Laminated Acoustic Panel with Viscoelastic Adhesive

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Solution Overview

Problem

Conventional acoustic building panels are heavy, expensive, and difficult to manufacture due to the use of thick adhesive layers to improve sound transmission coefficients, which results in increased weight and production complexity.

Innovation Solution

A laminated acoustic building panel with soft substrate layers made of gypsum, plasterboard, or cement, bonded with a very thin layer of adhesive having a low Young's modulus and high loss factor, significantly reducing the amount of adhesive used while maintaining effective soundproofing properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thick layer of adhesive is used to bond substrate layers, then the weighted sound reduction index (Rw) is improved, but the weight of the panel increases

Engineering Contradiction:
Improveweighted sound reduction indexVSAvoidpanel weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the physical parameters of the adhesive by selecting materials with specific dynamic Young's modulus values (0.1-10 MPa at 100 Hz, 0.5-100 MPa at 1000 Hz) and loss factors (≥50%). This allows achieving the same acoustic performance with significantly reduced adhesive thickness and quantity, thereby reducing panel weight while maintaining sound insulation properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structures combining soft substrate layers (gypsum, gypsum fibre, or cement with specific dynamic Young's modulus ranges) bonded with specially formulated adhesives. This composite approach enables effective sound wave damping at adhesive quantities of 50-200 g/m², reducing weight compared to conventional thick adhesive applications

Inventive Principle:
Principle #40Composite materials

2Reliability

If a thick layer of adhesive is used to bond substrate layers, then the weighted sound reduction index (Rw) is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveweighted sound reduction indexVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

By specifying precise parameter ranges for the adhesive (dynamic Young's modulus and loss factor) and substrate materials, the patent enables consistent acoustic performance with thin adhesive layers. This simplifies manufacturing by reducing adhesive application thickness requirements and eliminating the need for complex thick-adhesive processing equipment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies adhesive in controlled partial quantities (50-200 g/m²) rather than thick continuous layers. This partial action approach simplifies manufacturing operations, reduces adhesive spreading requirements, and enables easier handling during production while achieving sufficient bond strength and acoustic performance

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If a thick layer of adhesive is used to bond substrate layers, then the weighted sound reduction index (Rw) is improved, but the cost of the panel increases

Engineering Contradiction:
Improveweighted sound reduction indexVSAvoidadhesive quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the material parameters to use adhesives with optimized viscoelastic properties (specific dynamic Young's modulus and loss factor ranges) that provide superior sound damping efficiency per unit mass. This enables achieving the same Rw improvement with 50-200 g/m² of adhesive instead of thick layers, significantly reducing material quantity and cost

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies adhesive in localized thin layers at specific bonding interfaces between substrate layers rather than using thick uniform layers across entire surfaces. This local quality approach reduces total adhesive consumption while maintaining effective sound wave damping at the critical bonding zones, lowering material costs

Inventive Principle:
Principle #3Local quality

4Reliability

If soft substrate layers are used, then the panel construction becomes softer for better sound damping, but the structural strength may be reduced

Engineering Contradiction:
Improvesound wave dampingVSAvoidstructural strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs composite material structures where soft substrate layers (gypsum, gypsum fibre, or cement with specific dynamic Young's modulus ranges) are bonded using adhesives with carefully selected mechanical properties. This composite construction achieves effective sound wave damping through the soft layers while the adhesive bonds maintain sufficient structural strength for panel applications

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent specifies parameter ranges for substrate materials (dynamic Young's modulus of 0.1-10 MPa at 100 Hz, 0.5-100 MPa at 1000 Hz) and adhesives (0.1-10 MPa at 100 Hz, 0.5-100 MPa at 1000 Hz, loss factor ≥50%) that balance softness for sound damping with adequate structural strength. This parameter optimization ensures both acoustic performance and structural integrity

Inventive Principle:
Principle #35Parameter changes

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 panel achieves improved sound attenuation and reduced weight and production costs by using less adhesive, resulting in enhanced acoustic performance with a softer construction and increased weighted sound reduction index.

Implementation Method 1

a layer of adhesive having a low Young's modulus and high loss factor

Methodology Applied
Scientific EffectViscoelastic damping: Viscoelasticity

Implementation Method 2

sound waves caused by knocking or impact noise is surprisingly damped

Methodology Applied
Scientific EffectSound damping: Damping

Data Source

PatentEP2406437B1Laminated acoustic soundproofing panel
Publication Date: 2016.10.12 BPB LTD
  • EP2406437B1 patent drawingFigure 1~2

AI summary

A laminated acoustic building panel comprises a pair of plasterboard substrates (10,13) which are bonded together by an adhesive layer (16), the panel having a dynamic Young's modulus of 0.1 to 5 GPa and a damping loss factor of 5 - 30% (? = 0.05 – 0.3), and the ratio of the adhesive (16) to the applied surface area of the substrates (10,13) being 80 - 250 g/m2. The laminated panel is relatively soft in construction and hence sound waves caused by knocking or impact noise is surprisingly damped using considerably less adhesive (16) than known panels. The use of soft substrates (10,13) and less adhesive (16) significantly reduces the weight of the panel. Furthermore, the use of less adhesive (16) significantly reduces costs and makes production easier.