Regenerated cellulose fibers are eco-friendly materials with excellent mechanical strength. Among regenerated cellulose fiber spinning processes, the Lyocell process is more sustainable than viscose because it uses a recyclable, non-toxic solvent (N-methylmorpholine N-oxide).
In this study, a commercial oxygen-bleached paper pulp was processed by Lyocell-based dry-jet wet spinning, and spinnability was evaluated by the spinning draw ratio, defined as the ratio of take-up speed to extrusion rate. The spinnability of this cost-effective paper-grade pulp was limited due to its high hemicellulose and lignin contents relative to fiber-grade pulp. To address this issue, softwood-derived lignin was additionally incorporated into the pulp, increasing the draw ratio from 9.2 to 48.2 and improving fiber strength from 2.3 to 4.3 gf/den. The fibers produced in this study will be applied as mobility composite reinforcements and as potential carbon-fiber precursors.