What role does the FRP (fiberglass reinforced plastic) core play in optical cables?

Materials are fundamental to optical cables; without good materials, high-quality optical cables cannot be made. The structural strength of the optical cable reinforcing core is a crucial indicator of its mechanical performance. The reinforcing core plays a vital role in protecting the optical cable structurally, and as one of the structural components that fixes the cable, it plays a major role in enhancing the cable’s tensile and compressive strength.

Optical cable reinforcing cores are generally divided into metallic reinforcing cores and non-metallic reinforcing cores. Commonly used metallic reinforcing cores include single steel wires and steel strands. Commonly used non-metallic cores are fiber-reinforced plastics—glass fiber reinforced polymer (GFRP) and aramid fibers. GFRP is used in the cable core or on both sides of the cable core, while aramid fibers are used between the cable core and the sheath.

For non-metallic FRP reinforcing cores, the key to producing qualified FRP lies in the rational selection of reinforcing materials, substrates, and curing processes.

Tongnai Composites’ non-metallic FRP optical cable reinforcing cores are cylindrical rods formed by composite molding of resin as the substrate and glass fiber or aramid fiber as the reinforcing material. They are typically located at the center of the optical cable, with loose tubes and taut buffer fibers wound around the reinforcing core. FRP optical cable reinforcing cores combine the high performance of glass fiber and aramid fiber with a unique resin formula, resulting in a strong, high-energy, and economical optical cable reinforcement product.

Tongnai Composites’ FRP optical cable reinforcing cores are specifically designed for fully insulated optical cable applications. They have a smooth surface, extremely high dimensional stability, and have achieved long-distance (50km) seamless production, enabling continuous production of optical cables.

FRP optical cable reinforcing cores are insensitive to electrical shocks, avoiding interference from lightning strikes and strong electromagnetic fields, making them suitable for environments with frequent lightning and rain. Optical cables using KFRP (Knives-Fiber Reinforced Polymer) reinforcing cores can be installed close to power lines and equipment, unaffected by induced current interference from power lines or devices. Compared to metal cores, FRP reinforcing cores do not produce gases from the chemical reaction between metal and grease, thus avoiding impacts on fiber optic transmission performance. They also have a longer lifespan, higher tensile strength, and are lighter (approximately one-quarter the weight of steel wire), making them easier to process and lay.

FRP reinforcing cores offer significant advantages and are increasingly used in various optical cable products, including outdoor cables, indoor cables, FTTx drop cables, and power cables. They are also used in other telecommunications fields.