| 摘要 |
PURPOSE:To obtain an IR transmitting fiber low in transmission loss by working an ionic crystalline substance into a polycrystaline fiber, and heat treating this fiber at a temp. not growing the crystal particles or lower. CONSTITUTION:An ionic crystal substance 5 contained in a cylinder 1 is heated with a heater 4 to a prescribed temp., and extruded out of a die 2 by pushing a piston 3 through the inside of the cylinder 1 to work it into an IR transmitting polycrystalline fiber 6 a polycrystalline 6. The temp. to be heated with the heater 4 is controlled to a temp. lower than the m.p. of the substance 5, when it is, e.g. ionic crystalline substance KRS-5, to 200-300 deg.C lower than the m.p. of 414 deg.C. The fiber 6 is heat treated in a heating oven 7 below a temp. not growing a crystal particle diameter, but at normal temp. or higher to obtain an intended IR transmitting fiber. |
