涤纶高速纺丝过程非牛顿流体力学模型探讨

本文运用流体力学的基本定律,用Jaumann微商描述Jeffreys流体,研究了高速纺丝过程中的单抽拉伸流动,导出了沿纺程的速度方程:,并初步讨论了方程的解。     

甲壳质纤维的制备及应用

甲壳质及其衍生物具有天然的生物活性及良好的成膜成纤性能 ,已被广泛地应用到医药、纺织、食品、化工等多个领域。介绍了甲壳素纤维的制备、性能 ,并简述其在纺织领域中的应用     

腈纶干法纺丝油剂的国产化研制

提出了干法腈纶纺丝油应具备的使用性能标准，通过实验应用性能对比，验证了国产油剂良好的使用性能，为进一步开展工业应用试验提供了基础。     

纺丝组件中多孔介质对PA6熔体流动性能的影响

在毛细管流变仪上增加多孔介质金属过滤砂,研究了聚己内酰胺(PA6)熔体通过不同过滤精度的多孔介质时的流动规律。结果表明:随着多孔介质过滤精度与熔体流动速率的增大,PA6熔体的压力增加值增大;PA6熔体压力增加值与流动速率关系可用Forchheimer方程较好地描述,其方程的拟合相关系数均大于0.997,粘性阻力因子(1/k)与惯性阻力因子(β)都随多孔介质过滤精度的增加而增加,当温度为265℃时,β较1/k大2个数量级;随着熔体温度的升高,1/k与β均减小;在实验条件下,PA6熔体的压力增加值主要来自粘性损耗,但随着流动速率的增加,惯性损耗增加,过滤精度越高,惯性损耗增加越明显。     

凝胶纺UHMWPE纤维工艺及原理浅析

已用凝胶纺成功地开发了多种高性能纤维,本文简介了凝胶纺的由来,工艺,原理及应用前景,这种探讨将有助于凝胶纺技术的进一步发展。     

涤纶细旦丝纺丝理论及实践

本文根据纺丝运动学及动力学计算了涤纶不同纤度纤维的纺丝固化长度L_K及冷却速率dT/dX,定量地讨论了喷丝孔径d.对纺丝拉伸比S及剪切速率γ_w的影响,定性地分析了单丝纤度dpf对纺程上的摩擦力、流变力的影响,从而得出了细旦丝纺丝的特征.     

750D／24F竹浆连续纺粘胶长丝纺丝工艺探讨

采用常规制胶工艺，应用意大利FCT3000型连续式纺丝机纺制竹浆粘胶长丝，探讨适宜的生产工艺。     

甲壳素和壳聚糖纤维的制造与应用

该文介绍了甲壳素和壳聚糖的提取与特性，纺制纤维的工艺和该纤维在医疗方面的应用。     

腈纶转向纺丝设备的开发与应用

本文通过研究腈纶纺丝工艺特点,对国产转向纺丝设备进行了研究与开发,并结合实际应用提出国产转向纺丝设备的发展方向.     

醋酸纤维素纤维干法纺丝成形模拟

建立了基于Maxwell粘弹性本构方程的干法纺丝动力学模型,对醋酸纤维素纤维干法纺丝过程进行了模拟,预测了纤维成形过程中丝条的溶剂浓度、温度、速度、张力等沿纺程的变化关系。结果表明:纤维固化成形发生在闪蒸结束后离喷丝口不远处,此后丝条溶剂含量变化很小;丝条温度在闪蒸时略低于热吹风温度,闪蒸结束后迅速上升到热吹风温度;丝条张力主要来源于空气的摩擦阻力和卷绕张力,在纺程下半段以摩擦阻力为主;提高泵供量后溶剂蒸发速率变慢,丝条温度达到热吹风温度所需时间变长,丝条固化点离喷丝头越远;闪蒸速率随纺丝液溶剂含量增高而减小,同时丝条温度升到甬道温度的时间也越长。     

GENERALIZED SEMI-EMPIRICAL NON CUBIC EQUATION OF STATE FOR THE REPRESENTATION OF PROPERTIES OF PURE SUBSTANCES

The analytical equation of state first introduced by Ponce and Renon was modified. At a given temperature, the addition of a corrective term in virial form yields an equation with four parameters. All parameters are assumed temperature dependent and properties of pure substances can be represented with 11 parameters. A corresponding state form using the characteristic parameters T_c, P_c, ω was developed. It yields an improvement in representation of molar volumes compared with the generalized cubic (Soave, Peng-Robinson) and non cubic (Simonet) equations. Enthalpy can also be calculated.     

熔窑内玻璃液流层厚度对熔化的影响

通过对熔窑内玻璃液流层厚度公式的推导,得出不同规模的浮法熔窑玻璃液流层的厚度.由于不动层三角区厚度对玻璃熔化有较大的影响,因此稳定玻璃液热点位置和玻璃液温度是提高熔化质量的关键.     

M-H-EOS的理论基础

根据virialEOS的推导方式 ,从具有分子体积的准理想气体模型出发 ,利用巨正则分布和势能函数 ,从理论上推导了M -H -EOS ,并探讨了M -H -EOS的理论基础。结果表明 ,M -H -EOS与virialEOS具有相同的理论基础 ,只是在考虑实际气体对理想气体在分子体积和分子间相互作用的偏差上做了不同的近似。M -H -EOS为了计算简便 ,在实验的基础上对分子间相互作用做了合理的近似 ,从而避免了高阶virial系数求解困难的问题 ,因此在实用中取得成功。了解M -H -EOS的理论基础 ,对进一步发展和改进M -H -EOS的应用领域和计算准确度具有一定的意义     

A METHOD OF DETERMINATION OF THE DIFFUSION COEFFICIENT BASED ON KERNEL MOISTURE CONTENT AND ITS TEMPERATURE

Mathematical analysis of convection drying in the falling rate period was used to determine the overall coefficient of diffusion as a function of temperature and moisture content. The mass diffusion equation and its series solution was adopted for a single wheat kernel, assuming that it can be represented by a sphere as a model system. The results of the experimental data and the calculations are presented in the graphical form.     

强制回流在醇酸树脂生产中的应用

采用强制回流方法,可以通过设定回流速度,达到醇酸树脂生产过程的反应温度、反应时间等工艺条件的有效控制,制得优质醇酸树脂。介绍了强制回流工艺流程,以及回流速度和回流温度的控制方法。比较了强制回流系统和自由回流系统。     

醇酸树脂合成配方的设计与计算

用平均聚合度控制方程:控制数均聚合度,用途广、适应性强,不仅用于线形缩聚,而且可用于体形缩聚;该方程用于醇酸树脂合成的配方设计与核算。     

A METHOD FOR SEPERATING VELOCITY FLUCTUATION AND TEMPERATURE FLUCTUATION IN THE COURSE OF MEASURING TURBULENT PARAMETERS

A double hot-wire method is adopted to separate the mixed signal of temperature fluctuation and velocity fluctuation appearing in high temperature turbulences. The relationships among the various coefficients in the sensitivity equation for measuring turbulent fluctuations with constant temperature hot wire anemometer are deduced. Once these equations are being related to the temperature fluctuation sensitivity equation of a constant current hot wire anemometer, the temperature fluctuation signal may be taken out from the mixed signal, then the turbulent velocity fluctuation signal and other main turbulent parameters may be obtained.     

对苯二甲酸双羟丁酯合成过程中副产物四氢呋喃生成动力学的研究

对在工业生产条件下，以０．０５％（质量比）Ｔｉ（Ｏ－ｎ－Ｃ＿４Ｈ＿９Ｏ）＿４为催化剂，将对来二甲酸与１，４－丁二醇直接酯化，ＢＤ／ＴＰＡ＝１．７０（ｍｏｌ比），生成四氢呋喃（ＴＨＦ）的副反应动力学进行了研究，得出了ＴＨＦ生成的动力学方程ｄＦ／ｄｔ＝Ｋ（Ｍ＿Ｒ－Ｘ－Ｆ），反应速率常数ｋ＝１．７８×１０￣（１２）ｅｘｐ（－３２９００／ＲＴ）和ＴＨＦ生成的活化能Ｅ．＝１３７．５ｋＪ／ｍｏｌ，略高于酯化反应的活化能，表明以控制反应温度的方法抑制ＴＨＦ的生成是困难的。     

压出过程中胎面胶流动特性的研究

应用Monsanto加工性能试验机(MPT)对胎面胶进行压出流变试验。在实验条件下,考察试样熔体的流动特性及其影响因素,并作初步的分析和讨论。实验发现,试样的流动曲线可近似用指数方程描述;而熔体粘度对温度的依赖性则大体上符合Arrhenius方程。     

CONTROL OF THE DRYING PROCESS THROUGH THE RELATIONSHIP OF WOOD AND WET-BULB TEMPERATURES

The ratio of wood temperature to wet-bulb temperature (WT/ WBT) with the wood moisture, aiming at its use in the control of the drying process in drying kilns, were correlated. Slash pine boards measuring 25 mm thick and 750 mm length were dried in an electric forced convection kiln, using four temperatures and two air velocities. The process was controlled through a computerized system comprising a microcomputer and data acquisition unit. The analyses indicated a good correlation (0.97 < r < 0.99) between the coefficient WT/WBT and the moisture content of the wood. The adjustment of polynomial models was satisfactory in the range from green condition to 10% moisture content, at the temperature range and air velocity studied. These results, variables, together with the ease and speed of measurement of the suggest that the coefficient WT/WBT can be used as an alternative for the control of the drying process. However, the practical application of this system still depends on further research and development.