共查询到19条相似文献,搜索用时 125 毫秒
1.
热处理是一种应用广泛的木材改性方法,不仅能改善木材材色,还能提高木材的尺寸稳定性和生物耐久性。总结了热处理工艺对木材性能的影响,详述了热处理过程中木材化学组分变化。从处理过程和老化过程讨论了环境对处理材性能的影响,并概括了热处理木材材色变化机理。未来应深入解析热处理化学反应路径及其内在机理,建立木材材色与其他材性的关系,并通过联合改性处理提升热处理木材的耐久性。 相似文献
2.
不同油浴热处理对马尾松木材尺寸稳定性影响的研究 总被引:4,自引:1,他引:3
文章采用石蜡油和植物油浴热处理方法对马尾松木材进行热处理,并采用SPSS统计分析研究不同处理方法对马尾松木材的尺寸稳定性(ASE值)的影响。结果表明:在油浴热处理木材中,处理时间和处理温度都显著影响着木材的尺寸稳定性(ASE值)。在低温和浸泡时间短条件下,石蜡油热处理材的ASE优于植物油热处理材的ASE;而在高温或浸泡时间长条件下,植物油热处理材的ASE优于石蜡油热处理材的ASE。 相似文献
3.
采用主要成分为氯化锌、磷酸二氢铵及复合铜盐(硝酸铜+醋酸铜)的三种药剂对马尾松和桉树木材做浸渍处理后再进行短周期加热处理的方法,研究了处理工艺对热处理木材失重率和耐腐性能的影响。结果表明:处理木材的失重率和耐腐性能均随着处理温度升高和处理时间的延长而增大,氯化锌药剂热处理木材在较高温度下对木材的失重率影响最大,具有明显加速热处理反应的作用;但是在同样的热处理温度条件下,浸渍氯化锌和复合铜盐的热处理木材耐腐性明显优于未加药剂的热处理木材。三种药剂中,由复合铜盐浸渍处理的木材经190℃热处理后能达到强耐腐等级。 相似文献
4.
5.
以樟子松为原料,采用正交试验法,研究了不同木材含水率(10%、20%、30%)、高温热处理温度(180、200、220℃)、处理时间(2、3、4 h)三个因素对樟子松处理前后弦向干缩性和湿胀性、吸水性、密度的影响,以及樟子松高温热处理时,被处理材含水率、处理温度与处理时间的优化组合。结果表明:较高初始含水率、较高热处理温度和较长高温处理时间可改善木材的干缩性和湿胀性,使木材尺寸稳定性更好;在较剧烈的热处理条件下,初始含水率的大小不会影响热处理材密度降低的趋势;热处理温度、时间和含水率对吸水性的影响不呈线性关系。 相似文献
6.
7.
8.
真空热处理改性马尾松木材物理性能研究 总被引:3,自引:0,他引:3
文章采用间歇抽真空法及利用木材自身含有的水分对马尾松木材进行热处理,并研究了热处理温度和时间对马尾松木材的尺寸稳定性(ASE值)和力学性能的影响。结果表明:处理温度和时间均显著影响着木材的力学强度和ASE。综合考虑处理温度和处理时间对ASE、顺纹抗压强度和抗弯强度的影响,较佳的真空热处理工艺为:压力-0.09 Mpa、处理温度200℃,处理时间1 h。 相似文献
9.
热处理木材具有较低的吸湿性,较好的尺寸稳定性和耐腐性,是一种新型的绿色环保材料。本文介绍了热处理木材在建筑装饰领域的应用,并预计其未来的发展趋势。 相似文献
10.
11.
12.
木材改性技术发展现状及应用前景 总被引:2,自引:0,他引:2
系统阐述了木材改性的背景、方法及意义,重点介绍了热改性、乙酰化、糠基化改性,及压密化和热处理组合改性的基本原理和工艺,及其对木材性质的影响;分析了这些改性方法的应用现状及工业化应用前景,并提出了今后需着重研究的关键问题。 相似文献
13.
《Wood material science & engineering》2013,8(4):209-216
Abstract To investigate the role of extractives on heat-induced discoloration of wood, samples of black locust (Robinia pseudoacacia) wood flour were extracted with various solvents prior to heat-treatment. Analysis of their color parameters and chromophoric structures showed that the chroma value of the unextracted sample decreased while that of the extracted sample increased after heat-treatment. Both samples showed broad diffuse reflectance UV-Vis (DRUV) absorption bands with maxima around 360–380 nm after heat-treatment due to the formation of conjugated double bonds, carbonyl functionalities, and quinoid structures. Compared with the unextracted sample, the dominant chromaticity of the extracted samples hypochromatically shifted and the peak became narrower. This result showed that extractives contribute mostly to the reduction in the light reflection on heat-treated wood. In addition to extractives, lignin and hemicellulose also contributed to the formation of color substances upon heat-treatment. The increase in C3/C2 ratio in X-ray photoelectron spectroscopy (XPS) spectra signified the oxidation reactions in the heating process. The increase in O1/O2 for extracted sample after heat-treatment and changes in DRUV and Fourier transform infrared spectroscopy (FTIR) spectra support the hypothesis that discoloration can also arise from the degradation of hemicellulose and the condensation reactions of lignin. 相似文献
14.
圆盘豆木材力学强度对高温热处理条件变化的响应 总被引:1,自引:0,他引:1
以过热蒸汽为传热介质和保护性气体,在热处理温度为160℃、180℃、200℃、220℃,热处理时间为2h、4h、6h、8h的条件下对圆盘豆木材进行高温热处理,研究圆盘豆木材在不同热处理条件下的力学性能变化规律。结果表明,随着热处理温度升高和热处理时间延长,圆盘豆热处理材抗弯强度降低;弹性模量在160℃时最高,然后降低;硬度的变化趋势不明显。红外光谱分析表明,热处理使木材中的半纤维素、纤维素、木素发生降解反应,导致木材力学强度降低。 相似文献
15.
16.
《Wood material science & engineering》2013,8(1-2):55-61
Abstract In this study, mould growth on wood was investigated by image analysis. The studied parameters were drying and heat-treatment temperatures (20–210°C), original and resawn surface and different wood species (spruce and larch). Small specimens—some of which were inoculated with a spore suspension—were stored under humid conditions and photographed once a week. Mould growth was assessed by image analysis. In general, results found in earlier studies regarding the influence of several parameters could be confirmed. Image analysis was found to be a useful method to quantify mould growth in an objective and reproducible way. 相似文献
17.
木、竹、藤材的变色防治 总被引:5,自引:0,他引:5
对木材变色的机理、类型、成分和影响因素, 木材变色的预防和消除以及生物防治等研究的最新成果进行了概括总结, 综合论述了木材、竹材和藤材的变色防治研究现状, 得出以下几点结论:(1)低毒或无毒、高效、多功能的防变色剂的研制开发仍是木材工业变色防治研究的重要研究方向。(2)开展色变脱除, 恢复已变色材原有颜色和价值方面的研究很有必要。(3)以菌治菌的生物防治, 污染小, 成本低, 应加强其理论研究和实践应用。(4)通过热处理或光辐射等手段, 诱导木、竹、藤材变色, 进行调色处理, 将成为新的研究方向。(5)与木材相比, 竹材、藤材变色的研究落后, 尤其是藤材变色, 应得到进一步加强。 相似文献
18.
Christian Robert Welzbacher Christian Brischke Andreas Otto Rapp 《Wood material science & engineering》2007,2(2):66-76
The impact of heat-treatment temperature (180, 200, 210, 220 and 240°C) and various heat-treatment durations on selected biological, mechanical, optical and physical properties of thermally modified timber (TMT) was determined. The suitability of different measures for prediction of the treatment intensity was also investigated. Resistance to impact milling (RIM), lightness L*, equilibrium moisture content (EMC), and antiswelling efficiency (ASE) were correlated with corresponding fungal resistance achieved by heat treatments. The results show that the decrease in mass by heat treatments is a suitable measurand to describe the treatment intensity, which is a product of treatment temperature and duration, where the impact of temperature is dominant over the impact of time. The properties examined showed a strong reciprocally proportional relationship with the decrease in mass. Different correlations were found for the various treatment temperatures: the higher the temperature applied, the lower the decrease in mass required for an equivalent improvement in certain wood properties, e.g. biological durability, EMC and dimensional stability. However, mass loss by Poria placenta correlated well with RIM, lightness L*, EMC and ASE of the different heat-treated specimens, depending on the heat-treatment temperature. Consequently, a reliable estimation of improved fungal resistance of TMT, as well as quality control of TMT in general, requires certain process information. 相似文献
19.
《Wood material science & engineering》2013,8(2):66-76
Abstract The impact of heat-treatment temperature (180, 200, 210, 220 and 240°C) and various heat-treatment durations on selected biological, mechanical, optical and physical properties of thermally modified timber (TMT) was determined. The suitability of different measures for prediction of the treatment intensity was also investigated. Resistance to impact milling (RIM), lightness L*, equilibrium moisture content (EMC), and antiswelling efficiency (ASE) were correlated with corresponding fungal resistance achieved by heat treatments. The results show that the decrease in mass by heat treatments is a suitable measurand to describe the treatment intensity, which is a product of treatment temperature and duration, where the impact of temperature is dominant over the impact of time. The properties examined showed a strong reciprocally proportional relationship with the decrease in mass. Different correlations were found for the various treatment temperatures: the higher the temperature applied, the lower the decrease in mass required for an equivalent improvement in certain wood properties, e.g. biological durability, EMC and dimensional stability. However, mass loss by Poria placenta correlated well with RIM, lightness L*, EMC and ASE of the different heat-treated specimens, depending on the heat-treatment temperature. Consequently, a reliable estimation of improved fungal resistance of TMT, as well as quality control of TMT in general, requires certain process information. 相似文献