Sustainable dyeing of jute-cotton union fabrics with onion skin (allium CEPA) dye using banana peel (Musa) and guava leaves (Psidium guajava) extract as biomordants

Purpose This paper aims to evaluate the effects of banana ( Musa ) peel and guava ( Psidium guajava ) leaves extract as mordants on jute–cotton union fabrics dyed with onion skin extract as a natural dye. Design/methodology/approach The dye was extracted from the outer skin of onions by boiling in water and later concentrated. The bio-mordants were prepared by maceration using methanol and ethanol. The fabrics were pre-mordanted, simultaneously mordanted and post-mordanted with various concentrations according to the weight of the fabric. The dyed and mordanted fabrics were later subjected to measurement of color coordinates, color strength and colorfastness to the washing test. Furthermore, the dyed samples were characterized by Fourier transform infrared, and different chemical bonds were analyzed by X-ray photoelectron spectroscopy analysis. Findings Significant improvement was obtained in colorfastness and color strength values in various instances using banana peel and guava leaves as bio mordants. Post-mordanted with banana peel provided the best results for wash fastness. Better color strength was achieved by fabric post-mordanted with guava leave extracts. Originality/value Sustainable dyeing methods of natural dyes using banana peel and guava leaves as bio mordants were explored on jute–cotton union fabrics. Improvement in colorfastness and color strength for various instances was observed. Thus, this paper provides a promising alternative to metallic salt mordants.