EV Sound-Absorbing Material With Dot Adhesive for High-Frequency Noise
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Solution Overview
Problem
Existing sound-absorbing materials for electric vehicles are ineffective in absorbing high-frequency noise, which is a new noise source due to electric motors, while maintaining low-frequency noise absorption performance.
Innovation Solution
A sound-absorbing material comprising a heat-sealed non-woven fabric, a dot-pattern adhesive layer, and a melt blown non-woven fabric, with specific fiber thicknesses and weights, bonded together to enhance air permeability and sound absorption in the high-frequency range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If existing sound-absorbing materials are used for electric vehicles, then low-frequency noise absorption is maintained, but high-frequency noise absorption is ineffective
Solution Approach 1:
The patent employs a composite structure consisting of a heat-sealed non-woven fabric layer and a melt-blown non-woven fabric layer. This composite material design combines the advantages of both fabric types: the heat-sealed non-woven fabric provides structural stability and low-frequency noise absorption, while the melt-blown non-woven fabric with its fine fiber diameter (0.5 to 20 μm) and porous structure effectively absorbs high-frequency noise. The layered composite structure enables simultaneous effectiveness across both low and high frequency ranges.
Solution Approach 2:
The patent utilizes porous materials, specifically the melt-blown non-woven fabric with a porous structure and fine fiber diameter. The porous structure allows sound waves to penetrate and dissipate energy through friction and viscous effects within the pores, which is particularly effective for high-frequency noise. The controlled porosity and fiber arrangement create optimal conditions for high-frequency sound absorption while maintaining structural integrity.
2Strength
If adhesive layers are used to bond non-woven fabrics, then bonding strength is achieved, but air permeability is reduced
Solution Approach 1:
The adhesive layer is segmented into a dot-pattern configuration rather than a continuous layer. This segmentation creates discrete adhesive points that bond the heat-sealed non-woven fabric to the melt-blown non-woven fabric while leaving gaps between the adhesive dots. These gaps maintain air permeability pathways, allowing sound waves and air to pass through the layered structure without being completely blocked by the adhesive.
Solution Approach 2:
The adhesive is applied locally at specific dot positions rather than uniformly across the entire surface. This local application strategy provides sufficient bonding strength at the adhesive contact points while preserving air permeability in the non-adhesive regions. The dot-pattern adhesive layer creates a heterogeneous structure with localized bonding zones and open airflow zones, optimizing both adhesion and acoustic performance.
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 effectively absorbs high-frequency noise by improving air permeability and reducing air flow resistivity, maintaining durability and adhesive strength.
Implementation Method 1
a sound-absorbing material for an electric vehicle that utilizes heat-sealed non-woven fabric and melt blown non-woven fabric that may effectively absorb high-frequency noise
Implementation Method 2
utilizes a dot-pattern adhesive layer that may improve air permeability
Data Source
AI summary
Disclosed is a sound-absorbing material for an electric vehicle including a heat-sealed non-woven fabric, a dot-pattern adhesive layer disposed on the heat-sealed non-woven fabric, and a melt blown non-woven fabric disposed on the dot-pattern adhesive layer.