The dyeing of nonwovens: An examination of the adsorption behaviour of hydroentangled fabrics

The dyeing behaviour of nonwoven materials is an increasingly important area of research that has been the subject of few studies compared to traditional textile materials. Further developments in the dyeing of nonwovens depend in part on improving understanding of the factors contributing to dye levelness in such porous structures and determining the influence of fabric structure on dyeing behaviour and dyed fabric uniformity. Studies concerning the coloration of hydroentangled fabrics are necessary given the increasing number and variety of applications in which dyed fabrics are required. This paper reports on a systematic experimental study of the dye sorption behaviour of hydroentangled fabrics with different fibre compositions with reference to textile control samples and the role of fabric structure on the observed dye adsorption. Adsorption behaviour influences the observed quality of dyeing, for example the levelness, which is particularly important in the dyeing of hydroentangled materials. In this study, comparative dyeings were performed on hydroentangled, knitted and woven fabrics composed of fibres and differences in the kinetics of the dyeing mechanisms have been examined. In an examination of cotton structures, the hydroentangled fabrics exhibited higher dye adsorption and greater colour strength than their yarn-based counterparts. It was observed that for all fabrics examined, the kinetics of adsorption most closely followed the pseudo-second order model and that the initial sorption rate decreased in the order nonwoven > knitted > woven. These differences in the rate of adsorption are discussed and explained in terms of measurable differences in the accessible fibre surface area.