Although the “zero-emissions vehicle” is still some way off, plastics such as the Durethan polyamides and the Pocan polybutylene terephthalates (PBT) from LANXESS are playing a vital role in making it a reality. “Our high-tech plastics open up excellent opportunities in designing lightweight automotive components with excellent crash behavior, thanks to the fact that they weigh less than metal and exhibit high-quality mechanical properties. They’re also ideal for low-emission engine designs such as electric and hybrid drives,” says Lars Kraus, Head of Technical Marketing Services at the Semi-Crystalline Products business unit. LANXESS is therefore already collaborating closely with the automotive industry on numerous projects throughout the world to develop innovative and cost-effective technical solutions for sustainable mobility.
Hybrid technology – excellent opportunities in electric drives
One of the strengths of Durethan and Pocan is that they can be combined with other materials to make very strong, lightweight composites. One example of this is the already well-established hybrid technology, which specifically combines the benefits of metal and polyamide. Hybrid components are usually 20 to 30 percent lighter than pure steel components while offering the same performance. To date, over 50 million front ends have been manufactured using hybrid technology featuring Durethan. “We expect automakers will use this lightweight construction in the future to manufacture not only front ends, brake pedals and roof frames, as has so far been the case, but also such items as sills, doors and support modules for panoramic roofs,” says Kraus. The lightweight construction potential of hybrid technology also opens up major opportunities for use in electric vehicles. Battery trays are one possible application.
Lighter still with nylon composite sheet technology
Hybrid technology recently got a further boost. In conjunction with partners, LANXESS has once again significantly enhanced the lightweight construction potential of this technology by using nylon composite sheet instead of sheet steel or aluminum. Nylon composite sheets are lightweight thermoplastic sheets embedded with a reinforced continuous fiber fabric made of materials such as glass fibers. “We estimate that using nylon composite sheet instead of aluminum hybrid designs cuts component weight by around another 10 percent. The savings over hybrid components with sheet steel are even greater,” says Kraus. Potential applications include engine bulkheads, spare wheel recesses and tailgate frame components.
Foamed polyamides – “slimming down” components
Foamed plastics offer a completely different method of achieving lightweight components. LANXESS has optimized several Durethan polyamides for physical foams that produce component surfaces with high optical quality and are also ideal for visible components. “These materials are in high demand because foamed injection-molded parts weigh up to 10 percent less than their solid counterparts, and in some cases as much as 20 percent less,” says Kraus. The mechanical properties remain outstanding despite the foam structure. Potential applications under the hood include fan guards and covers.
Flame-retardant cable sheathings and plug connectors
Flame-retardant plastics will be increasingly found in electric vehicles, owing to the high voltages and strong currents present in the area of the battery and drive system. As a result, flame-retardant polyamide and PBT for plug connectors and cable sheathings, for example, will gain importance. “We have already developed highly fire-resistant versions of these materials, such as Durethan polyamides with very high tracking resistance and with flame-retardant packages free of red phosphorus and halogens.”
Polyamides for new engine concepts
One approach to cutting vehicle fuel consumption and CO2 emissions is to use fuels with a biological component and modified engine concepts such as forced induction engines. This also results in new requirements for polyamide, which has become widely established as an alternative to metals or rubber for the production of hollow-molded parts for airflow management, oil and cooling circuits and the engine fuel supply. “We have therefore tailored numerous Durethan polyamides for these applications. For example, we offer extremely heat-stable material grades for products such as charge air tubes and electrically conductive material grades for lines and filters of engines with direct fuel injection. We also have polyamides for components in contact with E10 fuel or AdBlue solutions,” says Kraus.
LANXESS is a leading specialty chemicals company with sales of EUR 7.1 billion in 2010 and currently around 15,500 employees in 30 countries. The company is at present represented at 46 production sites worldwide. The core business of LANXESS is the development, manufacturing and marketing of plastics, rubber, intermediates and specialty chemicals.