Optical fiber cable core manufacture for information transmission involves extrusion of a PBT cover around optical fibers and filling with thixotropic gel, the process parameters being specified

摘要

Optical fibers are fed into an extruder head and enclosed in a polybutyleneterephthalate cover which is simultaneously filled with a thixotropic compound. During cover production fibers are stretched. Processing temperature of the PBT is 245-275 deg C and of the gel 30-80 deg C. Extrudate is cooled to /}15 deg C and fiber haul off force is 50-200cN, preferably 110cN. 2-24 optical fibers (1), 1000-8000mm long are fed into an extruder head and enclosed in a polybutyleneterephthalate (PBT) cover (2) which is simultaneously filled with a thixotropic compound. During cover production fibers are stretched to 5-12, preferably 11(DDR value) and the equilibrium ratio is 0.9-1.3, preferably 1.2. Processing temperature of the PBT is 245-275degreesC and of the gel 30-80degreesC. Extrudate is cooled to not more than15degreesC and fiber haul off force is 50-200cN, preferably 110cN.