Driven by rising global emissions standards, lightweighting has been a growing trend in the automotive industry for many years. Manufacturers research alternative materials to reduce the weight of vehicles they build, thereby reducing fuel consumption.
In the United States, Corporate Average Fuel Economy (CAFE) standards are set to increase fuel economy for cars and light-duty trucks by model year 2025. Companies are gearing up to meet regulations and stay competitive in the market as it races toward better fuel efficiency and sustainability.
“Regulations are the biggest driver for improved lightweighting,” says Avinash Bhaskar, Segment Manager for Transportation Coatings at BASF. “That said, consumers are more cognizant of the discussion around emissions, global warming, climate change, et cetera.”
Beyond lightweighting, the automotive industry is constantly introducing new technology, from luxury options like wireless device charging pads to safety features like automatic emergency brakes (AEB). Two particular auto technologies will influence the development of lightweighting tech (and vice-versa) as they emerge and become more widespread: electric and autonomous vehicles.
Going the distance with electric vehicles
We’re seeing more electric vehicles on the roads these days, especially as availability grows to meet the demand for environmentally friendly transportation. A handful of barriers keep electric cars from becoming more ubiquitous among drivers.
Cost is one of them. Most electric cars currently on the market are in the luxury vehicle category and, despite the fuel savings, many car buyers are priced out of this vehicle class.
Bhaskar says the cost factor keeps getting better over time, but there’s one area where lightweighting can help make marked improvements in the electric vehicle arena: battery range.
“Increasing the range of batteries is one of the biggest conversations we have right now around electric cars,” he explains. “You can’t really plan a big road trip when your Tesla can only go 265 miles before you need to recharge the battery.”
Lightweighting is the natural solution to this issue. Put simply, a lighter car requires less battery power to move, which allows it to travel farther before it needs to be recharged.
In the case of bigger sedans or trucks, automakers can also achieve greater range by packing more batteries into the build. Lightweighting other parts of the vehicle offsets the additional mass.
Regulations are the biggest driver for improved lightweighting.
Segment Manager for Transportation Coatings
He goes on to explain that vehicles are made up of various materials, such as polycarbonate, plastics, steel and carbon fiber composites. Lightweighting means replacing those materials with lighter ones — like going from steel to aluminum, or plastic to nonwoven fiber — and sometimes securing them with adhesives instead of traditional welding.
“Pickup trucks are very popular in North America, but obviously they consume more fuel because of the weight,” Bhaskar says. “Ford® was the first to introduce a full-aluminum-body pickup truck to increase the fuel efficiency. That was a major technology milestone in the automotive industry.”
From heavy-duty trucks to already lightweight electric cars, any vehicle can benefit from the weight and cost reduction granted by lightweighting.
Preparing for the advent of autonomous cars
Unlike electric cars, autonomous vehicles are still several years away. A few related technologies — ones that fall under a similar umbrella, such as adaptive cruise control and self-driving cars — are setting the stage for full-fledged autonomous systems to take over.
To be clear, instances of this tech in the current automotive space all involve having a driver in the vehicle, whereas autonomous cars drive entirely on their own. In either case, these technologies require sensors to operate safely and effectively.
“When the whole autonomous vehicle infrastructure kicks in, there will be a lot of communication between the vehicle and the infrastructure and other vehicles. Internet of Things (IoT) data will power this sensor-to-sensor communication,” Bhaskar explains. “In order for all that to work properly, the materials used to construct a car must enable communication with those sensors.”
Automakers will need to consider the composition of lightweight materials and coatings — do they have the right amount of reflectiveness and transparency? Do they provide enough visibility where the sensors are embedded?
At the point where autonomous vehicles become more common, Bhaskar believes they will also be electric. A manufacturer’s lightweighting efforts will need to account for all those combined factors in future models.
How it all comes together
Bhaskar says lightweighting must meet three key demands: it must address fuel emission standards; it must be compatible with newer technologies (such as sensors on autonomous vehicles); and it must comply with stringent safety guidelines and multiple sets of standards, from collision guidelines to flammability specifications. They must do all this while staying durable and cost-effective to build.
Aside from the key factors, automotive manufacturers are also highly motivated to seek out sustainable materials. One example is CONTOURA™, a nonwoven fiber prepreg, a term that means the fabric is pre-impregnated with a resin and its curing agent. It only needs pressure and heat to cure.
The nonwovens can incorporate naturally-derived content — such as bast fibers, hemp or wood — or post-consumer synthetic fibers. The sheets are then compression-molded for use in various parts of a vehicle’s body, including underbody shields, package trays and headliners.
“There are many applications we can pursue,” says Bhaskar. “Because it’s so fiber-agnostic, this material can be made with natural fiber or a combination of recycled PET with ACRODUR®, our line of waterborne binders. In one of our current commercial products, we helped make an automotive interior part that is 80 percent natural fiber and 20 percent PET with our ACRODUR binder.”
Cadillac Products Automotive Company used CONTOURA to make an underbody shield for the Ford F-150, a project that reduced the part’s weight by more than half compared to the incumbent material (typically plastic).
The right combination of materials and binders means automakers can reduce their VOC emissions and their overall carbon footprint — and keep costs at a minimum.
The future looks light
Cars of the future are shaping up to look less like "The Jetsons," where hovercars still run on gas. Bhaskar says our vehicles will most likely run on electricity, drive autonomously and address the safety and environmental issues consumers care about. Automotive manufacturers will look to innovative lightweighting technology to meet these benchmarks.