Application of Terminalia chebula natural dye on wool fiber—evaluation of color and fastness properties

Abstract

In the present study, Terminalia chebula (Myrobalan/Harda) natural dye extract was used for the development of eco-friendly shades on woolen yarn with different hues and tones. The effect of dye concentration on color strength (K/S) of woolen yarn dyed with T. chebula was assessed. Increasing the concentration of dye decreased lightness (L*) values of woolen yarn samples, indicating darker shades. Different metal salts such as alum, ferrous sulfate, and stannous chloride were used to enhance the fastness properties (light, wash, dry and wet rubs) of dyed woolen yarn. Pre-treatment of woolen yarn samples with metal salts has shown encouraging results with better fastness properties and enhanced color strength values. Five percent ferrous sulfate mordanted samples show greater saturation with increasing dye concentration from 0.5 to 15 % (o.w.f.). Fourier-transform infrared (FT-IR) analysis of T. chebula dye extract shows presence of carbonyl and hydroxyl functionalities.