Utilizing Gelatin Extracted From Fleshing Waste for Eco-Friendly Textile Applications Ahmed Mohammed Nuru

Abstract

This study investigates the use of gelatin derived from leather fleshing waste as a sustainable and eco-friendly resource to enhance the dye-fiber interaction. Gelatin was extracted using an alkaline pre-treatment followed by controlled thermal hydrolysis at temperatures ranging from 70–100°C.The extract was filtered to remove impurities and obtain a highly purified gelatin. The extracted gelatin was applied to bleached cotton fabric to enable salt-free and alkali-free reactive dyeing, thereby replacing conventional electrolytes and hazardous mordents commonly used in Cotton dyeing. Grafting gelatin onto cotton fibers significantly improved dye–fiber interactions by introducing new functional groups, under mildly acidic conditions, generated NH₃⁺ cationic sites.

Chemical modification of the fabric was confirmed through FTIR spectroscopy, UV–Visible absorption analysis, and Colour-Eye K/S measurements. The gelatin-treated cotton fabric exhibited enhanced dye uptake, superior dye utilization, and improved coloration efficiency. UV–Vis analysis showed a 6.4% increase in dye exhaustion, while K/S values indicated a 7% improvement in colour fixation and 9.4% enhancement in overall dye utilization compared with conventional dyeing processes. Fastness testing exposed good performance, with ratings of 4/5 for washing, 5 for rubbing, and 4/5 for perspiration. Environmental assessment showed significant pollution load reduction, with BOD and COD decreasing by 61% and 63%, respectively, and TDS reduced by 22.5%, confirming the eco-efficiency of the gelatin-assisted, salt- and alkali-free dyeing process. In addition, the treatment improved the crease recovery angle to 120° due to crosslinking between amide and carboxylic groups. Overall, the results demonstrate that gelatin extracted from fleshing waste is a viable environmentally friendly substitute for synthetic chemicals in cotton dyeing process. This approach supports waste valorization, enhances fabric performance, and promotes sustainable and eco-conscious textile production.