Composite Materials Lightning Protection Conductive Particles

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Solution Overview

Problem

Conventional composite materials used in structural applications, such as aerospace, lack sufficient electrical conductivity to effectively protect against lightning strikes, leading to damage and delamination due to poor z-directional conductivity, and often compromise mechanical and aesthetic properties with the addition of metals for conductivity.

Innovation Solution

Incorporating a low volume fraction of conductive particles, such as carbon particles or silver-coated glass spheres, into the interleaf region of composite materials to reduce bulk resistivity and enhance z-directional electrical conductivity without compromising mechanical performance or increasing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal meshes or expanded foils are incorporated to improve electrical conductivity, then electrical conductivity is improved, but weight increases and mechanical properties degrade

Engineering Contradiction:
Improveelectrical conductivityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the form of conductive additive from bulk metal (meshes, foils) to fine particles with metal coating. This parameter change in the physical state and morphology of the conductive phase enables achieving the same electrical conductivity function with dramatically reduced weight and volume, while maintaining compatibility with the polymer matrix.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure where conductive particles (with metal coating on core particles) are dispersed within the polymer matrix. This composite approach combines the electrical conductivity of metal with the mechanical properties and light weight of polymer, avoiding the need for heavy metal meshes while achieving the desired conductive function.

Inventive Principle:
Principle #40Composite materials

2Reliability

If metal meshes or expanded foils are incorporated to improve electrical conductivity, then electrical conductivity is improved, but mechanical properties and aesthetic properties degrade

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmechanical properties
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the form of conductive additive from bulk metal (meshes, foils) to fine particles with metal coating. This parameter change in the physical state and morphology of the conductive phase enables achieving the same electrical conductivity function with dramatically reduced weight and volume, while maintaining compatibility with the polymer matrix.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure where conductive particles (with metal coating on core particles) are dispersed within the polymer matrix. This composite approach combines the electrical conductivity of metal with the mechanical properties and light weight of polymer, avoiding the need for heavy metal meshes while achieving the desired conductive function.

Inventive Principle:
Principle #40Composite materials

3Strength

If conventional composite materials are used, then mechanical properties are maintained, but electrical conductivity is insufficient for lightning protection

Engineering Contradiction:
Improvemechanical propertiesVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent extracts only the essential conductive function from bulk metal components and implements it through fine particles dispersed in the polymer matrix. This extraction approach provides the necessary electrical conductivity for lightning protection while maintaining the mechanical integrity of the composite material.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a composite structure where conductive particles (with metal coating on core particles) are dispersed within the polymer matrix. This composite approach combines the electrical conductivity of metal with the mechanical properties and light weight of polymer, avoiding the need for heavy metal meshes while achieving the desired conductive function.

Inventive Principle:
Principle #40Composite materials

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 use of conductive particles significantly improves electrical conductivity and thermal dissipation, providing enhanced protection against lightning strikes with minimal damage and maintaining the material's mechanical properties, as demonstrated by reduced resistivity and improved performance in simulated lightning strike tests.

Implementation Method 1

use of electrically conductive particles for reducing an initial bulk resistivity of a constituent polymeric resin of a composite material

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

improve the dissipation of electrical current in directions orthogonal to the plane of the fibre reinforcement (z direction)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

The use of conductive particles significantly improves electrical conductivity and thermal dissipation

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2540491B1Improved composite materials
Publication Date: 2023.08.16 HEXCEL COMPOSITES LTD (GB)
  • EP2540491B1 patent drawingFigure 1~2
  • EP2540491B1 patent drawingFigure 3~4
  • EP2540491B1 patent drawingFigure 5~6

AI summary

Use of a composite material, the composite material comprising at least one prepreg, said prepreg comprising at least one polymeric resin and at least one fibrous reinforcement; and conducting particles dispersed in the polymeric resin.