Beverage Can Grommet Valve Structure for Burr Isolation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional beverage can manufacturing processes result in burrs formed on the inboard side of apertures, which can compromise the integrity of the liquid product by lacking sufficient coating and potentially contacting the product, especially when using grommets for propellant charging in aerosol cans.

Innovation Solution

A method of forming a valve in a drawn and ironed beverage can body involves positioning tools to create an aperture with a burr on the inboard side of the rim, which is then deformed to form an upstanding wall, allowing the grommet to be inserted without compromising the sealing or charging functions, and ensuring the burr contacts the grommet rather than the liquid product.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an aperture is formed in the dome by opposing tools, then the grommet can be installed for propellant charging, but a burr is formed on the inboard rim that may contact the liquid product and compromise its integrity

Engineering Contradiction:

Improveaperture formationVSAvoidburr contact with liquid product

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional approach by intentionally forming the burr on the inboard side of the aperture rim rather than attempting to eliminate it. This inverted approach ensures the burr contacts only the grommet material, not the liquid product, thereby converting a harmful defect into a controlled feature that maintains product integrity.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The grommet serves as an intermediary element between the burr and the liquid product. By positioning the burr to contact only the grommet material, the intermediary prevents direct contact between the potentially harmful burr and the liquid product, thus protecting product integrity while maintaining manufacturing feasibility.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the burr is located on the inboard side of the aperture rim, then the grommet can be sealed against the can body, but the burr may lack sufficient coating and contact the liquid product

Engineering Contradiction:

Improvegrommet sealingVSAvoiduncoated burr contact with product

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful aspect of the uncoated burr into a beneficial feature by orienting it to contact only the grommet material. The burr's presence ensures proper grommet sealing against the can body while its uncoated nature becomes irrelevant since it never contacts the liquid product, thus transforming a potential hazard into a functional advantage.

Inventive Principle:

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

3Productivity

If conventional aperture formation methods are used, then manufacturing is simple, but the burr formation compromises product integrity and requires additional coating steps

Engineering Contradiction:

Improvemanufacturing speedVSAvoidburr orientation and coating

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent incorporates burr orientation control as a preliminary action during the aperture formation process itself. By designing the tooling to intentionally form the burr on the inboard side, the correct orientation is established before grommet installation, eliminating the need for subsequent coating steps or burr removal operations and maintaining high manufacturing efficiency.

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 approach prevents the burr from contacting the liquid product, maintaining the product's integrity and ensuring effective sealing and charging operations, even with modern grommets, by orienting the burr inwardly to contact the grommet, thus avoiding contamination and maintaining the can's structural integrity under pressure.

Implementation Method 1

forming an aperture in the dome by a first tool and a second tool such that a burr is formed on an inboard rim of the aperture

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

deforming a portion of the dome adjacent the aperture to form an upstanding wall

Methodology Applied

Scientific EffectDeformation: Deformation

Implementation Method 3

inserting a grommet into the aperture

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3445512B1Method of forming a valve in a beverage can and beverage can having a grommet

Publication Date: 2022.03.16 CROWN PACKAGING TECH INC

Figure 1~2
Figure 3~4
Figure 5~7

AI summary

A drawn and wall ironed beverage can body, method for forming same, and a sealed and filled can, include a through-hole or aperture in the base. A grommet for charging a propellant in can is located in the aperture. The aperture has a burr that is located on the inboard side of the rim of the aperture.