| 摘要 |
PURPOSE:To mold stably hollow optical fiber having improved fiber hollow molding properties, and especially large diameter and a small thickness, by making the pressure in a spinning furnace lower than the inner pressure of quartz tube, and carrying out spinning. CONSTITUTION:The quartz tube 1 is gradually sent to the spinning furnace 2 kept at about 1,800-2,000, and wound by the winder 5 to give the hollow fiber 4. In the operation, the outer diameter of the fiber is controlled by regulating the winding speed of the winder 5 depending upon the measured result of the instrument 6 for outer diameter of the fiber. The inner diameter of the fiber is controlled by driving the reduced pressure regulator 9 depending upon the measured result of the instrument 7 for inner diameter of the fiber and regulating the degree of reduced pressure in the spinning furnace 2. The prepared hollow fiber 4 is provided with a resin, metal, etc., as a reinforcing layer by the coater 8. Since spinning is carried out by reducing the pressure in the furnace 2 to a given degree of reduced pressure lower than the pressure (atmospheric pressure) in the quartz tube 1, the hollow fiber having improved fiber hollow molding properties, especially large diameter and small thickness can be stably molded. |
