Composite Filter Medium Plasma Treatment Adhesion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing composite filter media face challenges in maintaining effective repellency against water and oils while ensuring secure adhesion to PSA layers, leading to potential leaks due to poor adherence.

Innovation Solution

A composite filter medium is developed with a thin, highly hydrophobic and oleophobic coating applied via electrospinning and plasma treatment, followed by an additional plasma treatment step without polymer-containing gases to enhance adhesion to PSA layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a low surface energy coating is applied to ensure water and oil repellency, then liquid infiltration resistance is improved, but adhesion to PSA layers deteriorates

Engineering Contradiction:
Improveliquid infiltration resistanceVSAvoidadhesion to PSA layers
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies a plasma treatment step before applying the low surface energy coating to introduce polar groups and increase surface energy. This preliminary action creates a dual-layer surface structure where the inner plasma-treated layer provides adhesion to PSA while the outer hydrophobic/oleophobic coating provides liquid repellency, thus resolving the contradiction between liquid resistance and adhesion strength

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates different surface properties at different locations of the filter medium. The plasma treatment modifies the bulk surface to be adhesive, while the low surface energy coating is applied selectively to the outer surface to provide liquid repellency. This local differentiation allows the filter medium to simultaneously achieve both strong PSA adhesion and effective liquid infiltration resistance

Inventive Principle:
Principle #3Local quality

2Strength

If a regular base fabric is used as substrate, then structural support is provided, but air permeability and acoustic impedance performance deteriorate

Engineering Contradiction:
Improvestructural supportVSAvoidair permeability and acoustic impedance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent creates a composite structure combining a regular base fabric with an electrospun nanofiber layer. The base fabric provides mechanical strength and structural support, while the nanofiber layer with controlled porosity and surface properties enhances air permeability and optimizes acoustic impedance. This composite material approach allows simultaneous achievement of structural integrity and acoustic performance

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs a nanofiber layer with controlled porosity deposited on the base fabric. The porous structure of the nanofibers allows high air flow through the filter medium while maintaining structural support from the base fabric. The pore size and distribution are optimized to balance mechanical strength with acoustic permeability requirements

Inventive Principle:
Principle #31Porous materials

3Object-affected harmful factors

If nanofiber layer is deposited on base fabric by electrospinning, then particle filtration is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveparticle intrusion protectionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses the base fabric as an intermediary substrate to support the nanofiber layer during electrospinning and subsequent processing. This intermediary structure provides a stable platform for nanofiber deposition, simplifies handling of the delicate nanofiber mat, and facilitates integrated processing of the composite structure in a single manufacturing line, thereby reducing overall manufacturing complexity despite the advanced filtration capability

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution maintains high repellency against water and oils while ensuring strong adhesion to PSA layers, preventing leaks and facilitating easier assembly and cleaning.

Implementation Method 1

a layer of nanofibers (4) deposited on the base fabric (2) by means of an electrospinning process

Methodology Applied
Scientific EffectElectrospinning: Electrohydrodynamics

Implementation Method 2

a plasma coating is applied to the base fabric (2) and the nanofibers (4)

Methodology Applied
Scientific EffectPlasma coating: Plasma

Implementation Method 3

the repellency to water and oily liquids represents an obstacle to effective adhesion

Methodology Applied
Scientific EffectHydrophobicity: Hydrophobe

Implementation Method 4

repellency to water and oily liquids

Methodology Applied
Scientific EffectOleophobicity: Hydrophobe

Data Source

PatentEP3880335B1A method for preparing a composite filter medium and the composite filter medium obtained with this method
Publication Date: 2023.03.29 SAATI SPA
  • EP3880335B1 patent drawingFigure 1~3
  • EP3880335B1 patent drawingFigure 4~5
  • EP3880335B1 patent drawingFigure 6

AI summary

A method for preparing a composite filter medium (1), which involves a step of forming a first filter medium (8) by depositing nanofibers (4) on a base fabric (2) by means of an electrospinning process, a subsequent step of forming said filter medium (1) through plasma deposition of a coating (7) on said first filter medium (8) and a step of forming irregularities on the surface of said coating (7), through plasma treatment of the filter medium (1) obtained in the previous plasma deposition step. With respect to the known filter media, that of the invention offers the advantage of maintaining the desired level of water and oil repellency, without interfering with the secure adhesion of the filter medium to the body on which is located the opening to be protected against liquid infiltration.