By presenting a black ceramic version of its new Big Bang Integral in 2020 (featuring a bracelet totally integrated into the case as its name suggests), Hublot reasserted its position as a pioneer in the Research & Development of modern and innovative materials.
In 2021, the Big Bang Integral in coloured ceramics was launched, and some models, including the yellow ceramic version, caught my attention to the point of inciting me to take a closer look at the technical and watchmaking aspects of these little beauties.
What I discovered simply fascinated me, both in terms of the watchmaking aspect and all the research and development work done on the materials. I thought it was such a shame that these points were not sufficiently highlighted, which is why we have now decided to provide fill the gap with a lot of technical information designed to perhaps give you a different view of these exceptional watches.
So where should I start?
Why not with ceramics, since it was this colourful look that caught my eye at Watches & Wonders?
First of all, it is worthwhile introducing ceramics, its properties and its complex production process.
Ceramics is a so-called "technical" material because it is produced according to a very complex process that I will lay out in detail. It appeared in the watchmaking world for several reasons, including its properties as a material, but also on aesthetic grounds.
From a technical standpoint, it is an extremely scratch-resistant material thanks to a specific structure that makes it very hard. Its physical properties also make it a material with a relatively low density compared to those generally used, thus ensuring it is both light and comfortable to wear.
From an aesthetic point of view, the interesting thing about ceramics is that one of the stages in its production process is injection moulding. You get the idea: you can give it any geometric shape you want, as long as you have the right mould! Moreover, since ceramics has a relatively unalterable surface finish, a polished finish will remain so for ever.
The stages of ceramic production
Hold on to your hats, as I refer back to life as a materials physics student in order to share the steps involved in producing a ceramic piece. The fact that I do so in detail is also intended to help you realise that ceramics is not "just a fashionable material to look cool", but instead a technical and aesthetic choice involving many constraints in its production process. At the end of the day, a completed ceramic watch entails having successfully conducted a whole bunch of critical stages that I will now describe.
1. The ceramics recipe and constituting the feedstock
The story begins with powdered material and the choice of that material determines the final result. In watchmaking, the powder initially used for the production of ceramics is usually alumina or zirconia (aluminium oxide or zirconium oxide respectively). It is quite conceivable that each ceramic has its own recipe and that, depending on the mix of powders used, the subsequent production process will be irrevocably changed.
If one were to stop at this stage, the result would be just a bowl full of powder, which is not exactly dreamy, so this powder is mixed with a binder serving to obtain a material with a certain viscosity that can be injection-moulded. The choice of binder will also be decisive, since it will be eliminated in one of the following stages.
So far, so good. We take "ceramic powder" and combine it with a binder to achieve the right consistency, which basically seems a bit like baking. The difference is that here, the slightest iota will have an absolutely crucial consequence in the course of events, whether it be the elements composing our feedstock (the powder/binder mixture), their own properties or their proportion. Let's try and explain why by heading straight on to the next step.
2. Injection moulding
During this stage, the feedstock obtained is injected into a mould using an injection moulding press. This stage seems to be the simplest, as it takes me no more than a few lines to describe. It is nevertheless one of the most critical steps because many parameters have to be taken into account, including injection pressure and injection time, as well as the temperature of the material and that of the mould. In the end, each parameter will influence the final part, as poorly done injection could create defects such as cracks in the material. All these parameters must be adapted to the feedstock, hence the importance of materials and proportions. Changing one element means changing the whole injection set-up – as well as everything else.
At the end of this production stage, the result emerging from the mould is called a green blank, also known as a body or compact.
3. Debinding
As the name suggests, the purpose of this step is to remove the binder from the green blank, since the only purpose of the binder is to enable moulding of ceramics, which would be impossible with powder alone. Depending on the binder(s) used, one or two debinding operations will be carried out. In all instances, the principle remains the same: removing the binder.
The binder can be removed in the first phase by subjecting the green blank to chemical compounds for reaction, dissolution, or by increasing the temperature to vaporise the binder. The second phase (or the only phase when there is just one) is usually thermal, i.e. vaporising the binder residue by increasing the temperature.
4. Sintering
Finally, sintering is the production stage that we all remember, not necessarily by its name, but at least by its effect on the green blank, because it is during the sintering phase that we witness the famous shrinkage phenomenon: the blank dwindles until it reaches its final size and format.
The principle is as follows: the green blank is heated to a very high temperature (the benchmark is a temperature higher than half the material’s absolute melting temperature, generally a little below the melting point), which causes a phenomenon of attraction of the atoms constituting the material (to put it simply). By heating this blank, which is ultimately a mass of compacted powder, the particles will come closer together and weld to each other. From a porous and voluminous green blank, we obtain a totally compact, denser body. The spaces formerly occupied by the eliminated binder will disappear as the grains come closer together, leading to a reduction in the size of the part: this is called shrinkage.
This shrinkage is said to be controlled, because the percentage of shrinkage is very precise and is calculated according to all the parameters determined at the outset: hence the extreme importance of each detail and each stage.
Hublot Big Bang Integral Ceramic
So, now that we have looked at the production process of a ceramic object, what do you think of these new Big Bang Integral Ceramic models? Impressive, aren’t they? Because above and beyond the aesthetic choice (which I view as successful), launching a watch with a ceramic case is a real challenge!
Having been lucky enough to chat with the Production Director at Hublot, I grasped the different challenges that confronted the brand! First of all, the obvious goal – but only when you realise what is at stake in such a challenge – is a final product that is both original and appealing.
Now for three key points that are worth highlighting with these coloured ceramics:
Challenge 1: Successfully pigmenting the ceramic to obtain a homogeneous final result, a homogeneous material and to ensure that the operation is reproducible without any variation in colour from one piece to another! Remember: each component of the feedstock (the starting mixture) will have an impact on each configuration point of each production stage... A real headache that Hublot's R&D researchers took on and handled!
Challenge 2: Making the coloured ceramic as resistant as the black ceramic. Depending on the powder used at the outset, the ceramic will be "naturally" white or black and the production process for black ceramic is well mastered at Hublot. On the other hand, incorporating pigments into the powder will certainly modify the production process, but also, and above all, the final structure of the material. The addition of pigments will necessarily alter the proportions of powders and therefore the final outcome. This is another puzzle that seems to have been solved to obtain very good and satisfactory results.
Challenge 3: Respecting the geometry and dimensions of the components. This is probably the biggest challenge and it concerns all ceramics, regardless of their colour – because as you probably know, in watchmaking, the dimensions of the components must be extremely precise for elementary technical reasons such as the adjustment of the parts that will guarantee the water-resistance of the watch. In the case of the Big Bang Integral Ceramic, the precision of the components will have a direct impact on the adjustment of the bracelet – with the case on the one hand, as well as between all the links of the bracelet. This latter point is essential because the comfort of a watch depends on the quality of the adjustments of its bracelet...In the case of coloured ceramics, given that each pigment has a totally different impact on the entire recipe and on all the configurations of the production process, I leave it up to you to interpret the amount of research work conducted by the R&D teams to achieve a perfect final result, whatever the colour of the model.
Hublot and 100% in-house control of materials
It is widely acknowledged that for several years now, Hublot has sought to establish itself as a major player in the mastery of materials, through its various coloured ceramics as we have just seen, as well through the creation of new materials such as Magic Gold, which is an alloy (the only one, in fact) of scratchproof 18K gold!
Whatever the innovative material used by Hublot, it should be noted that everything is developed in-house by the Research & Development department, which has 100% control over this expertise.
Hublot, contemporary watchmaking
Hublot is a contemporary watchmaker. There can be two interpretations of the term "contemporary”. The first is that the brand is relatively youthful in terms of watchmaking history since it was born in 1980, although it was mainly from 2004 onwards and the arrival of Jean-Claude Biver that Hublot took a new turn and embarked on the path for which it is known today. The second is that it is contemporary because its positioning, its commitment, its aesthetics and its culture are all resolutely modern.
The watch industry is both highly critical and very severe. But if one were to take a step back and observe the situation, which brand can currently boast of having developed so many innovations in less than 20 years, both in terms of the materials used and the numerous movements developed in-house? Very few, in my opinion.
It is also the desire to broaden my point of view that encouraged me to look in more detail at the movements developed by Hublot, and even more so at the brand-new Unico 2 powering the new Hublot Big Bang Integral Ceramic. What I discovered and what I also learned led me think that it is a real waste not to highlight this movement, since it is fully imbued with fundamental principles of mechanical watchmaking!
Today I'm talking about something you may have missed: the Unico 2 movement.
Hublot Unico 2: The new version of the famous Unico chronograph movement
Let's start at the beginning by presenting, in a succinct yet necessary way, the characteristics of this movement as they are classically found in any movement description:
Movement dimensions: 30mm x 30mm x 6.75mm
Number of components: 354
Power reserve: 72 hours
Functions: Hours, minutes, seconds, chronograph
The most attentive readers will have noticed that the movement is thinner than its first version, by a little more than one millimetre, which is actually not negligible for a chronograph movement.
What is important to understand is that this movement, despite bearing the same name as its predecessor "Unico", is different in many ways. This Unico 2 has been entirely redesigned in terms of both its architecture and the integration of the chronograph. From now on, the Unico 2 therefore fully integrates the chronograph function into the movement, unlike the Unico movement whose chronograph part was an add-on module. We thus have a real chronograph movement entirely and exclusively dedicated to this function, with many elements redesigned for this purpose.
Technical points reworked by Hublot
1. Reintegrating the regulating organ into the movement
The Unico 2 abandons the "escapement-balance-spring holder" system and returns to a more classic form. Indeed, in its previous version, the Unico had an ingenious "module" system serving to intervene on the whole "escapement and regulator" block. The choice to return to a more classic formula was based on the desire to return to a fully integrated movement (with the chronograph function), and also to further improve the Unico's stability and already high-performance precision.
2. A lot of work on the silicon escapement system
Silicon is a relatively contemporary material in watchmaking, and its application in our wristwatches has long been (and I think still is) a topic of debate. I am one of those watchmakers that expressed reservations about the use of silicon for the escape wheel and pallet-lever, but my recent discussion with Hublot's Production Director has changed my mind. Not that I have become an absolute fan of this solution, but I am much more respectful of this alternative now, and I will explain why.
What you need to know about silicon is that it is a material whose physical properties logically interest watchmaking R&D researchers because it is non-magnetic, very light and extremely hard. Above all, if it is well produced, a silicon component can have an extremely smooth surface finish, which is very useful in that it reduces friction forces (which has always been a key issue for watchmakers).
However, a very hard material also means a brittle material. Nevertheless, at Hublot, a lot of work has been done on the geometry of the components in order to respond to this problem. On the first version of the Unico, important work had already been carried out and this movement did not apparently show any particular breakage in terms of the distributing organ. On the Unico 2, these additional modifications seem to have completely done away with the issue and only time will bear witness to these substantive engineering efforts.
3. Improvements to the chronograph functions
As the chronograph is the central complication of the Unico 2 movement, a point of honour has been made of improving the chronograph in this new version. Personally, I have always found the Unico's release controls delightfully pleasant and smooth and they turn out to be even more so with the Unico 2.
Some time ago, upon receiving some Hublot watches equipped with this new movement, I took the time to have a careful look through the loupe, a typical watchmaker’s approach. This was a chronograph with an open dial, enabling me to enjoy its architecture to the full. Nevertheless, one element literally jumped out at me, and I was really surprised not to have heard about this point as it is both aesthetically beautiful and functionally very interesting: the new clutch wheel and pinion.
The clutch wheel is that which, when the chronograph is activated, changes position so as to engage with the chronograph wheel in order to simultaneously drive it forwards and trigger the measurement. In our case, what struck me was the shape of this clutch wheel, equipped with elastic toothing that seems to wind around its axis! It is absolutely beautiful to observe!
This type of toothing serves several functions and enables various improvements. Due to their elasticity, the teeth completely match those of the wheel in contact, thus eliminating any jerking of the chronograph hand. Backlash is thus compensated, and time reading is very smooth.
Another point is the improvement in reading accuracy following the activation of the chronograph's "stop" function. This unique toothing enables a clearer stop and enhanced measurement accuracy.
Finally, and this is probably one of the essential points that will lead me to the next area of improvement: a reduction of the energy consumption during activation of the chronograph function, notably enabled by the elasticity of the teeth.
4. Improved energy consumption through an innovative friction system
This point totally blew me away, as I found the principle so very effective and terribly clever. In the case of a classic chronograph, or if we take the example of the Unico, the chronograph wheel has a "classic" friction system with a spring blade and a polymer part that comes into contact with the wheel plate in its central part. The purpose of the friction is to allow the chronograph wheel to move by limiting the play, and consequently the backlash mentioned above, and also to ensure the stability of the wheel. The disadvantage of such a system is the energy consumption, since the friction surface is relatively large and can cause regularity issues over time.
The new friction system developed by Hublot is a ceramic ball bearing system (yes, ceramics again). To keep things simple, the friction occurs at the end of the chronograph wheel pivot. The latter rotates in a central tube inside which a polished ceramic ball bearing is housed, itself supported by a spring maintained by an adjustment screw serving to adjust the friction. This system has the advantage of being adjustable, but it also and above all serves to improve the energy-consumption performance of the chronograph wheel, since on the one hand the surface in contact between the drop of the chronograph wheel pivot and the ceramic ball bearing will be tiny (a single point of friction), and because these two surfaces are extremely well polished and hard (due to the structure of ceramics and the burnishing of the pivot).
5. An exclusive Hublot self-winding system
A final point of improvement concerns a new self-winding system about which I cannot really go into detail because... I did not have access to these details for reasons of exclusivity. What we do know is that this new automatic module enables transmission of the winding torque in a more direct way and that it has an innovative ratchet retaining system. That's it. We naturally remain hungry for more details, but I can't help that! Who knows, maybe we'll know a bit more in a while?
Hublot Big Bang Integral Ceramic: Form and substance
To conclude this article, which I hope will have fascinated you as much as it did me, I would say that through these new models, Hublot shows us the extent to which it does not focus exclusively on aesthetic features or communicating about the latter. Hublot should be recognised for its true watchmaking expertise in terms of both purely movement-related aspects – as is notably visible in the numerous calibres developed in-house, including the Unico 2 that I have discussed in the second part of this article – as well as with regards to the case and bracelet constructions that go beyond a merely design-driven approach by integrating real technical challenges. There are very few players in the industry who master ceramics and Hublot can be proud to be among them.
Hublot has totally won me over with its new Big Bang Integral Ceramic and I salute the prowess it embodies, as much for the watchmaking content as for the aesthetic and technical facets.
Thanks for reading!
Romain