Effect of Zeolite Treatment on Dyeing of Silk.

Abstract

Effect of zeolite treatment on silk dyeing by synthesized dyes was investigated and the properties of the dyeings were compared to that of a traditional silk dyeing with mud treatment. A silk hank was gently crumpled up in zeolite suspension and the effect of the zeolite treatment on weight increment, rubbing fastness, color properties such as L * a * b * and on the color fastness to light was investigated. The dyes used were direct, acid and metallized dyes of various colors. A silane coupling agent, 3-aminopropyltriethoxysilane, was necessary for the tight adsorption of zeolite to silk fiber. The best result in color fastness and weight increment was obtained by following procedure: dyeing in a hot bath followed by zeolite treatment in an acidic suspension of 1.0% zeolite including 0.5% silane coupling agent and the second zeolite treatment in an alkaline suspension, and finally finishing with a fiber treatment agent such as softener. About 10% of weight increment was obtained. The rubbing fastness was improved by finishing with an agent containing silicone compounds. The rubbing fastness and the color fastness to light were practical grade except for dyeing by acid red 97. Change in L * a * b * indicated slight color change by the zeolite treatment. The mechanical properties of the silk yarn treated by zeolite and the woven cloth were also measured and compared to those treated by mud. The zeolite treatment increased the fluff index between 0.3 and 0.5mm, but the total fluff index did not change. The zeolite treatment made the silk cloth close to the cloth woven with the silk yarn treated in mud.