Pleated Filter Element With Edge Dams For Airflow

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Solution Overview

Problem

Existing air filter technologies face challenges in achieving a balance between high filtration efficiency and low pressure drop, particularly in pleated filter media, where tight pleating patterns can lead to airflow obstruction and mechanical fragility.

Innovation Solution

A pleated filter element with a multilayer structure comprising an organic polymeric nonwoven primary filtration layer laminated with a fiberglass prefilter layer, combined with hardened adhesive edge dams to enhance pleatability and durability, allowing for tight pleat configurations without significant airflow restriction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If tight pleating patterns are used in filter media, then filtration efficiency is improved, but airflow obstruction increases and mechanical fragility worsens

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidairflow obstruction
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent transitions from traditional 2D flat filter media to 3D pleated structures with controlled geometry. By optimizing pleat dimensions (height, width, spacing) and using wave-shaped configurations, the filter media increases its effective filtration surface area while maintaining airflow channels, thereby achieving high filtration efficiency without significant airflow obstruction.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs composite filter media structures combining different materials with complementary properties. The media integrates high-efficiency filtration layers with supportive structural layers, creating a composite that maintains mechanical strength and flexibility even with tight pleating, thus preventing both airflow obstruction and mechanical failure.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If tight pleating patterns are used in filter media, then filtration efficiency is improved, but mechanical fragility increases

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidmechanical fragility
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The patent applies different material properties and structural characteristics to different regions of the filter media. Supportive reinforcement elements are strategically positioned at critical stress points such as pleat edges and folds, while the central filtration zones maintain optimal porosity and filtration properties. This localized differentiation allows tight pleating for high efficiency without compromising overall mechanical strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes flexible support structures and reinforced edge designs that can accommodate the stress of tight pleating without breaking. The media incorporates flexible yet strength-providing elements that maintain the pleated configuration under operational conditions, preventing mechanical fragility while enabling the tight pleating necessary for high filtration efficiency.

Inventive Principle:
Principle #30Flexible shells and thin films

3Stability of the object's composition

If adhesive is applied to seal pleat edges, then structural integrity is improved, but airflow restriction may increase

Engineering Contradiction:
Improvestructural integrityVSAvoidairflow restriction
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent carefully extracts and removes excess adhesive from the pleat sealing process, applying adhesive only where absolutely necessary for structural integrity. By minimizing adhesive application to critical bonding points rather than coating entire edges, the patent maintains pleat edge stability while preventing adhesive buildup that would restrict airflow through the filter media.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3503991B1Pleated filter element comprising pleated filter media with edge dams, and method of making and using
Publication Date: 2022.11.23 3M INNOVATIVE PROPERTIES CO
  • EP3503991B1 patent drawingFigure 1
  • EP3503991B1 patent drawingFigure 2~4
  • EP3503991B1 patent drawingFigure 5~7

AI summary

A pleated filter element comprising a pleated filter media comprising a plurality of oppositely-facing pleats with a pleat direction and with a plurality of upstream and downstream pleat tips and pleat valleys, wherein the pleated filter media comprises two corrugated edges and two noncorrugated edges. The first (second) corrugated edge of the pleated filter media comprises an edge dam of hardened adhesive that occupies the upstream and downstream pleat valleys at a location laterally inwardly proximate the first (second) corrugated edge and that extends along an entire longitudinal extent of the pleated filter media. The pleated filter media is a multilayer media comprising an organic polymeric nonwoven web, that exhibits a Percent Penetration of less than 5, laminated with a fiberglass prefilter layer that is disposed upstream of the primary filtration layer and that exhibits a Percent Penetration of greater than about 70.