Alternating Layer Filter Medium for Reduced Pressure Loss

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Solution Overview

Problem

Existing filter media for air flow cleaning have a thicker structure due to the duplication of non-woven fabric layers, leading to increased material consumption and pressure loss, which affects filtration performance.

Innovation Solution

A filter medium design where non-woven fabric systems and adsor systems alternate, eliminating the duplication of non-woven fabric layers, resulting in a thinner and more material-efficient structure with improved filtration performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If nonwoven fabric layers are arranged in parallel with adsorbent layers in traditional filter media, then the filter medium provides comprehensive filtration functionality, but the nonwoven fabric layers are doubled inside the filter medium resulting in increased thickness and material consumption

Engineering Contradiction:
Improvematerial consumptionVSAvoidthickness of filter medium
Core Design Contradiction:
Quantity of substanceVSLength of stationary object

Solution Approach 1:

The patent inverts the traditional layer arrangement by placing the adsorbent layer at the center with nonwoven fabric layers alternately positioned on both sides, rather than having nonwoven layers stacked parallel to each other. This inversion eliminates the doubling of nonwoven fabric layers while maintaining filtration functionality, directly reducing material consumption and thickness.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from a traditional parallel stacking arrangement to an alternating layered structure where nonwoven fabric and adsorbent layers are interleaved. This dimensional reorganization optimizes space utilization, allowing the filter medium to achieve comprehensive filtration functionality with reduced thickness and material consumption.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If traditional filter media structure with doubled nonwoven fabric layers is used, then complete filtration coverage is achieved, but pressure loss increases and filtration performance decreases

Engineering Contradiction:
Improvefiltration performanceVSAvoidpressure loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

By inverting the layer arrangement to place adsorbent material at the center with alternating nonwoven fabric layers, the patent reduces the total thickness of nonwoven fabric while maintaining filtration coverage. This reduces flow resistance and pressure loss, thereby improving filtration performance and reducing energy loss.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent creates a composite structure combining adsorbent layers and nonwoven fabric layers in an alternating pattern. This composite arrangement optimizes both filtration efficiency and airflow characteristics, reducing pressure loss while maintaining reliable filtration performance.

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 alternating layer structure reduces material thickness and consumption, leading to lower pressure loss and enhanced filtration performance, including higher separation efficiency and reduced material costs.

Implementation Method 1

The filter medium according to the invention serves to purify an airflow and has a plurality of nonwoven layers and adsorbent layers

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

a first layer consisting of a nonwoven fabric layer bonded to an adsorbent layer, and a second layer consisting of an adsorbent layer with nonwoven fabric layers applied to both sides

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3865197B1Multiple layer filter medium
Publication Date: 2025.05.07 CARL FREUDENBERG KG
  • EP3865197B1 patent drawingFigure 1
  • EP3865197B1 patent drawingFigure 2
  • EP3865197B1 patent drawingFigure 3

AI summary

The invention relates to a filter medium. The filter medium (10) serves to purify an airflow (L) and comprises a plurality of nonwoven layers (4) and adsorbent layers (5), wherein the nonwoven layers (4) and the adsorbent layers (5) are arranged parallel to each other. According to the invention, the filter medium (10) has at least two superimposed layers (1, 2), with a first layer (1) consisting of a nonwoven layer (4) bonded to an adsorbent layer (5), and a second layer (2) consisting of an adsorbent layer (5) on which nonwoven layers (4) are attached on both sides. Compared to filter media with a doubling of nonwoven layers, the filter medium according to the invention is thinner and more material-efficient.