An overview of faba bean: utilisation of husks in natural dyeing

Abstract

Purpose The purpose of this paper is to reveal the potential use of faba bean husk as natural dye, to create a color gamut and to observe the effect of different mordants. Dyeing properties of polyamide/elastane fabric using faba been husk were investigated. The effect of alum [KAl(SO4)2], iron II sulfate Fe(SO4)7H2O, tin II chloride (SnCI22H2O), copper II sulfate (CuSO4), citric acid (C6H8O7), tartaric acid (C4H6O6), oxalic acid (H2C2O4), ammonium sulfate [(NH4)2SO4], sodium acetate (C2H3NaO2), combination of alum-iron, iron-tin and alum-tin were evaluated in terms of color yield, color coordinates and wash fastness. Design/methodology/approach Mainly, dyeings were conducted in accordance with a simultaneous mordanting method. However, pre-mordanted dyeings were also implemented with selected concentration (0.8 g/L) of metallic mordants to enrich color gamut. Control sample (without mordant) was used as a reference for examining the effect of different mordants. Dyed samples were compared mutually in the light of visual evaluation and color measurements and alternatives to metallic mordants were also assessed. Findings Significant differences occurred in color coordinates of dyed samples. The biggest color difference and completely different color shades were achieved with tin II chloride. The type of acid did not create visible color differences. As alternatives to metallic mordants; all of them may be used instead of alum (0.8 g/L). Tartaric acid and oxalic acid, instead of iron II sulfate (0.2 g/L), and ammonium sulfate (0.2 g/L) and sodium acetate (0.8 g/L), instead of alum (0.8 g/L), can be used. Sodium acetate cannot be replaced with iron. A combination of alum-iron and iron-tin can be the alternative to 0.2 and 0.8 g/L copper, respectively. All the samples provided good wash fastness (4/5) values. Originality/value Valorization of industrial, agricultural and domestic wastes as novel natural dye sources is an ecological and sustainable approach. Moreover, the use of man-made fibers in natural dyeing is an issue that needs to be developed and expanded. Few literatures have been found concerning the use of husks of faba bean as a natural colorant. In this initial study, husks of faba been as a vegetable waste were utilized in natural dyeing of polyamide/elastane fabric. It is suggested that this waste can be turned into an economic value through its valorization in natural dyeing.