Fine Fiber Filter Medium for Variable-Flow Efficiency

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Solution Overview

Problem

Filter media efficiency is adversely affected by variations in flow rate during hydraulic applications, leading to increased pressure drop and reduced performance under dynamic conditions.

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 without increasing pressure drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

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

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

Solution Approach 1:

The filter media is divided into multiple functional layers: a support layer providing structural integrity, a fine fiber layer (5-50 μm thick) with controlled pore size distribution (P95/P50 ratio of 1.5-2.5) for particle capture, and an efficiency layer with higher P95/P50 ratio (2.0-3.0) for enhanced filtration. This segmentation allows each layer to perform its specific function optimally without compromising overall pressure drop

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite structure combining different fiber types and pore size distributions in specific layers. The fine fiber layer uses fibers with diameters of 5-50 μm while the efficiency layer uses fibers with different properties, creating a composite material system that achieves high efficiency under dynamic flow conditions while maintaining acceptable pressure drop characteristics

Inventive Principle:
Principle #40Composite materials

2Reliability

If the filter media is designed for high efficiency under dynamic flow conditions, then the filter media efficiency is improved, but the filter life decreases due to increased pressure drop

Engineering Contradiction:
Improvefilter media efficiency under dynamic flowVSAvoidfilter life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The fine fiber layer is designed with specific dynamic properties including fiber diameter of 5-50 μm and controlled P95/P50 ratio (1.5-2.5) that allow it to adapt to varying flow conditions. The layer maintains its structural integrity and filtration efficiency under cyclic and dynamic flow rates, preventing the efficiency degradation that normally occurs with flow variations

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention optimizes critical parameters including the thickness of the fine fiber layer (5-50 μm), fiber diameter (5-50 μm), and pore size distribution ratios (P95/P50 of 1.5-2.5 for fine fiber layer, 2.0-3.0 for efficiency layer). These parameter optimizations enable the filter to maintain efficiency under dynamic flow while controlling pressure drop to extend filter life

Inventive Principle:
Principle #35Parameter changes

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 variable flow conditions while keeping pressure drop within acceptable limits, extending filter life and improving hydraulic system performance.

Implementation Method 1

A filter medium that minimizes the adverse effects of variations in flow rate on filter medium efficiency without a corresponding increase in pressure drop

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP4729151A2Filter medium comprising a fine fiber layer
Publication Date: 2026.04.22 DONALDSON CO INC
  • EP4729151A2 patent drawingFigure 1A
  • EP4729151A2 patent drawingFigure 1B~2A
  • EP4729151A2 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.