DOUBLE-LAYER CO-EXTRUSION METHOD FOR EXTREMELY-TINY AIR BLOWN OPTICAL CABLE, AND EXTREMELY-TINY AIR BLOWN OPTICAL CABLE

摘要

A double-layer co-extrusion method for an extremely-tiny air blown optical cable. The method comprises the following processes: putting optical fibers in storage, coloring the optical fibers, coating for two times, carrying out SZ-stranding, and covering with an outer sheath. The process of coating for two times comprises: respectively drying and extruding a PC material and a PBT material by using different extrusion molding machine sets, and extruding an inner layer of a loose tube (2) by using the PC material and extruding an outer layer by using the PBT material by means of different material separating cones and runners in a machine head. The method adopts a double-layer co-extrusion technology of the PC material and the PBT material to prepare an extremely-tiny air blown optical cable, thereby enabling a loose tube (2) of the optical cable to have the advantages of two materials; furthermore, the method realizes the limit control for geometrical dimensions of the optical cable by accurately controlling technological parameters so as to reduce the external diameter of the optical cable to a theoretical minimum value; and the extremely-tiny air blown optical cable has the advantages of being high in intensity, small in cable diameter, light in mass, and the like.