Improved Coloration and Fastness to Washing and Light by Applying Smectite to Cationic Dyeing

Two processes were tested for improving the washing and light fastness of cationic dyeing. The first method was to make pigments by intercalating the cationic dye into smectite and the second was post-treating the cationic dyed fabric with smectite. It was found that the coloration with pigments of dye-intercalated smectite was not as deep as dyeing cotton, silk and wool with a cationic dye, although the washing fastness was improved. Post-treating the cationic dyed cotton, silk and wool fabrics with smectite achieved a considerably deeper color and greatly improved the washing fastness. The depth of coloration of the post-treated fabrics depended on the particle diameter of the smectite used. The low light fastness of cationic dyed natural fibers could be considerably improved by intercalating the dye into smectite or post-treating the dyed fiber with smectite.