Plastic-Metal Compound Sealing via Form-Fit Connection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional metal-plastic connections in food technology face challenges with reliability, tightness, and hygiene due to the use of adhesives and mechanical fasteners, which can release undesired substances and require complex post-processing for surface quality, especially under varying temperatures and pressures.

Innovation Solution

A method forming a collar-shaped bead and shoulder step on the metal surface with a strip-shaped seal, allowing a form-fitting, elastically supported connection between metal and plastic surfaces, creating a seamless and step-free transition without additional fasteners, using an elastic seal like Viton or rubber, and optimizing the plastic surface's profile for secure bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesives are used to seal the connection between metal and plastic surfaces, then sealing reliability is improved, but hygiene properties deteriorate due to release of undesired substances and insufficient aging resistance

Engineering Contradiction:
Improvesealing reliabilityVSAvoidhygiene properties
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates the adhesive substance from the sealing system entirely. Instead of using chemical adhesives that release undesired substances, the patent employs a purely mechanical forming process where the plastic material is directly formed into an interference fit connection with the metal surface, creating a seal without any chemical bonding agents.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the chemical bonding mechanism (adhesives) with a mechanical bonding mechanism (interference fit through plastic deformation). The plastic surface is formed to create elastic compression against the metal surface, achieving sealing through mechanical contact pressure rather than chemical adhesion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If mechanical fasteners are used to connect metal and plastic surfaces, then connection strength is improved, but device complexity and hygiene properties deteriorate due to additional components and cleaning difficulties

Engineering Contradiction:
Improveconnection strengthVSAvoidfastener components
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention merges the functions of connection and sealing into a single integrated forming process. The plastic surface is formed to simultaneously achieve mechanical interlocking (connection strength) and elastic compression sealing (tightness), eliminating the need for separate fasteners and seals.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plastic material itself serves as both the structural component and the sealing element. Through forming, the plastic creates its own interference fit connection and sealing interface without requiring additional fastening components or separate sealing elements.

Inventive Principle:
Principle #25Self-service

3Reliability

If conventional joining methods are used to connect metal and plastic, then connection reliability is improved, but manufacturing precision deteriorates due to complex post-processing steps required for surface quality

Engineering Contradiction:
Improveconnection reliabilityVSAvoidsurface quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention performs the surface forming and sealing action during the primary joining process itself, rather than requiring subsequent post-processing steps. The plastic surface is formed in advance to create the precise interference fit geometry needed for both connection and sealing, eliminating the need for later polishing or machining operations.

Inventive Principle:
Principle #10Preliminary action

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

This method enables an adhesive-free, impermeable composite with enhanced hygiene and aseptic properties, suppressing the incorporation of substances, and eliminates the need for post-processing steps, ensuring reliable sealing and surface smoothness without mechanical or chemical fasteners.

Implementation Method 1

a form-fitting elastically supported connection is generated

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2213405B1Plastic-metal compound
Publication Date: 2011.03.30 PEPPERL & FUCHS GMBH
  • EP2213405B1 patent drawingFigure 1~4

AI summary

The method involves combining a side surface of a plastic surface (50) with a side surface of a metal surface (10). A form-fit flexibly supporting connection is produced by deformation between a part of the side surface of the metal surface and a part of the side surface of the plastic surface. A jointless and step-free transition is formed between the metal surface and the plastic surface at a connection position on an upper side of the metal surface and the plastic surface. A returning profile is formed at the side surface of the metal surface. An independent claim is also included for a metal-plastic compound comprising a metal surface and a plastic surface.