Winery wastes: A potential source of natural dyes for textiles

Abstract

The main goal of the present study was to explore textile dyeing ability of colorants extracted from winery wastes. Extractions with water at different pH and with a water/ethanol solution were performed. Cotton (natural and with a cationization pre-treatment) and wool were used in the dyeing process with two different time duration (100 and 200 min). The colorimetric and fastness properties, in terms of washing (with hot and cold water) and natural light exposure, were evaluated and the cationized cotton substrate was the one with the highest values of ∆E* (parameter representing the difference in color for the fabric after and before dyeing) for all the conditions used to obtain the pomace grape extracts. Hue and tones obtained in the fabrics resulted in uniform colors going from the gray to brownish-gray with potential commercial acceptation, showing that the eco-valorization proposed for grape pomace wastes deserves further studies.