Comparison of the effects of various pre-settings on the colour yield of polyester dyed with disperse dyes

Abstract

Comparison of the effects of various pre-settings on the colour yield of polyester dyed with disperse dyes During textile production with synthetic fibres such as polyesters, stress is generated within fibre structure such that, when the material is subsequently subjected to either wet or heat treatment, it will shrink due to structural relaxation. Heat setting is an important industrial process, since it rids them of their instabilities. The heat setting process also affects fibre properties such as dye ability. This article presents results of a study on the effects of various pre-settings (heat setting, hot water setting and steam setting process) on the dyeing properties of polyester fibres with disperse dyes. It was found that the colour yield of dyed samples after dry heat setting at 180-220 degrees C is higher compared to the unset dyed sample. In the case of samples that have been hot water set or steam set, colour yield decreases by rising setting temperature. Furthermore, it was found that type of pre-setting and its conditions - temperature and time - has higher impact on colour yield of dyes having low-medium diffusion numbers.