| 摘要 |
In the manufacture of optical fibre cable a secondary coating such as a Nylon material is applied by extrusion to the optical fibre by pulling the fibre through an extruder crosshead (12) and along a cooling air path. Obtaining adequate cooling while providing for a reasonable production rate is difficult without needing an excessively long air path. In the present arrangement the above desiderata are achieved by passing the coated fibre through three cooling rings (13, 15, 16) spaced along the fibre's air path. The second ring is further from the first ring than the first ring is from the crosshead, and the third ring is further from the second ring than the second ring is from the first ring. Each cooling ring preferably has a bore of Venturi form, to enhance the air cooling effect. <IMAGE> |
