Speciality nylon and gas injection keep designer chair sturdy but lightweight
Gas injection technology has been used to produce a lightweight but stable weather-resistant chair by designers Ronan and Erwan Bouroullec in cooperation with Swiss furniture manufacturer Vitra. The chair is moulded in a 15 per cent glass fibre-reinforced grade of BASF’s Miramid nylon 6, optimised for gas injection moulding.
In developing their new chair, the Bouroullec brothers were inspired by a fashion dating back to the beginning of the 20th century: in North America, young trees were trained to grow in the shape of chair-like structures. The central element of the Vegetal chair is a seat shell that looks like branches of different thicknesses woven together.
The four legs and part of the seat shell of the chair are hollowed by the gas injection process. As a result, the chair weighs only 5·5 kg. It is made up of three components: the seat shell and the two front legs are formed in one step while the two rear legs are moulded in a second step.
One factor in the choice of Miramid was that it could be dyed in a series of earth colours, appropriate to the vegetation theme of the chair design, which is not an easy prospect with gas injection moulding grades. The particular grade used, Miramid B3EG3, has recently been improved by BASF for use in automotive interiors by making it available in the trim colours used by car manufacturers and has gone into serial production for the beige and black seat-adjustment levers of the Opel Insignia.
The Miramid range differs from BASF’s main Ultramid nylon brand through its greater customer orientation. It is produced by the Leuna plant in Germany, which BASF retained as a separate unit after revamping its nylon business in 2007. Leuna concentrates on small volume speciality materials and customer-specific options, such as coloured compounds.
The Vegetal chair will make its public debut at the Salone Internazionale del Mobile furniture fair in Milan, Italy, next week and will be available in six colours from the middle of this year.