Development of a novel, sustainable and protective multi-flow dyeing methodology for silk substrate

Abstract

To achieve a sustainable and greener coloration, as well as to protect silk substrate well, a completely novel multi-flow dyeing methodology by employing different liquid flow statuses for different coloration stages was successfully developed for the first time. The effect of liquid flow statuses on the AR-134 dye (C.I. acid red 134) adsorption behaviors at different coloration stages was explored and optimized by orthogonal experiments as well as a single factor screening way. Additionally, for the purpose of disclosing the superiority of the multi-fluid dyeing methodology, investigations on the structure and property of the silk colored under different coloration flow statuses were carried out. The results demonstrate that the developed multi-flow dyeing methodology mainly consisted by controlling coloration fluid statuses to be laminar flow in the temperature increasing stage, and turbulent flow in the coloration stages at elevated temperature and cooling stage, respectively. Particularly, controlling an appropriate coloration liquid flow status, namely a suitable fluid Reynolds number, at each coloration stage was not only crucial to improve the uptake performance of the AR-134 dye on silk, but also significant to reduce damages to the silk surface structure for improving the silk glossiness and mechanical properties. Additionally, the rubbing and washing color-fastness of colored silk under the multi-flow dyeing methodology were all at 4-grade or above and commercially accepted, as well as for a color durability for washing. The obtained results further clearly indicate that the multi-flow dyeing method under different coloration stages is highly beneficial to an efficient, protective and greener coloration of fabric.