Effect of Scouring on the Color of Naturally-colored Cotton and the Mechanism of Color Change

摘要

The effect of scouring on the color of naturally-colored cottons was studied. Three naturally-colored cottons (buffalo brown, coyote brown, and green cotton) were scoured with two alkali solutions (sodium carbonate and sodium hydroxide) and one enzyme solution (mixture of pectinase and cellulase). After alkali scouring, the color of cotton fibers became deeper and darker, and the scouring solutions were also deeply colored. Wax extraction, light microscopy, scanning electron microscopy (SEM), X-ray analysis, and inductively coupled plasma (ICP) analysis were used to study the mechanism of color change. Results showed that the fibers became swollen and pigment in the colored cottons moved toward the outer layer of the fiber after alkali scouring. The colored solutions can be explained by released pigment from the cotton. Potassium loss also occurred.