Self-supporting pleated filter with alternating major and minor pleats

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Solution Overview

Problem

Pleated filtration media in filter elements often suffer from deflection and 'masking' issues due to lack of structural support, leading to reduced surface area and performance, and existing methods to address these challenges are costly or not versatile.

Innovation Solution

A pleated media pack configuration with alternating major and minor pleats, where some pleats are inverted at the ends, optimizing the pleat depth to outlet diameter ratio to enhance structural stiffness, flexibility, and compressibility, while maintaining cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If simple alternating zigzag pleats are used, then manufacturing is simple, but the pleats are prone to deflection and masking

Engineering Contradiction:
Improvepleat formation simplicityVSAvoidpleat structural integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The pleat structure is segmented into multiple zones along its length, with different folding patterns in different sections. The pleats are divided into a first section with a first folding pattern and a second section with a second folding pattern, allowing each segment to serve a specific functional purpose while maintaining overall structural integrity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces asymmetric pleat configurations where adjacent pleats have different folding patterns. Specifically, pleats alternate between having a first section with a first folding pattern and a second section with a second folding pattern, creating an asymmetric structure that prevents uniform deflection and masking while remaining manufacturable

Inventive Principle:
Principle #4Asymmetry

2Area of stationary object

If deep pleats are used to maximize surface area, then filtration surface area increases, but deflection and masking become more severe

Engineering Contradiction:
Improvefiltration surface areaVSAvoidpleat spacing maintenance
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The pleat structure incorporates dynamic characteristics through varied folding patterns that allow the pleats to maintain their spaced configuration under operational forces. The asymmetric folding patterns enable the deep pleats to flex and adapt while maintaining structural integrity and preventing masking

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention adds complexity in the longitudinal dimension by varying the folding pattern along the length of each pleat. Instead of a simple two-dimensional zigzag, the pleats have different folding patterns in different sections, effectively utilizing the third dimension (length) to prevent masking while maintaining deep pleat configuration

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

3Reliability

If structural supports are added to prevent deflection, then pleat spacing is maintained, but manufacturing cost increases

Engineering Contradiction:
Improvepleat spacing maintenanceVSAvoidstructural support requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pleat structure is designed to be self-supporting through its asymmetric folding patterns. The varied folding patterns create inherent structural stability that prevents deflection and masking without requiring additional external structural supports, adhesives, or fasteners

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of adding external supports to prevent deflection, the invention inverts the approach by designing the folding pattern itself to provide the structural support. The asymmetric folding patterns inherently resist deflection forces, eliminating the need for additional support structures

Inventive Principle:
Principle #13The other way round (Inversion)

4Volume of stationary object

If filtration elements are made compact to reduce size, then volume is reduced, but surface area to volume ratio decreases

Engineering Contradiction:
Improvefiltration element volumeVSAvoidfiltration surface area
Core Design Contradiction:
Volume of stationary objectVSArea of stationary object

Solution Approach 1:

The deep pleats are nested within a compact cylindrical housing, allowing the filtration surface to be folded into a small volume. The asymmetric folding patterns enable the pleats to be packed densely while maintaining their expanded surface area configuration during operation

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention maximizes surface area within compact volume by utilizing the radial dimension through deep pleats and the longitudinal dimension through varied folding patterns. This multi-dimensional approach to surface area generation allows high surface area to volume ratio in a compact configuration

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

Data Source

PatentEP3129123B1Self-supporting folded sheet material and filter elements
Publication Date: 2021.05.05 DONALDSON CO INC
  • EP3129123B1 patent drawingFigure 1
  • EP3129123B1 patent drawingFigure 2
  • EP3129123B1 patent drawingFigure 3

AI summary

A pleated media pack includes a section of media configured into a tube defining an interior volume and an open opening at one end. At least some of the pleats at both ends of the media pack are inverted. In some examples, the pleats include major pleats alternating with minor pleats.