In August, against the spectacular backdrop of the Colonial Palace, part of the Royal Museum for Central Africa in Tervuren, Brussels, the Belgian Punch Power Solar Team presented their self-built solar racing car Punch One to their industry partners and sponsors. A vehicle packed with innovative technology and materials, including Openair-Plasma® technology.
Covering a distance of over 3000 km through the Australian outback and with temperatures well over 40°C, the Word Solar Challenge is regarded as the toughest solar car rally in the world. And there are just a few weeks to go before the 16-strong team of students from KU Leuven University take part in the unofficial world championship for the most efficient electric car. From the moment when the starting pistol fires in Darwin on the 18 October, the 47 teams from 25 countries will focus their minds on one thing only: energy efficiency.
Punch One is a masterpiece of aerodynamics – smooth, sleek and built for maximum endurance and minimum energy consumption over long distances. Working autonomously, the team had just 15 months to design and build the single-seater vehicle, which is powered entirely by the sun's energy.
Less weight means less energy consumption and with a maximum overall weight of 165 kg, Punch One should be 10 kg lighter than its predecessor and a good 25 kg lighter than most of its rivals. Despite significantly reducing the weight of the engine, suspension and control system, the team still fell short of their target weight. However, they managed to make up this shortfall with the chassis design; a 1.72 meter wide and 4.50 meter long monocoque construction comprising an outer and inner shell made from CFRP (carbon-fiber-reinforced plastic). These shells need a framework of stiffening ribs to prevent bending and twisting of the substructure.
In earlier models the anti-torsion elements were attached to the inner surface of both shells with the aid of multiple laminated layers of CFRP prepreg strips, which added a lot of extra weight. In a bid to save time and weight, the team decided to replace the extremely complex lamination process with a simple adhesive process and at the same time to pretreat the adhesive surfaces with Openair-Plasma®. As a result, the task was not only far easier, it was also completed in a third of the time previously required for lamination. But more importantly, thanks to the plasma adhesion process, the team managed to reduce the weight by almost three kilos; Punch One now weighs in at exactly 165 kg.