Effects of N₂post-discharge plasma treatments on wool fabrics

Direct low temperature plasma (LTP) has been studied for some years now as an alternative eco-friendly technology for achieving shrink-resistant wool fabrics, its action being attributed to the varied active species existing in the plasma. In this paper, for the first time, the efficiency of a post-discharge plasma treatment on the shrink-resistance of wool fabrics has been evaluated. The density of active species present in the nitrogen plasma post-discharge (PD) has been determined by optical spectroscopy and their effects on the increase of hydrophilicity at different treatment times have been recorded through drop test and contact angle techniques. Analysis of the surface by X-ray Photoelectron Spectroscopy (XPS) has shown the increase in N and O – containing functionalities. The post-discharge has shown to be effective in reducing the area shrinkage of the fabrics and its effects have been compared to those obtained by direct LTP.