Investigations on the effect of carriers on meta-aramid fabric dyeing properties in supercritical carbon dioxide

Dyeing of meta-aramid fabric with dimethyl terephthalate, ethyl alcohol and CINDYE DNK as carriers was investigated in supercritical carbon dioxide fluid. The effect of different carriers on the dyeing properties of meta-aramid fabric with Disperse Blue Black 79, Disperse Rubine H-2GL, and Disperse Yellow EC-3G was examined by measuring the color strength with different dyeing temperatures, dyeing pressures, dyeing times, dye concentrations, carrier concentrations and carbon dioxide flows. The results showed that the carriers added in supercritical carbon dioxide were beneficial to the diffusibility of disperse dye molecules into the amorphous region of the meta-aramid fiber, thereby improving its dyeability. In these three carriers, the K/S values of the dyed meta-aramid samples with ethyl alcohol were higher than the samples with dimethyl terephthalate, and the greatest improvement on K/S values appeared upon adding CINDYE DNK in supercritical carbon dioxide. In addition, the dyed meta-aramid fabrics in supercritical carbon dioxide presented good wash fastness, rub fastness and light fastness, which was rated at 4-5.