The extrusion process of aluminum is a robust process that consists of heating and forcing the softened metal through an opening in the shape of a die until the profile emerges. This process allows to take advantage of the qualities of aluminum and offers a larger number of design options. The range of shapes that can be produced by extrusion is almost infinite. This is the reason why there is a variety of general rules that detail potential solutions and applicable tolerances. Aluminum extrusions are increasingly used in end-user sectors, such as construction, transport, electricity, machinery and consumer goods due to the strength, flexibility, durability and sustainability they offer.
The use of aluminum alloys in the extrusion sector has grown by 6 % annually during the last 5 years. It is estimated that 28 million tons were processed in 2017 worldwide. Despite this consumption volume, it remains below the total processing capacity of all the companies combined in the sector, which surpasses 40 million tons per year. However, trends indicate that the demand moves in such a way that it can reach that total of the current capacity in under 5 years. Unlike the rest of the countries, the German industry has achieved a utilization rate of its total installed capacity of around 90 %, becoming one of the largest production centers of the European aluminum extrusion industry. This is driven by the country’s total demand of around one million tons per year, which is relevant outside Asia where the numbers that China throws on the market exceed 50 % of what is used in the world. The extrusion industry keeps increasing its productivity and competitiveness. Plants are betting on modernization and use presses with higher pressure forces, replacing old and weak systems. The evolution of the market requires bigger presses because nowadays more resistant and difficult to press aluminum alloys or larger parts are processed.
The Construction Sector Leads the Demand
The construction sector consumes about 62 % of the global extrusion production. The housing market in the United States maintains a positive momentum and demand is slowly increasing. In Europe the housing market is regaining momentum and a gradual improvement is expected. In South America it is returning to positive from low levels. Weak construction activity has affected China’s demand in the past year, however, it is slowly recovering after environmental reforms have been concluded. However, in the rest of Asia, demand is constantly increasing. It is expected that more than 70 % of the world’s population will live in urban areas by the year 2050, leading to increasing demand on part of the building sector and to investments in road infrastructure, electricity and water distribution, sewerage, communications, and transportation. The trend of the new cities will be dominated by a vertical expansion rather than a horizontal one. Jean-Marc Luvisutto of Hydro expresses in his article “Materials for supertall buildings” that the design of buildings is evolving due to the growing use of computer programs in design and architecture. He claims that extruded aluminum makes it possible to construct complex buildings, with shapes that meet specifications for the facade in terms of aesthetics and performance. Due to the combination of different mechanical characteristics, this material ensures the ability of the facade to resist stress factors such as wind pressure, the weight of other components as well as a capacity to accommodate possible movements of the structure. These movements may range from small natural thermal or structural movements to large displacements when the buildings are exposed to earthquakes.