Ribbon-type optical cable with skeleton

A skeleton-type ribbon optical cable features optical fiber ribbons placed in HDPE skeleton grooves, reinforced centrally, with water-blocking, metal or aramid layers, and an outer protective sheath.

Core Structure

The skeleton-type optical fiber ribbon cable is built around a central skeleton that contains multiple skeleton grooves arranged circumferentially. Each groove holds an optical fiber ribbon, allowing high-density fiber placement while maintaining a compact cable diameter . A central reinforcing element, such as a steel wire or aramid rod, provides mechanical strength and stability to the cable core .

Reinforcement and Sheathing

Surrounding the skeleton, the cable includes:

• Water-blocking tape to prevent moisture ingress .
• Metal tape (often double-coated aluminum) or aramid fiber layers for tensile strength and lateral pressure resistance .
• Outer sheath made of polyethylene (PE) or low-smoke zero-halogen (LSZH) material, sometimes with alternating reinforcing and sheath layers to enhance impact resistance and facilitate stripping during installation . The reinforcing layer is positioned above the skeleton grooves to protect the optical fiber ribbons effectively .

Key Features

• High fiber density with a small outer diameter, saving pipeline space .
• No filling grease, simplifying construction and environmental compliance .
• Good lateral pressure resistance and stable structure, suitable for indoor, outdoor, or dual-purpose applications .
• Convenient branching: optical fiber ribbons can be pulled out through branch windows without cutting the main cable, ideal for FTTH/FTTB deployments .

Manufacturing Considerations

The optical fiber ribbons are inserted into the skeleton grooves using specialized cabling machines that ensure precise placement and consistent spacing . The process avoids secondary coating operations, streamlining production and maintaining fiber integrity.

Applications

Skeleton-type ribbon optical cables are widely used in:

• FTTH (Fiber to the Home) and FTTB (Fiber to the Building) networks.
• Indoor and outdoor installations, including pipelines, overhead lines, and direct burial.
• High-density optical networks where space efficiency and easy branching are critical . This structure maximizes fiber utilization, reduces splicing requirements, and improves installation efficiency while maintaining mechanical and environmental protection.