| 摘要 |
PURPOSE: To prevent the deterioration of the tensile strength of the optical fiber by disposing ceramic spacers at parts where the oven body is close to a carbon member, in the drawing and heating furnace equipped with a stainless steel oven body and used for the optical fiber. CONSTITUTION: A carbon core pipe 5 is disposed in an oven 2 produced from stainless steel, and a carbon heater 4 is disposed on the outer periphery of the core pipe 5. A carbon heat-insulating material 3 is further disposed on the outer periphery of the heater 4 to produce the drawing and heating furnace for the optical fiber. Ceramic spacers 6 are disposed at parts where at least the oven body 2, the carbon member 5, etc., are close to each other. The optical fiber preform material 1 is introduced into the core pipe 5 from the upper end part and subsequently melt-drawn. Thereby, a phenomenon that the carbon member 5, etc., contact with the stainless steel of the oven body 2 to corrode the stainless steel and produce the fine particles of Cr and Cr carbide can be prevented. Thus, the adhesion of the fine particles to the surface of the optical fiber preform material 1 is not caused to prevent the deterioration of the strength of the optical fiber. |
