Conductive Strip for Composite Materials with Insulating Layers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for integrating electrical conduction into laminated composite materials, such as those used in aeronautical structures, are inefficient for thin and large parts like fuselage panels, particularly when compared to pre-impregnated layup processes, due to productivity issues with resin transfer methods.

Innovation Solution

A semi-finished product in the form of a conductive strip with insulating and connecting layers, where the insulating layers are made of partially vulcanized elastomer and the connecting layers of thermosetting adhesive, allowing for bonding and cohesion during draping and curing, enabling integration into pre-impregnated plies using manual or automated techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resin transfer process is used to integrate conductive cables into composite materials, then electrical conduction properties are achieved, but productivity is reduced for thin and large parts

Engineering Contradiction:
Improveelectrical conduction propertiesVSAvoidmanufacturing productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The conductive cable is pre-insulated with dielectric material and pre-impregnated with resin before integration into the composite structure. This preliminary preparation allows the cable to be directly embedded during draping without requiring subsequent resin transfer operations, thereby maintaining electrical conduction properties while significantly improving productivity for thin and large parts

Inventive Principle:
Principle #10Preliminary action

2Reliability

If conductive cables are integrated using resin transfer process, then electrical conduction is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improveelectrical conductionVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple functions into a single integrated component: the conductive cable is simultaneously insulated with dielectric material and pre-impregnated with resin. This combination eliminates the need for separate resin transfer operations and reduces manufacturing process complexity while maintaining electrical conduction reliability

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If pre-impregnated plies are used for manufacturing, then productivity is improved, but integration of conductive layers becomes difficult

Engineering Contradiction:
Improvemanufacturing productivityVSAvoidintegration ease
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The conductive cable is self-sufficient with built-in insulation and pre-applied resin coating. This self-service design allows the cable to be directly handled and integrated like standard pre-impregnated plies during draping operations, maintaining both high productivity and ease of manufacture without requiring special handling or additional resin application steps

Inventive Principle:
Principle #25Self-service

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

This solution allows for the efficient and productive integration of conductive layers into composite materials, ensuring electrical insulation, mechanical protection, and cohesion, while maintaining flexibility and rigidity for draping operations, thus enhancing the manufacturing efficiency and performance of composite parts.

Implementation Method 1

the insulating layers consist of a partially vulcanized elastomer

Methodology Applied
Scientific EffectVulcanization:

Implementation Method 2

two electrically insulating layers consisting of a dielectric material completely enclosing the conductive strip

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

the connecting layers consist of a thermosetting adhesive

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2715742B1Semi-finished product in the form of a conductive strip that can be embedded in a composite material, and method for manufacturing such a strip
Publication Date: 2019.07.24 AIRBUS (SAS)
  • EP2715742B1 patent drawingFigure 1~3

AI summary

The invention relates to a semi-finished product in the form of a strip (101, 102) that can be deposited by drape-forming so as to constitute a laminated composite material, characterized in that it includes, along a cross-section thereof and along the entire length thereof: a first conductive layer (105, 106) made of an electrically conductive material; two isolating layers (121, 122) made of a dielectric material completely surrounding the conductive layer (105, 106), the widths of the cross-sections of which is greater than the width of the conductive layer; two bonding layers (111, 112) extending in the thickness direction on either side of the isolation layers (121, 122) and outside the strip (101, 102). The invention also relates to a method for the continuous production of such a strip.