Technology and Practice: Aluminium fabrication. Heatherwick Studio has pioneered aluminium technology to produce the world’s first extruded single-component furniture
The extruded aluminium mullion, commonly used within most curtain wall systems, is generally considered a banal architectural component. Yet Thomas Heatherwick of Heatherwick Studio, intrigued by the precision and intricacy of aluminium extrusion technology, has reworked it to produce large-scale objects of extraordinary beauty. In fact, these objects are extruded single-component furniture, a world first, and currently on show at the Haunch of Venison Gallery in London.
Heatherwick says manufacturers have never used aluminium extrusion technology ‘to its full extent’. For 18 years he has been working on a project to manufacture extrusions of unprecedented cross-sectional dimensions. As a rule of thumb, these dimensions should not exceed 350mm. Larger cross-sections require machinery that can exert enormous pressure and, until now, it has only been possible to cross the 350mm threshold along one axis.
Also, if the extrusions are to be thin, additional pressure is needed to overcome the resistance that is encountered as the aluminium is forced through the dye. ‘The width’, he explains, ‘affects the resistance to pressure.’ Heatherwick has taken on this challenge as well.
In order to develop this project, which sets out to manufacture benches comprising legs, seat and back from single extrusions, Heatherwick needed very powerful and expensive machinery. ‘The hardest thing was finding a machine that not only did the seat and back but the legs as well’, he explains.
For most factories the cost of interrupting large-scale production to install a new dye was prohibitive. Yet the potential to expand the horizons of this project saw Heatherwick embark on a global quest to find a factory with a machine big enough to enable the project.
Understandably, the artist hesitates to disclose every detail of the manufacturing process. ‘I’m not in a rush to let everyone else know’, he remarks. Nevertheless, Heatherwick explains that gallery prototypes have been manufactured in a factory in the Far East that produces components for the aerospace industry. He adds that the alloy chosen is particularly suitable for high-pressure extrusion and that the machine can exert pressures of 10,000tons. He also suggests that variations in temperature may have influenced the form of the seats.
The six pieces in the exhibition, which range from 1,660mm to 4m in length, have 750mm-high and 540mm-wide cross-sections and are 10mm thick at their narrowest points. Although they have all been extruded from a single, specially designed dye, they are all different.
Heatherwick has taken a long-standing interest in the random output that is possible in the extrusion process, especially where machinery is operating at the limits of its capacity. Manufacturers are naturally anxious to overcome this deviation, seeking to work to manufacturing tolerances with a variation of just 1mm or less. For the purposes of a limited-edition exhibition collection, this variety does not seem to have been a concern. In fact, using gantries, Heatherwick manipulated the units as they were extruded. The piece that was most difficult to produce was relatively straight, taking several attempts.
As Heatherwick’s project is developed to produce a writhing 100m-long assembly of seating units, it seems likely that it will become increasingly necessary to control the form of the pieces. In spirit, the seats have a certain resonance with Russian constructivism and Italian futurism. They have been polished to a chrome-like finish using hand-held mechanical mops.
Visually, this reinforces the dynamic linear effect of folds and grooves on their surfaces. The ends of the extrusions are left unpolished and their twisted forms bear the marks of the abrupt stop-start process in the factory. The ends have not been sliced off by a guillotine process. There are continuous notches at the extremities that can be used to house members that would serve to connect adjacent pieces.
Heatherwick is acutely aware of the enormous range of possibilities that this project, which uses what he describes as ‘the world’s largest ever aluminium extrusion’, has opened up, for example, in the design of seating in large public areas, such as airports. The success of the project will set an example to other artists and designers, demonstrating the benefits of engaging with and challenging industry. Heatherwick has invested £60,000 in this project. This may well turn out to be money well spent.
Heatherwick Studio’s Extrusions at the Haunch of Venison Gallery in London ends on 8 November. You can read more about the exhibition in this month’s edition of The Architectural Review and about the Studio’s creative business units at Aberystwyth University in the July issue.