Polyolefin materials suitable for optical fiber cable components

摘要

Optical fiber cable components such as buffer tubes, filler rods, or jackets are produced using a thermoplastic polyolefin characterized by a high melt flow index. The use of material with a high melt flow index versus conventional "extrusion grade" materials which are characterized by a low melt flow index results in substantial improvements in buffer tube crystallinity and crystallization rates, improved buffer tube crush resistance, reduced post extrusion shrinkage, improved gel compatibility, and improved excess fiber length control. The advantages of using materials with a high melt flow index are most evident when processing thermoplastic materials such as nucleated copolymers of ethylene and propylene at high line speeds (shear rates) of over 50M/min.