The Effect of Functional Finishes and Laundering on Textile Materials Part I: Surface Characteristics

The effects of finishes and laundering on the surface characteristics of cotton and polyester fibers are evaluated in this investigation. Changes in the surface properties of the fibers are monitored through contact-angle determinations (the Wilhelmy technique) before and after treatment of the fabrics with durable-press, fluorocarbon stain-repellent, and antistatic finishes. The durable-press and stain-repellent finishes did not produce a noticeable change in the wettability of the cotton fibers. However, the wettability of the polyester fibers was increased, and the polar contribution to the surface free energy increased after treatment with stain-repellent finishes. Treatment of cotton with cationic surfactants as antistatic finishes converted the surface to a hydrophobic character. A reverse phenomenon was observed on the surface of polyester fibers after treatment with antistatic finishes. The different effects of the surfactant treatments were attributed to different deposition patterns of the surfactant molecules at the fiber surfaces. Laundering was found to increase the wettability of unfinished cotton and polyester fibers, presumably owing to surface roughening from mechanical agitation and the removal of oil-borne contaminants. The effect of laundering on the finished fibers was dependent on the retention of the finishes on the fabrics in the laundering process.