The textile industry has recently renewed its interest in natural dyes due to growing concerns about the environmental and health hazards of synthetic colorants. However, traditional dyeing processes using natural dyes often suffer from challenges such as low extraction efficiency, poor color fastness, and prolonged processing times. In this study, a novel approach combining the pressurized hot water extraction method (PHWEM) with nonionic surfactants (Kenon 10 and Tween 20) was proposed to enhance dye yield and reduce dyeing time. Natural dyes were extracted from madder ( Rubia tinctorum ), weld ( Reseda luteola ), pomegranate peel ( Punica granatum ), and walnut husk ( Juglans regia L. ) and applied to cotton fabrics. The results showed significant improvement in color strength (K/S values), increasing from 3.5 to 5.4 for madder, 2.3 to 6.5 for weld, 4.1 to 7.9 for pomegranate peel, and 3.2 to 6.3 for walnut husk. Moreover, the dyeing time was remarkably reduced from approximately 2 h in conventional methods to only 20 min, with enhanced dyeing quality. Color fastness evaluations revealed improvements of 1-2 units in washing, light, and rubbing fastness. Additionally, antibacterial assessments indicated a notable enhancement in activity against E. coli and S. aureus . The antibacterial efficacy for dyed fabrics increased from 40%, 61%, 52%, and 59% to 57%, 73%, 65%, and 74%, respectively, for madder, walnut husk, weld, and pomegranate peel, when PHWEM was combined with Tween 20. This eco-friendly strategy presents an effective approach for sustainable textile dyeing with potential for environmentally friendly textile production, pending further validation.
Sadeghi‐Kiakhani et al. (Wed,) studied this question.