Nov. 6, 2017 | Source: Composites Manufacturing | Photo courtesy of General Motors 2017
There’s little doubt that composite components are going to play a major role in shaping the future of the automotive industry. Between federal mandates to lower fuel consumption and expanded use of composites in commercial trucking and similar industries, it seems inevitable. Experts have predicted that the wide-scale manufacture of composite-intensive vehicles will become the norm in the next five years. But they’ve been singing that tune for at least six years now.
In 2011 when BMW unveiled its all-electric i3 car, with its comprehensive specification of composite parts including a CFRP passenger cell, there was a sense that the use of composite components would leap forward. Finally automotive designers and engineers would have the evidence they needed to confidently design future iterations of composite-laden automobiles.
And now? “The timeframe for penetration of composites in the automotive market seems to be moving out,” says Terrence J. O’Donovan, vice president of marketing and sales for Core Molding Technologies Inc. and chair of ACMA’s Automotive Composites Alliance (ACA).
Many composites experts looking to gain a bigger chunk of the automotive market agree that the 5-year forecast for more explosive use of fiber-based materials didn’t exactly hold true. But these experts add that this moving target doesn’t make the automotive market any less promising – and the forecasts may not be far off.
Lightweighting is Part of a Bigger Puzzle
The majority of the respondents to a 2017 survey on the federal government’s Corporate Average Fuel Economy (CAFE) standards, sponsored by DuPont with WardsAuto and conducted by Penton Market Research, indicated that lightweighting is still considered the best solution for meeting the 2025 fuel efficiency standards. The majority of the nearly 750 surveyed professionals in automotive design, manufacture or component supply indicated that improvements to lightweighting through the use of lighter structural materials remains the best way to achieve the fuel reduction necessary. Additionally, 44 percent of survey respondents indicated that powertrain and chassis are the top two vehicle systems that automakers are targeting for weight reductions.
Composite materials are still seen as a leading material in terms of meeting these lightweighting expectations. Solutions like Core Molding Technologies’ lower-density sheet molding compounds (SMCs) achieve new strides in lightweighting. The company now has a full range of SMC systems at a 1.2 specific gravity, which O’Donovan says has become the new de facto standard for low-density composites. More specifically Hydrilite®, with its 0.98 specific gravity, takes the density of sheet molding thermosets below the range of thermoplastics and below the density of water. “We have developed material systems and innovative manufacturing methods that have found application in underbody shields and electric vehicle battery covers,” O’Donovan adds.
However, fuel efficiency improvements are simply one requirement that manufacturers are striving to meet. “Requirements like heat, crash worthiness and others are increasing and require properties greater than just being lightweight,” points out Keith Bihary, corporate sales director for Molded Fiber Glass Companies. And in those areas, composites face tough competition from competitive materials that have a much greater stake in this industry.
Composite suppliers are quick to point out that steel and aluminum have a significant head start when it comes to demonstrated performance. “Compared to its metal competitors, automotive composites is a ‘baby’ material system at about 60 to 70 years old,” says O’Donovan. And while it will ultimately take time for automotive designers and engineers to gain the necessary comfort in composites’ performance, there’s no room for suppliers to sit and wait for the automotive industry to embrace the promise of these materials.
“While composites have advanced – and continue to do so – so have the competing material systems: advanced high strength steel and aluminum,” O’Donovan says. “In particular, aluminum has emerged as the winning material (to displace steel for weight savings) in many of the current generation of vehicles.”
Bihary agrees. “The competitive materials are not sitting on the sidelines silently,” he says. “They are constantly making improvements and lobbying to retain their presence on the vehicles.”
This makes it more important than ever for the composite industry to drive the changes that need to happen in terms of cost and manufacturing efficiency if suppliers truly want to gain a larger part of this market’s business.
Hitting Cost and Manufacturing Goals
Cost and production efficiency remain among the most significant obstacles for the industry to address. “Aerospace carbon prices are dominating the market, so although you’re getting significantly higher performance the cost remains a barrier,” points out Uday Vaidya, chief technology officer of IACMI – The Composites Institute.
Material end users need education about alternatives to aerospace-grade materials, as this can make carbon fiber a much more attractive option for wide-scale applications. They also need reminders that the cost of carbon fiber has decreased. “The cost of carbon fiber, still relatively high, has been reduced by factors of two to three times in recent years,” says O’Donovan. “Many projects are underway to drive the cost down even further.”
Philip Schell, executive vice president of carbon fiber for Zoltek Corp., adds that when it comes to cost-effectively incorporating carbon fiber, cost is driven down by using the most efficient manufacturing processes. “Processes that efficiently use the material and transfer greater than 95 percent of that material into the final part are going to have some advantages,” he says.
Thermoplastic processes may be more likely to find greater use in this industry over fabric-based or prepreg systems where as much as 15 percent of the continuous fiber may not make it into the final part.
Then of course there’s the issue of production time. Large-scale production has always been a problem for composites based on the extended cycle times compared to more traditional materials. But improvements are being made.
For example, O’Donovan says, resin companies are working to improve resin and catalyst formulations that can drive cure times down to single-digit minutes, allowing composite cycle times to approach those of steel and aluminum.
While improvements have been made here, Bihary notes that consistency in manufacturing also has to be up to the task. “I think those challenges are being met but that also needs to be proven to give the OEMs a comfort factor,” he says.
“While composite parts are consistently lighter, stronger and more durable than the metal materials used today, the rate of manufacture and overall cost does not yet convince most OEMs to implement a move to composite materials,” agrees Chris Mikesell, sales manager for Chomarat North America. And this is a demand that requires not necessarily an adjustment to manufacturing, but to positioning. Mikesell adds, “Our industry needs to be smart as to how we present what can eventually become wholesale changes to the way we design and build cars.”
Exploring Combinations and Collaborations
In this regard, it could be most beneficial for the composites industry to harness the benefits of competing materials by focusing on areas where composites can be blended with or connected to other materials.
Ed Pilpel, senior advisor at PolyOne Advanced Composites, points to strategies European manufacturers have used to commercialize thermoplastic composites on a large scale. “The Europeans have done a lot of development in selective reinforcements in injection molding, and it’s now coming to the United States,” he says. “If you look at some of those companies that do injection molding, [many] now incorporate continuous fiber thermoplastic reinforcements into the injection mold to gain strength and stiffness.”
In the automotive industry, blends with more traditional materials help to provide designers and engineers with some familiar properties for testing. “We’re seeing examples of hybrids where they make parts of the car out of thinner gauge metal, such as steel or aluminum, and then stiffen or strengthen that with a carbon composite,” Schell says. “That way we’re getting a good portion of the lightweighting, but minimizing the total part cost.”
For example, Chomarat’s C-PLY™ essentially formats carbon tow into a pre-specified weight and direction. The C-PLY is then stitched together creating a ‘stack’ of angled carbon fiber. “The C-PLY construction can eliminate angles that are not necessary for part integrity, focusing solely on where the fiber needs to be. This eliminates cost and waste while helping to create a stronger part,” Mikesell explains.
Moreover, C-PLY can incorporate mixed materials within this carbon stack. “The ability to put materials like thermoplastics, aramids and toughening veils in between plies can enhance overall properties and move these materials closer to a finished part,” Mikesell adds. The end result is being used today in wheel assemblies, among other applications.
In addition, O’Donovan notes, new fastening methods have been developed that are capable of joining composites to metals, and this technology can help further this integration of materials.
But the industry might be aided not simply by working better with other materials – but also working better with each other and leading industry groups. Chomarat partners with many consortiums, including IACMI, the United States Council for Automotive Research (USCAR) and Stamping Technology for Automotive Manufacturing Processing of Composites (STAMP). “These groups can give Chomarat access to other companies with technologies that are vital to presenting overall product solutions to the automotive industry,” says Mikesell. “These collaborations will be what reins in that moving target.”
In fact, this may be an area where composites have a distinct advantage. “The metal counterparts are for the most part supported by a single raw material supplier and a single part manufacturer,” O’Donovan points out. “Composites involve cooperation among resin, fiber, additive, molder and often secondary and assembly suppliers, all working together to achieve a predictable result that an automotive OEM can be confident can be replicated around the world.”
Passing the Biggest Test
The biggest disadvantage that composites still have to overcome is simply the lack of proven performance in specific automotive applications. It’s a challenge that can only be overcome by time – and good data.
“Data, data, data is the way to convince OEMs that the materials are up to the task, not only in small lab batch trials but also in large-scale production,” Bihary says. “As that data base grows, more engineers become comfortable designing with it.”
O’Donovan notes that research is presently underway to characterize composite properties and feed that data into computer design databases and software that can model performance. This research is aimed at creating methods to characterize damage that might occur during automobile use and to develop reliable repair methods. “Composites are highly tailorable in their applications, yet are generally anisotropic and non-homogenous, making it more difficult for engineers to evaluate performance under dynamic load conditions,” he adds.
Pilpel notes that the industry now has access to a resource that wasn’t there five years ago. He points to the Composites Manufacturing & Simulation Center, launched in 2015 at Purdue University, as a game-changer. “One of the challenges we face is the education of engineers and designers on not only how to design with composites but also how to manufacture with it like they already do with aluminum and steel,” Pilpel says. “I think that problem will now be solved with the Simulation Center.”
Despite the challenges, suppliers with stakes in the automotive market see a bright future for composites in automotive applications.
“The hurdles are steep for composites, but so are the future fuel economy expectations. Thus, the reward for expanding use of composites in automotive applications will be high, and the future of the industry should be bright,” O’Donovan says. Given that automotive products generally see design generation cycles of approximately five years, the industry is looking to the next phase of development. It’s there that composites can advance their place in the lightweight materials race – knowing that competitive materials are advancing as well.
Given the work currently underway, composites experts predict that it won’t be long before more composite-intensive components are integrated into mainstream cars. “Many of the IACMI projects are looking at 2020,” Vaidya says.
The five-year projection may have been ambitious several years ago, but we’re now well on our way toward making it a realistic goal.