| 摘要 |
PURPOSE:To improve heat resistance by coating a protective coating layer via a buffer protective layer on an assemblage formed by assembling plural optical fibers each having a coating layer then heating the same to the max. temp. in use and forcing a theremosetting resin into the crack generated in the protective coating layer. CONSTITUTION:Plural pieces of optical fibers 2 each having a coating layer consisting of silicone or the like are assembled to form an assemblage. A buffer protective layer 3 consisting of silicone rubber, etc. is coated integrally on said assemblage into roughly a circular section thereby forming an integral buffer unit 6. On the other hand reinforcing fibers such as glass fibers are positioned so as to be disposed uniformly ground the unit 6 and a resin such as an unsatd. polyester resin is impregnated and is cured to form a protective coating layer 4. Such optical fiber unit 1 is heated up to about 400 deg.C which is the max. temp. anticipated as a composite optical overhead earth wire to generate a crack 5 in the brittle part of the layer 4 and thereafter a thermosetting resin 20 is coated and forced into the crank 5 and is thermally cured. |
