This research sought to determine why differences in dye uptake may occur between cottons with near identical fibre properties.

The aim of this project was to improve understanding of cotton dyeing by identifying properties affecting dye uptake aside from those routinely measured such as maturity and micronaire. This knowledge could help reduce the occurrence of off-shade dyeings, which can result in costly re-dyes or batch losses for mills and may dissuade repeat purchase from the source as the cotton may be perceived as lower in quality. This project had a focus on Australian cotton in an effort to maintain a good reputation in international textile markets. The prevailing conclusion throughout the experiments conducted in this project was that cotton base colour is the factor primarily influencing dyed colour, whether that be the colour of the raw fibre or the colour after treatment. The key properties influencing raw fibre colour were found to be fineness, reflectance, and yellowness. The biggest impacts for the cotton industry from this project relate to mills, with the work highlighting a need for more extensive colour measurement and a revision of fibre selection criteria. The work also demonstrates the importance of consistency in pretreatments and proper rotation of cotton in storage.

Mills select cotton on the basis of similar HVI properties, yet despite this control there are still cases where dyed colour differs on a time/batch basis. Inconsistent dyeing can be costly for mills in terms of both time and money, and may deter mills from repeat purchase from the source due to perception of lower quality. This project had a focus on Australian cotton in an effort to maintain a good reputation in international textile markets.