Slimming plan for automobiles

A slimming plan for automobiles: how can nonwovens give wings to lightweight construction?

Automotive manufacturers and suppliers are putting vehicles on a diet. We talked to Dr. Alen Nosic, Global Strategic Business Unit Manager Automotive, about how and where they can save weight, why lightweight construction is the most heavyweight topic in the industry, and what Freudenberg Performance Materials (Freudenberg) is contributing.

Are a few grams of weight more or less really so important when it comes to the future of the automobile?

Lightweight construction

Not a few grams, but if we move towards kilograms, then it is significant. Major premium manufacturers have developed the rule of thumb that every kilo saved is worth three to four Euros to them. For volume manufacturers, this figure tends to be a little less. However, extrapolated to the individual vehicle and to the entire mass of production, these sums become considerable.

Is that why lightweight construction has become such an issue in automotive engineering?

No. The EU regulation on the avoidance of CO2 emissions stipulates that, from 2020 onwards, new cars will only be allowed to emit a maximum of 95g CO2/km. Similar regulations exist in other countries. Failure to achieve that level could result in fines. To avoid this, manufacturers must either produce more CO2-friendly electric vehicles or more efficient cars with internal combustion engines that consume less fuel. One way of becoming more efficient is by bringing lighter cars onto the road.

Is it possible to calculate exactly what weight loss will save a certain amount of CO2?

Yes and no. It wholly depends on where in the car you reduce the weight. For example, if a weight reduction results in the car becoming too top-heavy, the manufacturer may experience considerable problems with driving stability. But it is not possible to generalize here either, because it always depends on the exact model. Lightweight construction is a very complex topic.

Lightweight construction

How does Freudenberg come into the picture?

Our nonwovens can be used very efficiently in lightweight construction. A textile underbody made of nonwoven material is substantially lighter than an injection molded underbody. With injection molding, the material has a much higher density.

The same applies to acoustics. One option is to use heavyweight barrier layers to block the noise source, whereby a noise hits this layer and is then reflected. However, our nonwoven solutions are absorbing: they absorb this noise and convert the sound energy into heat energy within the material. Absorbing solutions are somewhat more voluminous, with a large number of air inclusions, and are therefore substantially lighter.

However, lightweight construction is not the only factor in favor of our absorbing solutions. Various countries are planning regulations that aim to significantly reduce the level of noise created by a car. In Japan, for example, a car is only permitted to produce a maximum background noise level. But if you are using a reflective system, the noise bounces off, making the car sound louder to people outside the vehicle, such as pedestrians. Our lightweight solution absorbs noise, thus making the car quieter to the outside world.

Can you give other examples of how Freudenberg is supporting vehicle manufacturers in lightweight construction?

Sure. For example with modern luggage compartment partitions, so-called cargo covers. These are currently mainly made of PVC. Our team in Korea worked with an automotive manufacturer to find alternatives to this PVC solution. For environmental and health reasons, they want to dispense with the use of PVC. A further reason is the issue of weight, which they want to reduce. If they replace PVC with nonwovens, they save up to 400 grams per square meter of material. With 1.0 to 1.5 square meters of cargo covers in the car, that makes a big difference. Aside from the question of weight, traditional PVC cargo covers often freeze solid in cold weather, which makes them hard to move. In contrast, our solution remains flexible even at extreme temperatures.

How long has Freudenberg been working in the area of lightweight construction?

We have been developing lightweight carpets for vehicles since 2007. Underbody systems has been optimized since 2014, and acoustic solutions have been in development for years as well.

So we’re not talking about one material that Freudenberg uses in different ways, but about various performance materials.

Lightweight construction

Yes. They are different types of nonwovens. In general terms, we work with four basic technologies that we can combine at will. In this way, we are able to find a tailor-made solution that has the right properties for every problem. If you look at our acoustic pads, for example, you’ll see that they are made of a cotton-soft, airy material. Our underbody systems, on the other hand, are almost rock-hard and are also made from a nonwoven fabric.

What has Freudenberg got in the pipeline?

All issues related to electrification will take on a greater relevance with regard to lightweight construction. One example is e-mobility in winter. When it’s cold, I no longer have the “free” heat provided by an internal combustion engine to heat the interior. The battery discharges therefore faster. There is thus a requirement for thermal or thermoregulatory solutions, but they must not be too heavy. This will be very, very important in the medium term. In this area, we have a clear competitive advantage: we are a world leader in thermo-regulating nonwovens for outdoor clothing. This expertise is something we will naturally transfer to the automotive sector. And another important topic for the near future is natural-fiber-reinforced materials. Overall, the automotive industry offers us enormous long-term growth potential. At the same time, it is good to see our technical textiles being used in ways that benefit the environment and, ultimately, improve quality of life for people across the globe.

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