Comparing various dyeing techniques using plant extracts on cotton fabrics

Natural dyes were extracted from marigold flowers, onion outer skins, fenugreek seeds, and green coffee, and were used to color 100% Giza 86 cotton fabric using alum as a mordant. The dyeing process was conducted using three techniques: conventional, microwave, and infrared radiation. The surface properties of the cotton fabric were evaluated using FTIR spectroscopy. Additionally, the dyed fabrics were assessed for color strength (K/S) and fastness properties including washing, light, rubbing, and perspiration fastness. The results indicated a moderate affinity between cotton fabric and the extracted dye. The use of metal mordant improved dye exhaustion in alum-dyed cotton fabrics. There was a significant variation in color shade depth among the different natural dyes. Specifically, marigold extract resulted in a significantly darker yellow shade, while green coffee extract yielded a lighter yellow hue. The dye derived from marigold flowers demonstrated exceptional efficiency in color fastness tests, with the microwave dyeing process yielding the best results for (K/S). However, the use of green coffee and fenugreek in dyeing resulted in superior fastness compared to other methods.