METHOD FOR CONTROLLING OPTICAL FIBER DRAWING MACHINE

摘要

PURPOSE:To reduce waste fibers and shorten fiber drawing operation time, by setting a fiber drawing speed at a higher value than the set speed in the initial fiber drawing until the fiber outside diameter is stabilized in carrying out fiber drawing of an optical fiber at a set rod feed rate. CONSTITUTION:A rod 12 is fed to an optical fiber drawing machine 10 and fiber drawing is carried out by passing the rod 12 through a heating furnace 14, a die 18 and a coating heating furnace 20 at a rod feed rate (VR) expressed by the formula (Vf is the linear velocity of the optical fiber; D is the outside diameter of the rod; d is the outside diameter of the optical fiber) while measuring the outside diameter of the optical fiber 16 with a laser outside diameter measuring instrument 30. The resultant optical fiber 16 is then taken off by a capstan 22. In the process, the rod feed rate is temporarily set at a higher value than the rod feed rate (VR) expressed by the formula in the initial period of fiber drawing. After the given outside diameter of the optical fiber 16 is obtained, the fiber drawing is carried out at the rate (VR) expressed by the formula.