Transplanar and in-plane wicking effects in sock materials under pressure

Abstract

The moisture transfer and absorption properties of fabrics play an important role in the evaluation of the overall wear comfort of the textile. The location of moisture in the textile influences the skin wetness as well as the skin/textile friction process. In this study, we used X-ray tomography to analyze the transplanar and in-plane water transport in different sock materials when two defined pressures were applied to the inner side by means of an adjustable screw. The materials used were polyamide, polypropylene and wool, and had very distinct hydrophilic/hydrophobic and hygroscopic properties. The in-plane wicking effect showed a clear time dependency for the polyamide and wool samples, while the spreading of the polypropylene samples was very scattered. This effect was generally larger in the outer side of the sock than in the inner side, showing a clear tendency of these socks to wick the moisture away from the skin. Applying a pressure generally increased the in-plane water transport, but it affected the water distribution throughout the thickness of the sock for the wool samples, as more water remained in the inner half. The transplanar wicking effect was the most efficient with the polypropylene sock under the high pressure condition, but with the low pressure, this sock was not able to absorb all the moisture and a small quantity of water remained at its inner surface. X-ray tomography was shown to be a powerful tool to analyze not only the water distribution in static conditions, but also the transient 3-dimensional water transport.