The invention relates to a screw extruder (29) having a housing (30) comprising an intake housing (4), a degassing housing (5), and at least one housing bore (21, 22) running in the interior of the degassing housing (5) and implementing at least one internal wall segment (25; 26; 27; 28) of the degassing housing (5) and serving for receiving at least one auger shaft (7), and wherein the at least one wall segment (25; 26; 27; 28) of the at least one housing bore (21, 22) comprises at least one partition wall (13, 33) protruding into the at least one housing bore (21, 22) in the region of the degassing housing (5), and wherein at least one filter element (8) is disposed in the interior of the degassing housing (5) and at least partially encompasses the at least one auger shaft (7) and bears on the partition wall (13) in regions for implementing at least two spatial pressure regions (11, 12) sealed off from each other.

It is provided 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. The extruder consists of a housing and a screw arranged in the housing. The extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable nozzle, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material.

It is provided 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. The extruder consists of a housing and a screw arranged in the housing. The extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable nozzle, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material.

It is provided 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. The extruder consists of a housing and a screw arranged in the housing. The extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable nozzle, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material.

It is provided 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. The extruder consists of a housing and a screw arranged in the housing. The extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable nozzle, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material.

A single screw micro-extruder for a 3D printer includes a feed chamber with an opening for receiving solid plastic pellets. An extrusion barrel extends from the feed chamber and has an inner conically shaped bore between input and output ends. The bore has a mouth at the input end and an exit opening at the output end with a melt section therebetween. A rotatable screw is attached to a torque drive of the printer, and extends through the feed chamber and conical bore of the barrel. A constant or tapered diameter of the screw root core, from the input end toward the output end of the barrel, forms a decreasing channel root depth in a helical path for compression between a root core surface and an inner surface of the bore for pressurizing melt in the melt section of the barrel to exit an extrusion nozzle.

An apparatus and process to maintain control of the temperature of low-melting compounds, high melt flow polymers, and thermally sensitive materials for the pelletization of such materials. The addition of a cooling extruder, and a second melt cooler if desired, in advance of the die plate provides for regulation of the thermal, shear, and rheological characteristics of narrow melting-range materials and polymeric mixtures, formulations, dispersions or solutions. The apparatus and process can then be highly regulated to produce consistent, uniform pellets of low moisture content for these otherwise difficult materials to pelletize.

A method and an apparatus for extrusion of fiber-reinforced plastic material for the additive manufacture of a component is disclosed. The fiber-reinforced plastic material is supplied to the extrusion apparatus and heated in a heating zone of the extrusion apparatus in order to then supply the fiber-reinforced plastic material to an extrusion nozzle of the extrusion apparatus, at which a material thread comprising fiber-reinforced plastic material is extruded for the component to be manufactured. In order to convey the fiber-reinforced plastic material through the heating zone, a screw conveyor of the extrusion apparatus is utilized, which has a length-diameter ratio of less than a set value. In the heating zone a maximum volume is provided for the fiber-reinforced plastic material and a rotational speed of the screw conveyor is limited to a maximum of speed.

Polymeric Materials An injector (14) for injecting liquid formulation into molten polymer includes a conduit (117) having regions (44, 46) which are secured within a wall of an extruder (19). Conduit (117) includes an annular collar (120) having an upwardly facing annular surface (122) which is arranged to bear against part of a sleeve nut (124). Conduit (117) is arranged within a port (125) which includes a screw-threaded wall (126). The sleeve nut (124) includes a cylindrical body (146) having an inwardly facing cylindrical wall which is arranged to define a cylindrical air gap (148) between itself and an outer wall (147) of conduit (117). Region (150) of the sleeve nut is screw-threadedly engaged in wall (126) of the extruder. In use, cool compressed air is introduced into the assembly in the direction of arrow (170) and it flows through the assembly to cool it.

Polymeric Materials An injector (14) for injecting liquid formulation into molten polymer includes a conduit (117) having regions (44, 46) which are secured within a wall of an extruder (19). Conduit (117) includes an annular collar (120) having an upwardly facing annular surface (122) which is arranged to bear against part of a sleeve nut (124). Conduit (117) is arranged within a port (125) which includes a screw-threaded wall (126). The sleeve nut (124) includes a cylindrical body (146) having an inwardly facing cylindrical wall which is arranged to define a cylindrical air gap (148) between itself and an outer wall (147) of conduit (117). Region (150) of the sleeve nut is screw-threadedly engaged in wall (126) of the extruder. In use, cool compressed air is introduced into the assembly in the direction of arrow (170) and it flows through the assembly to cool it.