Soda cans are everywhere-in your fridge, vending machines, and convenience stores. But have you ever stopped to wonder how these lightweight, shiny aluminum containers come to be? The process of making soda cans is a blend of high-tech engineering, precision, and sustainability, designed to produce billions of cans efficiently every year. Let’s take a friendly, step-by-step look at how cans of soda are made, from raw aluminum sheets to the finished product ready to hold your favorite fizzy drink.
Step 1: Choosing the Right Material
Most soda cans are made from aluminum, prized for being lightweight, corrosion-resistant, and highly recyclable. Some cans, especially for certain beverages, use tin-free steel, which is durable and resistant to acidic contents. Aluminum’s recyclability is a huge plus, as it reduces waste and energy consumption in production.
Step 2: Creating Aluminum Sheets (Coil Stock)
The journey begins with large rolls of aluminum sheets, called coil stock. These sheets are very thin-about 0.3 to 0.8 millimeters thick-and can be up to 1.2 meters wide. The aluminum coil is unwound and lubricated with a food-grade substance to ensure smooth processing in the next steps.
Step 3: Cutting and Forming the Can Body
From the lubricated aluminum coil, circular blanks are punched out. These blanks are roughly 5.5 inches in diameter and will form the bottom and sides of the can. This step results in some material loss (about 12-14%), but the scrap aluminum is recycled back into the process.
Next, these circular blanks are drawn into shallow cups by a powerful press machine. This drawing process stretches and shapes the aluminum into a cup form. Then, the cup is ironed by passing it through a series of rollers, which smooth out the walls and elongate the cup into a tall, thin-walled can shape. This ironing step removes any sharp edges and prepares the can for printing and filling.
Step 4: Shaping the Can Bottom
The bottom of the can is domed inward to withstand the pressure of carbonated beverages inside. A punch presses the cup’s base to create this dome shape, which strengthens the can and prevents it from bursting under pressure.
Step 5: Cleaning and Preparing for Printing
Before printing, the cans are thoroughly cleaned using chemicals and water to remove any residues. They are then dried and a protective food-grade lubricant is applied. This ensures the cans are spotless and ready to receive vibrant, high-quality graphics.
Step 6: Printing and Coating the Can
The cans are printed using a high-speed rotary printing process that can apply up to six colors in a seamless 360-degree design. This step brings the can to life with logos, colors, and other branding elements. After printing, a clear lacquer coating is applied to protect the ink from scratches and fading. The cans then pass through an oven to cure and harden the ink and lacquer, ensuring durability during shipping and handling.
Step 7: Applying the Inside Coating
To prevent the soda from tasting metallic and to protect the aluminum from the acidic beverage inside, a special water-based coating is sprayed on the inside of the can. This coating acts as a barrier between the drink and the metal. The cans are baked again to cure this internal coating, making sure it adheres perfectly.
Step 8: Necking and Flanging the Can
The top of the can is gradually narrowed in a process called necking. This is done in multiple steps to avoid damaging the thin aluminum. Necking allows the can to fit the standard size lid. After necking, the can’s rim is flanged outward to prepare for the lid to be sealed on later during the filling process.
Step 9: Making the Can Lid and Pull Tab
The can lid, or end, is made separately from aluminum coils. Circles are cut out and shaped into lids with a scored section that will open when the pull tab is lifted. The pull tab itself is manufactured from narrow aluminum strips, pierced, cut, and formed into shape before being attached to the lid. The lid is coated with a sealing compound to ensure it will form an airtight seal when crimped onto the can body.
Step 10: Quality Control and Packaging
Throughout the manufacturing process, cans undergo rigorous quality checks. They are inspected for leaks, pinholes, and defects using automated systems. Only cans that pass these tests proceed to packaging, where they are stacked and prepared for shipment to beverage manufacturers.
Making soda cans is a marvel of modern manufacturing, combining speed, precision, and sustainability. From aluminum coil to printed, coated, and sealed cans, every step ensures you get a safe, attractive container for your favorite soda. Next time you pop open a can, you’ll know the fascinating journey it took to get to your hands.