical properties of three-layer composites were studied. The modulus of elasticity, modulus of rupture, and modulus of hardness were improved compared to many types of structural composite lumber. This increase in mechanical properties of N. pumilio and N. antarctica wood opens the possibility for its use in structural composites and added value to these otherwise underutilised and undervalued species. 相似文献
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Effects of short-term thermomechanical densification on the structure and properties of wood veneers
Pavlo Bekhta Stanisław Proszyk Tomasz Krystofiak Jan Sedliacik Igor Novak Miroslava Mamonova 《Wood material science & engineering》2017,12(1):40-54
The effects of short-term thermomechanical (STTM) densification temperature and pressure on the changes in surface roughness, wettability, mass loss (ML), thickness and density of alder, beech, birch, and pine wood veneer with low moisture content (~5%) were investigated. The anatomical structure of veneers was also observed. Veneer sheets were densified using pressure levels of 4, 8 and 12 MPa at three temperatures: 100°C, 150°C and 200°C for 4 min. The results were compared with those of the non-densified veneers. The obtained results show that STTM densification of veneers similarly to long-term densification of solid wood causes irreversible changes in their properties. The STTM-densified veneer surfaces became smoother and more hydrophobic, ML increased slightly while roughness and thickness values decreased significantly, the cell lumens collapsed and a certain amount of fractures in cell walls developed with increasing densification temperature and pressure. All of the investigated wood species showed higher density values after densification. It was found that an even STTM densification of veneers provides stable properties under normal atmosphere conditions; in particular, the thickness and contact angle values were stable for 24 hours after densification, which is an important consideration for industrial applications. 相似文献
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基于纳米压痕技术的木材胶合界面力学行为 总被引：1，自引：0，他引：1
【目的】研究木材胶合界面的静态和动态力学行为,探讨树脂渗透对木材管胞壁层力学性能的影响,为木质复合材料制造工艺优化和增强改性提供理论依据。【方法】采用纳米压痕静态和动态力学测试技术(Nano-DMA),对针叶材火炬松与酚醛树脂(PF)、脲醛树脂(UF)胶黏剂所形成胶合界面区域各相材料的静态弹性模量、硬度、蠕变性能以及储能模量和损耗模量等力学行为进行分析。【结果】静态力学行为方面,在界面区域,PF和UF渗透进入管胞壁层后,木材管胞壁的弹性模量( E r)和硬度( H )提高;经PF渗透后,木材管胞壁的 E r和 H 分别增加7%和26%;Burgers蠕变力学模型可有效描述胶合界面区域管胞壁的纳米压痕蠕变特性,经树脂渗透后,木材管胞壁的瞬时弹性模量增加,黏弹性模量和黏性系数减小;在保载初期,PF界面区域木材管胞壁的蠕变柔量约下降60%,UF界面区域木材管胞壁的蠕变柔量约下降58%。动态力学行为方面,随着加载频率增加,界面材料的储能模量( E ′ r)逐渐增大,而损耗模量( E ″ r)和损耗因子(tan δ)呈减小趋势;当加载频率为10 Hz时,PF和UF树脂渗透使得管胞壁层的储能模量分别增加16%和29%。【结论】胶合界面区域胶黏剂进入管胞壁层,对木材管胞的静态力学性能具有增强作用,同时胶黏剂可提高管胞壁的短期抗蠕变能力;木材管胞壁具有较高的储能模量和损耗模量,而树脂的储能模量和损耗模量较低,经树脂渗透后,木材管胞壁的储能模量增加,但损耗模量和损耗因子呈下降趋势,可能对界面传递和分散应力产生不利影响。 相似文献
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人工林软质木材表面密实化新技术 总被引：16，自引：7，他引：16
采用一种新型木材改性处理剂，分别以改性异氰酸酯浓度5％、10％、15％、20％，对美国人工林火炬松（Pinus taeda）进行表面密实化处理。结果表明，随着树脂浓度的增加，无论是冷水浸泡还是煮沸，木材的吸水厚度膨胀率和压缩变形恢复率明显降低。表面密实化后，火炬松处理材的MOR和MOE值分别比素材提高43．9％和30．1％；水浸24h和煮沸2h后的湿状抗弯性能比素材略低，干状抗弯性能明显比素材高，MOR分别高28．0％和25．76％；MOE分别高22．55％和27．79％。改性异氰酸酯浸渍处理后的表面密实化木材，具有一定的阻燃效果；表面耐磨耗性能和表面硬度亦明显改善。 相似文献
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Lauri Rautkari Milena Properzi Frédéric Pichelin Mark Hughes 《Wood Science and Technology》2010,44(4):679-691
The chemistry and wetting behaviour of surface densified wood were investigated using FT-IR spectroscopy and contact angle
analyses. Furthermore, set-recovery of the surface under conditions of fluctuating humidity was measured and quantitative
microscopy analyses were undertaken. FT-IR indicated that no significant chemical changes took place during the densification
process. However, the wettability of the densified surfaces was significantly lower than unmodified surfaces. Following several
high humidity-oven dry cycles, it was found that this densification process was almost completely reversible, i.e., there
was full set-recovery. 相似文献