Flocked Elastomer Damper Coating for Low-Temperature Fire Protection

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Solution Overview

Problem

Articles made from elastomeric mixtures used in vehicle suspension and vibration damping fail to meet stringent fire protection requirements due to high heat release rates and toxic smoke production, and existing fire-retardant solutions compromise physical properties or are ineffective at lower temperatures.

Innovation Solution

A polymeric article with a surface completely or partially flocked using fire-resistant fibers and a reflective substance, applied with a flocking adhesive or isocyanate-based composition, which enhances fire protection and flame retardancy even at temperatures below the expansion onset of expandable graphite.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If flame-retardant substances are directly incorporated into rubber compounds, then fire protection behavior is improved, but physical properties such as resilience, settling, and vibration properties deteriorate significantly

Engineering Contradiction:
Improvefire protection behaviorVSAvoidphysical properties
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The fire protection function is separated from the base rubber compound by applying a flame-retardant coating layer on the surface. This segmentation allows the base compound to maintain its physical properties while the coating provides fire protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A composite structure is created by combining the base rubber compound with a flame-retardant coating layer containing expandable graphite and other flame-retardant substances. This composite approach enables both fire protection and maintenance of physical properties.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If fire-resistant coatings are applied to articles, then fire protection is improved, but tensile strength is reduced leading to poor resistance to cracking or detachment

Engineering Contradiction:
Improvefire protectionVSAvoidtensile strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The coating formulation is optimized by adjusting parameters such as polymer matrix selection, crosslinking density, and flame-retardant filler content to achieve a balance between fire protection and tensile strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

A composite coating system is used combining multiple components including polymer matrix, crosslinking agents, and flame-retardant fillers to achieve both fire resistance and adequate tensile strength.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If fire-resistant coatings are applied to articles, then fire protection is improved, but compression set increases particularly at elevated temperatures detrimental to resilience, settling, and vibration properties

Engineering Contradiction:
Improvefire protectionVSAvoidcompression set
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The coating formulation parameters are optimized including selecting heat-stable polymers, adjusting crosslinking density, and controlling flame-retardant filler content to minimize compression set at elevated temperatures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

A composite coating system with heat-stable polymer matrix and optimized flame-retardant fillers is used to maintain dimensional stability and reduce compression set under thermal conditions.

Inventive Principle:
Principle #40Composite materials

4Object-affected harmful factors

If expandable graphite is used as fire protection coating, then fire protection is improved at high temperatures, but adhesion and processing are problematic and insulating effect is only achieved at high temperatures

Engineering Contradiction:
Improvefire protection at high temperaturesVSAvoidadhesion and processing
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

Expandable graphite is used as an intermediary material within the coating system that activates at high temperatures to provide fire protection. The coating matrix ensures proper adhesion and processing at lower temperatures, while the graphite provides thermal insulation when needed.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating formulation is designed to maintain processability at application temperatures while incorporating expandable graphite that activates at higher temperatures to provide fire protection.

Inventive Principle:
Principle #35Parameter changes

5Reliability

If elastomeric compounds based on NR and/or IR are used, then elastic properties are improved, but heat release rate during combustion is particularly high

Engineering Contradiction:
Improveelastic propertiesVSAvoidheat release rate
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The fire protection function is separated from the base elastomeric compound by applying a flame-retardant coating layer on the surface. This segmentation allows the base compound to maintain its elastic properties while the coating reduces heat release rate during combustion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A composite structure is created by combining the elastomeric compound with a flame-retardant coating layer containing expandable graphite and other flame-retardant substances to reduce heat release rate while maintaining elastic properties.

Inventive Principle:
Principle #40Composite materials

6Reliability

If elastomeric compounds based on CR are used, then weather, mineral oil, and heat resistance are improved, but smoke gas is toxic to humans and animals

Engineering Contradiction:
Improveweather and heat resistanceVSAvoidsmoke toxicity
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The smoke toxicity issue is addressed by applying a flame-retardant coating layer on the surface of the CR-based elastomeric compound. This segmentation allows the base compound to maintain its weather and heat resistance while the coating reduces smoke toxicity during combustion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A composite structure is created by combining the CR-based elastomeric compound with a flame-retardant coating layer containing expandable graphite and other flame-retardant substances to reduce smoke toxicity while maintaining weather and heat resistance.

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 solution provides improved fire protection and flame retardancy at lower temperatures, maintaining the necessary physical properties and allowing for effective fire resistance without significant increases in manufacturing complexity, ensuring compliance with stricter fire protection standards like EN 45545.

Implementation Method 1

The structure and/or material of the flocking results in improved fire and flame protection in the form of less flammability even at temperatures below the starting temperatures of expandable graphite

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

Expanded graphite itself only expands at relatively high temperatures, so its insulating effect is only achieved at relatively high temperatures

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3350469B1Damper
Publication Date: 2024.11.27 CONTITECH LUFTEDERSYSTEME GMBH
  • EP3350469B1 patent drawingFigure 1~2
  • EP3350469B1 patent drawingFigure 3~3b

AI summary

The invention relates to an article (1) comprising a main body that consists of a polymer material having elastic properties, particularly an air spring bellows (1), a metal-rubber element or a vibration damper. In order to improve its fire-retardant and/or flame-retardant properties, the article is partially or completely coated with a flock (9).