Dyeing Technique Using Supercritical Carbon Dioxide
Department of Chemical Engineering, Fukuoka University, Fukuoka, Japan
Nippon Gomu Kyokaishi,(2004),77(8),282-286 General Review in Japanese.

The use of water and organic solvents in dyeing processes causes environmental problems. The textile industry is putting significant efforts into its social obligation to reduce the large amount of waste discharged into the environment during their dyeing process. Due to this environmental task, dyeing in supercritical carbon dioxide (SC-CO2) has been receiving much attention as an environmentally benign procedure. The synthetic fibers, such as polyester, polypropylene(PP), polyethylene terephthalate(PET) etc., were successfully dyed by SC-CO2 based technology. Recently several investigators have attempted to dye cellulose fibers in SC-CO2, because of its large share on the market. They reported that the modified cottons were successfully dyed, but a very high degree of modification of fabric was required. Their results suggest that further experiments are required. In this work, the dyeing of cellulose fibers with reactive disperse dyes was attempted using SC-CO2 as a solvent. For pretreatment, cellulose fibers were treated with ethylene glycol derivatives. The dyeing was compared with the dyeing using other disperse dyes under the same conditions. The color yield of the fibers was assessed by K/S measurements before and after washing to investigate the quality of the dyeing in this medium. Good color intensity and wash fastness were obtained.

Supercritical Dyeing, Supercritical Carbon Dioxide, Cellulose Fiber, Reactive Disperse Dye