Extrusion system for additive manufacturing and 3-d printing

This is a 3D printer that builds objects layer by layer using a screw-based extruder. Instead of melting plastic filament, it uses a rotating screw inside a barrel to push and process various materials like plastics, metals, or composites. This processed material is then forced through a nozzle onto a moving platform, with a computer controlling the precise movements to create the desired shape. The claims specifically describe a screw with a compression zone that changes diameter.