Carbon Nanotube Elastomer Seals for Low-Wear Dynamic Sealing

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Solution Overview

Problem

Existing sealing elements for dynamic applications suffer from high wear due to the use of large amounts of hard fillers, leading to increased hardness, abrasion on counter surfaces, and premature failure, especially under high temperatures and pressures, while conventional conductive fillers exacerbate wear and electrostatic issues.

Innovation Solution

Incorporation of carbon nanotubes in a rubber-containing elastomeric material at low concentrations (0.1 to 20 phr) provides reduced wear, moderate hardness increase, and improved electrical conductivity, effectively dissipating electrostatic charges, with uniform distribution and crosslinking enhancing mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large amounts of hard fillers are used to reduce wear, then wear resistance is improved, but hardness increases undesirably and abrasion on counter surface worsens

Engineering Contradiction:
Improvewear resistanceVSAvoidhardness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the type of filler from conventional mineral fillers to carbon nanotubes, and optimizes the filler content to 0.1-20 phr. This parameter change enables achieving wear resistance without the undesirable increase in hardness and counter surface abrasion that occurs with traditional filler approaches.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses carbon nanotubes as a filler material in the elastomeric sealing body, creating a composite material with superior properties. The carbon nanotubes provide wear resistance while maintaining suitable hardness levels and reducing counter surface abrasion compared to conventional filler systems.

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If large amounts of hard fillers are used to extend service life, then wear is reduced, but abrasion on counter surface increases causing leaks

Engineering Contradiction:
Improveservice lifeVSAvoidabrasion on counter surface
Core Design Contradiction:
Duration of action of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the filler content parameter to a low range of 0.1-20 phr carbon nanotubes, which is significantly lower than conventional filler amounts. This parameter optimization extends service life through wear resistance while minimizing abrasion on the counter surface that would otherwise cause leaks.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs carbon nanotubes which have exceptional inherent wear resistance properties at the nanoscale. These nanotubes provide protective functionality that reduces both seal wear and counter surface abrasion, effectively copying the beneficial low-wear特性 without the harmful side effects of conventional fillers.

Inventive Principle:
Principle #26Copying

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 sealing bodies exhibit reduced wear, low friction, and improved mechanical properties, maintaining integrity under high temperatures and pressures, while offering electrical conductivity and quiet operation.

Implementation Method 1

incorporating even a small amount of carbon nanotubes, a significant reduction in the wear of sealing bodies in dynamic applications can be achieved... improved electrical conductivity, effectively dissipating electrostatic charges

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3201284B1Sealing body for dynamic applications
Publication Date: 2025.07.23 CARL FREUDENBERG KG

AI summary

The invention relates to a sealing body for dynamic applications having a Shore A hardness of between 60-100, comprising an elastomer material and carbon nanotubes distributed in the elastomer material in an amount of between 0,1 - 20 phr, with respect to the total amount of elastomer material.