Cover Story: Future Forward

Giving the keynote address at this year’s Society of Automotive Engineers World Congress, James Queen, vice president General Motors North America Engineering, put it best: “It’s a great time to be an engineer in the automotive business.” Likewise, with so much new technology being commercialized, it’s a great time to be a plastics automotive supplier. Yes, the headaches are there, but so too are the opportunities.

The range of hot-button issues taken up by both the technical conferences and exhibitors at the show is indicative of the variety and depth of these opportunities: safety systems, fuel economy, fuel systems, interconnectivity, hybrid technology, increasing electrical demand. Innovations are quickly coming to market in every one of these areas, and in every case plastics is playing an integral, essential role.

Growth in hybrid models creates new material/processing opportunities

Once considered the domain of the tree-hugger set, hybrid gas-electric vehicles are now being targeted at soccer moms and Nascar dads. Next-generation technology, coupled with high demand, are prompting car companies to push hybrid technology beyond economy-class cars and into their mainstream bread-and-butter lines–trucks, luxury SUVs and sedans.

Ford Motor Company is planning to have a full-hybrid version of its Escape SUV in dealer showrooms by the end of summer. The launch may just beat the introduction of the Lexus hybrid RX400h mid-size luxury SUV, which the Toyota division will begin selling in late summer or fall. Toyota has also announced it will have a hybrid version of its Highlander SUV ready for sale sometime in the first quarter of 2005. General Motors expects to unveil its hybrid Chevy Silverado and GMC Sierra trucks by the end of the year, and Honda is introducing a hybrid edition of its mid-size Accord this fall.

The success of Toyota’s Prius, the 2004 North American Car of the Year has demonstrated the public’s keen interest in hybrid vehicles. Toyota has sold about 200,000 of the cars since its first launch in 2001, and demand currently exceeds supply. The new larger hybrid models are expected to ramp up that interest and most industry analysts expect gas-electric hybrid vehicles to become mainstream retail products over the next five years. Electric motors, exotic batteries and high-tech control systems currently make hybrids as much as 15-25% more costly than comparable gas-powered base models. Thus the critical question about the ultimate market success of hybrid vehicles centers on cost. With gas prices at an all-time high, consumers can recover the higher cost of a hybrid from savings on fuel much quicker. The cost recovery rate on the hybrid version of a gas-guzzling SUV is even faster than that for a fuel-efficient economy car.

“Studies have shown that if the cost premium (for a hybrid) can be recouped through fuel savings in three to four years, then the customer considers it a rational decision to purchase the higher cost vehicle,” said David Hermance, executive engineer at Toyota Technical Center.

Hybrid vehicles, and growing electrical demand in conventional cars and trucks, are expected to create new opportunities for materials applications and fresh approaches toward system designs.

“Automotive electronics are going to explode,” Diane Gulyas, group vice president, DuPont Electronic and Communication Technologies reported during a press conference at the SAE. Gulyas noted that electronics is DuPont’s fastest growing market segment, currently accounting for about $3 billion in annual sales.

Examples of new systems and components being developed for hybrid vehicles include integrated started-alternators (ISA), energy storage systems, electric pumps and compressors, motors and hosts of standard components such as solenoids, sensors, connectors and actuators that must function in an environment of higher electrical demand. Equipped with new materials, engineers have implemented design innovations that have raised the performance of hybrids to higher levels. For instance, a high-performance grade of DuPont’s Zytel nylon was used in the design of an electric water pump in one commercial hybrid model. Electric pumps do not have to be connected to the engine by belts or pulleys, providing better functionality and efficiency. DuPont has also developed a special encapsulation process using Rynite PET for producing space-saving electric motors. The encapsulation process eliminates the need for a separate metal housing. This and other kinds of innovative plastics technology will inevitably be employed in future hybrid technology, ultimately improving performance.

“Fuel economy may not be the main selling point in the next generation of hybrid vehicles,” said Toyota’s Hermance. “These vehicles will sell on superior performance.”

Toyota’s second-generation 2004 Prius has a 0 to 60 mph acceleration of 10 sec, an acceleration comparable to the Camry midsize sedan. The time betters the acceleration of the first-generation 2001 Prius by 2.7 seconds. To achieve this Toyota engineers redesigned and upgraded most components of the Toyota Hybrid System (THS).

Consumers can expect similar performance from the Toyota hybrid Highlander SUV and Lexus hybrid RX400h. According to Hermance, the quest to lower cost and improve the performance of hybrid technology will continue and involve analysis of all elements–batteries, motors and control systems–ensuring more opportunities for plastic applications down the road.

The quest for lighter, stronger materials

Increasingly stringent emission standards, as outlined in a speech at SAE by an official from the U.S. EPA, as well on-going consumer preference for trucks and SUVs, continue to make improving fuel economy a top priority for automotive companies. Materials engineers are attacking the problem on several fronts.

Professor Chul Park, Canada Research Chair in Advanced Polymer Processing Technologies at the University of Toronto, reports working with a major Canadian Tier 1 supplier on a project to reduce the weight of bumpers. The project involves the use of microcellular foamed TPO and is funded in part by Auto 21, a federally-supported research initiative focused on enhancing the competitiveness of the Canadian automotive industry. Chul, who as a graduate student developed the MuCell microcellular foaming process now licensed by Trexel Inc., received a $1.8 million grant from the federally-funded Canada Foundation for Innovation to buy equipment and support research on automotive applications of microcellular foaming

Using CO2 and nitrogen as blowing agents, Park and his group have been able to make foam with an expansion ratio of 40–i.e. foamed material with 40 times the volume of a given weight of neat polymer. The net result is foam with extremely small cell size (less than 10 micron) and low density. The foam can be used to make automotive parts with lower weight and superior mechanical properties.

“No one has achieved this large of an expansion ratio using carbon dioxide or nitrogen as a blowing agent,” says Park. He explains that foam with smaller cell size has fewer free paths and networks. The microcellular structure creates a “blunting effect” against crack propagation, resulting in stronger material. Tests have found that microcellular foamed PVC has up to five times greater impact strength and toughness, and 14 times longer fatigue life, compared to a variety of conventional foamed and unfoamed plastic materials.

Park says the project’s objective is to reduce the weight of bumpers by 20% without sacrificing mechanical properties and maintaining a Class A surface. Results so far have been encouraging and, according to Park, the project is moving into its second stage and closer to commercial viability.

Recent years have seen the first commercial use of natural fibre thermoplastic composites in automotive interior applications. Almost all of these applications have been in Europe. A group of Canadian researchers led by University of Toronto professor Mohini Sain has studied the thermal and mechanical proper
ties of various grades of wood-fibre filled polypropylene composites and hybrid composites (wood and glass) for injection molded automotive interior parts, such as instrument panels, door panels, rear parcel shelves and seat backs. The objective of the study was to find materials capable of meeting the performance standards for these types of parts. Natural fibres are up to 30% lighter than glass and other synthetic fibres. Additionally natural fibres cause less wear in processing equipment than synthetic-filled composites.

Sain and his group found that, with the exception of notched impact strength, mechanical properties of hybrid wood/glass plastic composites were superior to other composites. The research suggests that these composites can compete with other plastics, including engineering resins, in interior applications where impact strength is not a critical criterion. Additionally, targeted OEM specifications for flexural modulus and impact strength were met using the hybrid composite containing 15% wood and 15% calcium carbonate. Further work is needed however to find ways of improving the melt flow of these materials without altering mechanical properties.

Safety, comfort, convenience changing car design

Car designers have always been compelled to build cars meeting minimal safety requirements and consumer expectations for comfort. The goal today is to exceed those minimum requirements and expectations with a variety of new systems that deliver important information or enhance interactivity between the driver and his/her surroundings.

One example of this new twist in car engineering and design is blind spot detection. The U.S. National Highway Traffic Administration estimates nearly 830,000 vehicles will be damaged or destroyed this year as a result of blind-spot-related lane-changing accidents.

Siemens’ VDO Automotive’s new Blind Spot Detection System (BSDS) uses radar sensors invisibly mounted to the back of the rear wheels and the side exterior of the vehicle to detect objects approaching the driver’s blind spot. The BSDS is designed only to detect vehicles in adjacent lanes. An alert light on the side-view mirror illuminates to warn the driver of a potential collision. Siemens’ BSDS is flexibly packaged for easy integration into any vehicle design. The technology is expected to be commercial for the 2007 model year.

Mike Sanders, DuPont global director, automotive safety, says plastic has an essential role to play in new safety technology, such as blind spot detection systems.

“Radar systems need to be encapsulated and shielded to protect the electronics,” Sanders notes. “This can usually be accomplished with nylons of various types or polyester.” He reports that three or four suppliers are working to have blind spot detection systems commercial in various 2006-2007 models.

Heads-up display is another type of driver-interactive technology that is seeing wider use since it was first introduced by General Motors in 1996. Sanders says the technology has evolved from monochrome lighting displaying essentially redundant information found elsewhere on the dashboard, to four-color and LED lighting systems capable of providing the driver critical, timely information, such as collision avoidance warnings. DuPont is working with a number of suppliers and OEMs in the development of current heads-up display systems, such as the display going into the 2004 BMW 5 series and 2005 BMW 6 series, according to Sanders.

Once again, plastic materials are playing an integral role in the commercialization of advanced heads-up display technology. A wedge-shaped layer made of polyvinyl butacite (PVB) in the inner layer of the windshield helps facilitate clear optical display of the lighting. Plastics are also used in the instrumentation, the body of the mirror systems and other components.

These new technologies will also indirectly open doors for plastics applications in other areas, as the new systems require different approaches toward design and increasing amounts of electrical power (See Canadian Plastics, April 2003). No doubt, it is an exciting time to be an automotive designer and automotive supplier. CPL

USE OF BIOPLASTICS GROWING

One of the most intriguing developments at the SAE was the growing interest in the use of bioplastic, which are plastics derived from natural sources such as corn, sugar cane and other plants. Bioplastics emit no harmful gases and far fewer emissions when incinerated or degraded by natural processes. At present bioplastic costs about five times the price of conventional petroleum-derived plastics, but the cost could come down with larger production volumes.

Recently Toyota Motor Corp. said it expected its production of biodegradable plastics to grow into a $38 billion business by 2020. Toyota, along with Cargill Dow, are the two major producers of bioplastics in the world. Toyota began using bioplastics in some new cars last year, including the Raum and Prius models. Toyota has been producing bioplastics from a small-scale plant in Japan. If all goes as planned, the company has stated it will build full-scale production plant with an annual capacity of 50,000 tons.

Two researchers from Toyota Corporation presented a paper at the show investigating the use of bioplastics in automotive parts. The study found that adding natural fibres to polylactic acid (PLA) derived from plants greatly improved impact strength and heat resistance to levels better or comparable with polypropylene. However, the PLA/fibre blend did not meet the standards for hydrolysis resistance. The researchers suggest that the hydrolysis resistance of PLA could be improved by reducing the amount of residual lactide in the polymer. A copy of the report (#2004-01-0730) can be obtained by calling the SAE at 877-606-7323.