Polyolefin Foam Support for Waterproof Sound Membrane
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Solution Overview
Problem
Waterproof sound-transmitting membranes in electronic devices often introduce sound distortion, particularly due to the generation of high-order harmonics when sound passes through, which is a significant issue for maintaining high-quality sound reproduction in electronic devices.
Innovation Solution
A waterproof sound-transmitting member is designed with a support layer made of polyolefin-based resin foam, which has a loss modulus of 1.0×10^7 Pa or less and a loss factor of 1.0×10^-1 or more, joined to the waterproof sound-transmitting membrane to reduce sound distortion by absorbing high-order harmonics and stabilizing the sound transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a waterproof sound-transmitting membrane is attached to the opening to prevent water entry, then waterproofing is improved, but sound transmission quality deteriorates due to distortion and high-order harmonics generation
Solution Approach 1:
A support layer made of polyolefin-based resin foam is introduced as an intermediary between the waterproof sound-transmitting membrane and the external environment. This support layer absorbs high-order harmonics and vibration energy, preventing them from distorting the transmitted sound while allowing the membrane to maintain its waterproofing function.
Solution Approach 2:
The patent specifies precise parameter ranges for the support layer: loss modulus of 1.0×10^7 Pa or less and loss factor of 1.0×10^-1 or more. By controlling these viscoelastic parameters, the support layer optimally balances sound absorption capabilities with structural support, reducing harmonic distortion without compromising waterproofing performance.
2Reliability
If a waterproof sound-transmitting membrane is used, then waterproofing is achieved, but vibration noise and chattering noise increase due to membrane instability
Solution Approach 1:
The support layer acts as a pre-positioned cushioning element behind the waterproof membrane. It absorbs vibration energy and dampens chattering noise before these vibrations can propagate outward, preventing the membrane from fluttering and generating harmful vibration noise during sound transmission.
Solution Approach 2:
The invention creates a composite structure combining the waterproof sound-transmitting membrane with a polyolefin-based resin foam support layer. This composite material system integrates the waterproofing properties of the membrane with the vibration-damping characteristics of the foam, simultaneously achieving waterproofing and noise reduction.
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 use of a polyolefin-based resin foam support layer effectively reduces sound distortion by absorbing vibration energy and high-order harmonics, thereby improving sound quality and maintaining undistorted sound transmission in electronic devices.
Implementation Method 1
The support layer includes a polyolefin-based resin foam, and the support layer has a loss modulus of 1.0×10^7 Pa or less and a loss factor of 1.0×10^-1 or more
Implementation Method 2
the support layer has a loss modulus of 1.0×10^7 Pa or less and a loss factor of 1.0×10^-1 or more
Data Source
AI summary
A waterproof sound-transmitting member includes a waterproof sound-transmitting membrane and a support layer. The support layer includes a polyolefin-based resin foam. The support layer has a loss modulus of 1.0×107 Pa or less and a loss factor of 1.0×10−1 or more. The waterproof sound-transmitting membrane is, for example, a stretched porous polytetrafluoroethylene membrane. The waterproof sound-transmitting membrane may include an adhesive layer.