Reclosable Can Lid Microgap Sealing Without Metal Chip Formation

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Solution Overview

Problem

Existing methods for producing reclosable can lids are not economical and require complex structural designs, leading to material inefficiencies and potential hygiene issues due to protrusions and gaps.

Innovation Solution

A method involving a microgap in the metal lid surface sealed by a plastic film with a sealing frame and closing unit, using an adhesive lacquer layer for bonding, which allows for a simplified design, material savings, and improved hygiene by avoiding external plastic element exposure and microparticle formation during opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex structural design with protruding plastic elements is used for reclosable can lids, then the sealing and locking function is improved, but the device complexity and material usage increase

Engineering Contradiction:
Improvesealing and locking functionVSAvoidstructural design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the sealing frame and closing unit into a single integrated plastic component that is injection-molded directly onto the metal lid. This merging of previously separate elements (sealing frame, closing unit, and lid structure) into one composite component reduces device complexity while maintaining the sealing and locking functions through integrated design features.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated plastic component serves multiple functions simultaneously: it provides sealing through the sealing frame, enables opening/closing action through the closing unit, and attaches to the metal lid. This multi-functionality eliminates the need for separate dedicated components for each function, reducing overall structural complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If traditional punching methods are used to create the opening, then the opening is created, but metal microparticles are generated causing hygiene issues

Engineering Contradiction:
Improveopening creationVSAvoidmetal microparticle formation
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a plastic film as an intermediary layer between the punching tool and the metal lid. The film is punched first, creating the opening without direct metal-to-tool contact that would generate microparticles. The film acts as a mediator that transfers the opening function while preventing harmful particle generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potential harm of direct punching into a benefit by using the plastic film's properties. The film's flexibility and ease of punching become advantageous, allowing clean opening creation while the metal lid remains intact without microparticle contamination.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of operation

If plastic elements are exposed on the outside of the cover, then the opening mechanism is accessible, but hygiene is compromised due to dirt infiltration

Engineering Contradiction:
Improveopening mechanism accessibilityVSAvoiddirt infiltration
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent nests the opening mechanism within the lid structure itself, with the closing unit and tear-off element integrated into the lid body rather than protruding outward. The sealing frame encloses the mechanism, creating a nested configuration where the opening mechanism is accessible through the lid surface but protected from external contamination.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent uses a plastic film that can be punched and folded to create the opening mechanism. This thin film structure allows the mechanism to be integrated into the lid surface without creating external protrusions, maintaining hygiene while enabling operation through the film's flexibility and conformability to the lid surface.

Inventive Principle:
Principle #30Flexible shells and thin films

4Strength

If standard metal thickness is used for the can lid, then structural strength is maintained, but material costs and weight increase

Engineering Contradiction:
Improvestructural integrityVSAvoidmaterial usage
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent creates a composite structure combining a thinner metal lid with an integrated plastic component. The plastic injection-molded portion compensates for the reduced metal thickness by providing additional structural support and sealing function, allowing the use of thinner, lighter metal while maintaining overall structural integrity through the composite design.

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 method achieves significant material savings, improved hygiene, and cost reduction by creating a composite material with reduced metal thickness while maintaining structural integrity and functionality, allowing for easy opening and resealing without the need for special materials or complex assembly.

Implementation Method 1

both the sealing frame with the fixed lid surface and the closing unit with the metal lid area that can be swung open are materially bonded, in particular by a thermal process using an adhesive lacquer layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

by a thermal process using an adhesive lacquer layer that is preferably suitable for food and/or has lubricating properties

Methodology Applied
Scientific EffectThermal heating: Heating

Data Source

PatentEP3680191B1Method for obtaining an opening in a flat sheet material
Publication Date: 2023.05.03 PIECH GREGOR ANTON
  • EP3680191B1 patent drawingFigure 1~3
  • EP3680191B1 patent drawingFigure 4~5
  • EP3680191B1 patent drawingFigure 6~7

AI summary

A resealable can lid is described which, during the opening process, does not require the separation of a metal surface associated with chip formation, ensures the required tightness when resealing, even in the event of a pressure build-up in the respective container, and possesses a high degree of functional reliability with particularly economical manufacturing possibilities.