When we think of a fan, we do not imagine a piece of cutting-edge engineering with a tremendous complication, but a frame with a central motor with blades that rotate and breathe, which is moderately light, solid and above all cheap. You have to change the chip, since it is the mobile part of a more advanced PC and this is thanks to its materials.
From plastic to the steel industry, passing through chemistry: this is how fan materials are
20 years ago the fans were a pure plastic component where a motor with blades and a fluid shaft did all the work, with very basic electronics and materials that were not optimized at all.
Later came the engineering applied to the PC to give us a lesson on aerodynamics and understanding of fluids, where the maximum exponent was the Nidec GT-AP. The world of refrigeration began to interest more and more people and with it the advances occurred slowly, but the same fan reigned, although with increasing competition. Now the materials are as important as the aerodynamics, mainly because it seeks to compete in more sections in addition to performance.
This has made it go from common high-density plastics, such as the so-called thermoplastics in the industry, to give way to materials much more optimized for a fluid such as air. They are all polymers, but the structure, stiffness, costs and weight are not the same and in a fan these are tremendously important.
PBT or Polybutylene Terephthalate
It has been, is and will be widely used in the fan industry for its qualities and easy access, as well as moldability. Normally today it is used in the frames, but until very recently it has also been used in the blades and the engine body. In fact, it is the most common if we go out of the premium range.
The different viscosities that it can have, its high strength, dimensional stability and the almost zero stress rupture make it extremely suitable for injection molding of frames. But outside of this it has already been replaced.
ABS or acrylonitrile butadiene styrene
It is another type of injectable plastic with easy moldability and that is cheap on top of it, but it does not support deformations too much, so it has been used for low-end fans. Another of its problems is that although it is very heat moldable, it is really difficult to manufacture it, so today it is hardly used unless the company wants to compete in price.
Nylon polyamide or PA
It is possibly the most widely used compound in fans today for a very simple reason: the number of variants that can be found on the market and their properties. From a soft rubber to a hardness like metal, this material has been ideal for rotors and blades, since it allowed minimal torsion in certain variants, allowing LEDs to be included as it is semi-crystalline and semi-transparent.
Liquid Crystal Polymer or LCP
Unlike thermoplastics, here we find a high-performance resin. The molecular structure is much better than in any plastic, since it is aligned and oriented much better than these due to its liquid crystal composition. When it is injected or molded by extrusion, the molecules are oriented in the direction of the flow, so to create the blades it is perfect, since molecularly speaking it will improve the sound and flow of the air through them.
In addition, it is extremely rigid, which helps that after the rotation of the rotor there is almost no apparent deformation.
Steel, brass and aluminum
They are the three metals that are used in current fans, where each manufacturer, depending on the needs and with a view to the market, uses one or the other. These are not visible since they are part of the rotor, bearings and the lubrication / magnetic chamber of the fan, but in all cases they fulfill a very clear function: to improve the torsional rigidity of the fan by adjusting the shaft and motor so that don’t get off-kilter over the years.
In summary, all the materials of the described fans are valid, have been used or are currently being used, but the aerodynamic design and the turning properties or the motors make it necessary to innovate in terms of performance and sound, where normally the price is the loser. We are talking about a sector where we compete at the same level as that of processors, where in this case we change the nodes for materials, the transistor architectures for frame and blade designs as well as motors and therefore the giants of the PC sector and professional spend billions on R&D.
Not surprisingly, most TOP manufacturers turn to companies like SUNON, Nidec or EBM-PAPST such as AMD and NVIDIA turn to TSMC or Samsung, in search of the best technology.