Color enhancement of chrome tanned goat leathers using aqueous tea extracts as dyeing agent

Abstract

The leather industry is undergoing a transformative shift towards sustainable practices due to increasing environmental concerns associated with synthetic dyes. This research explores the potential of natural dyes derived from tea extracts as an eco-friendly alternative for leather dyeing. In this study, the aqueous extracts of dried commercial tea leave (Camellia Sinensis) (10%, 12%, and 15% w/v) with and without mordant were used for dyeing of chrome tanned goat leathers and its color intensity parameters were examined using Milton Roy Colormate HDS spectrophotometer. In addition, the quality of dyed leather was evaluated by dye exhaustion test, fastness test, tensile strength test, scanning electronic microscopy (SEM) imaging, and thermogravimetric analysis. The optimized application of dye extract was 12% (without mordant) showed better color intensities (L* = 56.33 ± 0.57, DL* = -13.74 ± 0.48), highest dye exhaustion (84.68 ± 0.06%), tensile strength (18.75 ± 0.25), and residual mass in TGA, better color fastness (wet-4/5, dry-4/5, perspiration-3/4, and light fastness-4/5 in Grey Scale rating), and best fiber orientation in SEM image. In addition, another optimized was (with mordant) 15% dye extract with 1% Copper (II) Sulphate produced the highest color intensity (L* = 51.21± 1.06, DL* = -18.86±0.72). These findings offer the potential of tea extracts as a viable solution for natural leather dyeing, offering both environmental and aesthetic benefits.

Bangladesh J. Sci. Ind. Res. 60(4), 251-262, 2025