Polyurea-Coated Filter Media Pack for Leak-Resistant Sealing

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Solution Overview

Problem

Conventional filter media packs are prone to puncturing and gouging during handling, lack strong bonding surfaces for seal members, and create leak paths due to difficult wrapping and binding, necessitating complex and expensive molding techniques.

Innovation Solution

A polymeric coating with a surface roughness of at least 1.27 µm and Shore A Durometer hardness of 60-95 is applied to the filter media pack, penetrating up to 228.6 µm, providing a durable and aesthetically pleasing surface that enhances handling and prevents leaks by integrating with the filter media.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional fabric or paper wraps are used to protect filter media packs, then some reinforcement is provided, but the wraps do not protect the filter media from puncturing or gouging during handling

Engineering Contradiction:
Improveprotection from puncturingVSAvoidvulnerability to puncturing and crushing
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies a polymeric coating to the outer surface of the filter media pack that changes the surface properties by providing enhanced hardness and puncture resistance. The coating material parameters are selected to specifically resist puncturing and crushing forces during handling, transforming the surface characteristics from vulnerable fabric/paper to a more resilient polymeric layer.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure by combining the filter media pack with a polymeric coating layer. This composite material approach integrates the filtering functionality of the media pack with the protective properties of the polymeric coating, achieving both filtration and enhanced mechanical protection against puncturing and crushing.

Inventive Principle:
Principle #40Composite materials

2Strength

If conventional fabric or paper wraps are used, then some reinforcement is provided, but they do not provide strong bonding surfaces for attaching structures

Engineering Contradiction:
Improvebonding surface strengthVSAvoiddifficulty to bind to filter media
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The polymeric coating changes the surface parameters of the filter media pack to provide optimal bonding characteristics. The coating creates a surface with appropriate roughness, porosity, and chemical properties that enable strong adhesion of seal members and mounting frames, making attachment operations easier and more reliable compared to conventional fabric or paper wraps.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conventional wraps are used, then some protection is provided, but they are difficult to bind to the filter media creating leak paths

Engineering Contradiction:
Improveleak preventionVSAvoiddifficulty to bind
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The polymeric coating creates a composite surface that integrates the filter media with a bonding-optimized layer. This composite structure eliminates the interface problems between separate wrap layers and filter media, providing continuous coverage and reliable bonding that prevents leak paths while simplifying the binding operation.

Inventive Principle:
Principle #40Composite materials

4Strength

If a molded protective layer is applied, then protection is provided, but it requires substantial space and complex, expensive molding tooling

Engineering Contradiction:
Improveprotection durabilityVSAvoidmolding tooling complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extracts the protective function from the complex molded structure and implements it through a simpler polymeric coating application. This eliminates the need for substantial molding tooling and associated complexity while maintaining the protective durability, as the coating can be applied using conventional coating equipment rather than complex injection molding tools.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The polymeric coating represents a more economical alternative to expensive molded protective layers. The coating material and application process are less costly than manufacturing molded structures, providing comparable protection without the substantial space requirements and complex tooling investments.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 polymeric coating improves puncture and crush resistance, stabilizes dimensions, and creates a bonding surface for gaskets, reducing leak paths and enhancing the overall durability and handling of filter media packs.

Implementation Method 1

the polymeric coating penetrates the filter media pack to a depth of at least 9,000 μin

Methodology Applied
Scientific EffectPenetration: Absorption (physical)

Implementation Method 2

the polymeric coating can have a surface roughness of at least 50 μin

Methodology Applied
Scientific EffectSurface roughness: Friction

Implementation Method 3

the polymeric coating can be impermeable to air and moisture

Methodology Applied
Scientific EffectImpermeability: Permeation

Data Source

PatentEP4324542B1Surface coated filter
Publication Date: 2026.05.06 BALDWIN FILTERS INC
  • EP4324542B1 patent drawingFigure 1~3B
  • EP4324542B1 patent drawingFigure 4
  • EP4324542B1 patent drawingFigure 5~6

AI summary

A filter element (10; 400; 500), comprising a filter media pack (12; 212; 412; 512) including an outer surface (14; 214), the outer surface (14; 214) extending between a first flow face (16; 216; 416; 516) and a second flow face (18; 218; 418; 518), a polymeric coating (20; 220; 420; 520) applied to the outer surface (14; 214) of the filter media pack, wherein the polymeric coating (20; 220; 420; 520) is not a molded structure, and wherein the polymeric coating (20; 220; 420; 520) is polyurea.