Bach, Elke, Ernst Cleve, Andreas Schmidt, Eckhard Schollmeyer. DYEING OF TEXTILES IN SUPERCRITICAL CARBON DIOXIDE: AN OVERVIEW
Adlerstraße 1, Krefeld, Germany, 47798 (bach@dtnw.de)
In textile industry, water is used as a solvent in many pretreatment and finishing processes, such as washing, scouring, bleaching and dyeing. Many efforts have been done to reduce the water input by optimizing the machinery equipment or by recycling and reusing low polluted wastewater. Another way is to use other environmentally friendly solvents such as supercritical CO2. At DTNW such a process for dyeing of hydrophobic textiles has been developed and patented. In 1995 UHDE Hochdrucktechnik designed and built a supercritical CO2-dyeing plant on a technical scale with a 30-l autoclave based on the lab experiences of DTNW. Meanwhile the pumps, the dye vessel, and the extraction- and impregnation cycle of the machine were optimized by UHDE. Some other factors which affect the dyeing, concerning the fibers, the dyes, and the optimum dyeing conditions are reported but also CO2 dyeing of hydrophilic fibers such as cotton.