造纸原理与工程英文复习题(答案).doc

填空：纸是一种特殊的材料，是由纤维（主要是植物纤维）和其他固体颗粒物质（如胶料、填料、助剂等非纤维添加物质）交织结合而成的、具有多孔性网状物性质的特殊薄张材料。The paper and paperboard can be devided into 4 grades according to the industrial and consumer purposes, cultural paper, packaging paper, technical paper, domestic paper。The paper and paperboard manufacturing technologies can be classified into wet forming and drying forming。打浆的主要任务是：1）对水中纤维悬浮液进行机械等处理，使纤维受到剪切力，改变纤维的形态，使纸浆获得某些特征（如机械强度、物理性能）。2）控制纸料在网上的滤水性能，以适应造纸机生产的需要，使纸幅获得良好的成型，改善纸页的匀度和强度。打浆对纤维的作用包括：细胞壁的位移和变形、初生壁和次生壁外层的破除、吸水润胀、细纤维化、切断、产生纤维碎片、使纤维扭曲、卷曲、压缩和伸长以及半纤维素的溶解。纤维的结合力包括4种，1）氢键结合力2）化学主价键力3）极性键吸引力4）表面交织力。打浆的主要目的之一就是增加氢键结合力，从而提高成纸的强度。氢键结合的条件是：1）有游离羟基；2）两羟基之间的距离在0.28 nm以内。The parameters of effect refining are: refining intensity, consistency, temperature, pH, equipment. The parameters of the quality control for the refining process should include：浓度（Consistency）、打浆度（Beating degree)、游离度（Canada Standard Freeness)、纤维形态 （Fiber morphology）、筛分（Fractionation）、保水值（Water Retention Value）。贮浆池的形式有卧式和立式两种，现多用卧式浆池。卧式浆池又可分为普通卧式浆池和方浆池。Please list 4 types wet end chemicals: filler, dyes, dry strength agent, retention aids. 施胶是使纸和纸板具有抗拒液体扩散和渗透的能力。Sizing chemical additives are designed for providing paper and paperboard with resistance to liquid wetting, penetration, and adsorption.纸和纸板的施胶包括：内部施胶internal sizing、表面施胶surfacing sizing和双重施胶。AKD and ASA are the two major sizing agents for the alkaline papermaking system. 荧光增白剂的增白机理是：发射可见光，吸收紫外光并将其转化为可见的蓝色或蓝紫色的荧光。荧光增白剂可用于浆内、施胶或涂布。造纸增干强剂，如淀粉starch、CPAM、CMC。在造纸过程中，胶体吸附或聚集是细小组份留着的主要机理。造成流送系统中周期性的压力脉冲主要是由冲浆泵和压力筛引起的。纸料中存在的空气，其中以游离态的空气对纸料性质影响最大。纸料的除气方法，包括化学法、机械法。The objectives of wet pressing are: 1）to remove water 2）to consolidate the web 3）to improve the sheet quality.Hornification can be expressed by Water Retention Value, it determines the paper machine speed and paper properties. There are two types of dewatering, pressure controlled and flow controlled. Pressure controlled pressing means that the dryness increases with higher pressure. Flow controlled pressing means that there is a need of time to get higher dryness. The web transfer can be divided into two groups: open draw and closed transfer. The types of presses include plain roll type, suction roll, grooved roll press, blind drilled press roll, fabric press, shoe press.The unit of bulk is m3/kg, the stiffness、caliper and printablity of the paper can be improved if bulk of the paper is improved. The conditioning of press clothing in the press can be divided into a number of groups: high-pressure showers、press nip conditioning、suction boxes、chemical cleaning、lubricating showers.名词解释：游离状打浆：以降低纤维长度为主的一种打浆方式。黏状打浆：以纤维吸水润胀、细纤维化为主的打浆方式。打浆比压：单位打浆面积上所受的压力。细小组份：通过200目筛网（粒径约为75m）的粒子。高强微湍流：湍动强度很高而湍动尺度较小的流态。供浆系统的压力脉冲：流送过程中能引起上网纸料浓度不均匀和体积流量变化造成纸页纵向定量波动的压力波动。Press impulse：The product of nip residence time and nip pressure is called press impulse.Twosideness: Different degrees of surface roughness on both sides of the sheet.判断改正：Fiber cutting is usually considered undesirable because it results in slower drainage and loss of strength. As refining is increased, the pulp sheet becomes more bulky because of the increased porosity. As refining is increased, the pulp sheet becomes less bulky because of the reduced porosity.The lower pH of the stock, the easier refining process can be made. The higher pH of the stock, the easier refining process can be made.填料的留着是机械截留和胶体吸附综合作用的结果，并以机械截留作用为主。填料的留着是机械截留和胶体吸附综合作用的结果，并以胶体吸附作用为主。填料的留着，颗粒较大的填料是靠胶体吸附作用而留着，颗粒较小的填料是靠机械截留作用而留着。填料的留着，颗粒较大的填料是靠机械截留作用而留着，颗粒较小的填料是靠胶体吸附作用而留着。Flow controlled pressing means that the dryness increases with higher pressure. Pressure controlled pressing means that the dryness increases with higher pressure.Pressure controlled pressing means that there is a need of time to get higher dryness. Flow controlled pressing means that there is a need of time to get higher dryness.At a fixed dryness level of wet web, the roll press can produce higher bulk than shoe press. At a fixed dryness level of wet web, the roll press can produce lower bulk than shoe press.Shoe press can generate 4 times nip width than the conventional press roll, so shoe press have more retention time in the press nip. A increase of 10 yields an increase 1%-point in solids content after the press nip. 问答题： 以氢键结合理论为基础阐述纸页强度形成过程。根据此图，论述打浆与纸张性质的关系。 对比AKD和ASA施胶剂的异同。1） AKD是烷基烯酮二聚物，ASA是烯基琥珀酸酐，ASA的反应性能更好。2）AKD乳液的稳定性能更好，能保存几个月，ASA乳液的稳定性能较差，易水解，必须现场制备并立即使用。 3）ASA水解的产物如果留在纸页中会对纸页的施胶度有严重的影响。4）ASA 施胶纸页在离开纸机后立即实现施胶，AKD施胶的纸页往往需要更长的时间。5） AKD和ASA的水解和与纤维的反应总是竞争的。纸张加填的作用是什么？1） 节省纤维原料降低生产成本Reduce production cost-replace fiber2） 提高纸页的光学性能 Improve optical properties-brightness, opacity3） 提高纸页的印刷适性Improve printability 4） 提高纸页的形状稳定性Improve sheet dimensional stability5） 提高纸页的匀度 Improve sheet formation6） 满足纸张某些特殊性能的要求Meet some special paper requirements 7） 树脂控制 Pitch Control 根据此图绘制供浆系统工艺流程图。Explanation four phase wet pressing mechanism (Vertical dewatering).In phase 1, the compression begins. Air flows out of both sheet and felt until the sheet is saturated; no hydraulic pressure is built up. In phase 2, the sheet is saturated and the buildup of hydraulic pressure causes movement of water from paper into the felt. When the felt also reaches saturation, water moves out of the felt. Phase 2 continues up to the mid-nip, where total pressure reaches maximum. It has been shown that the hydraulic pressure reaches a maximum prior to mid-nip. In phase 3, the nip extends until the fluid pressure in the paper is zero; this corresponds to the point of maximum paper dryness in the nip.In the phase 4, both the paper and felt expand and the paper becomes unsaturated. Although a negative hydraulic pressure is created in both structures, the vacuum is greatest in the paper, causing a flow of water to return from felt to the paper.What is the press impulse? And how to improve the press impulse in the press section?The product of nip residence time and nip pressure is called press impulse.One is to improve the linear load, the higher linear load, the more water is taken out. The other is to improve the nip residence time. The nip residence tine is dependent on the nip width and machine speed. Paper machine speed is not normally used as an active variable for optimizing press section operation. This leaves nip length as the only parameter to affect the nip residence time. In the so-called wide nip presses, the nip has been made considerably longer than in conventional roll press nips. There are two main principles of forming a wide nip: Using high-diameter rolls with soft cover or a roll and a shoe to form a nip.答案填空：1 The objectives of wet pressing are: 1）to remove water 2）to consolidate the web 3）to improve the sheet quality.2 Hornification can be expressed by Water Retention Value, it determines the paper machine speed and paper properties. 3 There are two types of dewatering, pressure controlled and flow controlled. 4 Pressure controlled pressing means that the dryness increases with higher pressure. Flow controlled pressing means that there is a need of time to get higher dryness. 5 The web transfer can be divided into two groups: open draw and closed transfer. 6 The types of presses include plain roll type, suction roll, grooved roll press, blind drilled press roll, fabric press, shoe press.7 The unit of bulk is m3/kg, the stiffness、caliper and printablity of the paper can be improved if bulk of the paper is improved. 8 The conditioning of press clothing in the press can be divided into a number of groups: high-pressure showers、press nip conditioning、suction boxes、chemical cleaning、lubricating showers.名词解释：Press impulse：The product of nip residence time and nip pressure is called press impulse.Twosideness: Different degrees of surface roughness on both sides of the sheet.判断改正：1 Pressure controlled pressing means that the dryness increases with higher pressure. 2 Flow controlled pressing means that there is a need of time to get higher dryness.3 At a fixed dryness level of wet web, the roll press can produce higher bulk than shoe press. 4 Shoe press can generate 4 times nip width than the conventional press roll, so shoe press have more retention time in the press nip. 5 A increase of 10 yields an increase 1%-point in solids content after the press nip. 问答题： 1 Explanation four phase wet pressing mechanism (Vertical dewatering).In phase 1, the compression begins. Air flows out of both sheet and felt until the sheet is saturated; no hydraulic pressure is built up. In phase 2, the sheet is saturated and the buildup of hydraulic pressure causes movement of water from paper into the felt. When the felt also reaches saturation, water moves out of the felt. Phase 2 continues up to the mid-nip, where total pressure reaches maximum. It has been shown that the hydraulic pressure reaches a maximum prior to mid-nip. In phase 3, the nip extends until the fluid pressure in the paper is zero; this corresponds to the point of maximum paper dryness in the nip.In the phase 4, both the paper and felt expan