Effect of the flowing states of solution on silk coloration with acid blue dye

In order to achieve more efficient and environmentally friendly coloration, an effect of the different flow states of bath solution on silk coloration with C.I. Acid Blue 113 (AB-113) dye was explored by employing a self-built hydrodynamic coloration machine, especially for their various effects from different substrate positions in pip flow and different process parameters on coloration, etc., were disclosed for the first time. The results show that a turbulence flow brought a significant and positive effect on the dye uptake by improving surface color depth and color evenness most notably, then were the transition and the laminar flows. Significant effect from the distance of silk to pipe wall on the dye uptake in laminar flow was observed, while less or non-effect from transition and turbulence flows was also achieved. Similar effect tendences in the coloration performance of the AB-113 dye on silk from process parameters in different flow states were also obtained while accompanying with some more evident effects in turbulence flow than the other two. Moreover, the coloration performance could be significantly improved at a relative high temperature, while remarkably decreased in a weak alkaline or neutral solution and the application of anhydrous sodium sulfate or Peregal O under different flow states except for color uniformity. Meanwhile, less effect from laminar and transition flows on the surface morphologies and chemical structure of the silk was successfully achieved, while some alterations in the fiber surfaces and macrochain conformations, etc., were also observed in a turbulence flow along with a same situation in the mechanic properties of the colored silk. Moreover, less effects from the flow states on color fastness to soaping and rubbing of the colored silk were also observed by achieving grade 4 or above. The results further indicate that an appropriate flow state control in coloration solution not only can achieve high coloration efficiency and performance on silk, but also can protect the fiber and reduce the applications of coloration auxiliaries to perform a much greener and more efficient coloration in textile industry.