An alkali-free method to manufacture ramie fiber

Ramie is one of the most important fiber resources and it needs the degumming process to produce fibers. The traditional manufacturing process of ramie fibers requires a large amount of alkali, which causes serious environmental issues. This paper provides a novel path to manufacture ramie fibers without alkali. In this study, ramie bast was pretreated by steam explosion and then treated with deep eutectic solvent. The properties of ramie fibers prepared by the novel alkali-free method, including physical properties, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD), were compared with that produced by the traditional alkali process. Results showed that the fiber qualities, including residual gum content (4.68%), average fiber fineness (1419.99 N _m ) and breaking tenacity (5.98 cN/dtex), were comparable with the traditional alkali process, which all meet the requirement of the relevant Chinese National Standards. The FTIR, SEM and XRD results all confirmed the degumming ability of the novel method to manufacture ramie fibers. Moreover, the novel method was proved to be eco-friendly. Taken together, these data indicate that the novel alkali-free method is green and effective in manufacturing ramie fibers.