纸纱∕再生涤复合纱及其针织面料的性能

为了探究纸纱/再生涤纶复合纱的可织性及其针织面料的综合服用性,采用MACH2SIG全自动电脑横机将纸纱/再生涤纶(100/0、70/30、60/40)3种复合纱编织成纬平针织物,测试纸纱/再生涤纶复合纱的条干均匀度、力学性能以及针织物的热阻、透气性、透湿性、悬垂性、折皱弹性和力学性能。利用模糊数学综合评价方法对测试结果进行分析,对纸纱/再生涤纶织物的服用舒适性做出综合评价。结果表明:随再生涤纶含量比例增加,复合纱的条干均匀度下降,断裂强力和断裂伸长率提高;3种针织物经模糊综合评价所得的评判值分别为0.2942、0.3311和0.3737。依据最大隶属度原则,纸纱/再生涤纶(60/40)织物的综合服用性能最佳。

不同纤维结构特性下纤维集合体过滤性能的DPM数值模拟

为了探究过滤风速、纤维直径、纤维固体体积分数、纤维层厚度、纤维排列方式对纤维集合体内部气流速度分布、压力损失、过滤效率的影响,通过观察分析真实滤料结构特征和表面形态,利用Matlab随机算法,Solidworks建模软件生成直径为3-5μm、在空间中随机分布的三维纤维集合体,利用Digimat纤维建模软件生成纤维排列方向平行于X轴的三维纤维集合体,结合计算流体力学方法,基于拉格朗日离散模型和Laminar流场,利用雷诺相似准则对微米纤维模型内部气-固两相流动情况进行数值模拟。结果表明:过滤风速的增大对纤维集合体内部气相流场的影响表现为无规律性,纤维集合体内部压力损失随过滤风速的增大而增大;纤维过滤效率和压力损失随纤维固体体积分数、纤维层厚度的增大而增大;过滤效率和压力损失随着纤维直径的增大而减小;平行于X轴排列的纤维集合体的过滤效率和压力损失较空间随机分布纤维集合体的高。

Effect of Electron Irradiation on Polypropylene Films

Effects of both electron beam irradiation on the properties of polypropylene （PP） films and the irradiation on the different layers of a multilayer PP film are studied. A Fourier transform infrared spectroscope was used to investigate the chemical structure of the films. The results showed that the chemical properties of the first layer were improved, that is, more functional groups responsible for dye ability and hydrophilicity of the film were produced on its surface, while noticeable improvement was not detected on the surface of other layers. This was also confirmed by testing the dye ability of the layers. However, the results obtained by atomic force microscopy showed that the electron irradiation caused some topographical changes, not only on the surface of the first layer but also on the others.

Surface Modification of Poly Vinyl Chloride (PVC) Using Low Pressure Argon and Oxygen Plasma

In this study, commercial poly vinyl chloride （PVC） films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by mea- suring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy （AFM）. The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy （FTIR）. The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp de- crease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.

Dynamics of Wicking

An exponential model is proposed for the description of wicking, which is suitable for describing the whole process of wicking. Results are discussed and verified by the experimental data. Exponential model can be used to predict the wicking process in longitudinal and planar textiles.

纤维弯曲对其集合体过滤特性影响的稳态数值分析

为探究纤维过滤介质中纤维曲率对其内部速度分布、压力损失、过滤效率的影响,通过Digimat建模软件建立曲率K分别为0、2、4、6,固体体积分数为8%,在三维空间中随机分散排列的纤维过滤介质模型,结合计算流体力学方法,基于拉格朗日离散模型和Laminar流场,利用雷诺相似准则,设置入口速度分别为0.05、0.142、0.5、1、2 m/s,平均颗粒粒径为0.25、0.5、1、1.5、2.5、4、5 mm,对微米纤维模型内部气-固两相流动情况进行数值模拟。结果表明:随着纤维曲率K由0增大至6,在入口速度为0.5 m/s时,纤维曲率对速度场分布的影响不明显,速度场的分布呈无规律性;纤维曲率对模型内部压力损失有显著影响,随着纤维曲率的提高,纤维模型内部压力损失呈线性增大;纤维过滤介质的过滤效率随纤维模型曲率的增大而提高,在入口速度为1 m/s、模型曲率K为6时,对平均粒径为5 mm的颗粒过滤效率接近90%,明显高于相同粒径下K为0时的过滤效率。