Fluid Simulation and Dyeing Effect of a Multilayer Dye Dissolver for Supercritical Waterless Dyeing

Supercritical waterless dyeing is a kind of green dyeing technology, which has been expected by the dyeing industry. However, without dyeing auxiliaries, the formulation of high specific gravity dyes has been a difficult problem. Meanwhile, at high loadings, the agglomeration effect of dyes is enhanced, thereby influencing the dissolution efficiency and dyeing efficiency of the dyestuff. This study proposed a multilayer dye dissolver for dark and black dyeing in supercritical carbon dioxide. The structural soundness of the proposed design was verified by numerical simulation during the predesign process. Subsequently, dyeing results with different dye dissolvers demonstrated that the design of the multilayer dye dissolver could meet the requirements for dark and black dyeing. Furthermore, the samples exhibited satisfactory color fastness and K/S values. The color fastness of the samples was found to be at a level of 3–4 or above. Moreover, comprehensive energy consumption and carbon emission test results indicated that the equipment was capable of reducing energy consumption and carbon emissions by 92.56% and 92.05%, respectively, in comparison to conventional water dyeing. This provided an opportunity for further dissemination of supercritical waterless dyeing technology.