Flame-Retardant Optical Cables

Flame-retardant optical cables are a type of special optical cable that uses special fire-retardant materials as sheaths and coverings. The core design goal is "no spread when exposed to fire and low hazard of combustion". They can suppress the spread of flames and reduce the release of toxic fumes and corrosive gases in fire or high-temperature scenarios, while maintaining optical signal transmission for a short period of time. They provide key support for personnel evacuation and emergency equipment handling and are widely used in scenarios with stringent fire safety requirements.

The core safety performance of flame-retardant optical cables stems from "special fire-retardant materials + layered sheathing structure," with each layer working together to achieve flame retardancy, protection, and light transmission:

1.Fiber core and buffer layer: The fiber core is made of quartz optical fiber (single-mode/multimode) or PMMA plastic optical fiber, ensuring basic optical transmission performance; the fiber core is wrapped with a buffer layer (mostly flame-retardant silicone or flame-retardant non-woven fabric) to absorb external impacts and simultaneously prevent the spread of flames to the fiber core.

2.Flame-retardant sheathing (critical layer): Utilizing special fire-retardant materials, common types and characteristics are as follows:
Low-smoke halogen-free flame-retardant polyolefin (LSZH): Free of halogens (chlorine, bromine), it produces low smoke density and releases no toxic gases (such as hydrogen chloride) during combustion. It has weak corrosiveness and is the mainstream choice for environmentally friendly flame-retardant optical cables, suitable for indoor, subway, hospital, and other densely populated environments.
 

3.Outer Sheath: Coordinated with the cladding material, it is typically made of flame-retardant PVC, low-smoke halogen-free flame-retardant PE, or armored flame-retardant sheath (such as flame-retardant stainless steel armor). This enhances the optical cable's tensile strength, abrasion resistance, and aging resistance, while also strengthening flame protection to prevent direct contact between external flames and the internal structure.