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

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 non-uniform 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 total 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. [ABSTRACT FROM AUTHOR]