Lightweight and flexible impact resistant power cable and process for producing it

Process for producing an impact resistant multipolar power cable comprising a plurality of cores, each core comprising at least one conductive element and an electrical insulating layer in a position radially external to the at least one conductive element, the cores being stranded together so as to form an assembled element providing a plurality of interstitial zones;

• an expanded polymeric filler filling the interstitial zones;
• an impact resistant layer in a position radially external to and in contact with the expanded polymeric filler;
• and a solid polymeric jacket surrounding the impact resistant layer, the processing comprising:
• a) providing to an extruder a first polymer material with a shore D hardness ranging from 30 to 70, a flexural modulus of from 50 MPa to 1500 MPa at 23° C., and a LOI of from 27 to 95% for producing the expanded polymeric filler;
• b) providing to an extruder a second polymer material for producing the impact resistant layer, said second polymer having a flexural modulus greater than that of the first polymer;
• c) adding a foaming agent to the first and second polymer material, the foaming agent for at least the first polymer being thermally expandable microspheres;
• d) triggering the foaming agent of the first and second polymer material to expand the relevant polymer;
• e) coextruding the expanded first and second polymer material to form the polymeric filler filling the interstitial zones and the impact resistant layer;
• and
• f) extruding a solid polymeric jacket around the impact resistant layer.