| 摘要 |
<p>A loose-type extruder comprises an extruder head incorporating a nipple and a die arranged concentrically and extruding a tube from between the nipple and the die, a needle for feeding an optical fiber and a filler for filling the outside of the optical fiber into the extruded tube, and a tubular concentration member arranged in the needle. The concentration member has a concentration hole which can pass an optical fiber having a diameter smaller than the inside diameter of the tube in the center, and has a channel penetrating along the feeding direction of the filler between the concentration hole and the inner circumferential surface of the needle. In an extrusion method employing that extruder, the optical fibers are passed through the concentration hole and concentrated at the substantially central position of the tube. Furthermore, the periphery of the optical fiber is filled with the filler by passing the filler through the channel.</p> |
