基于非均匀毛细管结构的纱线导水机理

Liquid transport mechanism in yarn based on configuration of non-uniform capillary

纱线中液体的传递受到纱线中毛细管几何结构的重要影响.为考察毛细管几何结构对纱线中液体输运的影响,基于达西定律和毛细管压力方程建立N节藕节非均匀毛细管模型,研究纱线内部毛细管中液体的流动行为,得到非均匀毛细管关于藕节管粗细节高度比、宽度比及总管节数的芯吸高度-时间方程,并采用不同单丝线密度、不同捻系数的尼龙长丝纱线对其进行实验验证.结果表明:液体流动速度很大程度上取决于粗细节管的交替程度(即一定高度上的管节数),粗细节管交替频繁的毛细管具有较低的液体流动速率.在具有相同几何形状(相同高度和宽度比)的毛细管中,较粗的毛细管表现出较大的液体流动速度和芯吸平衡高度.尼龙长丝纱的实验结果与N节藕节非均匀毛细管模型的理论预测相当吻合.

Liquid transport in yarns is affected significantly by geometry of capillary.In order to investigate the mechanism between the structure of capillary and the liquid transport behavior,an N section lotus-rhizome-node-like nonuniform capillary model was established based on the Darcy's law and capillary pressure equation to investigate the transport of liquid in the capillary of yarns.The wicking height-time equation of the non-uniform capillary was obtained as a function of the height and width ratio between the converging and diverging nodes and their to-tal section numbers.Nylon filament yarns with different twist factor and different single filament fineness were prepared to verify the model.The results indicated that liquid transport velocity greatly depended on the alternate frequency between the converging section and diverging section(i.e.the section number in certain length).The non-uniform capillaries with rapid alternations between converging and diverging nodes have low liquid transport efficiency.The thick capillary exhibits a fast liquid transport efficiency and high balanced wicking height in those capillaries with the same geometry(the same height and width ratio).The experimental results from the twisted Nylon filament yarns agreed fairly well with the theoretical predictions of the N-section lotus-rhizome-node-like non-uniform capillary model.