Extrusion coating wire - by passing molten plastic transverse to advancement direction of wire

• Main Author: D.L. MYERS
• Format: Patent
• Language: English; French
• Published: 01.10.1973
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BASIC ELECTRIC ELEMENTS; CABLES; CONDUCTORS; ELECTRICITY; INSULATORS; PERFORMING OPERATIONS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

Plastic coating is extruded around a core, esp. an electric wire, advancing continuously through an extrusion chamber and an extrusion head, the stream of molten plastic material being forced in a transverse direction to the advancement of the core, by (a) incurving the plastic material into the direction of advancement of the core at a first predetermined radial distance from the core, (b) subdividing the incurved stream into a first series of separate partial streams distributed around the core at the first predetermined radial distance, (c) directing this first series of streams in the direction of the core, (d) subdividing into a second series of separate streams distributed around the core at a point closer to the axis of the core, and (e) reuniting the second series of partial streams in the extrusion head around the core. Uniform distribution of the plastic material around the wire is achieved, to form a uniform coating on the wire.