Can End Shell Coining and Reforming Against Buckling
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Solution Overview
Problem
The can making industry faces challenges in reducing the amount of metal used for can ends while preventing wrinkles and buckling due to internal pressures from contents, especially in thin gauge materials.
Innovation Solution
A method and tool assembly for forming a can end shell with a central panel, panel radii, and a chamfer, involving coining to create a coined section and reforming to form a step, which strengthens the can end and utilizes excess metal to reduce buckling tendencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the gauge of sheet metal is reduced to decrease material usage, then the amount of metal consumed is reduced, but the can end becomes more prone to wrinkling and buckling under internal pressure
Solution Approach 1:
The patent applies coining and reforming operations that permanently alter the physical parameters of the metal in the panel radius region. These operations change the grain structure and work harden the material, transforming it from a soft, formable state to a hard, pressure-resistant state. This parameter change allows thin-gauge material to achieve the structural integrity normally associated with thicker material.
Solution Approach 2:
The coining and reforming operations are performed during the can end manufacturing process, before the can end is attached to the can body and subjected to internal pressure. This preliminary strengthening action prepares the thin-gauge material in advance to withstand the future pressure loads that would cause wrinkling and buckling in unmodified thin material.
2Strength
If coining and reforming operations are applied to strengthen the panel radius, then resistance to buckling is improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent combines the coining and reforming operations into an integrated manufacturing sequence that is incorporated into the existing can end production line. By merging these strengthening operations with the standard manufacturing process flow, the patent avoids creating a separate, complex post-processing operation and instead embeds the strengthening steps within the established production framework.
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 effectively reduces material usage while enhancing the can end's resistance to buckling and bulging, allowing for thinner gauges without compromising structural integrity.
Implementation Method 1
coining the can end shell to form a coined section in the first panel radius
Implementation Method 2
reforming the can end shell to form a step in the chamfer
Data Source
AI summary
A method of forming a can end shell is provided which includes providing a can end shell having a central panel portion, a first panel radius around the central panel portion, a chamfer extending from the first panel radius, and a second panel radius around the chamfer, coining the can end shell to form a coined section in the first panel radius around at least a portion of the circumference of the central panel portion, and reforming the can end shell to form a step in the chamfer.