Thermoformed plastics play an integral part in the Avus lounge chair, designed by German studio Konstantin Grcic Industrial Design (KGID) for Plank Collezioni, the furniture company located in the Italian town of
Konstantin Grcic designed the chair with the assistance from Sami Ayadi of KGID to incorporate a rigid base in matt ABS plastic. This is produced using a twinsheet thermoforming process and incorporates integrated grip recesses. The characteristic hollow interior produced in this process is filled with flame retardant polyurethane foam, which increases rigidity without adding excessive weight.
However, flexibility is a feature of the seat shells and the fluted high gloss upper shell, which are made from a single 3mm thick thermoformed sheet in the same type of ABS material as the base.
Grcic says the Avus chair "pays tribute to the characteristic qualities of this classic furniture type: great comfort, attention to detail, fine materials and refined elegance. However, the use of modern materials processed with cutting-edge technology from the automotive and sports industry makes Avus a radical reinterpretation of the lounge classic."
The combination of plastic shells with leather upholstery is said to "generate an exciting diversity of surfaces and allows Avus to be produced in a wide spectrum of colour combinations, from complete monochrome to strong contrasts". With its choice of five back-shell and three base-shell colours, the lightweight Avus chair has overall dimensions of 80cm x 73cm x 73cm and is expected to be used in public lounges, offices and private homes.
Solera-Thermoform Group, an Italian thermoforming company with facilities in Fucecchio and Torreglia, produced the plastic parts for the Avus chair. The July/August 2010 issue of European Plastics News reported on the company's PastItaly pasta automat project, which was also made using twinsheet thermoforming.
The company's sales and marketing director Daniele Versolato said he first contacted Martin Plank and his son Michael in the second half of 2010 to discuss how the flexible, high-gloss, rear upper part envisaged in Konstantin Grcic's design could be realised in plastic. Versolato said: "During the first meeting I explained to Plank that we can also have the twinsheet technology that could be evaluated for the rigid matt base."
Plank then pulled in both Konstantin Grcic and Sami Ayadi of KGID to discuss the sheet and twinsheet solutions in more detail. This involved a meeting at Solera-Thermoform to give an overview of the technology to the designers, who had not been familiar with it.
That meeting allowed the KGID designers to prepare a 3D design of the Avus lounge chair so that it could be produced by thermoforming. The chair's production methods are traditional vacuum forming for the top part and structural twinsheet forming from two sheet halves for the base. The 3D design was then finalised with the assistance of Solera technical staff, leading to production of both the moulds and prototype parts in January 2011.
Following minor modifications, Plank and KGID decided to go into industrial production. Final moulds and the first complete chairs were ready within five weeks, well in time for the
Konstantin Grcic is scheduled to present a paper on the Avus chair project at the SPE European Thermoforming Division's 2012 thermoforming conference in
Other recent designs by KGID for Plank have included the Monza armchair (2009) in wood and injection moulded polypropylene back and arm rests, and the filigree net structured Myto cantilever chair (2007), a single-piece injection moulding in BASF's HighSpeed easy-flow PBT plastic.