Colour change of polyester dyed fabric during washing by ecological surfactants

Alkyl polyglucosides (APGs) have appeared on the market, offering good levels of biodegradability and ecotoxicity. These nonionic surfactants, obtained from natural substances, are 100% biodegradable and very suitable for washing. They are highly soluble, only slightly sensitive to electrolytes and rarely influenced by water hardness. This paper analyses the behaviour of APG and linear alkyl sulfonate, separately and in mixtures of different proportions, in order to show how dyed polyester fabric changed colour during washing and how dye transfers to white textile items (diacetate, polyamide, cotton, acrylic and wool). Before this process, the polyester was dyed with disperse dyes. Disperse dyes can become deposited on white polyester fabric during washing due to various mechanical, chemical, electrical or adsorption-related causes. In an attempt to explain the behaviour of the deposition of disperse dyes in the washing process, we assessed the total potential energy between disperse dye and polyester fabric based on the theory of heterocoagulation. The zeta potentials of the insoluble disperse dyes and the fabrics were related to the results obtained by staining white fabric during washin