In the craft beer sector, the aluminum can has transformed from a budget-minded container into a hallmark of advanced packaging technology. This introduction examines the factors behind its growing popularity among brewers and outlines the sophisticated manufacturing process that converts raw aluminum sheet into a finished can.
Why Choose Cans? Four Core Advantages
- Complete Light Barrier: Total protection against UV light, the cause of “skunking.”
- Superior Oxygen Barrier: The can body itself is more impervious to oxygen than glass.
- Lightweight & Portable: Significantly lighter than glass, reducing shipping costs.
- Cost-Effective: Generally lower material and production costs than glass.
From Sheet to Body: Cupping & Ironing
Can manufacturing starts with a roll of aluminum sheet. 
After lubrication, it enters a cupping press, which stamps out ~14 cm diameter circles and forms them into thick, short cups. These are just the blanks.
The cups then enter a bodymaker. Here, a plunger forces the cup through a series of progressively smaller rings in a process called “ironing,” stretching, thinning, and elongating it into a straight-walled can body with a formed bottom. Modern “lightweighting” has optimized wall thickness to ~115-120 μm, reducing weight from 80g to about 13g.
Washing, Decoration & The Vital Liner
The formed can body is trimmed and washed, often with hot hydrofluoric acid, then rinsed.
Decoration is typically done via rotary printing, applying different ink patterns at speeds over 1000 CPM, followed by a protective varnish coat. Alternatively, pre-printed shrink sleeves can be used, often after filling.
The most critical step is spraying a water-based liner inside the can. This barrier prevents the slightly acidic beer from slowly reacting with the aluminum, which could lead to corrosion and failure.
The Final Form: Necking & Flanging
In the final steps, the can enters the necker, where the top is gradually rolled inward in a dozen or so increments to form the neck. Finally, the flanger spins the can, crimping the top outward at a 90° angle to create the flange, crucial for the final seaming process.
Confronting the can’s inability to be evacuated, our Modular Canning Lines can be precisely integrated with a Liquid Nitrogen Dosing System to instantly inert the can’s headspace before filling, building the first robust line of defense against oxidation for your beer.
