Conductive Butyl Rubber Buffer Tape for Corrosion-Free Cable Water Blocking

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Solution Overview

Problem

Existing water-blocking buffer tapes in high-voltage cables form high-resistance crystalline substances that cause electrochemical corrosion and electrolysis, leading to cable ablation and breakdown due to the inclusion of water-blocking powder.

Innovation Solution

A water-blocking buffer tape composed of a vulcanized butyl rubber substrate with dispersed conductive carbon black and a conductive metal film layer, which eliminates the need for water-blocking powder and enhances conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water-blocking powder is added to the buffer layer, then water-blocking performance is improved, but high-resistance crystalline substances form causing electrochemical corrosion and electrolysis

Engineering Contradiction:
Improvewater-blocking performanceVSAvoidelectrochemical corrosion and electrolysis
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes water-blocking powder from the buffer layer composition entirely, extracting the harmful substance that causes high-resistance crystalline formation. The buffer layer consists only of polyethylene and crosslinking catalyst without any water-blocking additives, thereby eliminating the source of electrochemical corrosion while maintaining water-blocking functionality through the inherent properties of the polyethylene matrix.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters of the buffer layer by eliminating water-blocking powder and using only polyethylene with crosslinking catalyst. This parameter change transforms the material from one that forms high-resistance crystals to one that maintains low resistance and prevents electrochemical reactions, resolving the contradiction between water-blocking performance and corrosion prevention.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional water-blocking buffer tape is used, then water-blocking function is achieved, but cable ablation and breakdown occur due to heat generation

Engineering Contradiction:
Improvewater-blocking functionVSAvoidtemperature rise leading to ablation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent extracts and removes water-blocking powder from the buffer layer composition, eliminating the substance that generates heat through electrochemical reactions. The resulting buffer layer made purely of polyethylene and crosslinking catalyst does not produce heat, preventing temperature rise and subsequent cable ablation while maintaining water-blocking functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful effect of water-blocking powder (heat generation and corrosion) into a beneficial outcome by completely eliminating the powder. The buffer layer achieves water-blocking performance through the natural hydrophobic properties of polyethylene without the harmful side effects, turning a potentially harmful material system into a safe and effective one.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The tape provides excellent air tightness, electrical insulation, thermal stability, and corrosion resistance, ensuring uniform electric field distribution and preventing cable ablation and breakdown.

Implementation Method 1

The conductive carbon black is evenly distributed in the rubber substrate to play a conductive role

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

the conductive metal film layer is deposited on the rubber substrate by magnetron sputtering

Methodology Applied
Scientific EffectMagnetron sputtering: Sputtering

Implementation Method 3

the conductive metal film layer is deposited on the rubber substrate by magnetron sputtering

Methodology Applied
Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Implementation Method 4

The butyl rubber has excellent air tightness, good electrical insulation, good thermal stability and chemical stability, and has good waterproofness

Methodology Applied
Scientific EffectHydrophobicity: Hydrophobe

Data Source

PatentEP4610299A1Water-blocking buffer tape for cable and method for preparing the same
Publication Date: 2025.09.03 GUANGZHOU POWER SUPPLY BUREAU GUANGDONG POWER GRID CO LTD
  • EP4610299A1 patent drawingFigure 1~2
  • EP4610299A1 patent drawingFigure 3~4
  • EP4610299A1 patent drawingFigure 5

AI summary

The present application relates to a water-blocking buffer tape for a cable and a method for preparing the same. A water-blocking buffer tape for a cable includes a rubber substrate and a conductive metal film layer covering a surface of the rubber substrate; wherein the rubber substrate includes vulcanized butyl rubber and conductive carbon black dispersed in the vulcanized butyl rubber.