Soil Guard and Soil Release Finishes of Fabrics Using Atmospheric Pressure Plasma Jet

Two atmospheric pressure plasma jet (APPJ) treatments, APPJ-coating with hexamethyldisiloxane (HMDSO) and APPJ-oxidation, were investigated as soil guard and soil release finishes of textiles. The plainwoven cotton and polyester fabrics were treated by both APPJ treatments and common chemical resins. SEM observation showed that granular particles precipitated on the fiber surfaces after the APPJ-coating. From Xray photoelectron spectroscopy, silicon atoms were detected at the intensity of about half of oxygen after the APPJ-coating, which suggested the silicon oxide, mainly SiO2, film deposition onto the fiber surfaces would occur. After the APPJ-oxidation, oxygen concentration on the treated polyester fiber surface increased by several % in the spectrum, suggesting the production of polar functional groups on the surfaces. As a result, the sessile drop contact angle on the fabric drastically changed : the APPJ-coating increased the water and oil repellency of both fabrics, and the APPJ-oxidation remarkably reduced the water contact angle on the polyester fabric. Wettability of single fiber determined by the Wilhelmy method suggested that the fiber surface was heterogeneously treated by the APPJ due to the variation in the penetration depth of active species in the plasma jet into the fibrous assembly. Using carbon black and red clay as model particulate soils, their deposition onto the fabrics in the air was investigated. In addition, the soiled fabrics were cleaned in a nonionic surfactant solution with applying stirring action. The deposition of particulate soils and their removal were evaluated by the surface reflectance method. It was found that the APPJ-coating prevented the deposition of particulate soils and the APPJ-oxidation promoted their removal. Comparing with the wet chemical treatment, the APPJ treatment was found to be effective for the deposition and removal control from the viewpoint of the soil guard and release balance.