Statistics show that new cars are becoming heavier, due to, for example, improved safety functions and more electronic equipment. This increase in weight means higher levels of gas consumption, an aspect that goes against the goal of reducing CO2 emissions.
Weight is also an important factor for electric vehicles, because they need bigger and, as a result, heavier batteries to maximize their autonomy, a decisive sales argument. So much so that, according to a study carried out by McKinsey, the proportion of lightweight parts in cars will have to increase from 30 to 70% by 2030 to make up for the weight increase of the vehicles.
The preferred solution so far has been lightweight steel and plastics reinforced with carbon fiber, but this also has some disadvantages. First of all, it means important challenges in machining, repairing, and recycling. Secondly, the manufacturing of these materials requires large amounts of energy, reducing the value of the positive environmental aspect of weight reduction.
Regarding this, researchers at Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut WKI (Germany) raised the question of whether or not fibrous materials could be used to reduce the weight of components, using only carbon fibers in those places where they provide a structural advantage. They researched different eco-friendly materials, easily obtainable considering their technical properties, availability, and profitability, since a feasible solution must have positive technical, environmental, and financial impacts.
According to researchers, in terms of sustainability, organic fibers improve the environmental impact of high-performance composite industrial materials for bodyworks during manufacturing, use, and removal.
In financial terms, the use of renewable raw materials is beneficial because the natural fibers of flax, hemp, wood, and jute are less expensive than carbon fibers and require less energy during their manufacturing. Therefore, the advantages of weight reduction do not mean a prohibitive price.
There are also additional advantages during industrial processing, with applications for the vehicle: the natural structure of organic compounds gives these materials muffling properties and reduces shattering, which is important in the case of a crash.
These arguments have been essential for Porsche to test the advantages of using vegetable fibers in the composition of the bodywork of their model 718 Cayman GT4 Clubsport. These materials, developed at the Fraunhofer WKI Application Center for Wood Fiber Research HOFZET, would contribute to reducing the body weight without decreasing the performance that the industry demands from traditional steel and carbon fiber reinforced plastics.
Porsche is not the only maker to use this type of materials. Ford has been researching for years, together with different partners, the use of tomatoes or cotton for upholstery and other components. In this regard, they have recently signed an agreement with McDonald’s to create renewable plastic from coffee grounds. In addition, the North American maker is also working with soy, rice, cellulose, wheat, castor oil, jute or coconut in order to replace the use of plastics. Meanwhile, the prototype ME.WE. by Toyota has bamboo on the floor due to its hardness, resistance, and flexibility.
Also, the Nissan Leaf uses recycled plastic resins for plastic components like the control panel and parts of the doors. Also, the control panel and door panels of the BMW i3 are made of renewable natural fibers like open pore eucalyptus. The Toyota Prius uses bioplastics in the seat cushions and in several areas of the interior, while the Kia Soul EV uses bioplastics for ten different pieces; from the door panels to the seat upholstery or the floor mats.
Another example we can find is the NCV project (Nano Cellulose Vehicle), launched in Japan in 2016, which has been exploring the application of cellulose nanofibers that are derived from plants (CNF) in an attempt to reduce the vehicle weight and reach carbon neutrality in its life cycle. The result has been a spectacular super sports car that was exhibited at the last Autoshow in Tokyo.
As we can see, the strict anti-contamination regulations require a reduction in the weight of the vehicles. Because of this, new metallic alloys and materials have been introduced into the bodywork, being the best tool to accomplish this weight reduction. This requires garage professionals to be proactive in terms of training and adapting to these new materials, that might require specific knowledge during bodywork repair and maintenance.