Effect of solvent pretreatment and selective dye bath additives on physical properties and dyeing behaviour of microdenier polyester fabric

Abstract

Polyester microdenier (0.8 dpf) and normal denier (2.17 dpf) multifilament fabrics have been subjected to swelling pretreatment in single and mixed solvents of varying ratio at room temperature for different durations prior to dyeing with disperse dye. The treated fabrics have been evaluated for changes in denier, weight loss, area shrinkage, breaking tenacity, breaking elongation, critical dissolution time, surface depth of colour, dye uniformity and light fastness. Among the three single solvents used, the pretreatment with 100% xylene for 60 min at room temperature shows significant improvement in

<span style="font-size:14.0pt;line-height:115%;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";color:black;mso-ansi-language:en-in;="" mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">surface depth of colour and better balance of above properties for both mi crodenier and normal denier polyester fabrics . The use of a mixture of xylene and dimethyl formamide in the ratio of 1:2 for 60 min at room temperature shows the highest increase in surface depth of colour without much affecting the above physical properties. Dye bath additives like antioxidant and UV absorber were used and UV absorbers are proved to be beneficial for improving light fastness. Among all the UV absorbers used, benzophenone shows the best results even at a very low dose(0.5%).</span>