Study On The Dyeing Of Derylene Fabric With Disperse Red 343 And Disperse Blue 366 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 derylene fabric desized or not in supercritical CO₂ at the temperature range from 70 to 140℃and for pressures from 14 to 26MPa with different time (5 to 80 minutes), with disperse red 343 and disperse blue 366, respectively.The results revealed that the uptakes of dyes and the dyeing deepness (K/S value) increased with increasing temperature, pressures and contact time. The max K/S value appeared at 110℃when the pressure was constant (20MPa), and appeared at 18MPa when the temperature was constant (110℃). It was also indicated that size in the fabric did not influence the dyeing effect. Compared with fabric not desized, the dye uptakes and the K/S value of fabric desized were little lower at low temperature and pressure, but with the rise of temperature and pressure, the results inversed. The obtained fastness poperties were rated to be as good as that obtained in aqueous medium. The partition coefficients (Keq) of dyes between fabric and supercritical carbon dioxide decreased with the increasing of density of carbon dioxide, and decreased with the increasing of temperature at the same density.The dyeing experiements of derylene fabric with the dyes mixture were also carried out. The uptakes of disperse blue 366 in the ternary system were close to the uptakes in the binary system (average 93.0%). However, the uptakes of disperse red 343 were much lower than that in the binary system (average 51.5%). The total uptakes of the mixture were more than the uptake of any single dye in the binary system (149.4% of disperse red 343 and 140.8% of disperse blue 366), and lower than the summation of them (average 70.4%).The "film roll method" was used to measure the diffusion coefficients of dyestuffs permeating derylene 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.