Modelling of Dyeing of Modified Polyester at Lower Temperature by Ultrasound

Abstract

This article discusses the process of polyester dyeing through the modelling process, i.e. the ability of adsorption of dyes for chemically modified polyester fibres of knitted fabrics in aqueous environment in the presence of ultrasound waves, at lower temperature and without carrier. Previous processing before dyeing, i.e. the alkali-alcohol hydrolysis with ultrasound, changes the surface morphology, decreases the mass and thickness of knitted fabric, improves the sorption features, capillarity and absorption of water, and wetting. The process of dyeing a modified polyester knitted fabric in the presence of ultrasound at lower temperature gives much better results than dyeing without ultrasound and it is very close to the standard process of dyeing a raw sample at higher temperature. By modelling the system, it has been found that the Freundlich non-linear and linear isotherm are the most efficient in simulating the isothermal adsorption of disperse dye on polyester knitted fabric, whereas Langmuir and Nernst give weaker results.

Keywords

• dyeing
• polyester
• disperse dye
• ultrasound
• modelling
• Langmuir isotherm
• Freundlich isotherm
• Nernst isotherm