How does outdoor covered optical cable resist UV aging and corrosion?
Publish Time: 2025-11-03
In modern communication network construction, optical cables often need to traverse complex indoor and outdoor environments. They must meet the flexibility and aesthetics of indoor cabling while withstanding the harsh tests of outdoor exposure to sunlight, rain, and extreme temperature changes. Ultraviolet (UV) radiation is one of the main factors causing aging, performance degradation, and even failure of optical cable materials. Prolonged exposure to sunlight can cause ordinary plastic sheaths to break molecular chains, become brittle, and crack, leaving the internal optical fibers unprotected and leading to signal attenuation or interruption. Outdoor covered optical cables, with their special structure and material formulation, successfully solve this problem. While achieving advantages such as small outer diameter, light weight, and high flexibility, they effectively resist UV aging and corrosion, making them an ideal choice for integrated indoor and outdoor cabling.1. UV-resistant outer sheath: The first line of defenseThe core of outdoor covered optical cable's UV resistance lies in its high-performance outer sheath material. It typically uses modified low-smoke halogen-free flame-retardant polyolefins or black high-density polyethylene, with the addition of highly efficient UV absorbers. These additives actively absorb or quench ultraviolet (UV) energy, converting it into harmless heat energy, thereby preventing the photo-oxidative degradation of polymer chains. The black sheath, in particular, contains carbon black, possessing naturally excellent UV resistance—carbon black particles can scatter and absorb over 95% of UV rays, forming a physical shielding layer. Therefore, even under prolonged exposure to strong sunlight, the optical cable sheath remains flexible, crack-free, and powder-free, ensuring structural integrity.2. "Covered" Structure: Multiple Protections for Synergistic EffectThe term "covered" does not refer to a literal movable cover, but rather to an enhanced protective layer structure in the optical cable, such as longitudinally wrapped aluminum-plastic composite tape, corrugated steel tape armor, or high-density braided layers. These structures not only improve pressure resistance and rodent resistance but also further isolate the internal materials from the influence of the external environment. For example, the aluminum-plastic composite tape combines waterproofing and UV reflection, reflecting some residual UV rays back, reducing the burden on the sheath layer; while the armor layer forms a physical barrier, ensuring that even if the outer sheath ages partially, the internal optical fibers remain tightly protected. This dual mechanism of "external resistance + internal protection" significantly extends the outdoor lifespan of the optical cable to over 20 years.3. Synergistic Material and Process Design: Balancing Protection and Construction PerformanceNotably, while enhancing UV resistance, this optical cable does not sacrifice its core advantages as an indoor cabling product: small outer diameter, light weight, high flexibility, and easy stripping. This is thanks to precise material formulation and extrusion process control. For example, the use of high-flow polyolefin base material ensures sufficient dispersion of UV-resistant additives while reducing sheath stiffness, resulting in a smaller bending radius and easier installation in confined spaces. Simultaneously, an easy-peel interface is designed between the sheath and the tight-packed layer, allowing for quick stripping without special tools during construction, significantly improving splicing efficiency.4. No Grease or Transition Box Required: Reducing Total Life Cycle CostsTraditional outdoor optical cables often require waterproof grease for moisture protection, but this grease contaminates the fiber end face, increasing cleaning difficulty and connection loss. This outdoor covered optical cable, however, uses a dry water-blocking structure combined with a tight-packed fiber design, achieving "grease-free and cleaning-free" operation. More importantly, its tightly packed fiber can be directly connected to equipment ports without the need for additional pigtails or transition junction boxes, reducing signal attenuation points and significantly lowering material and labor costs. This "plug-and-play" characteristic allows it to be used for outdoor ground connections and overhead laying, as well as seamlessly extended to indoor cabinets and instrument panels, truly achieving "one cable to the end."The outdoor covered optical cable, through the deep integration of UV-resistant material formulations, multi-layered protective structures, and advanced manufacturing processes, resists UV aging while also ensuring lightweight, flexibility, and ease of installation. It breaks down the traditional clear-cut distinction between indoor and outdoor optical cables, reducing deployment complexity and maintenance costs with an integrated design, providing a solid foundation for building efficient, reliable, and green all-optical networks.
