改善高定量纸板层间结合强度的思路和途径

对于多层纸板来说,层间结合强度是一项重要的质量指标。纸板层间结合强度直接影响印刷质量,同时对纸机抄造也有一定的影响。影响纸板层间结合强度的因素较多,且各因素对纸板层间结合强度的作用效果各不相同。笔者主要从原料工艺调整、化学品使用工艺以及纸机操作等方面,提出一些改善纸板层间结合强度的思路、途径和方法。     

基于互穿网络化机浆作为芯层的白卡纸生产工艺探讨

介绍了互穿网络化机浆配抄生产白卡纸的工艺特点,探讨了影响白卡纸松厚度、挺度及层间结合强度的影响因素.     

喷淋淀粉混合物改善双层纸板的层间结合强度

工厂将天然淀粉液喷淋到成形的湿纸幅上以改善多层纸板的层间结合强度。文中研究了回收针叶木硫酸盐浆手抄片湿纸幅干度、淀粉液喷淋量及干燥温度对双层纸板层间结合强度的影响。淀粉喷淋到湿纸幅上可以大幅度提高湿纸板的层间结合强度。湿纸幅干度在10％-11％左右时,强度达到最大。针对高温快速干燥影响淀粉的胶凝化作用,降低纸板的层间结合强度,提出了一种高干燥速率下提高纸板层间结合强度的方法,实现淀粉逐步胶凝化,大大提高纸板层间结合强度。     

助留剂对多层纸板层间结合强度的影响

多层纸板如箱纸板、白纸板、白卡纸等在包装工业中有广泛的应用。层间结合强度是这种纸板的一项重要的性能指标 ,它是指纸板抵抗层间分离的能力。例如 ,白卡纸在凹版印刷过程中 ,受到很高的剪切力 ,易发生脱层现象 ,因此 ,增加多层纸板的层间结合强度具有特别重要的意义。目前 ,增加层间结合强度的方法很多 ,如控制纸料的打浆度 ,使各层纸料的打浆度差异不超过３～５ｏＳＲ ;正确控制纸机的流浆箱浓度、伏辊和压榨辊的压力 ;层间喷淋淀粉以增强层间结合等。助留剂是造纸过程中常用的一种助剂 ,它可以提高细小组分和填料的留着率 ,改善滤水性…     

干强剂在白卡纸生产中的应用

研究干强剂在白卡纸生产中的应用,主要考察干强剂对白卡纸胶印性能、芯层内聚力和层间结合强度的影响,并对纸机系统首程保留率、电荷和电导率的变化进行评价。结果表明:干强剂可以有效地提高白卡纸的胶印性能、芯层内聚力和层间结合力;干强剂还可以提高纸机首程保留率,降低纸机系统的阳电荷需求和电导率。     

聚丙烯酰胺系造纸增强剂

影响纸的强度的因素一般来说主要有四种：单根纤维的强度；纤维间的结合强度；纤维间的结合面积；纤维的分布状况，即纸的匀度。由于我国大量使用的是草类纤维和二次纤维，单根纤维的强度差，不能满足我国日益发展的高档包装纸和纸板的要求。对于剩余的三项影响因素可以通过加入助剂来改善纸的强     

纸用层间喷雾淀粉的合成新技术

层问结合强度是某些纸产品（各类板纸、沙管纸）的一项重要技术指标．它的高低、大小甚至决定着产品的质量优劣：而要达到良好的层间结合强度,必须要达到和满足相应的一些工艺、生产要求,比如良好的纤维结合程度（合适的打浆度、充分的分丝帚化程度）、纸页复合面处的细腻程度（一般要求一面较细腻而另一面略显粗糙）、适当的细小纤维含量、     

增强创新:METRIX~(TM) BULL技术在造纸中的应用

METRIX BULL技术是纳尔科公司(艺康集团子公司)近期推出的纸张增强创新方案,可以全方位提高成纸强度、成纸灰分、灰分保留及网部/压榨部脱水。在帮助造纸商实现原料成本节降、化学品方案优化、高强度纸种开发、纸机效率提升以及能源节省等方面具有广泛的应用前景。本文从实验室和现场纸机试验中对METRIX BULL技术进行了全面的研究。实验室结果表明:METRIX BULL技术在纸张内聚力、湿强度、成纸灰分与首程留着率方面都表现出比市场常用干强剂更为优异的性能;现场纸机试验结果表明:METRIX BULL技术可以提高约20%成纸层间结合强度,提高成纸灰分3~5个百分点,显著地降低生产成本,取得了客户满意的试验结果。     

低定量高白度胶印新闻纸打浆工艺的探讨

本文结合岳阳纸业集团公司1#新闻纸机实际生产情况,探讨了如何从打浆工艺方面改善纸机抄造性能,提高成纸质量。着重研究了浆料叩解度对成纸水分、不透明度、撕裂指数、平滑度、两面差、填料留着率的影响及其随浆料叩解度变化的规律,还探讨了上网浓度、浆料叩解度对成纸匀度的影响,及淀粉加入量、浆料叩解度对新闻纸表面强度的影响,当上网浓度在0.75％～0.8O％,浆料叩解度60～64°SR时,对纸机抄造性能及成纸质量有较大改善。     

新型纸机交流变频调速系统

采用矢量控制技术实现纸机传动的交流变频调速控制。基于西门子PCST设计，将纸机的传动系统与过程控制系统结合起来，形成纸机间面向工艺的现场总线控制体系。     

Einfluß der Lagerung von Industrierestholz der Klefer und Fichte auf seine Eignung für die Herstellung von Spanplatten und mitteldichten Faserplatten (MDF)

Particle- and medium density fibreboards (MDF) were prepared from chips of spruce and pine, a byproduct of sawing wood in a saw mill with a profiling unti. The wood residues were stored in piles of 40 m³ volume for different time periods. The physical-technological properties of the particle- and fibrebroads prepared therefrom were evalutated and the formaldehyde release of the boards was assessed. The results reveal: In general, there is a positive influence of storage on the thickness swelling and internal bond strength of UF-bonded particleboards; the bending strength of UF-bonded particleboards showed no pronounced response to storage. The prositive influence of storage onthe thickness swelling and internal bond strength was much higher in case of boards made from pine chips than in case of spruce boards. On using PMDI as a binder for particleboards no significant influence of storage on the thickness swelling, internal bond strength and bending strength was detected. The influence of storage on the thickness swelling of UF-bonded MDF from pine fibres was much less pregnant than on that of UF-bonded particleboards. On UF-bonded MDF from spruce the influence of storage, if any, was negligible. On using PMDI as a binder for MDF there was no detectable change in the thickness swelling due to storage. The internal bond strength of UF-bonded MDF experiences only subtle positive change due to storage of pine wood chips. However, no notable change was detected in case of MDF from spruce. Storage has almost no influence on the chemical properties of boards.     

Einfluß der Holzart und der Holzartenmischung auf die mechanischen Eigenschaften von Spanplatten bei Verwendung chilenischer Hölzer

The influence of Chilean wood species and mixtures of the same species on particleboard properties was studied. Species and mixture ratio had a great influence on board properties. It was also determined that bending strength and internal bond of particle board from wood mixtures can be calculated using the recorded strength of particle boards based on single wood species.     

热熔胶与环氧树脂胶粘结试件对人造板内结合强度检测值影响探讨

使用热熔胶和环氧树脂胶粘结法进行人造板内结合强度检测试验对比,结果表明,在使用热熔胶粘结时,金属卡头的冷却方法对内结合强度影响很大,板材由于金属卡头温度的升高而引起的附加应力很难避免,会造成内结合强度检测的不确定性;在精确检测或者在出具质检报告时,要尽量使用环氧树脂胶粘结试件。     

胶黏剂种类对人造板内结合强度检测结果的影响

使用聚乙酸乙烯酯乳液(PVAc)、单组份聚氨酯(PUR)和热熔胶(EVA)3种胶黏剂粘结金属卡头与试件,检测并分析它们对强化木地板和地板基材用纤维板内结合强度检测结果的影响。结果表明:使用PUR粘结时检测的内结合强度值比使用PVAc、EVA高,其中强化木地板内结合强度高出0.47MPa,地板基材用纤维板内结合强度高出约0.40MPa。     

胶黏剂种类对人造板内结合强度检测结果的影响

使用聚乙酸乙烯酯乳液（PVAc）、单组份聚氨酯（PUR）和热熔胶（EVA）3种胶黏剂粘结金属卡头与试件,检测并分析它们对强化木地板和地板基材用纤维板内结合强度检测结果的影响。结果表明：使用PUR粘结时检测的内结合强度值比使用PVAc、EVA高,其中强化木地板内结合强度高出0.47MPa,地板基材用纤维板内结合强度高出约0.40MPa。     

Einfluß der Trocknungsbedingungen auf Kiefernspäne und ihre Verleimbarkeit mit UF-Harzen

Increasing intensity of drying conditions lowered the pH-value, increased the buffering capacity towards alkali and enhanced the liberation of volatile acids from pine flakes. Drying under excessive thermal conditions led to a significant decrease in equilibrium moisture content by adsorption (EMC). During drying, terpene compounds liberate from the flakes. Drying exerted a pronounced influence on the strength properties of UF-bonded boards of pine flakes. The decrease of the flakes m.c. from 5.5% to 2.5% by drying led to an increase of the internal bond and to a decrease in thickness swelling. However, excessive drying to less than 1% m.c. adversely affects internal bond and thickness swelling. Drying, under the conditions investigated, seams to have no detectable influence, neither on the density profile of the boards, nor on the formaldehyde release when bonded with UF-resins of extremely low molar ratio.     

The effect of fine strands in core layer on physical and mechanical properties of oriented strand boards (OSB) made of beech (Fagus sylvatica) and poplar (Populus tremula)

This paper discusses the influence of three different content levels of fine strands in the core layers on the physical and mechanical properties of European beech and poplar oriented strand boards (OSB). The results show that increasing the fines content in the core layer from 10 to 50 %, based on total board weight has no significant effect on bending strength and modulus of elasticity (MOE). All panels exceeded the minimum requirement for bending strength and MOE set by EN standards. The highest modulus of rupture (MOR) and modulus of elasticity (MOE) was determined for panels solely made of poplar with different level of fines content. Increasing the amount of fines in the core layer raised the internal bond (IB). Panels made with 30 % fines in the core layer showed highest internal bond strength values. As the fines content increased from 10 to 50 %, thickness swelling decreased. Water absorption after 24 h showed the same declining trend as thickness swelling.     

Die Eigenschaften formaldehydarmer HF-Leimharze und daraus hergestellter Holzspanplatten

The influence of the molar ratio of urea: formaldehyde on the properties of UF-bonded particleboards was investigated. The molar ratio influences the thickness swelling but not the internal bond strength and the bending strength of the particleboards if the manufacturing process is optimized. Strength losses correlate with the molar ratio when humidity affects the particleboards. Sensitivity against humidity increases with decreasing molar ratio. Brashness of low formaldehyde content UF-resins seems to correlate with their differing ability to adsorb humidity.     

Research on Effect of Biolatex Surface Sizing on Paper Properties

Biolatex, a new type of paper coating adhesive that has been developed in recent years, has mainly been used in pre-coating and middle coating, due to its advantages of decreasing the associated cost and pollution by partly replacing petro-latex. In this paper, application of biolatex as a surface sizing agent and effects of various factors, such as titanium dioxide addition, on the properties of the sized paper were compared. The results showed that, addition of titanium dioxide to biolatex could improve the whiteness, internal bond strength, and ink absorption. Furthermore, application of the No.4 biolatex resulted in better surface strength, bond strength, and ink absorption of the sized paper than application of polyvinyl alcohol.