Dyeing of cellulosic blended fabrics with natural dyes: Process optimization by response surface methodology

Textiles are sectors with high environmental impact potential, known for their intensive use of water and chemicals. As sustainability becomes increasingly important, the development of environmentally friendly products is a crucial requirement. With rising consumer awareness, the demand for ecological and functional textile products is also increasing. Therefore, research using sustainable cellulosic fibers and natural dyes has accelerated as an alternative to the widespread use of synthetic fibers and dyes. In this context, solutions that offer functional value with a low environmental footprint are needed. In this study, a woven fabric containing 78% cotton, 21% hemp, 1% elastane was colored with the natural dyestuff olive leaf (Olea europaea L.) in conjunction with biomordants. Pomegranate peel (Punica granatum L.), acorn (Quercus ithaburensis), and lemon peel (Citrus spp.), known for their high phenolic and flavonoid content, were used as biomordants. Rock salt, an ionic compound, was also used in the dyeing process. In the first stage, the effects of mordant type, mordanting method, mordant concentration, and rock salt concentration on negative ion release were systematically investigated using the Taguchi method. After identifying the combinations that yielded the best results, the optimum values for mordant and rock salt concentration were determined using Response Surface Methodology (RSM). In addition to the functional properties of negative ion release, the RSM study also optimized color yield (K/S). When the obtained results were evaluated, it was determined that the type of biomordant used in natural dyeing, the mordanting method, and the use of rock salt contributed to maintaining electrostatic balance by increasing the release of negative ions. This holistic evaluation of negative ion release contributes to the development of eco-friendly and functional textiles.