Extruder for extruding an electrically insulating layer comprising an extrusion screw having a liquid injection channel

Abstract

An extruder (5) for extruding an electric cable includes at least one elongated electrically conductive element and at least one extruded thermoplastic layer surrounding said elongated electrically conductive element. The extruder has a member (4) for feeding a polymer in solid form, a barrel (6) fed by the feed member, and an extrusion screw (7) arranged inside the barrel (6) and making it possible for the polymer to melt gradually to form an extrusion composition and for this composition to be transported along the extrusion screw (7) to a distal end (21) of the extrusion screw (7). The extrusion screw (7) extends along a longitudinal axis (A). The extrusion screw has a barrier zone having at least two threads with an extrusion head (8) arranged at a distal end (21) of the extrusion screw (7) and configured to apply the composition around an elongated electrically conductive element. At least one liquid injection channel (22) is formed in the extrusion screw (7). The at least one injection channel (22) emerging inside the barrel (7) level, with at least one outlet orifice (30) formed on an outer surface of the extrusion screw (7).

Dependencies are inferred from the claim text.