Influence of supercritical carbon dioxide (scco2) dyeing parameters on color fastness of polyester fabric dyed with disperse dye : A study towards minimizing the energy consumption of polyester (pet) fabric dyeing with azo disperse dye

Sammanfattning: Amid growing environmental concern and continuous depletion of natural resources (such as water), the textile industry is constantly searching for sustainable production process. Traditional dyeing processes, notorious for their enormous water consumption, have led society to search alternative dyeing method. Super critical carbon dioxide (scCO2), emerging as a promising dyeing medium shows a potential solution to mitigate water utilization, consequently raising sustainable textile material wet processing. As this innovative technology characterize by its waterless nature, no effluents are generated and conserves enormous amount of water, energy while increasing productivity. Although it has attained commercial focus in polyester fabric dyeing, the imperative remains to reduce energy demand during dyeing process including commercially available dyes. As a result, the optimization of dyeing conditions assumes crucial importance, broadening the feasibility of these eco-friendly dyeing techniques. The objective of this thesis work is to find out the optimum dyeing conditions of polyester (PET) fabric dyeing with an azo disperse dye (Corangar orange PE3330) utilizing supercritical carbon dioxide (scCO2) as a dyeing medium. The investigation aims to unravel the dynamic correlation withing scCO2 dyeing conditions and dye performance. To conduct this study, comprehensive methodology employing a statistical design of two-level three-factor (23) full factorial design was adopted. The studied factors enclose temperature, pressure and dyeing durations, enclosing ranges of 80-1200C, 10-25Mpa and 1-2 hours respectively. Dye concentration was kept constant at 0.2%. The study looks for individual conditions of studied parameters and their impacts on color strength (K/S). Moreover, an analysis of color fastness attributes, comprising washing, sublimation, rubbing and extraction, is carried out. The statistical analysis shows that the prominence of pressure and temperature as the principal factors in scCO2 dyeing medium. Differential scanning calorimetry (DSC) analysis proves the negligible morphological transition in PET fabric following dyeing (crystallinity % for dyed and undyed fabric is 28.80 and 28.42% respectively). Findings also shows that comparable color properties to the traditional standard of PET fabric can be obtained by adapting dyeing pressure (20Mpa) and time (1 hour) while keeping the dyeing temperature (1200C). The findings concluded that satisfactory color strength (K/S) and color fastness related to the standard scCO2 dyeing process can be obtain with reduced energy and pressure. The outcome of this study subtle the relationship between temperature, pressure, and time towards color strength (K/S) and color fastness properties. Nonetheless, investigation of this study remained confined to laboratory-scale and for the purpose to upscale this finding for commercial use, it is crucial to carry out rigorous industrial trials.