Material of the outer sheath of optical cable

Common outer sheath materials for optical cables include PE, HDPE, PVC, LSZH, PU, and specialized armored or anti-rodent sheaths, chosen based on environmental and mechanical requirements.

Overview of Outer Sheath Functions

The outer sheath of an optical cable serves as the primary protective layer, shielding the internal fibers from mechanical damage, moisture, chemicals, UV radiation, and fire hazards. It also contributes to the cable's flexibility, tensile strength, and long-term durability in specific deployment environments.

Common Sheath Materials and Applications

Polyethylene (PE) / High-Density Polyethylene (HDPE): Widely used for outdoor installations due to excellent UV resistance, weather durability, low water absorption, and electrical insulation.

HDP

E is preferred for long-term outdoor exposure, while LDPE offers more flexibility but less toughness. Polyvinyl Chloride (PVC): Common for indoor and general-purpose cables, offering good chemical resistance, weathering resistance, and low cost.

PV

C is flame-retardant but produces dense smoke and halogens when burned, which can be hazardous. Low Smoke Zero Halogen (LSZH): Designed for indoor environments where fire safety is critical.

LSZ

H sheaths emit minimal smoke and no toxic halogens during combustion, making them suitable for data centers, tunnels, and public buildings. Polyurethane (PU): Used for submarine or underwater cables due to excellent water, abrasion, and impact resistance.

Flame-

Retardant P

E / AT Material: Modified PE with additives for high-voltage or flame-prone environments, providing anti-tracking and flame-retardant properties.

Anti-

Rodent or Armored Sheaths: For underground, tunnel, or industrial applications, sheaths may include aramid yarn, metallic armor, or chemical deterrents to prevent rodent damage and enhance mechanical protection.

Considerations for Selection

Environmental Conditions: Outdoor, indoor, industrial, or underwater environments dictate the choice of sheath material. Mechanical Protection: Armored cables require compatible outer sheaths to protect against physical damage. Fire Safety: Indoor cables often require LSZH or flame-retardant materials to meet building codes and minimize toxic emissions.

Chemical and U

V Resistance: Industrial or exposed outdoor cables benefit from PE, HDPE, or PVC with additives for chemical and UV resistance.

Summary

Selecting the right outer sheath material is crucial for cable longevity, safety, and performance.

PE and HDP

E are ideal for outdoor use, PVC for general indoor applications, LSZH for fire-sensitive areas, PU for underwater deployment, and specialized armored or anti-rodent sheaths for harsh or high-risk environments. The choice should align with environmental exposure, mechanical stress, and regulatory requirements.