环保型不溶性偶氮染料在防伪纸中的显色研究

采用非欧盟禁用不溶性偶氮染料制备一种新型的显色防伪纸。在纸浆中加入固体色酚颗粒,抄纸后在纸基表面上喷上一层色基的重氮盐溶液,干燥。制备出的纸张在滴加酒精后会显现出红色斑点。通过对色基红B、色酚AS-BO(偶合后显红色)用量的控制,以优化出不溶性偶氮染料在纸张上防伪显色的最佳工艺条件。对显色后的纸张进行白度、色差和物理性能的检测,结果表明,使用色基B和色酚AS-BO抄造出的纸张具有良好的防伪效果,添加色基和色酚后纸张的主要物理性能变化不大。     

玉米秸秆包装材料的开发研究

利用玉米秸秆的外皮为主要原料,选择适宜浓度的预处理剂,采用化学预处理与机械磨浆相结合的方法,制得了较高得率的纸浆。抄造出了超过国家标准规定的一等品质量要求的瓦楞原纸,制浆过程中产生的废液可全部循环回用。开展该研究有利于保护环境、节约资源、增加农民收入。     

Review: nanoparticles and nanostructured materials in papermaking

The introduction of nanoparticles (NPs) and nanostructured materials (NSMs) in papermaking originally emerged from the perspective of improving processing operations and reducing material consumption. However, a very broad range of nanomaterials (NMs) can be incorporated into the paper structure and allows creating paper products with novel properties. This review is of interdisciplinary nature, addressing the emerging area of nanotechnology in papermaking focusing on resources, chemical synthesis and processing, colloidal properties, and deposition methods. An overview of different NMs used in papermaking together with their intrinsic properties and a link to possible applications is presented from a chemical point of view. After a brief introduction on NMs classification and papermaking, their role as additives or pigments in the paper structure is described. The different compositions and morphologies of NMs and NSMs are included, based on wood components, inorganic, organic, carbon-based, and composite NPs. In a first approach, nanopaper substrates are made from fibrillary NPs, including cellulose-based or carbon-based NMs. In a second approach, the NPs can be added to a regular wood pulp as nanofillers or used in coating compositions as nanopigments. The most important processing steps for NMs in papermaking are illustrated including the internal filling of fiber lumen, LbL deposition or fiber wall modification, with important advances in the field on the in situ deposition of NPs on the paper fibers. Usually, the manufacture of products with advanced functionality is associated with complex processes and hazardous materials. A key to success is in understanding how the NMs, cellulose matrix, functional additives, and processes all interact to provide the intended paper functionality while reducing materials waste and keeping the processes simple and energy efficient.     

多种植物纤维复合制备纸质蛋盒及其静力学特性研究

研究了一种把大米草处理成热磨机械浆后,再与化学浆料复配,制备纸质蛋盒包装的方法,对所研制的蛋盒包装材料进行了静态压缩实验。结果表明:在相同湿度与温度条件下,利用瓦楞纸板浆制备的蛋盒材料承载性能最强,其最终承载能力达到了380N,利用废报纸浆复配40%(质量分数)大米草纤维以及纯白竹浆复配30%(质量分数)大米草纤维制备成的蛋盒,最终承载能力分别为302,300N,说明利用大米草复配化学浆料制备蛋盒包装材料具有良好的应用前景。     

凝固浴中糖含量对纺制Lyocell纤维的影响

介绍了用高效液相色谱法测定Lyocell纤维和浆粕原料中各种单糖的组分含量,建立了凝固浴中混合糖总含量的测定方法。并且,模拟研究了不断积累在凝固浴中的低聚糖含量对纺制Lyocell纤维的影响。结果表明,Lyocell纤维和浆粕原料中各种单糖的组分含量几乎相同,当凝固浴中混合糖含量不断增加甚至达到饱和值时,对纺制Lyocell纤维及纤维的质量也没有明显的影响。     

强韧包装纸板用落叶松半化学浆的研究

主要研究一种可以替代传统硫酸盐化学木浆，来生产强韧包装纸板或瓦楞纸箱箱板纸的落叶松碱性亚硫酸盐－蒽醌半化学浆。这种采用碱性亚硫酸盐添加蒽醌助剂的制浆方法研制的落叶松半化学浆，当纸浆得率为５６．９％时，在低打浆度情况下纸浆强度性能可以达到我国２号未漂硫酸盐化学木浆的标准，而且有可能达到１号未漂硫酸盐化学木浆的标准，纸浆得率比落叶松硫酸盐木浆得率实际指标（４３％）绝对值提高１３％以上。用于制作强韧包装纸板或瓦楞纸箱箱板纸的落叶松碱性亚硫酸盐－蒽醌半化学浆，蒸煮终点宜于控制在得率约６２％、卡伯值１００左右。     

蔗渣爆破法制浆生产高强蜂窝原纸的研究

进行蔗渣蒸汽爆破法制浆的中试研究,分析了各爆破条件对爆破浆物理性能的影响,并以蔗渣爆破浆进行了抄造蜂窝原纸的生产性试验.研究表明,采用蔗渣爆破浆生产的蜂窝原纸强度明显高于废纸浆和半化学浆生产的蜂窝原纸,且生产成本低,是一种理想的蜂窝原纸产品.     

PEO/Cofactor助留体系应用于ONP/OMG脱墨浆生产纸材料

介绍了PEO/Cofactor助留体系应用于ONP/OMG脱墨浆生产纸材料.实验结果表明:PEO/Cofactor助留体系对以ONP/OMG脱墨浆为主要纤维原料的助留作用效果良好,并可有效控制浆料中的树脂.脱墨浆中的水溶性杂质和非离子性表面活性剂不利于PEO/Cofactor助留体系的作用效果的发挥;PEO/Cofactor助留体系与阳离子壳聚糖共用时,效果更好.PEO/Cofactor助留体系对细小组分的留着没有选择性.     

废纸浆增强HDPE复合材料的力学性能

将废旧瓦楞纸板粉碎制浆,与高密度聚乙烯通过注塑成型制备废纸浆/HDPE复合材料。研究了废纸浆含量,相容剂HDPE-g-MAH和LDPE-g-GMA,加工助剂S-105、TKM-M80和Deoflow A对废纸浆/HDPE复合材料力学性能的影响,通过扫描电镜SEM分析了复合材料的冲击断面,结果表明,HDPE-g-MAH和...     

The role of hardwood pulp fibers in mitigation of early-age cracking

The availability, relative consistency, and renewability of hardwood pulp fibers have prompted interest in their use in fiber–cement composites, in which they may be used for a variety of purposes. This study clarifies the ability of hardwood pulp to reinforce mortar, its capacity to provide internal curing, and its role as early-age crack-control reinforcement through a coordinated series of restrained shrinkage, free shrinkage, and mechanical testing on mortar samples. It finds that hardwood pulp improves the restrained shrinkage behavior of mortar at an early age. That is, 0.5% and 0.75% (by volume) hardwood pulp-reinforced mortars exhibited a lower rate of stress development and lengthened time-to-cracking by about 1.6 times and 2.3 times, respectively, compared to a companion crack-prone ordinary mortar. The initial crack width also decreased by 88% in 0.75% hardwood pulp-reinforced mortar samples, which suggested an application aimed at assisting self-healing in cement-based materials with an appropriate binder composition. Hardwood pulp successfully provided internal curing to crack-prone mortar and thus reduced autogenous shrinkage. This reduction in shrinkage, together with a combination of increased early tensile capacity, reduced stiffness, and improved post-cracking toughness were identified as the key contributions of hardwood pulp in the improved resistance of mortar to early-age cracking.     

废纸浆/陶瓷纤维抄造纸的性能研究

目的 节约植物纤维用量,以陶瓷纤维加填抄片,评估废纸浆/陶瓷纤维抄造纸的实用性.方法 使用KH-550硅烷偶联剂对陶瓷纤维进行表面处理,将未处理陶瓷纤维与处理的陶瓷纤维以一定比例加填到废纸纤维中,抄造手抄片,比较手抄片的紧度、撕裂度、环压强度、耐折度和抗压强度,并对手抄片的微观形貌进行观测.结果 陶瓷纤维交错分散于纸纤维之间.经过KH-550硅烷偶联剂处理的陶瓷纤维加填后,当质量分数<20％时,手抄片的撕裂度、环压强度、抗张强度随纤维含量的增加而下降;当质量分数>20％后,以上性能均随陶瓷纤维含量的增加而上升.手抄片的耐折度随含量的增加明显下降.抄片的环压强度显著提高,陶瓷纤维质量分数为40％时,环压强度为3.81 kN/m,为废纸纤维手抄片的2.06倍.结论 加填陶瓷纤维质量分数至40％,不仅节约了植物原材料,也会提高抄造纸的环压强度,可用于承受高环压强度的纸质材料.     

蔗渣浆和竹浆制备墙体装饰材料的研究

以竹浆和蔗渣浆为原料,采用纤维模塑热压成型制得环保墙体装饰材料。研究了蔗渣和竹浆的纤维形态,以及纤维不同添加量对墙体装饰材料挺度、抗张指数、耐破指数和滤水等性能的影响。实验表明,蔗渣浆和竹浆纤维的平均长度分别为0.78和1.22mm,两者在纤维形态方面具有很好的互补性。随着竹浆添加量的增加,浆料在成型过程中滤水速度加快,极大缩短了成形周期,并且制得的墙体装饰材料的挺度、抗张指数、耐破指数均呈先逐渐增大后缓慢减小的趋势。当竹浆的添加量为70%(质量分数)时,挺度、抗张强度、耐破指数均达到最大,分别比纯蔗渣浆制得的墙体装饰材料提高了77.02%、26.69%和21.77%,很好地改善了墙体装饰材料的物理性能。材料表面微观结构采用SEM进行表征。     

IN-LINE MEASUREMENT OF THE REFINING EFFECT-AN IMPORTANT NEW TOOL FOR USE IN THE PULP AND PAPER INDUSTRY

ABSTRACT

In the production of paper, pulp fibers are put through a refining stage. This greatly enhances the fiber characteristics and the resulting quality and properties of the paper that is being produced.

This paper outlines the various detailed processes which occur during the refining stage and what the resulting effects are on paper quality. It discusses the measurements of 'freeness’ and 'drainage rate’, which are used today as the primary means of measuring the'refining effect’, and provides a brief evaluation of the effectiveness and limitations of these techniques.

With the Scanning Laser Microscope, one can now observe the 'refining effect’ on a microscopic basis by analyzing the structure of individual fibers. In particular one can measure the changes in the mean fiber diameter and the amount of fines that are produced. These changes are measured on a statistically significant basis in real time and provide valuable information for control of the refining process itself.

This paper reports actual test results and provides a preliminary analysis of the significance of these results and how the findings could best be implemented in an actual control strategy for operating a refiner.     

Moulded Pulp Manufacturing: Overview and Prospects for the Process Technology

Eco‐friendly packaging such as moulded pulp products have gained commercial importance in the recent years. However, it remains a greatly under‐researched area, and there is an arising need to consolidate the best practices from research and industry in order to increase its implementation. The goal of this paper is to give an overview of the main aspects involved in the manufacture of moulded pulp products. This includes a classification of moulded pulp products, historical and current applications, production processes, materials, mechanical properties and environmental sustainability. Moreover, based on the latest research in the field, an innovative drying technique that utilizes concepts derived from impulse drying is presented, and the implementation of this process technology is discussed. Copyright © 2017 John Wiley & Sons, Ltd.     

废纸浆增强玉米淀粉基复合材料的制备及其力学性能研究

以甘油和尿素作为混合塑化剂、废纸浆为增强体,玉米淀粉、聚乙烯醇为基体,利用熔融共混法制备了废纸浆增强玉米淀粉复合材料。研究了混合增塑剂、废纸浆、水含量、氢氧化钠浓度对复合材料力学性能的影响。力学性能测试结果表明,甘油和尿素混合塑化剂对复合材料有反增塑作用,当甘油/尿素含量分别为10/20份时,拉伸强度最佳为10.26MPa;氢氧化钠浓度为4%时,复合材料综合力学性能最好;废纸浆对复合材料有增强作用,当含量为35份时,拉伸强度最佳为11.35MPa;随着含水率的增加,材料的拉伸强度降低,断裂伸长率先增加后降低;扫描电镜观察发现,甘油和尿素混合塑化剂能够增塑淀粉,很好的改善废纸浆和玉米淀粉之间的相容性。     

PPTA纤维原纤化过程及结构变化

聚对苯二甲酰对苯二胺(PPTA)纤维有典型的皮芯层结构,原纤化后的浆粕可以用于摩擦材料、密封材料、绝缘、特种纸基材料等复合材料领域。文中使用PFI型立式磨浆机对聚对苯二甲酰对苯二胺(PPTA)纤维进行处理,对原纤化过程中纤维的形态结构变化进行了研究,最后对制备的PPTA原纤化浆粕进行了表征。结果表明,PPTA纤维通过皮层脱落、逐步剥离、纵向劈裂、进一步分丝而实现原纤化,且制得的浆粕打浆度达到75°SR,保水值为380%,比表面积18 m2/g,结晶度49.4%。     

Influence of crushed aggregate fines with micro-proportioned particle size distributions on rheology of cement paste

This paper presents a study on how crushed concrete aggregate fines affect rheological properties of cement paste. The fines (≤250 μm) were produced by high-speed vertical shaft impact (VSI) crushing of rock types from 10 different quarries representing a wide range of local Norwegian geological variety with respect to rocks of different mineralogy and mechanical properties (mono- and multimineralic igneous (intrusive and extrusive), metamorphic and sedimentary rocks). The results show that the rheological properties of cement paste are governed mainly by the specific surface of the fines calculated from SediGraph measurements, and their surface properties causing different interaction with the superplasticiser (SP) molecules, as detected by zeta potential measurements. The rheology of cement paste is proportional to the specific surface and can be controlled by both altering particle size distribution (PSD) and volume fraction of crushed fines. The effect depends on the SP dosage and total surface of the fines present in the mix. The effect of the shape of the VSI crushed fine particles is of less importance at constant PSD for the materials studied here, because VSI crushing effectively normalised the equi-dimensionality of the grains, i.e. created similar particle shapes.     

Applying LDS to Monitor Flocculation in Papermaking

Flocculation of fines and fillers is important in the papermaking industry. To fulfill the need for accurate control of flocculation, laser diffraction spectroscopy (LDS) was selected to supply the floc size distribution. LDS allowed the detection of different flocculation mechanisms depending on the flocculant characteristics. The analysis relied mainly on the collection of two parameters: the size distribution of the flocs, characterized by its median, and their fractal dimension. Floc resistance to shear was assessed and related to the floc structure through the analysis of the fractal dimension. For the lower charge density, flocs grow faster, becoming less compact and, thus, less resistant. LDS proved to be a valuable technique to monitor flocculation processes. However, to obtain significant results, a close control of obscuration in the measuring cell is required.     

Applying LDS to Monitor Flocculation in Papermaking

Flocculation of fines and fillers is important in the papermaking industry. To fulfill the need for accurate control of flocculation, laser diffraction spectroscopy (LDS) was selected to supply the floc size distribution. LDS allowed the detection of different flocculation mechanisms depending on the flocculant characteristics. The analysis relied mainly on the collection of two parameters: the size distribution of the flocs, characterized by its median, and their fractal dimension. Floc resistance to shear was assessed and related to the floc structure through the analysis of the fractal dimension. For the lower charge density, flocs grow faster, becoming less compact and, thus, less resistant. LDS proved to be a valuable technique to monitor flocculation processes. However, to obtain significant results, a close control of obscuration in the measuring cell is required.     

Comparison of pyrolysis and oxidation actions on chemical and physical property of anthracite coal surface

Hydrophobicity of coal surface is determined by its physical property and chemical composition. Once coal was oxidized or spontaneously ignited under natural conditions, the surface properties would change greatly, which inevitably affect the hydrophobicity of coal surface. To reveal the changing regulations of coal surface’s hydrophobicity after oxidation and pyrolysis treatment, in this paper, two conditions (pyrolysis and oxidation) of heating treatment were used to produce a series of coal surfaces, and then characterizing their physical and chemical properties through SEM and XPS. Meanwhile, induction time and flotation tests were performed to measure the hydrophobicity of coal. Results showed that the pores and cracks were well developed on the coal surface after both oxidation and pyrolysis processes. But they contributed to opposite aspects later in the flotation test. Additionally, the content of oxygen-containing functional groups on the surface decreased after pyrolysis, whereas having a sharp increase after the oxidation process, which predicted that the hydrophobicity of coal surface under two heating conditions would be completely different. Coal after pyrolysis owned a very short induction time, and its flotation recovery was high. For oxidation process, the coal surface became more hydrophilic and their induction time could reach at about 4000 ms, very hard to float.