Patent ID: 9156200
Filing Date: 2015-10-13
Classification: B29C,Y10S

Abstract:
1. An extrusion facility for extruding a plastic sheath around a tubular structure, said facility comprising an extrusion screw configured and operable to supply a hot softened viscous plastic; wherein said viscous plastic supplied by said extrusion screw has, at constant temperature, a viscosity that varies from a value μ an extrusion head comprising an annular chamber having an inlet opening configured to receive said viscous plastic and a circular outlet, said extrusion head comprising a plurality of passages formed within said annular chamber, the plurality of passages are configured and operable to form a plurality of flows of viscous plastic and to cause said plurality of flows to converge toward one another in junction zones situated inside said annular chamber so as to form a sleeve of viscous plastic, said annular chamber and said circular outlet being configured and operable so that said sleeve of viscous plastic flows through said circular outlet to form said plastic sheath, said extrusion head and said outlet are configured to allow said tubular structure to pass through said extrusion head in order to receive said plastic sheath; and said facility further comprises a buffer chamber between said extrusion screw and said extrusion head configured and operable to store said viscous plastic at constant temperature for a given period and allow said viscous plastic to reach said viscosity value μ