Toning Dyeing Of Terylene Fabric With Mixed Disperse Dyes In Supercritical Carbon Dioxide

Compared with traditional dyeing technology,supercritical carbon dioxide dyeing is an innovative method to reduce wastewater discharge and need even less dyeing time with desired dyeing effect.A flow-type dyeing apparatus was used to dye terylene fabric in supercritical CO₂ at the temperature range from 80 to 120℃and pressures from 14 to 22MPa with different time(15 to 90 minutes),with disperse red 343 and disperse blue 366.The results revealed that the mixed-dye dyeing can be achieved on the percentage of 98%at 60min at 120℃,20MPa condition;flow rate of supercritical CO₂ fluid has a significant impact on evenly dyeing of polyester,and a very good result can be get when the flow rate of 100kg/h with dyeing time for 60min at condition of 100℃,18MPa;The uptakes of mixed dyes and the dyeing deepness increased with increasing temperature and pressure under the condition of quantitative toning dyeing.The rate of mixed-dye staining reached up to 37.17%which decreased with increasing dosage when the disperse red dosage followed by disperse biue dosage of 1-5 times.The rate of mixed-dye staining reached up to 54.83%which increased with increasing dosage when the disperse blue dosage followed by disperse red dosage of 1-5 times.The evenly dyeing performance of polyester increased with increasing time in multi-storey toning dyeing condition,a very desirable effect of multilayer dyeing can be get at 100℃,18MPa and flow rate of 100kg/h with 60min.The partition coefficients(K_eq) of dyes between fabric and supercritical carbon dioxide range from 34600-403290.The result indicated that the coefficients increased with the rise of temperature and pressure.The "film roll method" was used to measure the permeation of dyestuffs permeating terylene fabric in supercritical dyeing system at different conditions.The result indicated that the coefficients decreased with the rise of temperature and increased as the pressures increased.