New technologies are pushing the adoption curve for carbon composites in automotive applications, especially in Europe. Not so much in the United States, where we suddenly live once again in a land of (relatively) cheap gasoline.
In a recent example, the SGL Group and BASF have concluded joint research into a new composite material system based on reactive polyamide. The next step of the collaboration is to develop specific applications for the automotive industry.
Use of reactive polyamide (nylon) is expected to improve the cost-effectiveness of the manufacturing of thermoplastic carbon-fiber composites through use of faster production systems, specifically thermoplastic resin transfer molding and reaction injection molding.
Part of the technology is development of a carbon-fiber surface or sizing specially designed for the matrix system as well as tailored thermoplastic reactive systems. Special processes for manufacturing carbon-fiber-based textiles such as fabrics and braidings were also developed. To produce non-crimp-fabrics (NCF), special threads are used that enable processing in the reactive polyamide system.
BASF’s role in this project was to process SGL Group’s newly developed carbon fibers using the T-RTM technique and to characterize them comprehensively both chemically and mechanically. The BASF research team is continuing to work intensively on the development of caprolactam-based thermoplastic reactive systems.
Josef R. Wünsch, head of Structural Materials and Systems Research at BASF, says: “In close collaboration with plant manufacturers as well as tiers and automotive OEMs, we are working on the development of robust polyamide 6 carbon-fiber composite systems. The mechanical characteristic values arising from the interaction of the fiber and matrix are crucial input parameters for our simulation tool Ultrasim.” Most current CFRP systems are made with thermoset matrix resins such as epoxy.
Thermoplastics-based carbon-fiber composites combine the properties of carbon fibers such as high rigidity and low weight with the processing advantages of thermoplastics, allowing them to be formed, recycled (theoretically) and welded. This helps make carbon fiber technology more viable for large-scale production.
Separately, SGL is teaming with BMW in Germany for what may be the most ambitious plan in the automotive industry to use light weight carbon composites. BMW uses CFRP (carbon fiber reinforced plastic) in the i3 and M models.
A recent report from Lux Research forecasts that light-weight carbon-fiber reinforced plastics will dwarf current technologies in ten years. Advances now underway in fiber, resin and composite part production will lead to a $6 billion market for automotive CFRPs in 2020, more than double Lux’s earlier projection.
“Current trends strongly indicate significant mainstream automotive adoption of CFRPs in the mid-2020s, and companies throughout the value chain must position themselves to take advantage of the coming shifts. However, long-term megatrends towards urbanization, connectivity and automation suggest that there could be a limited time window beyond that for penetrating the automotive space,” says Anthony Vicari, a Lux research associate. “CFRP developers will have to continue the pace of innovation to overcome the high cost that has so far limited the material to less price-sensitive markets like aerospace and sporting goods.”
Carbon fiber, at $28/kg for standard modulus fiber, represents 22 percent of the cost of a final CFRP part. Additional advances are needed to reduce capital, labor, energy, resin and processing costs, which together make up the remainder.
The number of direct partnerships between carmakers or Tier-1 automotive suppliers and carbon fiber players has nearly doubled to 11 since 2012, according to Lux. One of the major private hubs of CFRP development in the United States centers around an Israeli company based in the Detroit-area called Plasan Carbon Composites. Plasan has a partnership with Toray and Magna. GM is involved in CFRP research with a consortium called USCAR, and is also using Plasan components in the new Corvette.