Method for extrusion-molding loose tube and apparatus therefor, and loose tube

Abstract

An extrusion-molding apparatus for a loose tube includes: an extrusion head that includes a tip and a die concentrically arranged therewithin and extrudes a tube between the tip and the die; a needle that feeds at least one optical fiber and filler to be filled around the optical fiber into the tube being extrusion-molded; and a cylindrical bundling member provided within the needle. The bundling member has a bundling hole being smaller than an inner diameter of the tube at a center thereof and into which the optical fiber can pass through, and a flow pass penetrating along a feeding direction of the filler between the bundling hole and an inner circumferential surface of the needle. In an extrusion molding method using the extrusion-molding apparatus, the optical fiber is passed through a bundling hole to be bundled at an almost center of the tube. In addition, filler is passed through a flow path to be filled around the optical fiber.

Dependencies are inferred from the claim text.