Silicon Core Tube Optical Cable Laying Process

Silicon core tubes provide low-friction, durable conduits for optical cables, enabling efficient installation and repeated cable extraction without damage.

Composition and Structure

Silicon core tubes are typically made with a high-density polyethylene (HDPE) outer and middle layer and a silicone-based inner layer that acts as a solid lubricant. The inner silicone layer significantly reduces friction, allowing optical cables to be pulled or blown through long distances with minimal resistance. The preferred material composition includes HDPE (95–100%), silicone (2.

5–3. 5%), active silicone oil (5–8%), dimethyl silicone oil (6–10%), initiating agents (0. 5–1.

5%), and antioxidants (1. 5–2. 5%),.

This combination ensures heat resistance, durability, and repeated cable extraction capability.

Manufacturing Process

The tubes are produced using a three-layer co-extrusion process, where HDPE and silicone are heated and extruded simultaneously through independent extruders. A precise metering system ensures uniform layer thickness and adhesion, preventing peeling or uneven lubrication. The silicone layer forms a permanent, low-friction inner surface that remains effective throughout the tube's lifespan.

Advantages for Cable Laying

Low Friction: The silicone inner layer has a friction coefficient as low as 0. 142, reducing labor intensity and allowing cables to be pulled or blown efficiently. Durability: The HDPE outer layers provide mechanical strength, weather resistance, and pressure resistance, protecting the cable from external damage.

Reusability: Cables can be repeatedly extracted and reinserted without damaging the tube or the cable. Ease of Installation: Tubes can rotate within the outer casing, simplifying cable insertion and reducing construction time and costs.

Installation Methods

Silicon core tubes are commonly used in pipeline (underground) installations. Optical cables can be laid using air-blown techniques, where compressed air suspends the cable inside the tube, allowing it to travel long distances efficiently. Tubes are often installed in urban pipelines, long-distance wild pipelines, or microduct systems along highways and railways.

Typical tube diameters range from 32mm to 40mm, with section lengths around 980 meters for long-distance pipelines.

Practical Considerations

Ensure proper alignment and minimal bends to maintain low friction. Use compatible cable blowing machines to optimize air flow and cable transport. Regular inspection of tube integrity is recommended to prevent blockages or damage during repeated cable insertions.

Silicon core tubes represent a modern, efficient solution for optical cable deployment, combining material science and engineering precision to improve installation speed, reduce labor, and extend the operational life of optical networks.