Capillary Rise in Core-spun Yarn

The kinetics of capillary rise follows the Lucas-Washburn equation. Capillary flow is studied in core-spun yarns by image analysis of coloured liquid rising into the core-spun yarn and the distance of liquid rise was determined as a function of time. The great variations of the experimental results in the cross and along the yarns are attributed to the yarn heterogeneity of the interfibre space. Yarn construction features, such as twist, linear density, and pretension of core component of core-spun yarns are shown to be related to the rate of liqUid transport in such fibre assemblies. The liquid transport properties of yarns in general provide useful information about fibre orientation in yarns. The results show that the continuity of capillaries formed by the fibres decreases either by random arrangement of fibres due to low pretension of core component or by increasing yarn twist. Also, decrease in the size of capillaries was governed by three parameters, namely; increased pretension of core component, decreased linear density of core component, and increased yarn twist. The present study indicates that an appropriate choice in production parameters of core-spun yarns is all important in obtaining the desired properties of capillary rise.