Olympic science

2002/02/17 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Diseinua
• Materialak

The materials developed for the Olympic Games will be available to everyone.

The Tolosarra bottom skier Haritz Zunzunegi probably won't know much about carbon chemistry, but he is a direct witness to the evolution of materials and designs since its inception in this sport. The same will happen to the Donostiarra Iker Fernández who participates in the modality half pipe snowboard.

However, since snowboarding is a young sport, it has undergone fewer changes than other sports of greater tradition. For example, few will remember those long straight wooden skis that were used a few decades earlier. The present, however, have only a wooden heart, and some do not.

Each ski type has a special material that adapts to its characteristics. In fact, sometimes more rigidity and hardness are sought than flexibility, and sometimes the most important thing is to absorb vibrations. In addition, Olympic athletes seek material adapted to their height, weight, movements and tastes. Therefore, in order to obtain these custom materials, both in its composition and in its design, a good work is necessary.

It is important to adapt the structure

The design of the skis starts with the core. It is usually made of wood or synthetic and in both it takes great care of its lightness and sensitivity. If you use wood, it is not surprising that the most chosen is the fir tree, since it is a tree adapted to snowy areas. However, we also take into account the fir species and the humidity: the wood is allowed to dry without losing flexibility until achieving lightness and it is very important to achieve the right point.

In several modalities the skis of wide shovel and narrow waist have been imposed.

In addition, to accelerate weight and increase flexibility, the core is drilled in several areas. Another way to achieve lightness is to alternate the folded wooden agglomerates leaving channels and flat layers of wood, that is, the ski core is organized as a sandwich. This way, in addition to reducing weight, it maintains durability and toughness.

The core of the ski is covered by the zig-zag arrangement around the axis, at a given angle, of glass fibres, carbon and other materials. In fact, the twisting angle of the fibres conditions the ski's response to the skier's revolutions. Along with other agents, the edge of the ski also influences the ability to grab snow. Keep in mind that, from wet snow to ice, the condition of snow can be very different, even variable, so it is essential to stick it well without preventing slippage in all situations.

To finish the ski, through molding procedures and other techniques, adheres to the central structure the top of an attractive decoration and the bottom of the material of great precision.

One of the materials used by almost all manufacturers is kevlar. According to DuPont, inventor of this material, besides being five times more resistant than steel, it is light, flexible and comfortable. It has many applications (used in bullet vests!) It is very appropriate because it has the capacity to be placed between the components of the skis, absorb the vibrations and react according to the angle of force. The structure of polymer fiber PPTA (p-phenyl tereftalamide) or poly (p-phenyl tereftalamide) have allowed obtaining the characteristics of Kevarra.

In order not to waste time when spinning is essential a proper design of the skis.

On the other hand, between snow and skis a wax adapted to the snow state is used. Thus, soft waxes are used to soften the hardness of icy snow, while to overcome the friction of soft snow, waxes are needed to facilitate the sliding. However, sometimes the problem is accentuated, as situations at the top and bottom of the slope are different. In these cases, the ideal is a wax invented by a chemist with a great fondness for skiing: Super HotSauce. When the snow is soft, the water molecules of the wax migrate outward, becoming a more slippery surface.

Design and clothing are not just a matter of fashion

In addition to the material, the design of skis has evolved significantly, especially in length and appearance. Regarding skis of a few years ago, the current skis of different modalities are shorter and have a wider blade and a narrower lumbar area. Turning with the old long straight skis, at some point the turn slowed down. On the contrary, skis with this special design facilitate and limit revolutions and by not having to make forces to bend skis to start spinning, less force is lost. In addition, stability is guaranteed.

Apart from skis, clothing has also undergone changes and novelties. There was a time when it was necessary to choose between allowing the entrance of the external humidity or impregnating it with the own sweat. Now, thanks to fabrics such as goretex, it is possible to protect yourself well from snow and at the same time expel sweat. The secret of goretex is based on the diffusion of polymer polytetrafluoroethylene, which allows to maintain about 22.5 billion small pores. Sweat vapor can escape these pores, but drops of snow and rain do not enter. To ensure the durability of the garment is given an external oily protection.

It is clear that the Olympic Games have revolutionized since its inception and the Greeks of the 5th century BC would not have imagined that one day they would play in the snow. How then to learn about current sports materials? Impossible! Of course, he would be glad to know that one of the four basic elements of chemicals remains essential: the Olympic fire is on.

Source: Olympic science

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