Extruded deposition of fiber reinforced polymers

A deposition fabrication method, comprising:

• establishing a pressurized stream of a first polymer through a tube, wherein the first polymer has a first melt temperature;
• entraining a carbon nanotube reinforcement within the pressurized stream, wherein the carbon nanotube reinforcement is pre-impregnated with a second polymer that has a second melt temperature, wherein the second melt temperature is less than the first melt temperature, and wherein entraining is performed above the first melt temperature but below the second melt temperature, and wherein entraining further comprises:
• feeding the carbon nanotube reinforcement into the tube, the tube being disposed inside an annular inlet of an entrainment barrel surrounding the tube, wherein the tube ends at an entrance to a capillary tube disposed inside the entrainment barrel;
• flowing the liquified polymer into the annular inlet and around the tube, including flowing the liquified polymer past the tube and into the capillary tube via a convergence region in which the liquified polymer is allowed to flow onto the carbon nanotube reinforcement just as the carbon nanotube reinforcement enters the capillary tube;
• and
• depositing a bead of the polymer and the carbon nanotube reinforcement from the tube onto a substrate.