Gradient Density Sound Attenuating Composite

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Solution Overview

Problem

Current sound attenuating materials used in automobiles, such as polyester, fail to meet temperature resistance standards and can cause skin and respiratory irritation, while also being heavy, which hinders fuel efficiency and acoustic performance.

Innovation Solution

A lightweight sound attenuating composite material comprising organic and inorganic man-made fibers, a thermosetting binder, and pure cellulose fibers, combined with granulated EVA and optional recycled materials, which is self-extinguishing and has improved acoustic performance without increasing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polyester is used as sound attenuating material, then sound attenuating characteristics are good, but the material burns and melts at high temperatures and does not perform well in open flame test

Engineering Contradiction:

Improvesound attenuating characteristicsVSAvoidburning and melting at high temperatures

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines polyester fibers with cellulose fibers and a thermosetting binder to create a composite material that maintains the sound attenuating properties of polyester while adding fire resistance through cellulose and thermosetting resin components that do not melt or burn easily

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters by incorporating cellulose fibers (20-80% by weight) and thermosetting binders (10-40% by weight) to alter the thermal and flammability characteristics of the original polyester material while preserving its acoustic performance

Inventive Principle:

Principle #35Parameter changes

2Reliability

If fiberglass is added to polyester to improve flame test performance and sound attenuation, then flame resistance and sound attenuation improve, but skin, eye and respiratory irritation occurs

Engineering Contradiction:

Improveflame test performanceVSAvoidskin, eye and respiratory irritation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material composition by using cellulose fibers instead of fiberglass, maintaining flame resistance through the thermosetting binder and cellulose's natural fire-resistant properties while eliminating the irritant fibrous particles that cause skin and respiratory issues

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses natural cellulose fibers (from wood pulp or cotton) as a biodegradable, non-irritating alternative to synthetic fiberglass, achieving similar fire resistance without the health hazards of fine fibrous particles

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If sound attenuating material weight is increased to improve acoustic performance, then sound reduction improves, but fuel efficiency decreases

Engineering Contradiction:

Improvesound reductionVSAvoidmaterial weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent creates a lightweight composite using cellulose fibers and thermosetting binder that provides high sound attenuation per unit weight, achieving excellent acoustic performance without the heavy mass of traditional fiberglass or dense polyester materials

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent utilizes the porous structure of cellulose fibers and the composite matrix to trap and absorb sound waves effectively, achieving high sound reduction coefficients with minimal material density and weight

Inventive Principle:

Principle #31Porous 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 composite material achieves better noise reduction coefficients while being lighter and safer, with self-extinguishing properties and reduced irritation risks, addressing the limitations of existing materials.

Implementation Method 1

a thermosetting binder and, pure cellulose fibers

Methodology Applied

Scientific EffectThermosetting:

Implementation Method 2

a granulated EVA, or a mixture of the granulated EVA and one or more of polyester, cellulose, fiberglass, and binder

Methodology Applied

Scientific EffectEncapsulation:

Implementation Method 3

sound attenuating composite material comprising an organic man-made fiber, an inorganic man-made fiber, a thermosetting binder and, pure cellulose fibers

Methodology Applied

Scientific EffectSound absorption: Acoustic Absorption

Implementation Method 4

The composite material achieves better noise reduction coefficients while being lighter and safer, with self-extinguishing properties

Methodology Applied

Scientific EffectSelf-extinguishing:

Data Source

PatentUS9715872B2Gradient density sound attenuating composite and process for making

Publication Date: 2017.07.25 CTA ACOUSTICS INC

AI summary

A sound attenuating material having a homogenous mixture of an organic man-made fiber, an inorganic man-made fiber, a binder, and a cellulose material wherein the organic man-made fiber is polyester, the inorganic man-made fiber is fiberglass, and the binder is a thermosetting resin. A sound attenuating composite is defined by the sound attenuating material and a ground EVA or a mixture of EVA and one or more recycled materials to define a gradient density sound attenuating composite material. Further, the gradient density composite may optionally include a polyfilm upon which the ground EVA or recycled materials may be disposed or two layers of polyfilm to surround the EVA or EVA mixture. The EVA may be pure EVA or may include a mineral fill.