Dyeing of Nylon Fabric with Two Natural Dyes, Saffron (Crocus sativus L.) and Weld (Reseda luteola L.), and Study Their Dyeing, Antioxidant, and Antibacterial Properties

The global demand for using natural colorants as a safe alternative for synthetic dyes is increasing due to their lower environmental impact and higher biodegradability. This requires finding a cost-effective and environmentally friendly strategy for dye extraction and dyeing. In this study, natural yellow colorants extracted from stamens of Saffron (Crocus sativus L.) and weld (Reseda luteola L) were used for dyeing nylon fabrics. The dyeing, antibacterial, and antioxidant properties of the natural colorants and dyed samples were investigated. A sonication-assisted extraction method was employed and the important parameters including the solvent type, the concentration of stamens of Saffron, temperature, and time duration of extraction were studied and optimized. Acetone was found to be a very efficient solvent for the extraction of the natural yellow dye from 10 g/l of stamens of Saffron (SS) at 50 °C for 30 min. The effects of dyeing parameters including the concentration of SS extracts, pH, temperature, and time on the dyeing properties were also studied. The pre-mordanting with a copper salt slightly improved the color strength, and wash- and light-colorfastness properties of the dyed samples. The antioxidant and antimicrobial properties of the dyed nylon fabric with the SS extract were measured to be 74% and 88%, respectively. The colorants extracted from SS showed good dyeing ability, color fastness, antibacterial, and antioxidant properties, comparable with those of a widely used yellow natural colorants extracted from weld.