GB698717A - Method and apparatus for the extrusion of aluminium or other readily oxidizable metals - Google Patents

Abstract

698,717. Extruding. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET. Nov. 23, 1951 [March 28, 1951], No. 27503/51. Class 83 (iv). In a method of extruding aluminium and other readily oxidizable metals in a continuous-acting screw press the metal is freed from oxide, divided into small pieces and fed into the press in a vacuum or a protective gas while at a temperature below the melting-point of the metal. In a press 1 for sheathing a cable 19, heated aluminium wire 10 is fed to a vacuum chamber 9, severed into small pieces 17 by shears 16 and fed through a funnel 18 to the screw 2. The wire 10 is scalped by a die 12 to remove the oxide layer and passes through a drawing die 11 into the chamber 9 through which it is advanced by rolls 13 ... 15 to the shears 16. Alternatively the wire 10 may be fed directly to the screw 2 which cuts it into pieces. The wire may be heated by passing an electric current through it between the drawing die 11 and the roll 13. The screw 2 is rotated by a shaft 3 which may be cooled and is supported by ball-bearings 4, the inner space being sealed from the atmosphere by packing 5. In modifications the metal is cleaned by brushing or pickling in a chamber containing an inert gas through which the metal passes into the vacuum chamber. Alternatively the cut pieces 17 may be cleaned by stirring in the chamber 9, resulting in abrasive action.