A Study of Wool Carbonizing

Abstract

During the time delay in rapid carbonizing, the distribution of sulfuric acid between surface acid and total acid inside the wool changes. At zero time delay there is 2.3% owf surface acid and 2.1% owf total acid inside the wool, while after 15 minutes delay the surface acid has dropped to 0.7% owf and the total acid inside the fiber has increased to 3.7% owf. Within the wool, the bound acid increases from 1.2% owf to 3.0% owf, leaving only 0.7% owf free acid inside the wool. Thus the amount of concentrated acid formed during drying and baking is minimized and less chemical attack occurs to wool in rapid carbonizing. The reduced chemical attack is indicated by a lower amino group content and a significantly higher disulphide bond content for rapidly carbonized wool compared with conventionally carbonized wool. These results show that there is both a reduced main chain and disulphide bond breakdown in rapidly carbonized wool. In the time range examined in this work, 10 minutes seems to be the optimum delay time. For delay times greater than 10 minutes, the delay is neither industrially practicable nor is the quality of the carbonized wool optimized.