Automakers are striving to make cars more efficientand thus more environmentally friendly. Lightweight components made of fiber-reinforced plastics could help, but they are expensive to produce. But now developers from Evonik Industries have found solutions that bring us a big step closer to series-produced lightweight components.
Mobility makes life easier. It gets us to work safe and dry, brings us home with full shopping bags, or takes us to the doctor quickly in an emergency. Many people’s mobility depends on their cars, and millions of people in emerging markets also dream of having a car. The worldwide vehicle fleet already passed the one billion mark in 2009, and it’s still growing. In order to limit these vehicles’ impact on the environment, lawmakers are increasingly raising environmental and emissions standards. For example, the EU will reduce the CO2 emission limits for all new cars from 130 grams per kilometer today to 95 grams per kilometer in 2020.
Systematic lightweight construction is one way that automakers could partially fulfill these requirements. With every 100-kilogram reduction in weight, a car’s fuel consumption decreases by up to 0.5 liters per 100 kilometers. But whereas fiber-reinforced composites already account for up to 50 percent of a modern airplane, for cars that figure is only approximately one percent. One important reason for this is that lightweight construction requires lots of manual labor, as there are no automated production processes for it. In addition, the processing of composite materials takes much longer than the punching, bending, and welding of metal parts. This increases costs and decreases the number of units produced.
Head of the Composites Project House
A team of Evonik developers has now brought a solution within reach. At the Composites Project House —a part of Evonik’s strategic innovation unit, Creavis— it cooperated closely for three years with the Evonik business lines, universities, and partners along the entire value chain to develop new materials and processes that make lightweight construction with fiber-reinforced composites more cost efficient. Their work was based on Evonik’s extensive know-how regarding of almost all composite material components.
A completely new material concept developed at the project house, called hybrid polymer systems, is well suited for series production. These systems combine the characteristics of two types of plastics that used to be regarded as incompatible. They can be processed as easily as thermoplastics, yet are as mechanically strong as thermosetting plastics. In order to create these systems, the developers used a trick. Thanks to specialty chemicals, these polymer systems can be reshaped at temperatures over 170°C, but at normal utilization temperatures they are dimensionally stable and mechanically very robust. As a result, components made of this hybrid polymer system can be produced much faster and are also recyclable.
The project house also entered uncharted territory when it developed unidirectional tapes—plastic tapes in which fibers are embedded lengthwise. When such tapes are layered on top of one another at various angles and then melted together, they become extremely stable components. To produce these tapes, the project house developed a new process that saves costs, time, and energy. The tapes have been produced for over a year in a pilot facility that is suitable for series production.
After the development phase in the project house, Evonik’s business lines are now forging ahead with the market launch. The reactions of potential customers who have received samples for testing already show that these developments from Evonik have struck a nerve.
Oil and gas extraction could also benefit from fiber-reinforced composite materials. When oil and gas are extracted from very deep waters, the pipes have to withstand tremendous pressures. They are stiffened with metallic mesh, but that makes them heavier. The unidirectional tapes from Evonik offer an alternative, because they’re extremely strong and very light, and they don’t corrode.