Thermo-Acoustic Heat Shield Composition for Low-Smoke Exhaust Areas

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Solution Overview

Problem

Traditional heat shields in vehicles face issues with smoke, unpleasant odors, and inadequate acoustic absorption at high temperatures, particularly near exhaust components, due to the burn-out of organic components, and existing thermal barriers fail to effectively manage these challenges.

Innovation Solution

A high-temperature thermal barrier material capable of withstanding temperatures up to 1000°C without producing smoke or odors, combined with acoustic absorption properties, is developed using a slurry applied on an acoustic absorption material, which is then dried and molded into desired shapes, providing a thermo-acoustic barrier that shields components from heat and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional thermal barrier materials are used in high temperature environments, then thermal insulation is provided, but smoke and unpleasant odors are produced due to burn-out of organic components

Engineering Contradiction:
Improvewithstand temperatureVSAvoidsmoke and odor emission
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the thermal barrier material by replacing organic binders and cellulosic fibers with inorganic materials such as water-reactive powders (calcium oxide, calcium hydroxide, calcium carbonate) and silicate-based binders. This parameter change eliminates the material's tendency to produce smoke and odors at high temperatures while maintaining thermal insulation properties up to 1000°C

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining water-reactive powders, silicate-based binders, and inorganic fillers in specific proportions. This composite structure provides both thermal insulation and high-temperature stability without organic component burnout, resolving the contradiction between temperature resistance and harmful emission

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If acoustic absorption material is placed near hot exhaust surfaces, then sound absorption is improved, but the material cannot withstand the high temperatures

Engineering Contradiction:
Improveacoustic absorptionVSAvoidwithstand temperature
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent introduces a water-reactive powder-based thermal barrier layer as an intermediary between the hot exhaust surface and the acoustic absorption material. This intermediary layer withstands high temperatures (up to 1000°C) and protects the acoustic absorption material from thermal damage, enabling sound absorption functionality near exhaust components

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent develops a composite structure where inorganic thermal barrier material (water-reactive powders and silicate binders) is combined with acoustic absorption materials. This composite provides both thermal resistance and acoustic absorption capabilities, allowing the assembly to function in high-temperature environments

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If organic binders and cellulosic fibers are used in thermal barrier material, then ease of manufacture is improved, but ignition and burn-out occur at high temperatures

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidignition resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the material composition parameters by eliminating organic binders and cellulosic fibers, replacing them with water-reactive powders (calcium oxide, calcium hydroxide, calcium carbonate) and silicate-based binders. This parameter change eliminates ignition and burn-out at high temperatures while maintaining manufacturability through proven construction methods

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses water-reactive powders that undergo controlled chemical reactions when exposed to moisture, transforming into stable inorganic compounds. This process eliminates the need for long-lived organic binders while maintaining structural integrity, providing a reliable high-temperature resistant material

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 effectively prevents smoke and odor emission, maintains structural integrity at high temperatures, and reduces thermal conductivity, resulting in a quieter and cooler vehicle environment by effectively shielding components from exhaust system heat while absorbing sound.

Implementation Method 1

The thermal barrier has a low thermal conductivity so that heat does not pass easily through to the acoustic absorption material

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

the acoustic absorption material functions to absorb sound that might otherwise penetrate into the passenger compartment

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Implementation Method 3

a water-reactive powder, such as calcium oxide, calcium hydroxide, or calcium carbonate, combined with a silicate-based binder

Methodology Applied
Scientific EffectWater-reactive chemical reaction: Chemical Bonding

Data Source

PatentEP3768957B1High temperature thermo-acoustic barrier with low smoke and odor
Publication Date: 2024.02.14 LYDALL PERFORMANCE MATERIALS US INC
  • EP3768957B1 patent drawingFigure 1~2
  • EP3768957B1 patent drawingFigure 3~4
  • EP3768957B1 patent drawingFigure 5~6

AI summary

A thermal barrier material is disclosed for applications such as heat shields in automobiles and other vehicles. The thermal barrier material is made on a Fordenier paper making machine from a slurry that is very low in organic compounds that can cause smoke and odor when exposed to high temperatures. A first thermal barrier material is disclosed that can withstand up to 650°C and a second thermal barrier material is disclosed that can withstand up to 1000°C, in each case, the barrier material withstands it max temperature specification while producing extremely iow quantities of smoke and extremely low levels of offensive odors. Prior art thermal barrier materials with similar temperature specifications on the other hand produce many times the smoke and offensive odors at the same temperatures and do so for a far longer time.