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Lightweight – with EMC Protection
Luxury sedans have dozens of electronic control units all over the vehicle. Freudenberg Sealing Technologies has now developed several processes that make it possible to use comparatively lightweight plastics as materials.
There are electric fields whenever current flows. And if a great deal of current is flowing, as is the case with electric cars, the fields are quite strong, at least at close range. This can disturb the smooth functioning of the electronic components in control units, the transmission of information inside the vehicle, or even communication outside it. So all vehicle electronics are designed for maximum electromagnetic compatibility (EMC). That’s why electronics boxes in vehicles almost always have aluminum housings. The metal conducts current well and is relatively easy to process. Replacing this lightweight metal with plastics could cut a few dozen kilograms per vehicle. But the plastics would have to be electrically conductive or reflect electromagnetic waves at their surface.
Electrically conductive plastics were discovered back in the 1980s. To some extent, they were considered exotic materials that did not meet other requirements for automotive materials. Freudenberg Sealing Technologies uses them only in extraordinary cases. Two of the latest developments are more practical. One idea, applying a conductive coating to a plastic housing like a lacquer, is quite close to series-production use. In another option, particles of a conductive material can be added to the plastic before the injection-molding process. Finally, a nonwoven fabric made of conductive fibers can be inserted into the mold during the production of thermosetting plastics. Freudenberg Sealing Technologies is working in parallel on all three approaches. In the field of conductive nonwovens, it is working closely with sister company Freudenberg Performance Materials.
Plastics are not likely to displace aluminum as a standard material solely on the basis of weight. But early calculations by Freudenberg Sealing Technologies based on real components show that cost factors can also make a strong case for plastics. Starting with an annual output of at least 30,000 housings, the higher total costs for plastic-injection molding can be offset by the extended use of the mold.
Seals from Freudenberg Sealing Technologies retain operating media in machines while protecting against the penetration of undesirable foreign matter. The company’s new ways of shielding against electromagnetic interference can be seen as new forms of sealing. The first patents show that classic seals could take over a number of new tasks in the future.
Plastics are our current focus. On single-use plastic as a burden on society – and how we can deal with the problem. And on the question of whether plastic can be a solution.
You can find more on the topic “Plastic – Breakthrough and Burden” in the latest edition of our magazine ESSENTIAL.
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Materials for Wind Power
If you were to stand a single rotor blade on end next to the Dresden Frauenkirche, it would rise more than 10 meters higher than the church’s tower cross. Without the use of composite materials, the blades of the latest wind turbine giants would be too heavy to function.