Supercritical Dyeing of Polyester Fibers in a Mini-Plant Possessing Internal Circulator

Abstract

The polyester fabric (PET) was dyed with C.I. Solvent Blue 35, C.I. Disperse Red 60 and C.I. Disperse Yellow 54 in supercritical carbon dioxide (scCO₂) using the apparatus that possesses circulation system. The experimental conditions were optimized to obtain both visibly and spectrophotometrically uniform dye uptake in PET fabric. The staining of the dye was suppressed by addition of stainless mesh and cotton fabrics between the PET specimen and the stainless cylinder settled in the high-pressure column. The visible difference of color depth between the layers of fabric was improved with circulation of the dye bath especially as the scCO₂ was released after the dyeing. The spectrophotometric measurements firmly indicated the invisible distinction of dye uptake between the fabric layers, which was inhibited by enhancement of duration in the process of scCO₂ release. The 88-97% dye uptake of C.I. Solvent Blue 35 and C.I. Disperse Red 60 was obtained in scCO₂ dyeing by the improved procedure.