Hybrid Co-Extrusion of Continuous/Short Fibers for High-Rate, Structural-Performance AM

Additive manufacturing with short-fiber-reinforced thermoplastics enables high deposition rates (>100 kg/h) but yields limited strength. By contrast, continuous-fiber printing delivers superior mechanical performance at much lower rates ( < 0.5 kg/h). To bridge this gap, we developed a hybrid co-extrusion process that targets semi-structural properties by combining the throughput of short-fiber systems with the strength of continuous-fiber reinforcement. In this approach, a suspension of short fibers in a molten polymer is co-extruded alongside a filament of continuous fibers pre-impregnated with a polymer compatible with the short-fiber matrix. Tensile specimens were fabricated from the hybrid material and from the short-fiber system alone to quantify strength gains attributable to the hybrid preform. Preliminary tensile tests indicate substantial increases in tensile strength relative to the short-fiber baseline. These findings position hybrid printing as a practical pathway to balance deposition efficiency and structural performance for semi-structural components.