The dyeing of cotton is influenced by chemical and physical interactions between dye molecules and the substrate, many of which are not well understood. This project reviews current knowledge of the relationships between the fibre properties of cotton, including surface and structural properties, and dye uptake by cotton fibres. Where available, research specifically pertaining to the dyeing ability of Australian cotton is reviewed.

The aim of this review is to guide the CRDC and researchers in understanding the issues associated with cotton dyeing and the current gaps in knowledge. Understanding and resolving these issues provides better quality, both in terms of breeding fibre with improved dyeing ability and improving dyed quality in mills. Increasing understanding around cotton’s dyeing ability also improves prospects for better water and energy efficiencies associated with dyeing cotton, and thereby the ‘social’ license to use cotton as a textile.

The review has been conducted in response to anecdotal information gathered over time from mills reporting colour appearance and dye uptake differences using Australian cotton (Gordon et al, 2002, Gordon et al, 2004 and Yang and Gordon, 2010).

While a large amount of research has been conducted in this area, there remain questions about the effect of the structural properties of cotton cellulose on dye uptake kinetics and substantivity, i.e. the adherence of the dye molecule to the substrate being dyed. The structural properties in question include the species of wax and associated chromophores on the outer surface of the fibre, the non-cellulosic fractions, e.g. pectins, within the fibre structure and the fine structure of cotton cellulose itself. The review concludes that there remains a gap in understanding how these surface and structural attributes affect dye uptake and dyed appearance in cotton.

Focus is given to research that describes cotton’s structural morphology, its cellulose structure and surface chemistry properties and the physical properties currently used to assess the dyeing ability of cotton. An overview of the dyeing of cotton including the dyestuffs used and procedures for preparing and dyeing cotton is given. This is followed by a review of research on the central issues that affect cotton dyeing. The central issues, as identified, are control of shade variation and water and energy consumption by the dyeing process.