HOLLOW PLASTIC OPTICAL FIBER AND ITS PRODUCTION

摘要

PURPOSE:To produce a hollow plastic optical fiber excellent in light transmitting ability and useful as a light guide. CONSTITUTION:A thermoplastic resin is filled into a bottomed cylindrical mold 1 with a core 1b protruded concentrically at the axis central part, vacuum defoaming treatment is carried out after heating to the melting temp. of the thermoplastic resin and the mold 1 is gradually cooled from the bottom in an inert gaseous atmosphere under pressure to solidify the molten thermoplastic resin. This solidified thermoplastic resin is released from the mold 1 and the resulting hollow preform is drawn. After or during this drawing, the periphery of the preform is coated with a cladding resin and then this resin is cured to obtain the objective hollow plastic optical fiber.