Temperature of optical cable sheath material

The forming temperature of optical cable sheaths typically ranges from 200°C to 370°C depending on the material and fire-resistance requirements.

Sheath Material Considerations

The outer sheath of an optical cable is made from materials such as LSZH (Low Smoke Zero Halogen), HDPE (High-Density Polyethylene), or LDPE (Low-Density Polyethylene), each with different thermal properties.

LSZ

H is commonly used for indoor applications where fire safety is critical, while HDPE and LDPE are preferred for outdoor or flexible applications. The forming temperature must be high enough to allow extrusion or molding but below the degradation point of the polymer.

Fire-

Resistant and Flame-Retardant CablesFor flame-retardant and fire-resistant optical cables, the temperature index of the sheath can reach up to 370°C, indicating the maximum temperature the material can withstand without significant degradation. During fire testing, these cables can endure short-term exposure to temperatures as high as 650–950°C with minimal impact on optical fiber attenuation, but these are extreme conditions rather than forming temperatures. Typical Forming Temperature RangesLSZH sheaths: 200–280°C for extrusion and molding, depending on the specific compound and additives.

HDP

E sheaths: 220–260°C, suitable for outdoor cable extrusion.

LDP

E sheaths: 180–220°C, offering flexibility but lower thermal resistance. Fire-resistant variants: Up to 370°C temperature index, allowing higher processing temperatures for specialized applications.

Practical Implications

When manufacturing optical cables, the forming temperature must be carefully controlled to avoid material degradation, loss of mechanical properties, or optical fiber damage. The exact temperature depends on the polymer type, additives, and whether the cable is designed for fire resistance or outdoor durability. Always consult the material datasheet or manufacturer guidelines for precise processing temperatures.