Low-load Lateral-compression Behaviour of Woven Fabrics

Abstract

The low-load compression behavior of woven fabrics is very important in terms of handle and comfort. The chief concern of the present work is to describe the pressure–thickness relationship of woven cotton fabrics in low-load regions by a mathematical expression. Although the surface structures of wool and cotton fabrics are different, in the present work, it is suggested that the equation proposed originally by van Wyk (van Wyk's law) is applicable to a cotton fabric's pressure–thickness relationship, which was applied to wool fabrics by de Jong et al. From this study, it is clear that the fit of the equation to the experimental curves may be improved considerably by using a non-linear-regression method. The comparison of fabric geometrical and mechanical thicknesses supports the layer theory of fabrics proposed by de Jong et al. However, a five-layer rather than a three-layer structure is revealed after this comparison, and the four outer layers consisting of crimp crowns and not only protruding hairs for most woven cotton fabrics are discussed. In this structure, the two primary outer layers on either side of a fabric contain hairy fibres and the crowns above the average geometrical thickness; the secondary layers on either side of a fabric represent another two compressible layers, which form the firm structure of the fabric; in the middle is the incompressible core of a fabric. The primary and secondary outside layers of this structure obey van Wyk's law. The incompressible core layer possesses about 40%; of the whole fabric thickness, which indicates that fabrics are highly incompressible; the two secondary layers have more than 20% and the first outside layers about 40%, which shows that the irregularity of the fabric surface is very great.