Composite Filter Medium With Nanofiber Web for Long-Life PM2.5 Filtration

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Solution Overview

Problem

Existing melt blown-based filter media suffer from reduced efficiency due to adhesion of dry dust, wet dust, and moisture, and electrostatic force degradation, leading to decreased filtration efficiency over time, and conventional methods for water/oil repellency shorten product lifespan or impair air flow.

Innovation Solution

A filter medium comprising a first porous support body electrostatically treated with a nanofiber web on one surface, and optionally additional support bodies, achieving high filtration efficiency and air permeability, with the nanofiber web providing water/oil repellency and maintaining efficiency over extended use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrostatic treatment is applied to melt blown filter media to achieve high filtration efficiency, then filtration efficiency is improved, but efficiency deteriorates over time due to adhesion of dust and moisture

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidservice life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent combines electrostatically treated melt blown filter media with a nanofiber web layer to create a composite filter structure. The nanofiber web provides water and oil repellency that prevents dust and moisture from adhering to the electrostatic fibers, thereby maintaining filtration efficiency over extended service life while preserving the high efficiency benefits of electrostatic treatment.

Inventive Principle:

Principle #40Composite materials

2Reliability

If fiber size is reduced to improve filtration efficiency, then filtration efficiency is improved, but manufacturing complexity and production costs increase

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a composite structure where the nanofiber web layer provides fine filtration capability without requiring the melt blown media to be manufactured with extremely small fibers. The nanofibers naturally provide water and oil repellency, eliminating the need for additional complex coating processes while achieving high filtration efficiency.

Inventive Principle:

Principle #40Composite materials

3Object-affected harmful factors

If conventional water/oil repellent processing is applied to non-woven fabrics, then water and oil repellency is improved, but product lifespan is shortened due to processing deterioration

Engineering Contradiction:

Improvewater and oil repellencyVSAvoidproduct lifespan

Core Design Contradiction:

Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The patent incorporates water and oil repellent properties directly into the nanofiber web material composition rather than applying them as surface coatings. This integrated approach provides durable water and oil repellency that does not deteriorate with use, thereby extending product lifespan while maintaining effective water and oil repellency.

Inventive Principle:

Principle #40Composite materials

4Object-affected harmful factors

If PTFE membrane is used to provide water repellency, then water repellency is improved, but air permeability and contaminant collection are reduced

Engineering Contradiction:

Improvewater repellencyVSAvoidair permeability and contaminant collection

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses a composite structure where the nanofiber web provides water and oil repellency through its material composition and three-dimensional network structure, rather than relying on a continuous PTFE membrane. This approach maintains water repellency while preserving high air permeability and effective contaminant collection capability through the porous nanofiber architecture.

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

The filter medium maintains 95% or more filtration efficiency for fine dust PM 2.5 and prevents significant efficiency loss over several months, while ensuring low pressure loss and improved air permeability.

Implementation Method 1

a first porous support body which has been electrostatically treated

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

the nanofiber web which is disposed on one surface of the first porous support body and formed by accumulating nanofibers

Methodology Applied

Scientific EffectWater and oil repellency: Hydrophobe

Data Source

PatentUS12539476B2Filter medium and composite filter including same

Publication Date: 2026.02.03 AMOGREENTECH CO LTD

AI summary

Provided is a filter medium. A filter medium according to an embodiment of the present invention comprises: a first porous support body which has been electrostatically treated; and a nanofiber web which is disposed on one surface of the first support body and formed by accumulating nanofibers. Accordingly, excellent air filtering efficiency is obtained even for fine dust of PM 2.5 or below, and furthermore, deterioration in air filtering efficiency may be prevented or minimized even when usage is extended for a long period of time. Therefore, the filter medium and the composite filter according to an embodiment of the present invention can be widely utilized as media of filters for various air filtering devices.