| 摘要 |
PURPOSE:To prevent generation of air bubbles in case of coating and to prevent degradation of the transmission characteristic of each optical fiber strand by heating optical fiber strands with a heater before extrusion coating of a protective layer. CONSTITUTION:Optical fiber strands 1... which are supplied from bobbins 3... and are coated with a resin hardened by ultraviolet rays are arranged and gathered by a mouth piece 4. Before extrusion coating of a protective layer 2 consisting of a polyethylene, a polypropylene, nylon, or the like, individual arranged and gathered optical fiber strands 1... are heated by a heater 5. Moisture absorbed in the resin hardened by ultraviolet rays which forms coatings of individual optical fiber strands 1... is evaporated, and the protective layer 2 is coated by an extrusion coating machine 6. Thereafter, the optical fiber is cooled by a cooling water tank 7 and is wound through a drawing machine 8 by a winder 9. |
