Comparison of industrial processabilities of cellulosic raw materials for lyocell textiles

Abstract The lyocell process is regarded as a sustainable industrial technology for producing regenerated cellulosic fibers and its production capacity has been expanded significantly in recent years. Although fibers are currently spun mostly from dissolving-grade pulp, the lyocell process has the potential to utilize a wide range of cellulose-based raw materials due to the dissolution power of N -methylmorpholine N -oxide (NMMO) monohydrate. This work assesses the suitability of different cellulose-based raw materials for the NMMO-lyocell technology with an emphasis on industrial processability. Selected raw materials were tested for their solubility in NMMO, and the resulting solutions (dopes) were thoroughly analyzed, emphasizing rheological behavior as a basis for assessing their potential spinnability in the lyocell process. Subsequently, dopes derived from different pulp samples were spun into fibers using a monofilament dry-jet wet spinning unit, and the fiber properties were analyzed. This work specifically addresses the influence of the hemicellulose content and wood type (hardwood vs softwood) on the spinning performance and the fiber properties. The insights gained in this study contribute to the understanding of the correlation between pulp composition, spinnability and mechanical properties of lyocell fibers, promoting the use of various cellulose sources. Graphical abstract