When it comes to solar powered vehicles, minimising weight to maximise speed and endurance is a critical factor in success. Team Hélios has been designing and building solar vehicle prototypes for over 15 years, and the company is currently developing its fourth prototype vehicle for the 5th Panasonic World Solar Challenge; a 3000km international race across Australia.
Hélios have used the Araldite / Aradur LY 5052 cold curing epoxy system to produce a range of lightweight, robust composite parts for the vehicle's bodywork. Hélios have also used this system to build a number of previous prototype vehicles.
"We start with a computer model of the car," explained Thibaut Leroy, Vice President of the Hélios Association. This is refined following a number of air tunnel and 'real air' tests to ensure the most fluid and aerodynamic design possible is achieved. This is a detailed process and development time can take anything up to two years.
A foam rubber scale model of the vehicle is then produced and used as the basis for building the bodywork's glass fibre moulds. From these, Araldite / Aradur LY 5052 is used in a vacuum pressure moulding system to produce the composite parts. These must be able to support the weight of the solar panel and to withstand the aerodynamic stresses put on the vehicle as it runs the race course.
"As the composite parts produced using Araldite / Aradur LY 5052 are primarily for the bodywork, they must meet a range of different criteria," said Thibaut Leroy. "They must be durable and mechanically strong while having a low component weight. They must also be tough enough to withstand the extreme environmental conditions encountered in Australia, such as very high temperatures."
The surface finish on composite parts produced using Araldite / Aradur LY 5052 means they can be painted and the vehicle used for public display and demonstrations. The new vehicle has already been seen and raced in the World Solar Challenge, Winston, USA and the Phébus, in France.
"We have worked successfully with Huntsman on a number of prototype solar powered vehicles," said Thibaut Leroy. The range of products available enables us to work with the Huntsman technicians to select the best possible and most appropriate products for any given project. Together we have overcome many challenges and made a winning team."
Araldite / Aradur LY 5052 is a matrix system suitable for a range of industrial and aerospace composite parts. Its low viscosity and low pot life allow for impregnation of reinforcement materials and ample processing time for the production of larger parts. It offers high temperature resistance - as required for the Helios project - with a glass transition temperature of 60°C after ambient cure and up to 120°C after a post-cure at 100°C. Laminates produced using this system has outstanding mechanical and dynamic properties; to the degree that it is approved by the German Aircraft Authority for the production of gliders.
In addition to pressure moulding system, Araldite / Aradur LY 5052 can also be used for wet lay-up, resin transfer moulding and filament winding applications.