Patent ID: 7993568
Filing Date: 2011-08-09
Classification: H01B,Y10T

Abstract:
1. A method for manufacturing an insulation by extrusion process, said method comprising the steps of: providing a molten polymer, said polymer being formed into an insulation in a polymer chamber within an extrusion die, said extrusion die maintaining an extrusion tip therewithin, the polymer chamber being formed between an inside wall of said extrusion die and said extrusion tip; said polymer flowing around at least one air chamber, each held in place and coupled to the outside of said extrusion die by a fin radially extending inwards from air vents formed through said die towards said extrusion tip, in said polymer chamber; choking the air in said at least one air chamber; and forming a profiled insulation having at least one collapsed cavity extending along the full length of said insulation, that corresponds to the location of said air chamber.