| 摘要 |
PURPOSE:To obtain stably and efficiently a fiber-reinforced optical fiber having excellent bending characteristic by extruding radially a molten thermoplastic resin to coat the same on the outside circumference of a reinforcing fiber bundle led from a forming nozzle and introducing the coated fiber bundle into a heat treating tank under pressure after cooling. CONSTITUTION:A fiber strand 2 is drawn continuously from a bobbin 1 and is supplied. Many glass fiber bundles 4 are continuously drawn from bobbins 3 separate from the bobbin 1 and are supplied. The bundles 4 are passed through the inside of a tank 5 contg. an uncured thermosetting resin so that the thermosetting resin is impregnated in the bundles 4. The inlet part of a preforming nozzle 9 opens on the same horizontal line as a central hole 6 in front of a guiding plate 8 and the bundles 4 passing through the circular hole 7 are radially converted in the inlet part of the nozzle 9 so as to enclose the strand 2 and enters the nozzle 9. As a result the fiber-reinforced fiber which has the thermosetting resin layer on the outside circumference of the strand 2 and is positioned annularly with the bundles 4 impregnated with the resin on the outside circumference thereof is obtd. |
