Hexagonal Blank Design for Aluminum Can Drawing
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Solution Overview
Problem
The manufacturing of aluminum alloy beverage cans using the stamping-drawing process is prone to the phenomenon of 'pinched horns,' which can lead to breakage during subsequent stretching, especially when using non-circular blanks that are sensitive to metal anisotropy variations.
Innovation Solution
A non-circular blank design is optimized by dividing the metal strip into regular hexagons with additional horns added in specific orientations to compensate for metal anisotropy, reducing the risk of pinched horns and improving formability by varying the blank diameter based on its orientation relative to the rolling direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If non-circular blanks are used to compensate for metal anisotropy, then the metal usage ratio is improved, but the manufacturing precision deteriorates due to pinched horns and folds
Solution Approach 1:
The patent applies local quality by adding horns specifically at the four diagonal positions (45° to rolling direction) where metal anisotropy causes greatest distortion. The blank is not uniformly modified but has localized protrusions exactly where needed to compensate for anisotropic behavior during stamping, thus improving cup quality while maintaining high metal usage ratio
Solution Approach 2:
The patent uses asymmetry by introducing four horns at diagonal positions relative to the rolling direction, creating an asymmetric blank shape that specifically counteracts the asymmetric distortion patterns caused by metal anisotropy during the stamping process
2Loss of substance
If non-circular blanks with compensated anisotropy are used, then the metal usage ratio is improved, but the reliability deteriorates due to sensitivity to metal anisotropy variations
Solution Approach 1:
The patent applies parameter changes by modifying the blank geometry parameters - specifically adding horns with defined dimensions at specific angular positions. This changes the blank's shape parameters to compensate for metal anisotropy, improving reliability by making the process less sensitive to variations in material properties while maintaining high metal usage ratio
3Manufacturing precision
If conventional circular blanks are used, then the manufacturing precision is maintained, but the metal usage ratio deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-compensating for metal anisotropy effects in the blank design itself. The four horns are built into the blank geometry before stamping, so that during the stamping process the anisotropic distortion is counteracted, achieving both high precision and high metal usage ratio
Data Source
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AI summary
The invention relates to a method for producing a beverage can, a bottle or an aerosol can from aluminium alloy, by means of drawing and ironing using a non-circular blank, in which: the metal strip from which each blank is taken is divided virtually into identical regular hexagons of which two opposing sides are substantially perpendicular to the rolling direction of the strip, forming a compact flat hexagonal system; the periphery of the blank is calculated by adjustment starting with a concentric circle having a radius smaller than that of the inscribed circle of the corresponding hexagon, so as to compensate for the anisotropy of the metal during drawing, using a method known to persons skilled in the art; at least four ears are added, extending from and beyond the periphery in the free zones of the hexagon, of which the main axis forms an angle of substantially 35°, 145°, 215° and 325° with the rolling direction. The invention also relates to a beverage can, a bottle-can or an aerosol can made from a flank having the aforementioned features, including a shaped bottle-can or aerosol can, i.e. the main walls of which are not strictly cylindrical.