Conductive Nonwoven Grounding Ring for Low-Resistance E-Mobility

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Solution Overview

Problem

Existing electrically conductive nonwovens used in grounding rings for e-mobility applications exhibit electrical resistances ranging from 50Ω to 500Ω, which are too high for effective electromagnetic tolerance, particularly when connected to motor vehicle components.

Innovation Solution

A conductive nonwoven comprising a raw nonwoven with embedded electrically conductive particles, such as silver particles, having a higher conductivity than the raw nonwoven, achieving an electrical resistance of ≤10Ω during operation, with optimized particle size, proportion, and thickness for enhanced conductivity and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrically conductive nonwovens are used in grounding rings, then the nonwoven provides basic grounding function, but the electrical resistance is too high (50Ω to 500Ω) for effective electromagnetic tolerance

Engineering Contradiction:
Improveelectromagnetic toleranceVSAvoidelectrical resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies composite materials by combining a raw nonwoven substrate with electrically conductive particles (such as silver particles) to create a nonwoven with enhanced electrical conductivity. The conductive particles are embedded within the nonwoven structure, forming a composite material that achieves electrical resistance ≤10Ω during operation, significantly improving electromagnetic tolerance while maintaining the nonwoven's mechanical properties

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies parameter changes by modifying the electrical conductivity parameter of the nonwoven through the addition of conductive particles. The electrical resistance is reduced from the conventional range of 50Ω to 500Ω to ≤10Ω during operation, achieving the required electromagnetic tolerance through controlled changes in material composition and structure

Inventive Principle:
Principle #35Parameter changes

2Reliability

If electrically conductive particles are added to increase conductivity, then electrical resistance decreases to ≤10Ω, but the complexity of manufacturing and optimizing particle properties increases

Engineering Contradiction:
Improveelectrical conductivityVSAvoidparticle optimization
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent systematically optimizes key parameters including particle size (0.1 μm to 10 μm), particle proportion by weight (1% to 50%), and nonwoven thickness (0.1 mm to 10 mm) to achieve the target electrical resistance of ≤10Ω while maintaining manufacturability. These controlled parameter changes balance performance requirements with production feasibility

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by distributing electrically conductive particles throughout the nonwoven structure, creating regions of enhanced conductivity where needed. The conductive particles are embedded within the nonwoven matrix, providing localized conductivity enhancement while maintaining the overall structural integrity and flexibility of the nonwoven material

Inventive Principle:
Principle #3Local quality

3Reliability

If the nonwoven achieves high conductivity through particle embedding, then electrical resistance is reduced, but maintaining flexibility and mechanical properties for dynamic applications becomes more difficult

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmechanical flexibility
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies composite materials by combining a flexible nonwoven substrate with embedded conductive particles, creating a composite structure that maintains the base material's flexibility while adding electrical conductivity. The nonwoven matrix provides mechanical flexibility and durability for dynamic applications, while the dispersed conductive particles provide the necessary electrical pathways without compromising the material's mechanical properties

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by strategically embedding conductive particles within the nonwoven structure rather than using a fully conductive rigid material. This localized approach to conductivity enhancement preserves the nonwoven's inherent flexibility and mechanical properties, allowing the material to deform and flex in dynamic applications while maintaining adequate electrical conductivity

Inventive Principle:
Principle #3Local quality

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 nonwoven achieves a significantly lower electrical resistance, ensuring reliable electrical conductivity and reduced friction, while maintaining mechanical properties suitable for dynamic applications, thus preventing mechanical damage and ensuring effective grounding.

Implementation Method 1

electrically conductive particles having a second electrical conductivity, wherein the second electrical conductivity is higher than the first electrical conductivity

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS12580459B2Electrically conductive nonwoven, grounding ring, comprising such a nonwoven and arrangement therewith
Publication Date: 2026.03.17 CARL FREUDENBERG KG

AI summary

An electrically conductive nonwoven includes: a raw nonwoven having a first electrical conductivity; and electrically conductive particles having a second electrical conductivity. The second electrical conductivity is higher than the first electrical conductivity. In an embodiment, the particles have a proportion by weight of from 30% to 60%. In an embodiment, the particles have a size of from 3 μm to 8 μm.