Method for manufacturing an electric cable by extruding a composition based on a thermoplastic polymer, a dielectric liquid and uniformly distributed nanofillers

A method for manufacturing an electric cable comprising at least one elongate electrically conducting element and at least one extruded thermoplastic layer surrounding said elongate electrically conducting element, said method implementing a device comprising at least one extruder containing a barrel, a barrier screw and an extrusion head, wherein said method comprises at least the following steps:

• i) a step of mixing an extrusion composition comprising at least one thermoplastic polymer in the form of solid particles, a dielectric liquid and at least one nanofiller,
• ii) a step of introducing said extrusion composition into a feed zone of the barrier screw which zone is situated at the inlet of the extruder, and
• iii) a step of applying the extrusion composition coming from step ii) around the elongate electrically conducting element at the head of the extruder,
• wherein the mixing step i) comprises a step of premixing the dielectric liquid with said at least one nanofiller to obtain an intermediate composition which is then mixed with said at least one thermoplastic polymer in order to obtain the extrusion composition.