首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 796 毫秒
1.
刘胜  张文杰 《林业科技》2011,36(2):48-50
用近红外光谱数据建立了相思树制浆得率的预测模型:将近红外光谱数据按波长进行分组,然后使用拟合方法建立了10个子数学模型,最后通过计算子模型制浆得率预测值的加权平均值给出了预测制浆得率的公式。预测结果表明,用近红外光谱数据建立的预测模型可用于快速估算相思树的制浆得率,其建模方法有望用于其他速生纸浆材制浆得率的预测。  相似文献   

2.
马尾松制浆造纸性能的群体变异及适应性试验   总被引:8,自引:0,他引:8  
研究马尾松木材化学组分,制浆性能在群体中的变异及不同伐木材制浆造纸适应性,结果表明上述性状天然群体和种源试林群体中都存在一定变异,具有一定选择潜力。该验发现20年生伐龄木材制浆性能有一定优越性。采用短周期速生材造纸是可行的,但其关键在于造育幼龄材木材密度高的品系。  相似文献   

3.
广东阔叶树材造纸的研究   总被引:3,自引:0,他引:3  
广东历来用马尾松木材作造纸原料,虽扩大利用甘蔗渣和草类,仍不敷用。本文试图探索一些阔叶树材作造纸原料。选择速生或常见的阔叶树23种,进行木材解剖,以其中18种作制浆造纸试验,并以马尾松作对照。  相似文献   

4.
为发展和科学利用速生阔叶工业用材种,对6种江西常见速生阔叶树木荷、苦楝、鹅掌楸、深山含笑、东京野茉莉及檫树的纤维形态及材性进行测定与分析。结果表明:木荷、苦楝、深山含笑、东京野茉莉的纤维都属长细型纤维,具有良好的制浆造纸性能,尤其苦楝属制浆造纸优等材,纤维长度最长,平均纤维长度达1.43 mm。檫树和鹅掌楸制浆造纸性能略差。11~12年生木荷和檫树密度已达中等密度木材范围,其中木荷平均密度最大,平均密度为0.69 g/cm3,但干缩性相对略大,深山含笑尺寸稳定性相对较好;木荷的综合强度最高,抗压强度50.52 MPa,属中级,抗弯强度和抗弯弹性模量分别为141.7 MPa、17.88 GPa,均属高等水平;鹅掌楸综合强度中等,顺纹抗压强度为50.52 MPa、抗弯强度84.99 MPa,抗弯弹性模量14.55 GPa;深山含笑抗弯强度和抗弯弹性模量均可达中等水平,但抗压强度略差;苦楝、东京野茉莉在材性综合强度方面稍差,抗压强度、抗弯强度和抗弯弹性模量方面均属低等水平。  相似文献   

5.
速生人工林种植面积大,生长周期短,在取代天然林资源方面具有得天独厚的产量优势,但存在结构疏松、密度小、强度低等缺陷,导致其使用范围大受限制。使用无机材料对人工速生材进行改性处理可有效提高速生材性能和用途。文中简要总结无机质复合木材制备方法——扩散法、溶胶—凝胶法和真空浸渍法,以及无机材料改性处理对速生木材在力学性能、尺寸稳定性、阻燃性、表面疏水性和表面耐候性方面的改善,以期为人工林速生材无机材料改性提供技术参考。  相似文献   

6.
参照国家木材物理力学试验方法标准对采自东北林业大学帽儿山实验林场的15年生人工林长白落叶松不同地理种源的试材,测定了气干密度、年轮宽度、晚材率、硬度、管胞长度、管胞长宽比等参数;并通过综合评估分析处理试验数据。鉴于落叶松主要作工程用材和制浆用材,从木材材性角度评价地理种源的优劣,旨在为速生人工林木的定向培育提供科学依据。  相似文献   

7.
为了满足对林产品日益增长的需要,未来的木材供应将大部分来自人工栽培的速生树种林木。这些林木采伐周期短,因而较正常材含有较多的幼龄材。美国林产品实验室对幼龄材单板的分等方法及对LVL结构性能的影响进行了研究。采用速生的  相似文献   

8.
前言近二十多年来,世界上速生材制浆工业的蓬勃发展,促进了阔叶树资源的开发与利用。不少国家营造了大量的速生人工林,因而解决了木材原料短缺的问题,并在经济发展中获得较大成就,如:巴西从60年代开始大量营造速生林,到七十年代成为世界上主要产浆国之一,并使经济上得到发展,新西兰从一个木材缺乏的国家变为木材出口国,西班牙从缺纸国  相似文献   

9.
本研究采用适宜木材染色的大红GR和嫩黄G酸性染料,对人工速生树种-杨木的漂白单板和未漂白单板进行染色.测定染色单板染色前后的颜色,计算染色前后的色差,并分析杨木单板染色后材色变化规律.试验结果表明,不同染料染色单板的变色度Eab与材色指数呈现不同的关系:红色染料a值增加和L值降低对Eab影响大;黄色染料b值增加决定了Eab的变化.  相似文献   

10.
为解决我国木材资源的不足,近年来对森林资源的利用正在迅速地向速生短轮伐期木材及间伐小径材等方面开拓。由于对速生材的材性及加工技术研究起步较晚,以往在利用上仅限于人造板及造纸原料。木材干燥是合理利用木材的基础,是保证木制品质量的关键,也是速生材能否取代传统商品材的一个重要技术因素,对速生材的利用将起积极的推动作用。我省速生树种中杨树、河柳占很大比例,杨树中黑杨、青杨居多,此外还普遍分布着泡桐、水杉等树种。由于多数速生材心边材含水率差异大,成材快速干燥时易产生翘曲、皱缩等缺陷,从而影响了它们的直接加…  相似文献   

11.
速生树种制浆造纸适应性能评估模型的研究   总被引:4,自引:0,他引:4  
开发利用新的速生纤维原料资源,定向培育速生纸浆材,首先必须对其制浆适应性能作出正确地评价。本文采用模糊数学理论中的欧几里德贴近度法为数学模型,此法数据处理方式简单,信息利用率和精度较高,权重计算较为合理,用TurboC语言编制了汉化的综合评估软件。运用本软件对四种主要速生树种制硫酸盐浆适应性进行了综合评价,结果表明,黑荆树、杉木、米老排和王桉为较优良的硫酸盐法制浆用材,实际情况相吻俣。  相似文献   

12.
《Southern Forests》2013,75(3-4):181-189
Near-infrared (NIR) scanning technology is regarded as a potential tool for rapid determination of wood properties, which can substitute time-consuming and costly traditional methods. Pinus patula is the most important softwood species in South Africa, and this study is aimed at developing NIR calibration models for quick prediction of its pulp yield and chemical composition. A total of 85 trees from 17 plots, covering the range of site conditions in the Mpumalanga escarpment area, were sampled. Two samples were taken from each tree: a 1 m billet above breast height and a 20 mm disc at breast height. The billet was pulped using the kraft pulping process to determine pulp yield. The disc was ground into sawdust and the chemical composition was determined using conventional wet chemistry. Sawdust was scanned on a NIR spectrophotometer to produce NIR spectra. Calibration models to predict pulp yield, cellulose and lignin content were developed by applying chemometrics and partial least squares regression. Validation and determination of prediction accuracy of the models were performed using independent data. The prediction of cellulose and lignin were acceptable with correlations of determinations (r 2) of 0.71 and 0.70 respectively. Standard errors of prediction were generally low (less that 0.86) for all the models. The prediction r 2 for both total and screened pulp yield were only 0.62. Although the cellulose and lignin models can be used with confidence, the expansion of the sample size for follow-up research must be considered in order to increase the variability of tested wood properties and improve the prediction strength of the models. The NIR calibration provided in this study can contribute to the efficient examination of forest site-to-wood quality relationships that would enhance precision forest management and wood processing efficiency.  相似文献   

13.
欧美杨107杨正常木与应拉木制浆造纸性能比较   总被引:1,自引:0,他引:1  
周亮  高慧  张利萍  刘盛全 《林业科学》2012,48(5):101-107
选取直立和倾斜欧美杨107杨为研究材料,根据正交试验确定正常木和应拉木最佳制浆条件,比较正常木和应拉木的制浆造纸性能,通过提高打浆转数对应拉木纸张性能的提高进行探讨。结果表明:正常木的最佳制浆条件为用碱量15%、最高温度164℃、最高温度保温时间75min;而应拉木最佳制浆条件为用碱量13%、最高温度160℃、最高温度保温时间40min。用碱量对正常木和应拉木制浆得率和卡伯值影响的通径系数在不同水平上显著。通过对正常木和应拉木制浆造纸性能比较发现,应拉木比正常木制浆得率高、卡伯值低、纸张力学性能均低,且抗张指数和耐破指数差距较大(约2倍),而撕裂指数差距较小。正常木和应拉木之间卡伯值、制浆得率、抗张指数、耐破指数均在0.001水平上差异显著,撕裂指数在0.05水平上差异显著。结合纸张断口形貌分析认为,胶质层的存在使得应拉木纤维成纸时不容易扁平坍陷,极大地阻碍了成纸时纤维之间的结合,因此降低了纸张力学性能;但是,由于其胶质层纤维素含量很高,因此其制浆性能优于正常木。随着打浆转数的提高,应拉木纸张力学性能增强,且接近正常木纸张水平,但过高会降低纸张力学性能。  相似文献   

14.
Both of straight and inclining poplar clone 107 tree were selected for studying materials in this paper.The optimal pulping conditions was established by orthogonal experimental design both for normal wood and tension wood,and the quality of pulping and paper-making between normal wood and tension wood was compared with each other. Finally,potential application for improving paper quality of tension wood through increasing beating revolutions was discussed.The result showed that the optimal cooking condition for normal wood was alkali concentration 15%,the highest temperature 164℃,time at highest temperature 75 min,and for tension wood it was alkali concentration 13%,the highest temperature 160℃,time at highest temperature 40 min.Path coefficient of effect of alkali concentration both on pulp yield and kappa value was significant at different levels.By comparison between average result of normal wood and tension wood in quality of pulping and paper-making,it was found that tension wood had higher pulping yield and lower kappa value than normal wood. Furthermore,for all mechanical properties of paper, normal wood hold higher value than tension wood, and even near two times than tension wood,such as burst index and tensile index.However,difference of tear index was quite narrow.Result of one way ANOVA showed that difference of burst index and tear index between normal wood and tension wood was significant at the 0.001 level,of tear index was significant at the 0.05 level.Based on observation of cross surface of paper,it was assumed that contribution of gelatinous layer to rigidity of single fiber had hampered collapse and compression of fiber during paper formation,which is essential for exerting combination between fibers in paper.So, mechanical properties of tension wood paper were decreased accordingly.However,owing to high cellulose content of gelatinous layer,tension wood was easier to pulping than normal wood.Mechanical properties of tension wood paper could be improved by increasing beating revolutions,  相似文献   

15.
有机溶剂法制浆研究最新进展   总被引:5,自引:0,他引:5  
综述了国内外关于有机溶剂制浆的最新研究进展,提供了一条解决制浆造纸行业环境污染和天然高分子资源充分利用的有效技术途径.  相似文献   

16.
Summary A central composition design was developed to study the influence of process variables (temperature, pulping time, sulphite concentration, anthraquinone concentration and liquid/solid relation) on the properties of pulps (yield, holocellulose, α-cellulose and lignin contents, and brightness) and the paper sheets (stretch, burst index and tear index) obtained from them, in the sulphite pulping of olive tree wood. Equations that reproduce the properties of pulps prepared by sulphite pulping and of paper sheets obtained from it are reported. The proposed equations fit the experimental yield and the holocellulose and α-cellulose contents of the pulps with errors less than 5%, as well as brightness with errors less than 10%. Also, they reproduce the lignin content of the pulps, and the stretch, burst index and tear index of the paper sheets with errors less than 15%. Obtaining pulps with acceptably high yield, holocellulose and α-cellulose contents, and also a high brightness, in addition to low lignin contents, entails operating at a temperature of 193 °C for 143 min, using a sulphite concentration of 19.85%, an anthraquinone concentration of 0.1% and a liquid/solid relation of 6.24. These are also the most suitable conditions for obtaining paper sheets with a high stretch, burst index and tear index. Received 23 April 1998  相似文献   

17.
The present study is focused on analysing the suitability of different Streptomyces strains for biomechanical pulping purposes using spruce wood (Picea abies) as substrate. After 2 weeks of incubation, no apparent variations in lignin Klason content of treated woods were detected compared with the control. However, the increase in acid-soluble lignin fraction pointed out chemical alterations in lignin moiety. Through Py-GC/MS analysis enrichment in cellulose and lignin molecule modifications were detected in treated woods. The increase in the relative abundance of the most G-type phenol units with a higher oxidation degree suggests that some oxidation occurred in the lignin C3-alkyl chain. In addition, the decrease in the phenylmethane + phenylethane/phenylpropane (phC1 + ph C2/ph C3) ratio would indicate the ability of Streptomyces strains to breakdown the C3-alkyl chain linkages once carbons had been oxidized. From this study it could be concluded that the assayed strains are able to produce a delignification of spruce wood which may improve mechanical pulping processes.  相似文献   

18.
木麻黄工业原料林多形地位指数模型的研究   总被引:1,自引:1,他引:0       下载免费PDF全文
以木麻黄工业原料林为研究对象,采用Richards非线性生长方程,通过参数置换法,建立了木麻黄多形地位指数模型。结果表明:(1) Richards方程的拟合精度较高,经检验,该模型优势高的理论值和实际值差异不显著,适应性较好,能对木麻黄的优势高生长进行正确预估;(2)研究地区木麻黄工业原料林的基准年龄可确定为3 a;(3)对多形地位指数模型的拐点进行分析,表明该模型能够客观地反映不同立地优势高的生长规律;(4)为推进国内木麻黄数表、模型的研究与应用提供了参考,为木麻黄林分立地质量评价,经营管理提供科技支撑。  相似文献   

19.
山杨木材材性的研究   总被引:2,自引:0,他引:2  
对北方六省六个地区天然林中的山杨木材解剖, 物理力学性质, 化学成分进行的研究。结果表明:六个种源的山杨木材解剖特征,化学成分无明显差异,物理力学性质存在不同程度的差异。此外,还对六组山杨的胶质纤维,侵填体,髓斑进行了研究。  相似文献   

20.
中国竹子资源丰富,分布广泛,发展竹材制浆造纸产业,对于缓解木浆原料短缺现状具有重要意义。根据对竹浆的理化性能分析,竹材是较好的造纸原料,竹材的纤维形态及化学组成表现出较好的制浆性能,仅次于针叶木,接近于阔叶木。从竹材应用于竹浆造纸的角度,综述了竹材的物理化学性能、现行的竹浆造纸工艺、竹浆造纸设备,并就竹浆造纸的发展潜力与发展方向提出了个性化观点,以期为探索绿色、低碳、环保的竹资源利用新途径,为开发高技术含量和高附加值竹产品提供借鉴,从而促进中国竹产业可持续发展。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号