Supercritical CO2 dyeing for nylon, acrylic, polyester, and casein buttons and their optimum dyeing conditions by design of experiments

摘要

Supercritical carbon dioxide (scCO(2)) dyeing for textile and polymer processing is considered as a green and energy-saving process for view-points of environmental friendly and sustainable development. We developed a compact scCO(2) dyeing apparatus and performed scCO(2) dyeing for plastic buttons of nylon, acryl, polyester, and casein with a uniformly color at the temperature T, pressure P, and dyeing time t. The dye sorption in the buttons was examined by the dyeing color depth, which was evaluated by K/S values calculated from Kubelka-Munk equation. From the range analysis and variance analysis based on the Taguchi design of experiments, we found an optimum dyeing condition of K/S values for dyeing plastic buttons at T = 125 degrees C, P = 27 MPa, and t = 80 min for nylon, T = 50 degrees C, P = 14 MPa, and t = 40 min for acrylic, T = 120 degrees C, P = 12 MPa, and t = 30 min for polyester, and T = 80 degrees C, P = 10 MPa, and t = 30 min for casein, as well as the most influential factor and rank of influence factors for all plastic resin buttons. In addition, the color difference Delta E* of plastic buttons of nylon, acrylic, polyester, and casein dyed at the optimum operation conditions was evaluated by CIE L*a*b* theory.