A team of students from Aachen University of Technology and Aachen University of Technology plans to enter their self-built solar electric vehicle, which may be the world's toughest solar car competition: the 2019 Bridgestone World Solar Challenge. After winning the first battle in last year's race, the Sonnenwagen team will make a second attempt to complete the 3000 km route in Australia at the fastest speed without requiring a drop of fuel.
Covestro shares the enthusiasm of the students and supports the project with different materials and technical services, and serves as the team's main sponsor. Partners want to prove that today's mobile concepts are already possible-considering aspects such as lightweight construction, electrics and photovoltaics. At the European Coatings Show 2019 from March 19th to 21st, Covestro will showcase Sonnenwagen at the first "Sustainable City" held in Hall 4A of NürnbergMesse, with booth number 528.
Bonding is the best solution
Teams hoping to be the first to cross the finish line in Adelaide need a vehicle that is fast and lightweight. Different materials are needed to make such vehicles, including high-quality plastics as well as composites and metals. The best way to permanently hold different substrates together is bonding; it is also a key technology in the automotive industry.
However, adding components to solar vehicles manually has its own challenges. This includes preparing surfaces and improving the adhesion strength of different substrate surfaces. However, the main concern is the long-lasting quality of the adhesive when the adhesive dries. Sonnenwagen will withstand extreme conditions as it travels through the Australian outback: high temperatures, extreme dryness, and continuous, occasionally intense vibrations will put the adhesive to the test.
But it is also constant, and sometimes severe vibrations can cause the adhesive to be tested.
Strong adhesive
For new solar vehicles, the Sonnenwagen team relies on Sika Automotive's two-component polyurethane adhesives, which are based on Covestro's Desmodur® and Desmophen® series of polyurethane raw materials. The products of the SikaForce® series offer outstanding mechanical stability and flexibility. They are ideal for bonding complex parts, such as carbon fiber reinforced plastics, and are tailored for this ultra-lightweight, high-strength design.
"Thanks to this adhesive, we were able to build this year's Sonnenwagen in the shape we want," said Severin Kobus, co-chair of the Sonnenwagen Aachen team. "We use different adhesives-from flexible to highly elastic-to meet the requirements of design, parts and substrates."
Pascal Obringer, Global Head of Product Management at Sika Automotive, added: "Polyurethane adhesives are well-suited for innovative concepts of future mobility. The Sonnenwagen project is an ideal example of our adhesives' role in the future."
Tough race
The Bridgestone World Solar Challenge is considered the toughest solar event in the world and is held every two years in Australia. Teams from around the world compete with home-made vehicles to overcome the more than 3,000 km route from Darwin to Adelaide as fast as possible-powered solely by solar energy.