PURPOSE: To improve temp. dependency of transmission characteristics by forming a thermosetting resin layer reinforced with reinforcing fibers around an optical fiber core, and a plastic layer further around this outer circumference.
CONSTITUTION: After reinforcing resin fibers 9 of aromatic polyamide fibers or the like are impregnated with a thermosetting resin, such as unsatd. polyester in a resin impregnation vessel 1, an optical fiber core 8 subjected to primary coating steps till primary coating and buffer layer forming is introduced into said impregnated fibers 9, and located in the center of the fibers 9 in a preliminary formation device 2, and the resin is hardened by heating it in a UV hardening oven 3. This hardening stage is completed extremely rapidly in a time as short as 5W10sec. Further, they are passed through a resin vessel 4 contg. a thermosetting resin and hardening dice 5 to coat the outer circumference of the FRP layer with a thin thermosetting resin layer.
ISHIDA YUKINORI
KUKIDA JIYUUZOU
NIPPON TELEGRAPH & TELEPHONE
| JPS5782149A | 1982-05-22 | |||
| JPS5494052A | 1979-07-25 |
Next Patent: WATERTIGHT OPTICAL CABLE UNIT