Abstract:

To reduce the amount of salt in dyeing cotton with reactive dyes, the dye-site improver was used to impart cotton fibers with increased dye-sites. The effects of modification with dye-site improver on the dyeability of cotton fabric were investigated, including effects on alkaline concentration and adding time, salt concentration, dye-uptake rate, color fastness, level dyeing property and hue of the dyed fabric. The results show that the absorptive behavior of the modified cotton during dyeing with Reactive Red R02 was conformed with Langmuir-type adsorption curve, and adsorption constant(K) and saturated adsorbing capacity(S) decreased along with rising of the temperature. The dye-site improver modified cotton needed less alkaline, less salt (reduced by 40% - 60% on weight), exhibited accelerated dye uptake rate, improved color fastness and level dyeing without affecting the shade. As to adding time of alkali, it was simile to traditional dyeing process.