| 摘要 |
PURPOSE:To substantially prevent running of water in a longitudinal direction even if a jacket is broken and water infiltrates the fiber cord and to provide excellent flexibility and the transmission characteristics over a long period of time by disposing a fiber mixture composed of high tensile strength plastic fibers and highly water absorbent fibers in the form of a layer on the outer periphery of coated optical fibers. CONSTITUTION:The fiber mixture 2 formed by mixing the highly water absorption fibers essentially consisting of water absorption acrylic fibers and the high tensile strength plastic fibers at (1:4) to (4:1) weight ratio is disposed in the form of the layer on the outer periphery of the coated optical fibers 1 and the plastic jacket 3 is provided thereon. The water absorption fibers disposed on the outer periphery gel while absorbing water and swelling simultaneously with the infiltration of the water, thus filling the gaps in the code and forming a water stopping dam. The expansion of the water infiltration in the longitudinal direction of the cable is, therefore, prevented. Since the water absorbent fibers consist essentially of the highly water absorptive acrylic resin fibers of a synthetic polymer system, the fibers are thermally stable. In addition, the decomposition of the fibers by microorganisms and the consequent generation of gaseous hydrogen, etc., are obviated. The transmission characteristic and water stopping property good over a long period of time are thus maintained. Further, the fibers are excellent in flexibility and the easy workability in production, connection, etc., is assured. |
