Laminated Air Filter Material That Preserves Air Permeability

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Solution Overview

Problem

Existing air filter materials, particularly those combining spun bond and melt blown nonwoven fabrics, face challenges in maintaining air permeability due to the use of adhesives that can fill openings in the spun bond fabric, reducing filtration efficiency.

Innovation Solution

The integration of a polyester nonwoven fabric with a specific 'Y4' shaped continuous filament and a powder or spider web type hot melt adhesive agent, which has a lower melting point than the fibers, ensures strong bonding without significantly reducing air permeability by minimizing adhesive presence in open areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If adhesive agent is used to bond ultrafine fiber nonwoven fabric with polyester nonwoven fabric, then bonding strength is improved, but air permeability is reduced due to adhesive filling openings

Engineering Contradiction:
Improvebonding strengthVSAvoidair permeability
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent employs powder type or spider web type hot melt adhesive agents that form porous or web-like structures rather than continuous films. This allows the adhesive to bond the nonwoven fabrics while maintaining open spaces for air flow, thus preserving air permeability while achieving adequate bonding strength.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The adhesive agent is applied in a distributed manner as powder or spider web patterns rather than uniformly across the entire surface. This localized application ensures bonding at critical points while leaving other areas open for air permeability.

Inventive Principle:
Principle #3Local quality

2Strength

If heat compression is used to laminate and integrate nonwoven fabrics, then integration strength is improved, but openings are filled with molten adhesive reducing air permeability

Engineering Contradiction:
Improveintegration strengthVSAvoidair permeability
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The hot melt adhesive agent is formulated to create a porous or spider web structure upon cooling, maintaining open spaces within the adhesive layer itself. This allows air to pass through the adhesive layer while still providing strong integration between the nonwoven fabric layers.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses a composite structure combining ultrafine fiber nonwoven fabric with polyester nonwoven fabric, bonded by a specially formulated hot melt adhesive that maintains porosity. This composite approach achieves both strong integration and preserved air permeability.

Inventive Principle:
Principle #40Composite materials

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

This approach maintains high air permeability and mechanical strength in the air filter material, preventing adhesive-induced reduction in filtration efficiency while ensuring robust bonding between the ultrafine fiber and polyester nonwoven fabrics.

Implementation Method 1

the ultrafine fiber nonwoven fabric is bonded with the polyester nonwoven fabric by powder type or spider web type hot melt adhesive agent having a melting point lower than the melting points of the ultrafine fiber and the polyester continuous filament

Methodology Applied
Scientific EffectHot melt adhesive bonding: Melting

Implementation Method 2

the polyester continuous filaments are heat bonded with each other

Methodology Applied
Scientific EffectHeat bonding: Heating

Data Source

PatentEP3127594B1Air filter material
Publication Date: 2018.11.28 UNITIKA LTD
  • EP3127594B1 patent drawingFigure 1~3
  • EP3127594B1 patent drawingFigure 4
  • EP3127594B1 patent drawing

AI summary

[Problem] To provide an air filter material in which spun bond nonwoven fabric and melt blown nonwoven fabric are laminated and integrated without reducing air permeability. [Solution] Spun bond nonwoven fabric comprises, as constituting filament, conjugate polyester continuous filaments having a cross-sectional shape of a nearly "Y4"-like shape. The continuous filament is composed of a nearly V-shape portion 6 in the nearly Y4-like shape, formed from low melting point polyester, and the other nearly + shape portion 5 therein, formed from high melting point polyester. The continuous filaments are heat-bonded with each other by the low melting point polyester. The spun bond nonwoven fabric is bonded by a powder type or spider web type hot melt adhesive agent with the melt blown nonwoven fabric.