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

An extruder for extruding an electric cable comprising at least one elongated electrically conductive element and at least one extruded thermoplastic layer surrounding said elongated electrically conductive element, said extruder comprising:

• a member for feeding a polymer in solid form,
• a barrel fed by the feed member,
• an extrusion screw arranged inside the barrel 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 to a distal end of the extrusion screw, said extrusion screw extending along a longitudinal axis, said extrusion screw comprising a barrier zone having at least two threads,
• an extrusion head arranged at a distal end of the extrusion screw and configured to apply the composition around an elongated electrically conductive element,
• wherein at least one channel for injecting a liquid is formed through the barrel, said at least one injection channel comprising at least one outlet orifice emerging in a zone of the extrusion screw in which the thermoplastic polymer is at least partially in the solid state.