共查询到10条相似文献，搜索用时 203 毫秒
1.
中国引种澳大利亚相思树种制硫酸盐浆适应性研究 总被引：2，自引：1，他引：2
无论是从林业角度还是在制浆性能方面，不同种源间存在明显差异。本文研究了我国亚热带工区引种澳大利亚相思树的基本密度纸浆产率、制硫酸盐浆和漂白性能，比较了不同种源间的差异。研究结果表明，在有效碱用量为１２．５％－１５．５％时纸浆得率达５１．２％－５３．６％，经ＣＥＨＤ四段漂白后，所得纸浆性能可以满足配抄印刷和包装类用纸要求。 相似文献
2.
The effects of chemithermomechanical pulping (CTMP), high-temperature (HT)-CTMP pulping, and kraft pulping on the distribution of the pectin polymer, methyl-esterified polygalacturonan have been qualitatively evaluated using immunocytochemistry. Pectin was immunolocalized using an antibody (JIM7) specific for partly methyl-esterified polygalacturonan. A fluorescent antibody was linked to JIM7 and analyzed by epifluorescence microscopy. Pectin was found in both chemithermomechanical pulps in similar uneven patterns: Some fibers showed no labeling, whereas others showed extensive labeling in patches restricted to the fiber surfaces. Pectin labeling of bleached and unbleached kraft pulps did not show any presence of pectin. Labeling was correlated to the presence of compound middle lamella tissue left on the CTMP-treated surfaces. Pectin on pulp-fiber surfaces may affect the interfiber bonds and thereby the pulp properties. 相似文献
3.
中试系统制备了杨木碱性过氧化氢机械浆。分别在水相 /有机溶剂相 /气相等条件下 ,使用乙酐处理杨木化机浆 (原浆及硼氢化钠还原后纸浆 ) ,分别抄造成 60g/m2 纸片 ,测定了不同时间紫外线照射后试样白度。运用返色值 (PCno .)和白度稳定效果 (BSE)等指标评价处理后浆料的光学稳定性。研究结果表明 ,有机溶剂相和气相乙酰化后的纸浆 ,光学稳定性的提高程度取决于乙酐用量和反应时间即乙酰化程度。通过乙酰化 ,可以获取光学完全稳定的杨木化机浆。紫外漫射反射光谱表明 ,杨木APMP机械浆光诱导返色的主要原因是纸浆木质素中羰基和酚羟基团吸收紫外光后变化形成发色结构所致。还原配合纸浆乙酰化处理 ,可能成为防止高得率纸浆返色的工业应用方法 相似文献
4.
The steam explosion (SE) pretreatment associated with the organosolv process was investigated to produce dissolving pulp from eucalyptus. Prehydrolysis Kraft (PHK) pulping was also done to produce viscose and acetate grade pulps as reference. The organosolv pulps were delignified in two steps with sodium chlorite. Viscose and acetate grade PHK pulps were bleached by OD0(EH)D1P and OD0(EP)D1PCCE sequences, respectively. Dilute acid-catalyzed (with acid addition) SE pretreatment dissolved more xylan than auto-catalyzed (no acid addition) SE pretreatment. Steam-exploded unbleached organosolv pulps showed lower residual lignin content and screened yield than unbleached organosolv pulps without SE pretreatment. Steam explosion pretreatment helped to decrease lignin content and damaged fiber length of unbleached organosolv pulps. The 1.0% H2SO4 organosolv pulp (organosolv dissolving pulp at bioconversion conditions) showed the highest reactivity. Even showing low viscosity for some applications, in general, the organosolv dissolving pulps produced in this study can be used for making lyocell fibers. 相似文献
5.
The importance of eucalypt as a raw material for pulping is steadily growing. Eucalyptus globulus was compared with European hardwood species using two alkaline pulping processes, kraft and alkaline sulfite, anthraquinone
pulping (ASA), which is a recently developed modified alkaline sulfite process. All cooks were performed to similar kappa
numbers. Poplar cooks resulted in the highest yields followed by eucalypt and birch which were on the same level. Yield of
beech pulps was definitely lower. ASA pulps show a moderate higher yield due to the less alkaline pH-profile of the cooking
liquor. This yield advantage was maintained and even enhanced after TCF-bleaching. The bleaching response of all pulps was
excellent. The birch pulps had the highest tensile strength followed by the poplar and beech pulps. Surprisingly eucalypt
pulps had the lowest tensile strength. But this was compensated by the very good tear index of eucalypt pulps. The runnability
factor, as an index for the overall strength potential, was on the same level for all pulps. Due to the higher hemicellulose
content of the ASA pulps their tensile strengths were higher, but tear strengths lower compared to the kraft pulps. The different
morphology of the hardwoods investigated resulted in different volumes and light scattering coefficients of the corresponding
pulps.
Dedicated to Prof. Dr. Dr. h. c. mult.Walter Liese on the occasion of his 80th birthday. 相似文献
6.
Influence of process variables on the properties of pulp and paper sheets obtained by sulphite pulping of olive tree wood 总被引：1，自引：0，他引：1
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
7.
卷荚相思组织培养育苗技术的研究 总被引：8，自引：1，他引：8
卷荚相思是从澳洲新引种的树种，具有生长迅速，干形通直，木材质量好的特点，试验采用ＭＳ基本培养基，芽增殖培养基附加ＢＡ０．５ｍｇ／Ｌ和ＫＴ０．５ｍｇ／Ｌ，芽增殖率可达４倍以上，壮芽培养基用改良ＭＳ，加活性炭２ｇ／Ｌ，芽可抽长２～３ｃｍ，生根培养基为１／２，ＭＳ，附加ＩＢＡ２ｍｇ／Ｌ，生根率达８５％以上，卷荚相思组织培养为解决种源不足和快速繁殖优良无性素开辟新途径。 相似文献
8.
本文根据近年来国内有关单位对桉树造纸和制人纤浆粕的研究所取得的进展和成果,作一综合性的简介。从原料特性、制浆工艺到产品性能等方面,初步论证我国多种桉树造纸和制人纤浆的适宜性。 相似文献
9.
本文经过5年试验研究,从良种壮苗、立地分类、造林密度、林地管理、产量指标和经济效益估测,提出了黑荆丰产林栽培技术。所培育的丰产林,只要4年零2个月,其树高、胸径、产量可达到省标6年生立地指数级11和9的水平。 相似文献
10.
In this study, the response of Eucalyptus camaldulensis and Acacia mangium kraft pulp to different options of ECF bleaching was investigated. Oxygen-delignified pulps of both species having similar
kappa number (c.a. 12) were used. Both the pulps were prebleached using conventional ClO2 stage (D0), combined use of ClO2 and O3 (DZ), hot acid treatment before D0 (AhotD0) and hot acid treatment before (DZ) i.e., Ahot(DZ), hot ClO2 treatment (DHT) and Ahot followed by DHT (AhotDHT). All prebleached pulps were finally bleached to 90%+ ISO brightness using D1 option. The overall benefits of other options were not considerable compared to D0 and (DZ). From the ClO2 consumption point of view, for a certain species, the option Ahot(DZ) was the best. Instead of D1 in final bleaching, pressurized hydrogen peroxide (PO) was also investigated in the case of D0 and (DZ) prebleached pulps. (PO)-bleached pulp produced higher brightness stability but lower viscosity compared to D1. 相似文献