Compatibility of a disperse dye mixture in supercritical carbon dioxide dyeing

The compatibility of three disperse dyes, CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, which are commonly used as a trichromatic combination for conventional dyeing, was studied in supercritical carbon dioxide dyeing. Both the dyeing rate and the build‐up of the selected dyes were measured. Experimental results showed that they were quite compatible. The dyeings of a binary combination (CI Disperse Orange 30 and CI Disperse Blue 79, mass ratio 1:1) and a ternary combination (CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, mass ratio 1:1:1) at different dye concentrations showed an on‐tone uptake and presented the same metric hue angles. This proved that the selected dyes could form a useful trichromatic combination in supercritical carbon dioxide dyeing. Furthermore, the uptake and exhaustion of the single dyes in supercritical carbon dioxide dyeing were similar to those in aqueous dyeing, implying that the dyeing media play only a minor role in the dyeing of polyester fibres with disperse dyes.