Oleophobic Polyamide Fine Fibers with Fluorochemical Urethane Additive

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Solution Overview

Problem

Current fine fiber materials used in filtration applications, especially those subjected to varying environmental conditions, lack sufficient mechanical stability and enhanced oleophobicity and hydrophobicity, which are crucial for maintaining performance over time.

Innovation Solution

Incorporating a fluorochemical urethane additive into fiber-forming polyamide fibers to enhance their oleophobicity and hydrophobicity, thereby improving their mechanical stability and filtration efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fine fiber materials are used in filtration applications, then basic filtration function is provided, but mechanical stability and oleophobicity/hydrophobicity are insufficient under varying environmental conditions

Engineering Contradiction:
Improvemechanical stabilityVSAvoidperformance under environmental conditions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies composite materials by combining polyamide fine fibers with fluoropolymer coating material to create a hybrid structure. The polyamide provides mechanical stability and structural integrity, while the fluoropolymer coating imparts oleophobicity and hydrophobicity. This composite approach resolves the contradiction by integrating two materials with complementary properties into a single functional filtration medium that maintains performance under varying environmental conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by coating only the surface of the fine fibers with fluoropolymer material, rather than altering the bulk properties of the entire fiber structure. The core polyamide fiber maintains its mechanical stability, while the surface coating provides the required oleophobicity and hydrophobicity. This localized modification allows the fiber to exhibit different properties at different levels (core vs. surface), resolving the contradiction between mechanical stability and environmental adaptability.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If filter media is subjected to wide range of environmental conditions, then broader application scope is achieved, but mechanical stability deteriorates

Engineering Contradiction:
Improveapplication scopeVSAvoidmechanical stability
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The composite structure of polyamide core fibers with fluoropolymer coating enables the filter media to withstand wide environmental conditions while maintaining mechanical stability. The polyamide provides robust structural support, and the fluoropolymer coating protects the surface from chemical degradation and maintains surface properties under varying conditions, thus expanding application scope without sacrificing strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The fluoropolymer coating acts as a thin protective film on the fiber surface that provides environmental resistance while maintaining flexibility. This thin film structure allows the underlying polyamide fiber to maintain its mechanical properties while the coating provides protection against environmental degradation, enabling broader application scope without compromising mechanical stability.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If filtration efficiency is increased through fine fiber technology, then particle removal is improved, but mechanical stability and durability are reduced

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

Solution Approach 1:

The composite structure combines the fine fiber architecture (which provides high filtration efficiency through increased surface area and pore density) with the robust polyamide material and fluoropolymer coating (which provide mechanical stability and durability). This allows the filter to maintain high particle removal efficiency while the strengthened composite structure extends filter life and mechanical durability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The fluoropolymer coating is applied locally to the fiber surface to provide enhanced durability and chemical resistance without significantly altering the fine fiber structure that enables high filtration efficiency. This localized reinforcement protects the delicate fine fibers from degradation, extending filter life while maintaining the high surface area and pore structure necessary for efficient particle removal.

Inventive Principle:
Principle #3Local quality

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 resulting fine fibers demonstrate improved resistance to water and oil penetration, extended filter life, and enhanced mechanical stability, making them suitable for applications in diverse environmental conditions.

Implementation Method 1

the fluorochemical urethane additive is present in an amount effective to enhance the oleophobicity and hydrophobicity of the fine fiber

Methodology Applied
Scientific EffectOleophobicity: Surface Tension

Implementation Method 2

the fluorochemical urethane additive is present in an amount effective to enhance the oleophobicity and hydrophobicity of the fine fiber

Methodology Applied
Scientific EffectHydrophobicity: Surface Tension

Implementation Method 3

improved resistance to water and oil penetration

Methodology Applied
Scientific EffectWater resistance: Hydrophobe

Implementation Method 4

improved resistance to water and oil penetration

Methodology Applied
Scientific EffectOil resistance: Surface Tension

Data Source

PatentEP3724381B1Oleophobic polyamide fine fibers, methods, filter media, and filter elements
Publication Date: 2024.11.06 DONALDSON CO INC
  • EP3724381B1 patent drawingFigure 1A~1B
  • EP3724381B1 patent drawingFigure 2~3
  • EP3724381B1 patent drawingFigure 4

AI summary

The present disclosure provides a unique fine fiber material that is formed from a fiber-forming polyamide with a fluorochemical urethane additive, a method of making such fiber material, as well as filter media and filter elements including such fibers.