Indigo dyeing and antimicrobial performance of cotton/bamboo blend denim fabrics

Purpose This paper aims to explain how the denim industry is adopting environmental and innovative technologies. This study explores the use of water-soluble indigo carmine (IC) dye as an alternative to typical indigo dye for dyeing cellulosic fabrics. The IC dye displays good dyeing performance of weft-wise cationized bamboo yarns used in the production of cotton/bamboo-blended denim fabrics. Design/methodology/approach Cotton/bamboo-blended denim fabrics were produced using indigo-dyed cotton warp and IC-dyed cationized bamboo weft yarns dyed with different dye concentrations. The untreated and cationized bamboo yarns were characterized by FTIR, SEM-EDX mapping to confirm the chemical modification and evaluate changes in surface morphology and elemental composition. The study estimated the colorimetric, ultraviolet protection, antimicrobial and colorfastness properties of the blend denim fabrics. Findings IC dye exhibited high affinity for cationized bamboo fibers, enhancing color matching in cotton/bamboo-blended denim fabric. IC dye improved the antimicrobial properties of the blend fabrics, achieving up to 97% reduction in Staphylococcus aureus, Escherichia coli and Candida albicans. Moreover, the ultraviolet (UV) protection factor values of the blend samples significantly improved UV protection against UVA and UVB radiations and very good to excellent colorfastness. Research limitations/implications The study examined the use of an alternative water-soluble indigo dye to cotton/bamboo blend denim fabrics. Further studies on natural and regenerated cellulosic fibers are necessary to validate their suitability for industrial applications. Practical implications The study explores the production of blend denim fabrics using indigo-dyed cotton warp and IC-dyed cationized bamboo weft yarns. This combination enhances the antimicrobial and anti-UV properties along with the indigo dyeing performance. Originality/value This study explores a new approach to the production of cotton/bamboo blend denim fabrics. The dyeing performance of IC-dyed cationized bamboo contributes valuable insights into eco-friendly dye–fiber compatibility and process optimization in the industrial denim sector.