US Patent 10293591 Additive manufacturing techniques and systems to form composite materials

A printer system may include a coaxial extruder head that extrudes a core, a bulk, and/or a core and bulk cladding to form complex structures without retooling. The coaxial extruder head may include a distribution channel with an entrance and an exit, a priming chamber that surrounds the distribution channel. The priming chamber may include an outlet and a first inlet, a heating element thermally connected to the priming chamber, and a nozzle connected to the outlet of the priming chamber. Further, the nozzle may converge from the outlet of the priming chamber to an orifice of the nozzle. In addition, the exit of the distribution channel may be disposed at the orifice of the nozzle. This structure facilitates extruding a core and cladding type composite from the extruder head.