Screw extruder for continuous extrusion of materials with high viscosity

摘要

A screw extruder for the continuous extrusion of materials with high viscosity, in particular metals such as aluminum and its alloys. The extruder includes an Archimedes screw (1) rotationally provided within a liner (2) of a screw housing (4) having 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 extruded product (7). The required compaction takes place at the down-stream end of the screw towards the extrusion chamber (5) corresponding to up to 540° of the rotation of the screw, or up to 1.5 turns of the screw flight length. The solid plug of metal formed at the end of the screw and extrusion chamber (5) is restricted from rigid rotation to obtain the required compaction and extrusion pressure.

主权项

1. A screw extruder system for the continuous extrusion of high viscosity metal, the screw extruder system comprising:
a metal to be extruded; a screw housing including an inner liner and an inlet formed in an upstream end of the screw housing for feeding the metal to be extruded; an Archimedes screw transporting the metal, the Archimedes screw being rotationally provided within the liner of the screw housing; an extrusion die assembly including a die configured to shape the extruded product; and an extrusion chamber formed between a downstream end of the screw and the extrusion die assembly, wherein the screw and inner liner define a compaction zone at a downstream part of the screw towards the extrusion chamber such that compaction of the metal takes place in the compaction zone, wherein the compaction zone corresponds to up to 540° of the rotation of the screw, or up to 1.5 turns of the screw flight length, and wherein a required compaction and extrusion pressure is obtained by the compacted metal in the compaction zone and a solid plug of metal in the extrusion chamber is restricted from rigid rotation.