Composite membrane and method for producing same

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Solution Overview

Problem

Existing acoustic components face challenges in protecting sensitive electronic components from harmful liquids, nanoscale dust, and environmental factors without compromising sound quality, as conventional membranes are either impermeable to air or contain harmful substances.

Innovation Solution

A composite with an electro-spinning membrane formed from superimposed nanofibers or microfibers, creating a three-dimensional network with defined pore structure for high porosity and air permeability, while maintaining water resistance and being free from halogens and harmful compounds, combined with a plasma coating for enhanced oil, grease, and water-repellent properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional membranes are used to protect electronic components, then protection against liquids is improved, but air permeability deteriorates

Engineering Contradiction:
Improveprotection against liquidsVSAvoidair permeability
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent employs a microporous membrane with specifically engineered pore structures that allow air molecules to pass through while blocking liquid penetration. The membrane features a hydrophobic pore surface that repels liquid while maintaining open pores for gas transmission, achieving both protection and breathability simultaneously

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention uses composite membrane structures combining different materials with complementary properties - a hydrophobic barrier layer for liquid rejection and a porous support layer for mechanical strength and air permeability. This multi-material approach resolves the contradiction between liquid protection and gas transmission

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If electrospinning membrane with high porosity is used, then air permeability is improved, but protection against liquids deteriorates

Engineering Contradiction:
Improveair permeabilityVSAvoidprotection against liquids
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies different properties to different regions of the membrane - the pore walls are treated with hydrophobic coatings while the overall structure maintains high porosity. This local differentiation allows the membrane to be permeable to air while resisting liquid penetration at the pore level

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention controls the pore size distribution and hydrophobicity parameters of the membrane to achieve optimal performance. By adjusting pore diameter, porosity, and surface energy parameters, the membrane simultaneously achieves high air permeability and effective liquid barrier properties

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If plasma coating is applied to enhance water resistance, then protection against moisture is improved, but manufacturing complexity deteriorates

Engineering Contradiction:
Improveprotection against moistureVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent incorporates hydrophobic properties directly into the membrane fabrication process through electrospinning parameter control and material selection, rather than requiring subsequent plasma coating steps. This preliminary integration of water resistance reduces manufacturing complexity while maintaining protection performance

Inventive Principle:
Principle #10Preliminary action

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 provides effective protection against moisture, sweat, grease, and dust while allowing air permeability, meeting strict protection standards and ensuring the sound quality of acoustic components, with a water column pressure of up to 35 m and air permeability of up to 50 L/m²*s, and is free from harmful substances like PFOA.

Implementation Method 1

a membrane is formed on the carrier layer using an electro-spinning process

Methodology Applied
Scientific EffectElectrospinning: Electrohydrodynamics

Implementation Method 2

The membrane is coated with a coating applied by a plasma coating process

Methodology Applied
Scientific EffectPlasma coating: Plasma

Data Source

PatentEP3348393B1Composite membrane and method for producing same
Publication Date: 2023.06.21 SEFAR AG
  • EP3348393B1 patent drawingFigure 1~4
  • EP3348393B1 patent drawingFigure 5

AI summary

The invention relates to a composite membrane with at least one carrier layer and an electro-spinning membrane which is arranged on the at least one carrier layer, the electro-spinning membrane being formed from fibers lying one on top of the other, forming a pore structure. The pore structure of the composite is designed in such a way that the composite has a water column of at least 1 m and an air permeability of at least 5 L/m2*s. The invention also relates to a method for producing a composite membrane, in which a carrier layer is provided and a membrane is formed on the carrier layer using the electro-spinning process, the membrane being produced from fibers lying on top of one another and having a pore structure.