An extruder (5) for extruding an electric cable has an extrusion screw (7) arranged inside a barrel (6) and making it possible for the polymer to melt gradually in order to form an extrusion composition and for this composition to be transported along the extrusion screw (7). An extrusion head (8) is arranged at a distal end (21) of the extrusion screw (7) and configured to apply the composition around an elongated electrically conductive element. The at least one liquid injection channel (22) is formed through the barrel (6), the at least one injection channel (22) having at least one outlet orifice (30) emerging in a zone of the extrusion screw (7) in which the thermoplastic polymer is at least partially in the solid state.

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).

A method for manufacturing an electric cable includes a step of mixing an extrusion composition having at least one thermoplastic polymer in the form of solid particles, a dielectric liquid and at least one nanofiller, a step of introducing the extrusion composition into a feed zone of a barrier screw which zone is situated at the inlet of the extruder, and a step of applying the extrusion composition coming from the prior step around an elongate electrically conducting element at the head of the extruder. The mixing step includes a step of premixing the dielectric liquid with the at least one nanofiller to obtain an intermediate composition which is then mixed with the at least one thermoplastic polymer in order to obtain the extrusion composition.

The present invention relates to a screw for an extrusion molding machine and an injection molding machine that is adapted to be inserted into a cylinder to convey a molding material injected from a hopper and heated to a molten state by means of a heater, and more particularly, to a screw that includes a wide width spiral portion (15) formed on the frontmost end periphery of a spiral portion (12) of a screw shaft in such a manner as to have a spiral blade having a wide width to prevent shaking and to reduce friction and abrasion against the inner peripheral wall of the cylinder to ensure a longer term operation than the conventional screw.

An extruder mixer and extruder mixer section are provided. The extruder mixer section includes inlet and outlet channels and an intermediate channel separated by pumps and bound by a flight portion. Also provided are methods of mixing polymers with the extruder mixer section. An extrusion system using the extruder mixer section is also provided.

An extruder mixer and extruder mixer section are provided. The extruder mixer section includes inlet and outlet channels and an intermediate channel separated by pumps and bound by a flight portion. Also provided are methods of mixing polymers with the extruder mixer section. An extrusion system using the extruder mixer section is also provided.

A screw has a spiral blade for extruding and kneading a high-silica plastic elastomer containing not less than 100 phr of silica. The screw has a first section located on the most downstream side in the extrusion direction and provided with a barrier extending between the adjacent spiral blade threads, while inclining with respect to the screw axial direction. The length of the barrier is 1.5 to 3.0 times the lead length of the spiral blade in the first section. The height of the barrier is 2 to 10 mm lower than the height of the spiral blade. The barrier thickness is 0.9 to 3.0 times the height difference between the spiral blade and barrier.

A screw has a spiral blade for extruding and kneading a high-silica plastic elastomer containing not less than 100 phr of silica. The screw has a first section located on the most downstream side in the extrusion direction and provided with a barrier extending between the adjacent spiral blade threads, while inclining with respect to the screw axial direction. The length of the barrier is 1.5 to 3.0 times the lead length of the spiral blade in the first section. The height of the barrier is 2 to 10 mm lower than the height of the spiral blade. The barrier thickness is 0.9 to 3.0 times the height difference between the spiral blade and barrier.