US Patent 11873582 Filaments for 3D printing

Presented herein are materials, methods, and systems for the improved 3D printing improved 3D printing of materials that include polypropylene. In some embodiments, the present disclosure provides a composite comprising a polymer matrix and a plurality of fibers for improved 3D printing. For example, the polymer matrix may have a composition that includes a polymer blend of polypropylene (PP) and polyethylene (PE) (e.g., high density polyethylene (HDPE), low density polyethylene (LDPE), linear low-density polyethylene (LLDPE)), impact modified polypropylene copolymer and/or polypropylene random copolymer with a plurality of fibers. In some embodiments, the plurality of fibers comprises cellulosic nanofibers (e.g., natural cellulosic nanofibers, e.g., cellulose nanofibrils). In some embodiments, filaments are prepared from the composites by melt compounding the polymer matrix (e.g., PP copolymers and/or PP/PE pellets) with a plurality of fibers and extruding the mixture.