Production of 24-core ADSS optical cable

24-core ADSS optical cables are manufactured as all-dielectric, self-supporting fiber optic cables designed for aerial deployment, using aramid yarns, loose tube fibers, and protective sheaths to ensure tensile strength and environmental resilience.

Cable Structure and Materials

A 24-core ADSS cable contains 24 individual optical fibers arranged in loose tubes, typically with 6 fibers per tube, filled with a water-blocking gel to prevent moisture ingress. The fibers are usually single-mode ITU-T G. 652.

D, ensuring high signal integrity and low attenuation. The loose tubes are stranded around a central strength member, which can be aramid yarn or fiberglass rods, providing tensile strength without using metallic components. This all-dielectric design makes the cable immune to electromagnetic interference and lightning strikes, ideal for installation near high-voltage power lines.

Reinforcement and Sheathing

The cable is reinforced with two layers of aramid fibers, twisted bidirectionally to enhance tensile performance and resistance to mechanical stress from wind, ice, and temperature fluctuations. The outer protective layer is typically high-density polyethylene (HDPE) or a tracking-resistant sheath for high-voltage environments, while some designs include a double-jacket system with an inner low-friction layer to reduce installation stress. This ensures durability and long-term reliability in harsh outdoor conditions.

Manufacturing Process

Fiber Preparation: Optical fibers are coated and tested for quality. Loose Tube Formation: Fibers are inserted into gel-filled loose tubes. Stranding: Loose tubes are stranded around the central strength member in an S-Z pattern to maintain flexibility and minimize strain.

Reinforcement: Aramid yarns or fiberglass rods are applied for tensile strength. Sheath Extrusion: The outer polyethylene or tracking-resistant sheath is extruded over the reinforced core. Quality Testing: Finished cables undergo tensile, environmental, and water-blocking tests to meet standards such as IEC 60794, TIA/EIA, ISO9001, and IEEE.

Applications and Advantages

The 24-core ADSS cable is suitable for overhead installation on transmission lines (35kV to 220kV), spanning long distances without intermediate supports, often exceeding 1000 meters. Its lightweight, small diameter, and high tensile strength reduce load on towers and simplify installation. The cable supports broadband, enterprise connectivity, smart grid monitoring, and surveillance systems, making it ideal for remote or challenging terrains.

Production Capacity and Delivery

Manufacturers like ZTO and GL Fiber report production capacities of millions of kilometers per year, with typical drum lengths of 3–4 km. Production cycles range from 2–3 weeks, depending on quantity and customization requirements. Quality control is maintained throughout the process, from raw material testing to final product inspection, ensuring compliance with international standards.