Vulcanizable Adhesive Bellows for Fluid-Sealed Filter Elements

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Solution Overview

Problem

Existing methods for manufacturing bellows for filter elements, such as those described in DE 10 2011 011 771 A1, DE 24 17 551 A1, and CH 231 610 A, face limitations in durability, fluid resistance, and sealing effectiveness, particularly when exposed to fuels or oils, and require complex processes or materials like thermoplastic or synthetic resin.

Innovation Solution

A method using a vulcanizable adhesive material with elastomeric properties, comprising rubber and sulfur-donating substances, is applied to connect and seal the end sections of a flat filter medium, allowing for deformation and enhanced resistance to fluids, with the adhesive material being heated to crosslink and penetrate the filter medium for a permanent, fluid-tight connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If thermoplastic material is used to bond end sections, then the bond provides structural connection, but the bellows cannot be highly deformable without damaging the bond

Engineering Contradiction:
Improvebond strengthVSAvoiddeformability
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent changes the material parameters from thermoplastic to vulcanizable adhesive with elastomeric properties. This transformation allows the bond to maintain strength while gaining deformability, as the elastomeric nature enables the adhesive to stretch and flex with the bellows without breaking the bond between end sections.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite approach by combining vulcanizable adhesive with elastomeric properties. This composite material system provides both the structural connection strength needed for bonding and the flexibility required for bellows deformation, resolving the contradiction between strength and adaptability.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If polyurethane adhesive is used, then the adhesive can bond end sections, but the viscosity is too low requiring a mold for application

Engineering Contradiction:
Improvebonding capabilityVSAvoidmold requirement
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent changes the viscosity parameter of the adhesive by selecting vulcanizable adhesive with significantly higher viscosity than polyurethane. This high viscosity eliminates the need for molds during application, as the adhesive can be applied directly and will not flow away, simplifying the manufacturing process while maintaining bonding capability.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional adhesive is used, then the end sections are bonded, but the bond is not resistant to fluids such as fuel or oil

Engineering Contradiction:
Improvebonding processVSAvoidfluid resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs a composite adhesive system comprising vulcanizable adhesive with elastomeric properties and high viscosity. This composite material provides both ease of application and superior fluid resistance, as the vulcanized network structure creates a bond that is resistant to degradation by fuels and oils, enhancing reliability in harsh environments.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters of the adhesive by using vulcanizable adhesive instead of conventional adhesive. This chemical transformation through vulcanization creates a cross-linked structure that provides resistance to fluid penetration and degradation, ensuring the bond remains intact when exposed to fuels or oil.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the adhesive material has low viscosity, then it can be applied easily, but it requires a mold to prevent running and control placement

Engineering Contradiction:
Improveadhesive applicationVSAvoidmold complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent changes the viscosity parameter to a significantly higher value, which allows the adhesive to be applied easily without running or requiring complex mold structures. The high viscosity enables direct application and precise placement while maintaining ease of operation, eliminating the need for complex mold systems.

Inventive Principle:
Principle #35Parameter changes

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 provides a durable, fluid-resistant, and permanently sealed endless bellows that can be deformed without damaging the adhesive bond, ensuring effective sealing and connectivity of the filter medium's end sections, even in harsh environments like those encountered in motor vehicles or aircraft.

Implementation Method 1

bonding a first end section of the filter medium to a second end section of the filter medium using the adhesive material, whereby the adhesive material is vulcanized

Methodology Applied
Scientific EffectVulcanization: Chemical Bonding

Implementation Method 2

the adhesive material is designed to impregnate the filter medium. This allows the adhesive material to penetrate the filter medium, thereby sealing the end sections fluid-tight and bonding them together

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

the adhesive material can be foamed and/or expanded by applying heat. This allows the adhesive material to penetrate even small cavities or gaps

Methodology Applied
Scientific EffectFoaming: Foam

Data Source

PatentEP3124091B1Bellows, filter element and method
Publication Date: 2020.10.07 MANN HUMMEL GMBH
  • EP3124091B1 patent drawingFigure 1
  • EP3124091B1 patent drawingFigure 2~3
  • EP3124091B1 patent drawingFigure 4~5

AI summary

A bellows (2) for a filter element (1), with a planar filter medium (3), wherein a first end section (14) of the filter medium (3) is bonded to a second end section (15) of the filter medium (3) using a vulcanizable adhesive material (16).