Extruder for a system for the additive manufacture of metal parts using the composite extrusion modeling (cem) method

An extruder for a system for the additive manufacture of freely formable metal parts with or without a supporting structure by means of an extrusion method from a composite material, which is arranged on a three-dimensionally movable kinematic mechanism, with a building platform, wherein the extruder consists of a housing and a screw arranged in the housing and wherein the extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable die, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material, wherein the housing is divided into a

• feed zone with active cooling, in which the housing is designed as a funnel and the material of the housing consists of a material with good thermal conductivity, wherein the screw has a small shaft diameter,
• separating zone, in which the housing consists of a material with poor thermal conductivity and separates the cooled feed zone thermally from the heated plasticating and homogenizing zone,
• plasticating and homogenizing zone, in which the housing consists of material with good thermal conductivity and is connected to active heating, wherein the screw has a greater shaft diameter than in the upper zones,
• and
• discharge zone, which consists of an exchangeable die of an abrasion-resistant material.