When was the last time you paused between sips of your favorite soda and wondered about that can in your hand? If you’re like most people, the answer is likely never. But that seemingly unremarkable object is actually a marvel of modern manufacturing. It is, in fact, a glorious thing.
A few years ago, I finagled my way into Can School, a small industry-only event hosted annually by the Ball Corporation, the world’s largest canmaker. There, in a conference room just north of Denver, engineers chatted about “improved pour rates” and “recloseability” and the “opening performance” of cans. One guy handed me a business card that said “Can Whisperer.” Another wore a shirt that said “Can Solo.” It was a scene of intense devotion, and as such, it was only fitting that the first thing I learned there was that manufacturing aluminum cans is so challenging, and requires such a vast amount of study, design, and precise machining, that many consider cans the most engineered products in the world.
If you drink beer, or soda, or juice, or sports drinks, or if you have ever preserved fruits or vegetables in glass jars, the name Ball probably sounds familiar. The people of the world go through 180 billion aluminum beverage cans a year; enough to build dozens of towers to the moon. Ball makes about a quarter of them. Yet even with that much practice, making perfect 12-ounce cans remains a battle. Throughout the process, the aluminum behaves begrudgingly. It tries to jam the machines. Once filled, it wants to interact with the product inside and change its taste. But mostly, cans yearn to corrode (thereby leaking onto other cans, and causing more corrosion). Rust, it turns out, is a can’s number one enemy—and a can’s only defense is an invisible epoxy shield, just microns thick. (Without that shield, a can of Coke would corrode in three days.) At Can School, I got a hint of what goes into that coating.