Textile and Apparel Science

Zero Waste Dyeing?- Application and Colorfastness of Spray Versus Vat Indigo Dyeing

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Abstract

Indigo has long been one of the most important dyestuffs in the world (Encyclopædia Britannica, 2019). Natural indigo vat dye has maintained a small market share and one that is forecasted to grow in the next few years (Cision, 2021). Despite being a natural dye, indigo is not immune to sustainability concerns. Prominent among these concerns are the chemicals used and the amount of wastewater vat dyeing generates (Saikhao et. al., 2018). To reach the needed alkaline conditions in the dyeing vat, strong chemicals, such as sodium dithionite (hydrosulfite, Na2S2O4), are used (Komboonchoo et. al., 2009). Na2S2O4, is most commonly used in industry to reduce indigo due to its efficacy at quickly reducing indigo and ability to provide a stable dyebath for continuous dyeing (Saikhao et. al., 2018). However, concerns surrounding the chemical’s use include it’s instability in alkaline solutions at elevated temperatures and the toxic, corrosive nature of the sulfite and sulfate ion by-products of the reaction (Saikhao et. al., 2018; Blackburn et. al., 2009; Meksi et. al, 2012). This research explored the possibility of spray application, reduced sustainably, in indigo dyeing. These results indicate that indigo is an effective colorant in both vat and spray applications. The spray samples displayed fairly good to very good performance in the crocking test, fairly good to very good in the light exposure test and fairly poor to moderately fair in the perspiration test.

Keywords: Indigo, Spray Dye, Vat Dye, Fructose, Colorfastness

How to Cite:

Harmon, J., (2022) “Zero Waste Dyeing?- Application and Colorfastness of Spray Versus Vat Indigo Dyeing”, International Textile and Apparel Association Annual Conference Proceedings 78(1). doi: https://doi.org/10.31274/itaa.13834