Sustainable Coloration and Functionalization of Silk Fabric Through Chinese Fringe Leaves (Loropetalum chinense) Extraction Using the Taguchi Method: An Alternative for Waste Management

Abstract

The escalating concern over the environmental impact of synthetic dyes in the textile industry has fueled a burgeoning interest in natural alternatives. This study aims to investigate the dyeing performance of silk fabric using dye extracted from Chinese fringe leaves (Loropetalum chinense), which are devoid of harmful chemicals, and to promote eco-friendly practices. The extraction process involved normal heating with crushed leaves, ensuring a purely natural dyeing method. Through experimentation, it was observed that higher dyeing temperatures, increased dye ratios, and longer dyeing durations enhanced color strength in the silk fabric treated with the Chinese fringe leaves dye. An orthogonal (L¹⁶) Taguchi method was applied to determine the optimal dyeing conditions, emphasizing the significance of dye dosage and temperature in achieving maximum color strength. The initial parameter of K/S was 11.3 and the predicted parameter of K/S was 11.43, where the confirmation test value of K/S was 11.49 for the dyed fabric sample. Moreover, assessments of color fastness demonstrated satisfactory results ranging from good to excellent for washing, perspiration, rubbing, and light fastness. Fourier transform infrared analysis elucidated the interaction between dye molecules and silk fabric while scanning electron microscopy revealed the dye absorption by the silk fabric's surface. Thermogravimetric analysis revealed differences in thermal properties between dyed and undyed silk fabric, with dyed fabric exhibiting lower melting points and reduced thermal stability. Additionally, the dyed silk fabric exhibited decreased air permeability of 122 ± 2 mm/s with an increased protection factor of 317.9 against UV and sun rays compared to its undyed silk fabric sample. In inference, the dye extracted from Chinese fringe leaves possessed a favorable affinity for silk fabric, presenting a promising alternative to synthetic dyes for sustainable coloration and functionalization in the textile industry.

Graphical Abstract