Ceramic might very well be the material of the moment, or at the very least vying for the top spot with titanium. It’s highly scratch resistant and has a tactile feel that few other materials can match. It’s also very hard and just as hard to make, enough so that most brands don’t bother making it in-house, preferring instead to go to third party specialists, just like many brands do for movements. The one possible exception – depending on how you define ‘in-house’ – is Swatch Group.
The reason for Swatch Group’s dominance in watchmaking is a simple buzzphrase that most company execs salivate over: vertical integration. Essentially, alongside the various names on dials, Swatch Group also owns the companies making their parts. That’s why most of us have heard of ETA, the group’s movement maker, but there are plenty of others alongside, and perhaps most interesting to us horological nerds is Comadur.
Comadur is a name you’ve probably not heard before, for good reason. Until recently, Swatch Group kept them a bit of a secret, but they’re a specialist in ultra-hard materials. That includes synthetic diamonds, synthetic rubies, sapphire crystals and, of course, ceramic. And it’s the latter that’s worth a closer look.
First off, we all know that ceramic is fired in ovens, but what you might not know is that there’s a good chance the ceramic in your watch started life in Japan. Or, more accurately, the zirconium oxide, the raw powder that makes up ceramic, and the raw materials that go into it would have been mined and produced in Japan. It begins as a fine white powder like flour and is the foundational element for all ceramics.
Unless we’re talking about one specifically treated ceramic – which we’ll get onto – the only real difference between one ceramic and the next is colour. Adding colour might sound like a relatively simple thing to do; surely you just add some coloured powder into the zirconium oxide mix? But not so. You need something completely inorganic to survive the firing process and many coloured pigments are activated in the kiln. This means that how the ceramic goes in and how it comes out can be completely different.
To put that in context, red, a key ceramic colour, enters the ovens as a pale white. Some colours darken or lighten in the heat, but red’s not alone in changing completely. This makes it a case of trial, error and some very exact formulae to get anywhere near a consistent colour. And consistency is key when you’re scaling things to Comadur’s level.
Consistency is also why there are some seemingly obtuse stages in the production process. To bond pigment and zirconium oxide powder, you need to add water, creating a high-end Play-Doh-like substance. But you don’t actually want water in the mix, so it’s then put through a big spray drying machine, essentially blowing a stream of the stuff through hot air so the water gets siphoned off. The result is a perfectly mixed, coloured powder. Then a binder is thrown in so that it can be turned into feedstock pellets that are in turn injected into moulds, the first step into it visibly becoming a watch.
There’s a problem though. Once again, you don’t really want the binder in there. So, the ceramic’s immersed in some piquant booze – solvents – to break it down, leaving the ceramic like expensive Swiss cheese. At this point the overall shape is bigger than the finished watch. The missing ingredient between this holey, oversized piece and something usable then? Heat.
This is the bit we all know and love, the baking. The ceramic is placed into ovens at 1,450 degrees Celcius. Unlike rising bread though it loses 25% of its size, getting dense and more intensely coloured, with some pigments activating in this heat to properly reveal their colours – like that aforementioned red. When it comes out, the ceramic is hard, colourful and ready to be turned into a watch. It’s machined to smooth off the rough edges, as well as production necessities like supports, and is then polished or sandblasted. Polishing is particularly cool as ceramic is hard enough that it can only really be polished by more ceramic. To that end, each part is placed in a big vat of ceramic beads shaped to polish specific areas – perfectly sized triangles to get between the lugs, for example – and shaken. Once each part is done, you have components ready to become a watch case, from tiny bracelet links to full, solid ceramic cases in blues, yellows, reds, whites, and blacks.
Of course, if you’ve seen what Swatch Group member Rado have been producing of late, you might have one other question: what about plasma ceramic? You’ll have seen it around, a dark grey ceramic with a particular metallic sheen. It’s not just coloured or finished differently though; it takes things to the next level.
Plain white ceramic (it can be coloured, but that’s a waste as all colour is removed later) is placed in an oven with argon, hydrogen and methane. It’s then heated to 20,000 degrees – almost four times hotter than the surface of the sun. The combination of heat and gasses means that the chemical composition of the ceramic changes, going from ZiO to ZiC, stripping out any colour and giving the material that unique finish. To put into context just how insane the process is, the baskets the pieces are held by are made from tantalum carbide, which is incredibly rare but one of the few metals that can withstand that level of heat time and time again. Those baskets might just be the most expensive part of the process.
Plasma ceramic is best known as a Rado thing, but you can also find it sneakily getting into some Omega and Blancpain action, as Comadur is a Swatch Group entity. However, it remains very exclusive. By comparison the regular ceramic is liberally spread across the group. It’s an impressive quantity for sure but more impressive is the quality.
To dwell on the scratch resistance again, have you ever taken a knife to a watch? Not in a Bond Street hooligan kind of way, but actually tried to scratch a ceramic watch? I took a relatively sharp knife, a screwdriver, a set of keys, anything I could get my hands on to one of Rado’s True Thinline pieces. The result? I got scratched, the ceramic did not. It’s easy to talk about ceramic as ultra-hard, be wowed by the heat of the ovens – and that plasma oven, jeez – but it’s that metaphorical taste test that really illustrates why ceramic is so important in watches and why Comadur especially is doing some incredible stuff.
More details at The Swatch Group.
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