Assessing the Atmospheric Pressure Plasma Treatment for Grey Cotton Knitted Fabric

enerally speaking, when cotton fabrics are in grey form, they contain natural and added impurities
such as natural oil, waxes, pectin and coloring matter, etc., i.e., impurities coming from the fibre itself,
the manufacturing process, as well as the environment, such as stains of machine oil and dust. 100%
grey cotton knitted fabric contains impurities and yellowness and needs to be prepared for processing
to make it suitable for coloration and finishing. Therefore, conventionally 100% grey cotton knitted
fabric undergoes a process of scouring and bleaching, which involves the use of large amounts of
water and chemicals, in order to remove impurities and yellowness. Due to increased environmental
awareness, pursuing a reduction of water and chemicals is a current trend in textile processing. In this
study, we explore the possibility of using atmospheric pressure plasma as a dry process to treat 100%
grey cotton knitted fabric (single jersey and interlock) before processing. Experimental results reveal
that atmospheric pressure plasma treatment can effectively remove impurities from 100% grey cotton
knitted fabrics and significantly improve its water absorption property. On the other hand, if 100% grey
cotton knitted fabrics are pretreated with plasma and then undergo a normal scouring process, the
treatment time is reduced. In addition, the surface morphological and chemical changes in plasmatreated
fabrics were studied and compared with the conventionally treated fabrics using scanning
electron microscope (SEM), Fourier-transform infrared spectroscopy-attenuated total reflection (FTIRATR)
and X-ray photoelectron spectroscopy (XPS). The decrease in carbon content, as shown in
XPS, reveal the removal of surface impurities. The oxygen-to-carbon (O/C) ratios of the plasma
treated knitted fabrics reveal enhanced hydrophilicity. In addition, the yellowness of plasma-treated
grey cotton knitted fabrics did not increase further after plasma treatment.