Fine Fiber Filter Medium for Stable Efficiency Under Cyclic Flow

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Solution Overview

Problem

Existing filter media designs suffer from reduced efficiency under varying flow conditions without a corresponding increase in pressure drop, leading to increased energy consumption and shorter filter life.

Innovation Solution

A filter medium comprising a support layer, a continuous fine fiber layer, and an efficiency layer, with specific P95/P50 ratios and configurations, minimizes the adverse effects of flow rate variations by distributing contaminant collection across the depth of the medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the efficiency of the filter media is increased to minimize the adverse effects of varying flow rates, then the filter media efficiency is improved, but the pressure drop increases correspondingly

Engineering Contradiction:
Improvefilter media efficiencyVSAvoidpressure drop
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The filter media is divided into multiple layers with distinct functions: a first layer (efficiency layer) optimized for particle capture and a second layer (support layer) optimized for structural support and flow distribution. This segmentation allows each layer to be optimized independently, enabling high efficiency without excessive pressure drop as the support layer maintains open flow paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the filter media have different properties tailored to their specific functions. The first layer has high filtration efficiency properties (fine fibers, high solidity) while the second layer has high support properties (coarse structure, high porosity). This local optimization allows the efficiency layer to capture particles effectively while the support layer prevents excessive pressure buildup.

Inventive Principle:
Principle #3Local quality

2Reliability

If the pressure drop is increased to maintain efficiency under varying flow conditions, then the filter media efficiency is preserved, but the energy consumption increases

Engineering Contradiction:
Improvefilter media efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

By segmenting the filter media into efficiency and support functions, the system achieves high efficiency without requiring high pressure drops. The support layer's open structure allows fluid to flow through with minimal resistance, reducing the energy required to maintain filtration efficiency under varying flow conditions.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the pressure drop is increased to maintain efficiency, then the filter media efficiency is maintained, but the filter life decreases

Engineering Contradiction:
Improvefilter media efficiencyVSAvoidfilter life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The segmented structure allows the efficiency layer to focus on particle capture while the support layer maintains structural integrity and flow paths. This division of labor enables the filter to maintain efficiency over longer periods without the pressure drop that would otherwise lead to premature failure or bypassing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support layer acts as a cushioning element that prevents excessive pressure buildup before it can damage the efficiency layer or cause bypassing. By providing this protective support structure in advance, the filter media can operate at high efficiency for extended periods without compromising filter life.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 efficiency under cyclic flow conditions without a significant increase in pressure drop, extending the life and performance of hydraulic systems.

Implementation Method 1

A filter medium comprising a support layer; a continuous fine fiber layer, having a thickness of up to 50 μm and wherein the fine fiber has a diameter of up to 10 micrometers (μm)

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP4041432B1Filter medium comprising a fine fiber layer
Publication Date: 2026.04.15 DONALDSON CO INC
  • EP4041432B1 patent drawingFigure 1A
  • EP4041432B1 patent drawingFigure 1B~2A
  • EP4041432B1 patent drawingFigure 2B

AI summary

This disclosure describes a filter medium that minimizes the adverse effects of variations in flow rate on filter medium efficiency without a corresponding increase in pressure drop. The filter medium includes a support layer, a continuous fine fiber layer, and an efficiency layer. The continuous fine fiber layer includes a continuous fine fiber that has a diameter of up to 10 micrometers and is located downstream of the efficiency layer.