Stretchable Paper Surface Material for Lightweight Sound Absorbing Structure

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Solution Overview

Problem

Conventional sound-absorbing materials for vehicles face challenges in reducing weight while maintaining effective sound absorption, especially in areas like the underside of the oil pan or headlining, where space is limited, and they often require increased density, which can lead to vibration issues and decreased sound absorption performance.

Innovation Solution

A shock and sound-absorbing material comprising a porous component made of thermoplastic resin with a laminated surface material featuring a stretchable paper layer, creating a cell structure that effectively absorbs sound waves by forming an air layer and utilizing a synthetic resin to adjust airflow resistance and elasticity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sound-absorbing materials use increased density to maintain sound absorption in limited space, then sound absorption performance is improved, but weight increases and vibration issues occur

Engineering Contradiction:
Improvesound absorption performanceVSAvoidmaterial weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent employs porous sound-absorbing materials with optimized pore structures to achieve effective sound absorption without increasing density. The porous structure allows sound waves to penetrate and dissipate energy through friction and viscous effects within the pores, maintaining acoustic performance while keeping the material lightweight.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention uses composite material structures combining different layers and materials (such as fabric layers, foam layers, and porous cores) to achieve both lightweight properties and effective sound absorption. The composite structure allows each layer to contribute specific functions while maintaining overall low weight.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional sound-absorbing materials use increased density to maintain sound absorption in limited space, then sound absorption performance is improved, but vibration resistance deteriorates

Engineering Contradiction:
Improvesound absorption performanceVSAvoidvibration resistance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The porous structure provides inherent vibration damping through the friction and energy dissipation occurring within the pore network. This allows the material to resist vibration effectively without requiring high density, as the porous architecture itself contributes to vibration control.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent optimizes parameters such as pore size, porosity, and material composition to achieve the desired balance between sound absorption and vibration resistance. By carefully controlling these parameters, the material achieves effective acoustic performance and vibration damping without increasing density.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conventional sound-absorbing materials are designed for effective sound absorption, then acoustic performance is improved, but ease of installation in space-constrained areas deteriorates

Engineering Contradiction:
Improvesound absorption performanceVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent employs flexible, thin-film sound-absorbing materials that can be easily conform to and installed in space-constrained areas. The flexible nature of the material allows it to adapt to complex geometries and limited spaces without requiring extensive installation procedures, while maintaining effective sound absorption performance.

Inventive Principle:
Principle #30Flexible shells and thin films

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 material achieves lightweight, high sound absorption and shock resistance, allowing for installation in space-constrained areas with improved structural damping and reduced noise emission, while maintaining effectiveness across various frequencies.

Implementation Method 1

a sound wave from a noise source are radiated as an incident wave into said cell through said sound absorbing material, and said incident wave reaches said base panel through said air layer as it stands to be reflected by said base panel as a reflected wave

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Implementation Method 2

a porous component and a surface material which is laminated onto said porous component

Methodology Applied
Scientific EffectPorosity: Porosity

Implementation Method 3

utilizing a synthetic resin to adjust airflow resistance and elasticity

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP2302620B1Impact and sound absorbing material and sound absorbing structure
Publication Date: 2021.03.03 NAGOYA OIL CHEM CO LTD
  • EP2302620B1 patent drawingFigure 1~3
  • EP2302620B1 patent drawingFigure 4~5
  • EP2302620B1 patent drawingFigure 6~7

AI summary

[Subject] The subject of the present invention is to provide a shock and sound absorbing material having a light weight, and demonstrating an excellent shock and sound absorbing performance. As a method for solving the subject, the present invention provides a shock and sound absorbing material 1 comprising a porous component 2, and a surface material 3 which is laminated onto the porous component 2, wherein the surface material 3 has at least one layer made of a stretchable paper material 5. The shock and sound absorbing material 1 is installed on a cover panel 7 covering a sound source such as an engine cover, and the porous component 2 is set so as to face the cover panel 7, with the surface material 3 being set so as to face the sound source, and form a cell structure between the cover panel 7 and the surface material 3.