Method and apparatus for co-extruding a tube and a gel filler around a fiber optic strand

摘要

A method and apparatus (1) for extrusion-moulding a loose tube (11) filled with gel (7) having an optical fibre (5) therein is disclosed. The extrusion-moulding apparatus includes an extrusion head (3) that includes a tip (13) and a die (15) concentrically arranged there within. A tube is extruded between the tip and the die. A needle (9) feeds at least one optical fibre and filler to be filled around the optical fibre into the tube. The method comprises passing the optical fibre through a bundling hole to bundle the optical fibre at an almost centre of the tube, the bundling hole being formed at a centre of a bundling member (23) provided within the needle. The bundling member has an inner diameter smaller than an inner diameter of the tube. Passing the filler through a flow path (19), the filler fills around the optical fibre, the flow path being provided between the bundling hole and an inner circumferential surface of the needle. The bundling member prevents the optical fibre contacting with the still molten tube.