A study on optical fiber cable sheath materials for multi-cable installation

摘要

With demand for optical access network increasing rapidly, multi-cable installation is means for effectively making use of the conduit line and using optical fibers efficiently. To realize this kind of installation, we have evaluated sheath materials with low friction. In this paper, we introduce our experiments on decreasing the friction by adding lubricants to sheath materials using the conventional linear low density polyethylene (L-LDPE) and high density polyethylene (HDPE) as the base polymers. We evaluated the reliability of lubricant added sheath materials and performed a test installment to a simulation conduit line. Lubricant evaluation results used in L-LDPF sheath materials showed that fatty acid amide lubricant was more effective than silicone. Because HDPE has a higher degree of crystallinity than L-LDPE, it is more durable against abrasion and therefore is a suitable material for multi-cable installation. Results of evaluation of the friction coefficient and the effect of lubricant showed that HDPE sheath materials with no lubricant had equal or superior friction coefficient than L-LDPE sheath materials added with the optimum amount of lubricant. With certain fatty acid amide lubricant, even though its effect was less than on L-LDPE, it was able to decrease friction in HDPE. We confirmed that both L-LDPE and HDPF added with lubricant had sufficient characteristics necessary for sheath materials. From the simulation conduit line having nominal diameter of 75mm, length of 50m, we obtained results which matched well with the sheet experiment. HDPE sheath materials are ideal for multi-cable installation as they have very low friction without the need of additives. They are also durable against abrasion and have superior mechanical characteristics, enabling very thin sheaths. Having no additives is also a merit for recycling the material.