Groundnut Testa: An Industrial Agro-Processing Residue for the Coloring and Protective Finishing of Cotton Fabric

Abstract

Textile grade dye from agro-residue, groundnut testa was produced by aqueous extraction. The extracted dye was used for the dyeing of cotton in the presence of alum, ferrous sulfate, and myrobalan. The fastness and functional properties of the dyed fabrics were studied. The results showed that the color fixation of groundnut testa dye on cotton is good, without the aid of mordants; however, the dye produced deeper shades in the presence of mordants. Irrespective of the mordants used, the dyed fabric showed excellent microbial resistance against gram-positive and gram-negative bacteria and ultraviolet protection. Lab to bulk correlation studies of groundnut testa dye was conducted with knitted cotton fabric so that the textile dyeing industry can benefit from this agro- residue natural resource. Color strength (K/S) of the bulk dyed sample is higher than the lab dip with the color difference (dE) found to be higher than the industrial shade approving limit of 1.0. The garment-dyed using tie and dye method exhibited good fastness properties. The printing with the dye extract was also attempted and it showed good printability on cotton. Thus, dyeing and printing using agro-residue of groundnut testa is a source of sustainable and cleaner production of natural dye for the medium and small-scale industries.