Automotive composites: which way are we going?

Thermoplastics, thermosets, ‘green’ composites, carbon fibre – the 7th Annual Society of Plastics Engineers Automotive Composites Conference and Exhibition (SPE ACCE) discussed the spectrum of materials available to car makers, and the challenges they face to get accepted. Pam and Mike Brady report.

Long glass fibre reinforced polypropylene (PP) is the most used and fastest growing composite material. Three conference days were filled with improved processes (direct in-line compounding – denoted as DLFT, lower mould pressures, etc), and examples of successes with long fibre reinforced PP.

Thermoset composites were looking for new applications. Better ways to use sheet moulding compound (SMC), whether moulded-in-colour (MIC) or powder priming, were investigated and methods to produce direct thermoset composites and direct SMC were covered.

Engineers and designers are gaining confidence in the predictive models and new models were introduced in virtual prototyping, analysis and testing sessions. Predictive modeling programs for long fibre PP had been used to make new products and were praised in many presentations. Pacific Northwest National Laboratories (PNNL) is using X-ray computer tomography and real time ultrasonic inspection, while Ashland Inc presented a summary of available modelling programs for thermosets.

Bioplastics, natural fibres, and ‘green’ engineering were discussed.

Carbon fibres are still on designers’ minds as we again hear about the successes (Boeing 787 aircraft) and the limitations (price and availability).

Nanocomposites continue to be a hot topic. Whether it is graphite, carbon nanofibres or nanoclays, new properties are possible with these materials.

Enabling technologies included nickel vapour deposition tooling for exact duplication of wood or leather grains, bond-line read through analysis, electrospin fibres and improved attachment methods.

Discussions

Michael Fisher, American Chemistry Council (ACC), presented Plastics are for Cars After All – the Rest of the Story.

  • Question: Are the Big Three (US) automotive companies ready to lead?
  • Answer: They may be ready. They’ll need help from Washington (federal government) and Wall Street (business) and global partners to accomplish their goals. Chrysler has new leadership including Jim Press, formerly of Toyota. Press had previously suggested that the automotive companies should present a uniform front and as such not just resist regulation but lead with suggestions for new standards. Alan Mulally, Ford, has suggested adding a fuel tax. GM Chevy Volt indicates the kind of creativity that will be needed in the future.

Fisher said that commonising standards (e.g. ISO, IEC) would be one such creative move. The US in the past has resisted common standards. One example of problem areas is the standard for bio-content calculations. Glass is inorganic so it is not counted. So a 40% glass filled bio-polymer can be classified as 100% natural product, while the same bio-polymer with carbon fibre instead of glass would be 60% natural product.

Fisher then listed the initiatives that are underway at ACC: plastic road map; create a new safety road map (finished next July); education initiatives (US$36 billion over three years); improve predictive engineering tools (National Laboratories); and recycling (CRADA, USCAR, National Laboratories).

Victor Liu of AZDEL Inc gave the keynote address Overview of Use of Composites in China Automotive Industry and reported on doing business in China. He indicated that in China today fibre reinforced plastic (FRP) is 75% of the market while glass mat thermoplastic (GMT) is 25%. Long fibre thermoplastic (LFT) is new to China. Natural fibres in thermoplastics are common but moisture, wicking, and odour are problems. The Chinese automotive industry is growing at a rate of 10% per year. Cost, quality, and flexibility are good in China while production development, engineering support and technical development need improvement. Micro vans and smaller cars (less than 1.6 litre engine) make up 42% of China's market.

Liu indicated that to become a supplier to the Chinese, in addition to low cost, one must have good technical support and engineering capability and some of that support must be in the region. Relationships are very important to the Chinese: they are looking for partners. They can be very demanding and expect good service but once trust is established they are loyal partners. The Chinese are ready to be flexible with their customers so they need and expect flexibility in their suppliers.

Carbon fibre

The major success of carbon fibre, the Boeing 787 Dreamliner aircraft, was again showcased, this time by Robert Kisch. It is the most successful launch in Boeing history, having more preorders at this point in the introduction than any other aircraft in Boeing history. But most interesting was the stated reason that Boeing decided to use so much carbon fibre composite in this airplane. Weight savings was only a minor consideration, as only 3% of the total 20% decrease in fuel consumption was the result of lighter weight of the composite. The driving force was a conviction that this was the technology of the future. It was 'a leap of faith,' going from aluminium to composite.

The improved performance showed up in many areas. In manufacturing the more expensive carbon fibre composite allowed a ten-fold reduction in fastener requirements, thus reducing the time to assemble the planes. The composite parts exhibited less variability, thereby increasing quality. In the final product, more comfortable cabin pressure and humidity are possible with more cabin space. The composite, less prone to corrosion, fatigue, or dents (no hail damage on Boeing 777 composite parts in a dozen years), exhibits lower maintenance time and cost. It also allowed the regulatory agency to require only one full tear down inspection in 30 years instead of the usual two.

Chuck Segal, OMNIA LLC, presented Is the Auto Industry Ready for the Carbon Fibre Industry & Vice Versa? Addressing price, supply, and production methods, he differentiated between high performance (higher cost) aerospace grade and modest performance (lower cost) industrial grade carbon fibres. The aerospace grade fibres have more consistent properties and more uniform handling characteristics. He outlined a number of programmes underway globally. Concluding, he answered his own questions:

Is the carbon fibre industry ready for the automotive industry?

  • Yes. Carbon fibres of appropriate strength and processability are available.
  • Maybe. Supply is adequate now but would require a coordinated effort and investment to meet automotive volume needs.
  • No. Acceptable low cost ($5US/ lb) carbon fibres will not be available near term.

Is the automotive industry ready for the carbon fibre industry?

  • No. While fabrication techniques used for glass fibres could be adapted to carbon fibres, price will remain the major hurdle.
  • Maybe. Metals and glass fibre plastics will be hard to displace.
  • Yes. Based upon the success in performance racing vehicles, super cars, and government tests, the automotive industry will find a place for carbon fibres in large volume production vehicles.

Upside down

Later in the conference, Richard Morrison, Molded Fibre Glass Companies, presented How the Thermoset Composites Industry can help meet the Changing Needs of the Transportation Industry. Morrison began with a short evolution of composites, from the 1950 Corvette, to heavy duty truck bodies, to the end of wood boats, to the Boeing 787. He mentioned power plant desulphurisation equipment and energy generating wind turbines that are becoming the largest composite users. He then turned to the automotive industry, pointing out that presently 72% of composites have Class A finish and he feels this is ‘upside down.’ He suggested (actually, he was impassioned) that composites should be challenging steel in the structural areas. With 70% of structural parts on the vehicle iron and steel, 7% thermoplastic, and 1% thermset, his advice was “Don’t fight over 1%. Fight over the 70%!”

Further, he pointed out that composites are not a commodity like steel and therefore trusting relationships with the original equipment manufacturers (OEMs) is the key to creative breakthroughs. Changes for the better (even at a cost) should be encouraged, Morrison said. If ever there was a time for GM, Ford, and Chrysler to get it right, now is the time, even if it means suppliers and the OEMs going open book. New trusting relationships must be established. Short term contracts and lack of relationships hurt research and prevent long term thinking and will severely hurt the US industry. Later, panelists agreed with Morrison on both points.

The first panel discussion, entitled Composites Industry Imperatives to Meet the Needs of the Next Decade was moderated by Jim Plaunt, AOC. Panelists agreed that improved fuel economy (FE) driven by new CAFE standards will be a major force in driving change in vehicle design. Gary Flint, Honda, used the Ridgeline truck, highest FE truck in a JD Power report, as an example of part integration which is the key to progress. He also indicated that Honda wishes to reduce the weight of every class of vehicle by one class. Carl Johnson, Ford Motor Company, felt that variability in production parts was a killer and drove over-design and thus increased weight. He wanted to see thinner SMC. George McCunn, John Deere Corporation, was an exception, saying heavy tractors work better, thus cost is the driving force.

When asked by the panel moderator about simply replacing steel parts, all panelists agreed clever design, innovations and ‘leaps of faith’ such as exhibited by the Boeing 787 or the Ridgeline truck box were necessary to push composites to new levels. It was also agreed that these types of success stories should be showcased to purge old perceptions, eg. steel is needed for crash worthiness. The Smart Car has lots of composites but passed all crash testing. Tom Hilborn, Continental Structural Plastics, added that plastic head lamps were used, even though they were more expensive, because of the design flexibility the composites allowed.

Plaunt quoted a GM source as saying “Some plastics are sold before their time”, adding that this is the worst thing for a product. Tyler Hardy, Meridian Automotive Systems, agreed saying, “there is no bad plastic, just a bad application.”

Paint-less parts were discussed but met with mixed comments. It was suggested that offline painting is highly discouraged but might produce better results.

The moderator queried panel members about ‘green’ composites. They agreed they must be at the same cost, and must be demanded by the customer. Usage of green composites will accelerate when Europe institutes new landfill regulations.

All panelists agreed that results are best with a team concept: OEM and suppliers. Sometimes purchasing agents were unreasonable, leaving some of the suppliers almost bankrupt. This desire for a better relationship with the OEMs was heard throughout the conference.

Going green

Amar Mohanty, Michigan State University, initiated a day of bio and natural fibre composite papers with a high speed, informative keynote entitled Introduction to Bio-Cars: Where We Are & Where We Are Moving! He covered corn and soy-based polymers, biomass and natural fibres. Europe is moving fast with the end of vehicle life and landfill directives. Ethanol and biodiesel from soybeans are fine but that leaves residual stalks, cobs, and soy milk. He suggested using soymilk to make a rubbery material to mix with natural rubber. By replacing glass fibres with hemp or flax he felt that 50 kg of natural fibres could be used per car, saving 10 kg per car. Further, he felt that natural fibres were low cost, low density, sound abating, non-abrasive, and safe handling. Conversely, he mentioned that moisture, microbe and low temperature limitations were drawbacks. Generally, these assets/liabilities were conclusions in all the ensuing papers.

Twelve papers dealt with natural fibres. While many of them were exploratory, a paper which outlined the use of natural fibres on the interior parts for the Smart Car showed many uses for natural fibres. However, at the end of one paper, Angela Harris, Ford, commented that a new bio-based resin with natural fibre SMC panel production part she had been working on was cancelled late in the programme and replaced with metal since the cost was equal. She felt management was supportive of green initiatives but it was clear ‘green’ parts must compete. Other papers concurred.

Marketing

Summing up composite marketing, Abbe Scheiner, Townsend Polymer Services & Information, presented Current & Future Market for Long Fibre Reinforced Thermoplastics. With 183 000 tons of LFT pellets and DLFT used globally (90% is PP), the split is Europe 51%, North America 29%, and Asia-Pacific 20%. Underbody, front-end modules and component panels make up 50% of these applications. The vast majority of DLFT is used in Europe and the US. Ticona is the largest supplier of LFT and 20 suppliers account for 98% of all composite products. Both DLFT and concentrate pellets are projected to grow rapidly. Townsend projected a 12% growth rate in LFT with Asia growing fastest and low cost will win out especially with the present over capacity.

Following the Townsend overview, there was a panel entitled Marketing the Value of Composites, which debated the question “If Boeing and Airbus can do it, why not the car markets?” Panelists agreed that more creative thinking is needed. The Boeing 787 was new from the ground up which allowed it to succeed. Many companies are risk adverse and many times composite products are designed and redesigned only to be cancelled. New car companies in China have less infrastructure and may be less risk-adverse and thus more open to novel designs with composites.

Cooperation

Harry Couch, National Composite Center, related a story about the lack of cooperation among the composite industry. When the Partnership for a New Generation of Vehicles (PNGV) was first introduced and the government-industry group met to discuss meeting the goals of 80 mpg with a 1500 kg car the group agreed it could not be done with steel. The composite industry went home happy and did nothing. The steel industry came back in six months with a steel car weighing 25% less. Lesson: the composites industry must cooperate with each other so they can speak as one.

The moderator asked why there is such resistance to composite parts. The panelists agreed that composite sales are growing at double digit rates even with car sales flat but there is still resistance to change. Even with many examples of success, OEMs are still reluctant to extend the material usage in other vehicle lines. Roeland Polet, Ticona, suggested a more focused approach was necessary. 20 years ago door modules made of plastic seemed impossible; now they are common. David Dyke, Meridian, said that SuperLite is now the headliner standard. Bill Mills, AZDEL, added you must give them a reason to buy. Len Nunnery, Bulk Molding Compounds, relayed a story about a throttle body design. They presented 25 reasons to design a composite throttle body but when a $150 000 prototype was needed, the OEM would not pay for it. The panel agreed that most automotive engineers understand metals but not composites. Case in point, only one school has a four-year course of study in composites.

The 2007 ACCE took place on 11-13 September in a suburb north of Detroit, Michigan, USA.