The Audi R8 sports car that has garnered rave reviews from car enthusiasts combines outstanding performance with a stylish exterior design. Among the vehicle’s most striking features is a carbon fiber/epoxy composite side blade. The part, which is key to the lateral contour design of the car, supports the R8’s trademark “high-tech” appearance while also playing a role in the vehicle’s air-ducting system.
To build the slide blades, Audi AG chose Fischer Composite Technology GmbH, based near Salzburg, Austria, a recognized specialist in the development and production of complex carbon-fiber composites for use in the automotive, aerospace, and sports-leisure equipment industries. Before starting the project, Fisher worked closely with Huntsman Advanced Materials to select the epoxy resin system used to resin transfer mold (RTM) large, 35" x 19.5" carbon composite shells. A Huntsman Araldite®epoxy adhesive is also used to bond shells together to form the side blades.
“Audi AG required a ready-to-install side blade assembly with all fixing and mounting items included,” said Gerhard Kölbl, Fischer Sales and Marketing manager. “The side blade also had to meet Class-A surface finish requirements, including protection against ultraviolet light and other effects of the weather.
“Working with the Araldite epoxy systems on the molding and joining of the side blade shells, Fisher was able to fulfill Audi’s exacting requirements in terms of appearance, precision fitting, and dimensional space tolerances.”
RTM ProcessTo fabricate each side blade half, Fischer places dry pre-formed carbon fibers into a mold and then injects the Huntsman low-viscosity, transparent epoxy resin. The inner shell is cast with all the fixing devices to mount the side blade onto the car already in place, so no additional auxiliary component bonding or finishing is required.
The outer shell comprises a three-layer carbon- and glass-fiber-composite structure. Once mounted, the visible outer side of the side blade is a 6K Twill 2/2 carbon fiber surface, protected from UV sunlight with a clear, glossy lacquer finish.
Completed shells are joined using Huntsman Araldite 2015 two-component epoxy adhesive paste. The material produces highly resilient bonds on SMC and GRP substrates. It is also easy to apply with a 35-minute pot life and good sag resistance (up to 0.39 inches thick) on vertical surfaces.
The Audi R8 is now available worldwide, and Fischer Composite Technology is currently manufacturing around 4,000 sets of the side blades annually.
About HuntsmanHuntsman is a global manufacturer whose operating companies make products for global industries including chemicals, plastics, automotive, aviation, textiles, footwear, coatings, construction, technology, agriculture, health care, detergent, personal care, furniture, appliances, and packaging. Originally known for pioneering innovations in packaging and, later, for rapid and integrated growth in petrochemicals, Huntsman now has 13,000 employees and operates from multiple locations worldwide. The company’s 2006 revenues were more than $13 billion.
For more information about Huntsman, please visit the company’s website at www.huntsman.com.
For more information on Araldite® systems for RTM and bonding, visit www.huntsman.com/advanced_materials.
For more information on Fischer Composite Technology, visit www.fischer-ct.com.