Improved Dyeing of Meta-aramid Based on Particle Flow Dyeing Mechanism Using Hot-pressing Dyeing Method

Abstract

In this study, a combined dyeing method by integrating the advantages of both carrier dyeing and hot-pressing dyeing was utilized for the dyeing of meta-aramid. A rapid dyeing with increased mechanical properties of the fibers was achieved for the meta-aramid fiber. A so-called particle flow mechanism involving both N,N-dimethylacetamide (DMAc) and dye molecules was proposed to explain the accelerating effect of this unique dyeing method. The mechanical properties and thermodynamic stability of the fiber after hot-pressing were both increased. XRD results showed increased corresponding fiber crystallinity. TEM showed that the disperse dyes were well dispersed in DMAc. Cross-sectional optical photographs of dyed fibers revealed that the dyes were successfully carried into the interior of the fiber under the synergic effect of temperature and pressure. Combined with hot-pressing dyeing, the dyeing cycle for the meta-aramid could be greatly shortened and the amounts of dyes and carriers could be significantly reduced.