Effects of hydrophobic yarns on liquid migration in woven fabrics

Liquid migration in woven fabrics was investigated by measuring the wicking coefficients of hydrophilic cotton and hydrophobic PVDF (polyvinylidene fluoride) monofilament fabrics and some other fabrics. The coefficients of fabrics with cotton warp yarns were essentially equal along the weft direction but differed along the warp because of variations in the warp yarn crimps. Then factors affecting the liquid migration along the weft direction were investigated, especially the effect of hydrophobic weft yarns, by using three different warp weave densities for fabrics with both cotton and PVDF weft yarns. The results showed that in the warp direction, liquid moved along longitudinal yarns and migrated to hydrophilic but not hydrophobic transverse yarns. In the weft direction, similar results were obtained for fabrics with cotton weft yarns. Fabrics with PVDF weft yarns, however, showed no migration through the longitudinal yarns, although liquid did move along the transverse direction of connected cotton warp yarns. The largest wicking coefficient was associated with the highest warp weave density. Liquid did not move through transverse yarns separated from one another. It is apparent that liquids can migrate along transverse, adjacent, in-contact hydrophilic yarns of fabrics incorporating longitudinal hydrophobic yarns.