The Future Build team loves to visit factories, especially those that are manufacturing a new green product for the first time in the region, and in a facility that has been assessed as the world’s most sustainable in its field. Richard Reynolds, Supply Chain Consultancy Manager at Masdar City, along with Michael Bories, Architect with Foster + Partners; and Robert Hilton, Operations Manager with Thomas Bennett Gulf, were invited by Modar Al Mekdad, General Manager of Gulf Extrusions Company to the company’s Dubai factory to observe the manufacture of the UAE’s first green aluminium extrusions for Masdar Institute’s Field Station.
Gulf Extrusions, one of the largest extruders in the GCC, will manufacture approximately 14 tonnes of green aluminium extrusion for the field station façade, using a 6063 Alloy with T5 Temper. The green extrusions are an Al-Mg-Si alloy characterised by its good extrudability, excellent corrosion resistance to atmospheric factors and very high electrical conductivity – all this, and it’s made with 81% post-consumer and post-industrial scrap content. The order for these ‘green’ aluminium extrusions are a combination of hollow and flat profiles for architectural applications and cut in 6m lengths.
Aluminium is the metal of choice for metal cladding systems for three primary reasons: it protects itself against corrosion; it accepts and holds a variety of attractive surface finishes, and through the process of extrusion, it can be fabricated economically into elaborately detailed shapes. However, the carbon footprint of primary aluminium produced from bauxite is very high. That’s why Masdar City and Gulf Extrusions launched a sustainability initiative to lower the carbon footprint of aluminium used in the city by boosting the level of recycled-aluminium content, since aluminium produced from scrap, uses only five percent of the energy that primary aluminium does.
>Launched 18 months ago, this sustainability initiative involved aligning the actions of many stakeholders, as well as hard work on the part of Masdar City and Gulf Extrusions to boost awareness of, and concern for, the processes and products that go into the design and build of buildings. Two months ago, Gulf Extrusions completed a lifecycle study of their factory process that validated its status as the world's most sustainable aluminium extruders.
The Masdar City supply chain project team had the opportunity to see the manufacturing process first hand, from the arrival of the green billets to the extrusion of the finished product. To manufacture a ‘green’ aluminium extrusion, a large cylindrical billet comprised of 81 percent recycled aluminium is heated to a temperature at which the metal flows under pressure but still retains shape when the pressure is released. The heated billet is placed in the cylinder of a large press where a piston squeezes it under enormous pressure through a die, a steel plate with a shaped metal orifice. The orifice imparts its shape to a long extruded column of aluminium that is supported on rollers, cooled, straightened as necessary, and cut into convenient lengths.
As with any new material, there were questions about the quality of the high-recycled-content aluminium and how it would perform, but the extruded product turned out to be just as good as, if not superior to, primary aluminium – a result verified by a third-party consultant. The end result is an extruded product that is not only as good, or better than, primary aluminium, but it’s also more sustainable.
The extruded aluminium from Gulf Extrusions is sustainable for two main reasons: first, the high recycled-aluminium content reduces the demand for virgin materials, thereby reducing the impacts associated with the extraction and processing of virgin materials; second, the manufacturing process at Gulf Extrusions uses less energy than conventional extrusion processes, thereby reducing CO2 emissions.
The result: Masdar City’s has access to a material it likes, sourced from a local manufacturer. As well, the city has encouraged the green building materials industry locally and helped a local manufacturer become a global leader and innovator in a sustainable building-material manufacturing process.