Eco-Friendly Dyeing of Wool with Natural Dye Extracted from Moroccan Crocus sativus L. Flower Waste

There has been lately a phenomenal rise in the use of natural dyes in different areas, although the principal problem with these natural dyes is their high cost for the production. The main idea of this study is to convert the waste of saffron flower to an eco-friendly natural colorant for sustainable textile coloration of wool fabric. This work studies the stability of saffron flower extract (SFE) by UV-Vis spectroscopic analysis, thermo-gravimetric analysis, and differential scanning calorimetry, the use of mordants, and the color fastness of wool fabric dyed. SFE has good thermal and pH stability under acidic conditions; it would be suitable for textile dyeing processes. The optimized dyeing conditions such as: dye concentration of 6 % for direct dyeing and 2 % for mordant dyeing (dyeing in the presence of mordant), pH value of 3, dyeing temperature of 90 °C, and dyeing time of 60 min are obtained for better dyeing performance of wool with about 60 % bath exhaustion rate after pre-mordanting. A range of colors from brown to green are obtained with good fastness to washing, wet and dry rubbing, acid and alkaline perspiration, and an acceptable color fastness to light. In general, the abundantly available agricultural by-product SFE has considerable potential to be utilized as a natural textile dyestuff.