Subsea & Marine Cable Applications: Seawater-Blocking Tapes

Subsea and marine power cables require water-blocking materials that can function in high-salinity environments.

Standard superabsorbent polymers (SAPs) exhibit significantly reduced swelling capacity when exposed to the high ionic concentration of seawater, as the dissolved salts suppress the osmotic pressure required for fluid absorption.

Tianrong has developed a series of water-blocking tapes optimised for marine applications, designed to provide sufficient swelling volume under high-salinity conditions to help restrict longitudinal moisture migration.

1. Inside the Conductor (Core Interstitial Protection)

Featured Product: ZSD403 (Non-Conductive)

Application: This non-conductive tape layer is applied directly between stranded copper or aluminium wire layers during the core manufacturing process to arrest internal longitudinal water migration.

Technical Parameters: Engineered for high swelling performance in marine environments. While ionic salt concentrations inherently limit maximum absorption compared to fresh water, this tape provides a high expansion volume relative to standard water-blocking alternatives to establish an effective physical barrier.

2. Around the Conductor (Seawater-Blocking Binders)

Featured Product: BZBD300HF (Semi-Conductive)

Application: This semi-conductive tape serves as a structural core binder while functioning as an outer conductor water barrier.

Technical Parameters: Provides a rated tensile strength of approximately 280 N/cm to bind the stranded core layers, combined with active swelling performance to seal the conductor outer interstices upon contact with seawater.

3. On Top of the Cable Core or Around Triple Cores

Featured Products: BZSD301HL, BZSD480, BZSD600H, BZSD851

Application: These semi-conductive tapes are applied over the insulated core or around triple-core assemblies to provide water blocking function and mechanical bedding under subsea armour layers.

Technical Parameters: Available in thicknesses ranging from 0.30mm to 0.85mm. These grades retain the electrical conductivity, thermal stability, and pressure resistance properties of Tianrong’s standard semi-conductive line, combined with a swelling response calibrated for seawater conditions.

Engineered Solutions for Your Application

Every application has unique performance and manufacturing requirements. At Tianrong, we work closely with our customers to develop tailored cable material solutions designed to meet specific technical needs.

From customised specifications and material adjustments to application-focused solutions, our experienced team provides the expertise and flexibility needed to deliver the right product for your project.