Dyeing rate of extended wool fiber. III. Relation between the initial rate of dyeing and the wettability of fiber surface.

Abstract

Relation between the initial rate of the sorption of Acid Orange 7 and the wettability of fiber surface was investigated on wool fibers modified by extension, abrasion and supercontraction. The wettabilities of the wool fibers were determined by the measurement of the contact angle of a water droplet on a single wool fiber using a photomicrographic technique.The modifications were found to accelerate the initial rate of dye sorption. The contact angular distributions for the abraded and supercontracted wool fiber were shifted toward smaller angles than that for the unmodified wool fiber, whereas the distribution for the extended wool fiber was shifted toward a slightly smaller angle than that for the unmodified wool fiber.Apparently, the increases found in the initial rates of dye sorption on the treated wool fibers are not directly correlated with the wettability of the fiber surface. The present results suggest that the initial dye sorption in the extended wool fiber is not attributable to the dye sorption on the cuticle component through the epicuticle, but to the preferential dye sorption in the cuticle component through the intercellular cement being exposed by the extension.