Regenerated cellulose in additive manufacturing

Environmental concerns within the 3D printing industry have attracted interest in processing biodegradable, eco-friendly materials. Cellulose is the most abundant natural polymer on the planet. Cellulosic pulp, derived from biomass, can be dissolved in eco-friendly solvents such as N-methyl morpholine N-oxide (NMMO) to produce lyocell. Lyocell has had applications in the textile industry for the last decade. It has shown promise in producing high-quality cellulosic fibers and the ability to be altered, tailored, and manufactured with ease. Despite this, additive manufacturing using cellulose is still an area of research with ample room to grow. In this work, we propose an in-depth study of using lyocell to manufacture 3D-printed parts using an affordable desktop 3D-printer modification. The 3D printing process of lyocell is completely circular as the solvent can be recovered from 3D-printed parts. The design of the developed 3D printing equipment, the rheological properties, and the 3D printing of the cellulose-NMMO solution are discussed in this work. Extrudate swell, filament distortion and NMMO diffusion in the regeneration process were key experimental factors to control interlayer adhesion and 3D print quality.