Tin-Antimony Cable Sheath for Lead-Free Water Barrier Durability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional power cables use lead as a radial water barrier, which is toxic and environmentally harmful, and alternative tin-based solutions face durability issues due to tin pest, with antimony doping posing supply chain risks and performance challenges.

Innovation Solution

A power cable with a water barrier sheath made of a tin alloy containing less than 4 wt.% antimony, enhancing mechanical stability and processability while reducing supply chain disruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lead is used as water barrier sheath, then water barrier function and mechanical properties are achieved, but environmental toxicity and harmful effects occur

Engineering Contradiction:
Improvewater barrier functionVSAvoidenvironmental toxicity
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using tin-antimony alloy instead of pure lead, maintaining the water barrier function while eliminating environmental toxicity. The specific composition range (Sn-3-7wt%Sb) optimizes both protective function and environmental compatibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite alloy material (tin-antimony alloy) that combines the benefits of tin (low toxicity, good malleability) with antimony (pest resistance, mechanical strength) to replace pure lead while maintaining all required functions.

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If tin is used as water barrier sheath, then environmental friendliness and low toxicity are achieved, but durability deteriorates due to tin pest

Engineering Contradiction:
ImprovetoxicityVSAvoiddurability
Core Design Contradiction:
Object-generated harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The patent converts the harmful tin pest phenomenon into a beneficial stability feature by adding antimony, which prevents the gray tin transformation. The alloy composition transforms the inherent instability of pure tin into long-term durability while maintaining environmental friendliness.

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

Solution Approach 2:

By creating a tin-antimony composite alloy, the patent combines the environmental benefits of tin with the stability-providing properties of antimony, achieving both low toxicity and long-term durability against tin pest.

Inventive Principle:
Principle #40Composite materials

3Duration of action of stationary object

If high antimony content is added to prevent tin pest, then durability is improved, but supply chain stability and mechanical processibility worsen

Engineering Contradiction:
ImprovedurabilityVSAvoidsupply chain stability
Core Design Contradiction:
Duration of action of stationary objectVSProductivity

Solution Approach 1:

The patent optimizes the antimony content parameter within a specific range (3-7wt%) to achieve the minimum effective concentration for pest prevention. This balanced composition ensures durability while maintaining good mechanical processibility and supply chain stability.

Inventive Principle:
Principle #35Parameter changes

4Duration of action of stationary object

If high antimony content is added to prevent tin pest, then durability is improved, but mechanical processibility and tensile strength deteriorate

Engineering Contradiction:
ImprovedurabilityVSAvoidmechanical processibility
Core Design Contradiction:
Duration of action of stationary objectVSStrength

Solution Approach 1:

The patent precisely controls the antimony content within the optimal range of 3-7wt% to achieve the threshold for pest prevention while maintaining adequate mechanical properties. This parameter optimization ensures both durability and mechanical processibility.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4607541A1A cable sheath of a tin-antimony alloy
Publication Date: 2025.08.27 NEXANS SA
  • EP4607541A1 patent drawingFigure 1
  • EP4607541A1 patent drawingFigure 2
  • EP4607541A1 patent drawingFigure 3

AI summary

The invention therefore relates to a power cable comprising a cable core comprising an electrical conductor and an electrically insulating layer arranged radially outside the electrical conductor, and a water barrier sheath arranged radially outside the cable core, wherein the water barrier sheath comprises a metal layer, wherein the metal layer is an Sn alloy comprising Sb and wherein the Sn alloy comprises less than 4 wt.% of Sb.