Sound Interlayer with Damping Patches for Broadband Noise Reduction
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Solution Overview
Problem
Current materials struggle to effectively reduce sound transmission loss across a wide range of frequencies, particularly in low and medium to high frequency ranges, due to the coincidence effect and limitations in mass and rigidity.
Innovation Solution
A sound interlayer comprising a first layer made from a polymer material, such as PVB, and a second layer with damping patches made from different materials like metals, ceramics, or glass, arranged to form a network with varying dimensions and spacings to absorb sound vibrations and minimize the coincidence effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If visco-elastic materials are applied to minimize coincidence effect in medium to high frequency ranges, then sound transmission loss is improved at those frequencies, but the material cannot effectively reduce sound transmission loss across low frequency ranges
Solution Approach 1:
The interlayer is segmented into multiple distinct layers: a first layer (PVB or fabric) and a second layer containing damping patches (metal, ceramic, or glass particles). Each layer targets different frequency ranges, with the first layer addressing low frequencies and the second layer addressing medium to high frequencies, thereby achieving broad-spectrum sound transmission loss improvement.
Solution Approach 2:
The invention uses composite materials by combining different materials with complementary acoustic properties. The first layer (polymer or fabric) provides baseline sound transmission loss, while the second layer (damping patches with metal, ceramic, or glass particles) adds targeted damping for medium to high frequencies. This composite structure enables effective sound transmission loss across the entire frequency spectrum.
2Reliability
If acoustic surface mass is increased to improve low frequency sound transmission loss, then sound transmission loss is improved, but the weight of the material increases
Solution Approach 1:
Instead of uniformly increasing the acoustic surface mass across the entire interlayer, the invention applies damping patches locally within the second layer. These patches are distributed throughout the interlayer volume, providing localized mass and damping properties that effectively reduce low frequency sound transmission loss without requiring a uniform increase in overall material weight.
Solution Approach 2:
The invention changes the physical parameters of the interlayer by incorporating damping patches with specific density and distribution characteristics. Rather than simply increasing overall mass, the patches are designed with optimal density values and spatial distribution to maximize sound transmission loss at low frequencies while minimizing weight increase.
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 interlayer achieves improved sound insulation performance by resonating with sound waves across a broader frequency band, reducing sound transmission loss by 3 to 4 dB and maintaining compactness while minimizing weight increase.
Implementation Method 1
The interlayer achieves improved sound insulation performance by resonating with sound waves across a broader frequency band
Implementation Method 2
the second layer comprises damping means comprising comprises at least one patch made from a second material different from the first
Data Source
AI summary
A sound interlayer includes a first layer made from a first material and a second layer, wherein the second layer comprises a damping system including at least one patch made from a second material different from the first material.