Sustainable Alternatives in Vat Dyeing Using Natural Sugar-based Reducing agents

Textile technology

Vat dyeing is usually done for cotton fabrics because of its exceptional durability and washing resistance. However, the conventional method of treating sodium hydrosulphite as reducing material poses a serious environmental problem, including high chemical oxygen demand, sulphite pollution, etc. This work explores a more sustainable alternative to the currently used reducing agents derived from sugar carbohydrates in the form of sugar derived from non-edible fruit peel waste such as banana, pineapple, orange, pomegranate, and watermelon. The main aim was to determine whether these natural extracts could be effectively used as substitute of these synthetic reducing agents without affecting the dye performance. Fruit peels were processed to obtain extracts rich in sugars, and sugar content of the extracts were analysed using preliminary as well as advanced laboratory method. Comparative vat dyeing experiments had been carried out keeping the same conditions using synthetic and natural reducing systems. The dyed fabrics were tested for color strength (K/S value), as well as wash, rubbing, and light fastness. Effluent samples were also analyzed for some environmental parameters viz., COD, BOD, pH and TDS. The results prove that fruit peel extracts can reduce the fact of dyes vat to leuco form and with similar shade depth and fastness properties but with significant decrease of environmental impact. Overall, the results point to the opportunities of agro-waste-based sugar reducers as bio-degradable and sulphur-free alternatives for more sustainable vat dyeing processes.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.