Optical cable sheaths are commonly made from PVC, PE, LSZH, and specialized armored or flame-retardant materials, chosen based on environmental and safety requirements.

Common Sheath Materials

PVC (Polyvinyl Chloride) PVC is widely used for indoor optical cables due to its good chemical resistance, weathering resistance, low cost, and moderate flame retardancy. It is flexible and durable but produces dense smoke when burned, making it less environmentally friendly in fire scenarios . PE (Polyethylene) PE is often used for outdoor cables because of its excellent low-temperature resistance, UV resistance, chemical stability, and low water absorption. Variants include HDPE (high density) and MDPE (medium density), which provide additional rigidity and durability for direct burial or overhead installations . LSZH (Low Smoke Zero Halogen) LSZH sheaths are designed for fire safety, producing minimal smoke and no halogen gases when burned. They are commonly used in indoor environments where fire regulations are strict, such as data centers and public buildings . Flame-Retardant and Anti-Rodent Sheaths For hazardous environments like mines or tunnels, optical cables may use flame-retardant PE or armored sheaths. Anti-rodent sheaths incorporate aramid yarn or metal armor to prevent damage from animals, while flame-retardant materials reduce fire propagation . Other Specialized Materials Additional materials include PVDF, Plenum, Riser, rubber, silicone, PUR, PA, and PP, which are selected for extreme temperature tolerance, flexibility, oil resistance, or industrial applications .

Selection Considerations

The choice of sheath material depends on:

• Installation environment: indoor vs. outdoor, buried, overhead, or underwater
• Fire safety requirements: LSZH or flame-retardant materials for high-risk areas
• Mechanical protection: armored or rodent-resistant sheaths for tunnels or harsh conditions
• Chemical and UV exposure: PE or HDPE for outdoor durability
• Flexibility and handling: LDPE or specialized polymers for easier installation . In summary, optical cable sheaths are engineered to protect fibers from mechanical, chemical, and environmental damage while meeting fire safety and regulatory standards, with material selection tailored to the specific deployment scenario.