What is the material of the outer sheath of optical fiber cables

The outer sheath of optical fiber cables is typically made from materials such as Polyethylene (PE), High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polyvinyl Chloride (PVC), or Low Smoke Zero Halogen (LSZH), depending on environmental and safety requirements.Common Outer Sheath MaterialsPolyethylene (PE) and High-Density Polyethylene (HDPE) are widely used for outdoor fiber optic cables due to their excellent resistance to UV radiation, moisture, temperature fluctuations, and chemical corrosion. HDPE provides higher toughness and long-term durability in exposed environments, making it ideal for feeder and distribution cables outdoors, while LDPE offers more flexibility but is less suitable for harsh conditions . Low Smoke Zero Halogen (LSZH) is preferred for indoor installations where fire safety is critical. LSZH sheaths produce minimal smoke and no toxic halogen gases when burned, making them suitable for buildings and enclosed spaces with strict safety requirements . Polyvinyl Chloride (PVC) is another common material, offering good wear resistance, chemical resistance, and aging resistance. PVC is cost-effective and suitable for general indoor applications, but it releases dense smoke and toxic gases when burned, limiting its use in fire-sensitive environments . Specialized materials such as Polyurethane (PU) are used for underwater or submarine cables due to their excellent water, abrasion, and impact resistance. Thermoplastic Elastomers (TPE) or chemically resistant sheaths may be used in industrial environments exposed to oils, chemicals, or mechanical stress .Considerations for Sheath SelectionEnvironmental exposure: Outdoor cables require UV-resistant and weatherproof materials like PE or HDPE, while indoor cables prioritize fire safety with LSZH.Mechanical protection: Armored cables may require compatible sheath materials to protect against physical damage.Rodent resistance: Some sheaths include additional layers or additives to prevent rodent damage.Temperature and chemical resistance: Materials like PE and PU provide stability under extreme temperatures and chemical exposure . Choosing the appropriate outer sheath material ensures the optical fiber cable maintains its performance, durability, and safety throughout its service life.