Thermal migration of selected disperse dyes on poly(ethylene terephthalate) and poly(lactic acid) (Ingeo^†) fibres

Abstract

A study has been carried out to correlate the wet fastness properties of dyed knitted fabrics, derived from both poly(ethylene terephthalate) and poly(lactic acid) (Ingeo) fibres, with the thermal migration properties of the disperse dyes during heat treatment. The results indicate a greater amount of disperse dye at the surface of the Ingeo fibre fabric than the poly(ethylene terephthalate) fabric, after post heat‐setting using the conditions needed for fabric stabilisation, correlating well with its slightly lower wash fastness properties.

Dyeing and Fastness Properties of Disperse Dyes on Poly(Lactic Acid) Fiber

“…The dyeing properties of PLA have been investigated, especially in comparison with PET fiber. The dyeing of 100% PLA fiber has been intensively studied (Scheyer & Chiweshe, 1999;Nakamura et al, 2001;Phillips et al, 2003Phillips et al, , 2004aPhillips et al, , 2004bPhillips et al, , 2004c. Owing to its relatively hydrophobic nature like PET, PLA can normally be dyed with disperse dyes.…”

“…The optimum dyeing conditions for dyeing PLA are 110 o C for 30 mins under an acidic pH (pH 5) (Fig. 4.) whereas PET dyeing is normally carried out at 20 o C higher (130 o C) under a more acidic condition (pH 4) (Phillips et al, 2004b). Disperse dyes which show good dyeing properties on PET do not always provide good dyeability on PLA.…”

“…A heat treatment for PLA fabrics is generally either to provide dimensional stability or in the application of a chemical finishing agent. The degree of thermal migration of a disperse dye is an important factor in determining the subsequent wet fastness properties of PLA fabrics (Avinc et al, 2009;Kim et al, 2004;Phillips et al, 2004b).…”

“…The authors suggested that the high degree of thermal migration of the disperse dyes at the surface of PLA was because the absence of - bonding forces between the disperse dye and the polymer chain. They also concluded that the wet fastness of the heatset PLA fabric was not directly proportional to the amount of disperse dyes that has migrated to the fiber surface (Phillips et al, 2004b). Avinc et al investigated the influence of different heat treatment conditions on the wet fastness properties viz.…”

“…Our work on thermal migration of disperse dye on PLA fabric was carried out by using six commercial disperse dyes from all three different sublimation classes. The quantity of dye migrated to the fiber surface and dye lost by sublimation to the atmosphere after heat treatment at 130 o C for 30 s was investigated according to the procedure in Phillips et al (2004b). Moreover, the wet fastness properties (wash, perspiration, and rub) were compared between the dyed PLA before and after heat treatment.…”