Exhaust dyeing of meta‐aramid yarn at low temperature and time

Abstract

AbstractExhaust dyeing of aramid fibre is difficult due to its high crystalline and compact structure. In this study aramid yarn is pre‐treated with solvent dimethyl sulphoxide to facilitate the dyeing process and then dyeing is achieved with a cationic dye. Pre‐treatment at high temperature leads to the reduction in tensile strength of yarn which is not desirable. Therefore, in this work pre‐treatment has been carried out at different temperatures and time to standardise those parameters to enhance the dye uptake with minimum reduction in strength. Further, dyeing temperature and time has been standardised keeping the standard pre‐treatment parameters fixed. From the study, pre‐treatment temperature of 30°C for 10 min and dyeing temperature of 100°C for 30 min are found suitable for better colour strength without much compromising on strength of yarn. The fastness properties of untreated and treated dyed yarns were comparable.