The Application of Sustainable Dyeing Techniques in Fashion Design: Reducing Environmental Footprints and Fostering Aesthetic Innovation

This study presents a comparative investigation of natural and synthetic dyeing systems for cotton fabric from a textile engineering perspective under rigorously controlled exhaustion dyeing conditions. Madder extract and C.I. Direct Red 23 were selected as representative natural and synthetic dyes, respectively. To ensure a fair comparison, a single-hue system and a target color strength (K/S ≈ 12.0) matching protocol were employed, while excluding metal mordants and cationic fixing agents. Water consumption, effluent chemical oxygen demand (COD), colorimetric properties, color fastness, process cost, and batch productivity were systematically evaluated. Results indicate no significant difference in specific water consumption between the two systems (p > 0.05), demonstrating that water use is governed by process parameters rather than dye origin. However, the natural dyeing system exhibited a 2.3-fold higher COD load and approximately 3.2-fold higher material cost due to lower tinctorial strength. Both systems displayed comparable intrinsic color fastness (ISO Grade 2–3). These findings highlight critical environmental and economic constraints for the industrial application of natural dyes in textile dyeing.