Composite Molded End Cap for Air Filter Structural Integrity

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Solution Overview

Problem

Existing air filter elements with closed end caps made from molded foam materials may not provide sufficient strength to withstand substantial inwardly directed air forces, especially when the filter media pack becomes heavily contaminated, leading to potential deformation and seal breaches.

Innovation Solution

A method of constructing air filter elements with closed end caps formed from first and second foam portions of differing physical properties, which are simultaneously cured to meet at a common juncture, providing enhanced structural integrity without the need for additional reinforcing plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a one-piece molded end cap is used, then manufacturing simplicity and cost are improved, but structural strength under substantial inward forces deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidstructural strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The end cap is divided into multiple foam portions (first foam portion and second foam portion) with different physical properties, each contributing different functions. The first foam portion provides sealing and compliance, while the second foam portion provides structural strength, resolving the contradiction between manufacturing simplicity and structural strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The end cap uses composite foam materials with different densities and physical properties in different regions. The first foam portion has lower density for compliance and sealing, while the second foam portion has higher density for strength, allowing the single-piece molded structure to achieve both ease of manufacture and adequate structural strength.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the filter media pack absorbs maximum contaminants, then filtration effectiveness is improved, but inward pressure forces increase causing deformation

Engineering Contradiction:
Improvefiltration effectivenessVSAvoidresistance to deformation
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

Different regions of the end cap have different physical properties tailored to local requirements. The first foam portion provides compliance for sealing against the housing, while the second foam portion provides rigidity for withstanding inward pressure forces on the media pack, allowing the structure to maintain strength and sealing under contaminated conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The compliant first foam portion acts as a cushioning element that absorbs and distributes inward pressure forces before they reach the housing seal interface, preventing deformation and maintaining the radial seal even when the media pack is heavily contaminated and under maximum pressure.

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

3Strength

If a reinforcing plate or pedestal is added to the end cap, then structural strength is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvestructural strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The reinforcing function is merged into the foam material itself by creating a second foam portion with higher density and different physical properties during the same molding process. This eliminates the need for separate reinforcing plates or pedestals, maintaining structural strength while avoiding additional manufacturing complexity and assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of adding discrete reinforcing elements, the patent uses composite foam materials with varying densities and properties within the single molded end cap structure. The second foam portion with higher density provides the necessary structural reinforcement without requiring separate components or complex assembly procedures.

Inventive Principle:
Principle #40Composite materials

4Reliability

If the end cap is made entirely from compliant foam material, then sealing capability is improved, but resistance to inward forces deteriorates

Engineering Contradiction:
Improvesealing capabilityVSAvoidresistance to inward forces
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The end cap employs local quality differentiation where the first foam portion has compliant properties optimized for sealing against the housing, while the second foam portion has rigid properties optimized for withstanding inward pressure forces. This spatial differentiation of material properties allows both sealing capability and force resistance to be optimized in their respective locations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The end cap is constructed as a composite structure with two foam portions having different physical properties. The first foam portion provides compliance for sealing, while the second foam portion with higher density and different cellular structure provides structural strength, allowing the single-piece end cap to simultaneously achieve both sealing capability and resistance to inward forces.

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 solution enhances the structural capabilities of air filter elements, allowing them to withstand operational loads effectively while maintaining a radial seal, thus preventing deformation and ensuring efficient filtration even under high pressure conditions.

Implementation Method 1

both portions of the end cap being simultaneously cured to meet at a common juncture

Methodology Applied
Scientific EffectCuring: Chemical Bonding

Data Source

PatentEP2007497B1Air filter element with composite molded end cap
Publication Date: 2011.11.09 BALDWIN FILTERS INC
  • EP2007497B1 patent drawingFigure 1
  • EP2007497B1 patent drawingFigure 2
  • EP2007497B1 patent drawingFigure 3~4

AI summary

A method and apparatus are provided for constructing a filter element, having enhanced structural capabilities, through use of a molded end cap having first and second foam portions of differing physical properties meeting at a common juncture of the first and second foam portions and simultaneously cured with one another.