Screw extruder for continuous extrusion of materials with high viscosity

Abstract

Screw extruder for the continuous extrusion of materials with high viscosity, in particular metals such as aluminium and its alloys. The extruder includes an Archimedes screw (1) rotationally provided within liner (2) of a screw housing (4) with an inlet (11) for the feeding of the material to be extruded, a compacting or extrusion chamber (5) and an extrusion die assembly with a die (6) which forms the shape of the desired extruded product (7). The design of the screw (1) and liner (2) is such that the required compaction takes place at the down-stream end of the screw towards the extrusion chamber (5) corresponding to up to 540 DEG of the rotation of the screw, or up to 1.5 turn of the screw flight length, and that the solid plug of metal thus formed at the end of the screw and extrusion chamber (5) is restricted from rigid rotation to obtain the required compaction and extrusion pressure.

Description

technical field

[0001] The present invention relates to a screw extruder for continuously extruding materials with high viscosity, especially metals such as aluminum and its alloys, the extruder comprising: Archimedes screw , disposed in a screw housing having an inlet for feeding material to be extruded; a pressing or extrusion chamber; and an extrusion die assembly having a die forming the shape of the desired extruded product. Background technique

[0002] Extrusion of materials with high viscosity, such as aluminum, requires relatively high pressures, typically 100 to 500 MPa, to force the aluminum through the die block and die. Regarding the state of the art in aluminum extrusion, ram extrusion dominates today and for the last 100 years. Punch extrusion is a batch process in which a billet is loaded into a container and forced (pressurized) through a die by means of a moving piston. A noteworthy method for continuous extrusion of aluminum is the so-called process, w...

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