With China's auto market booming and millions of new cars on the road, automakers are turning to plastics to improve the environmental impact of so many new drivers.
The automotive industry increasingly is viewing the lightweight, durable alternatives to metal and rubber as green.
“We believe that plastics really are a solution for sustainability,” said John Verity, vice president of the polyolefins global business unit at Houston-based ExxonMobil Chemical Co. “One of the greatest sources of energy in the future is finding ways to use energy more efficiently.”
Verity joined a panel of automotive and plastics executives May 16 in Guangzhou for the China Plastics in Automotive conference, organized by Plastics News Global Group.
Transportation is the third-largest consumer of energy, behind electric power generation and industrial demand, and energy demand from transportation is expected to grow rapidly over the next 20 years. Plastics will play a key role in helping temper the role automobiles will play in increasing demand.
The primary role plastics can play is in reducing the weight of an automobile. Keeping weight down could prove more important than developing alternative energy sources for cars.
“You can work on the efficiency of the powertrain,” said Venkatakrishnan Umamaheswaran, automotive marketing director for Sabic Innovative Plastics. “But lightweighting is key.”
Contrary to popular belief, over the past 50 years cars actually have gotten heavier. In the 1970s, vehicles averaged about 1,650 pounds. By 2010, cars weighed an average of 2,970 pounds. Even the heavy-looking 1966 Ford Mustang weighed less than today's compact-seeming Prius.
Sabic hopes to reduce the average car weight to 1,870 pounds by 2020, which will save fuel and lower carbon dioxide production.
Other speakers emphasized that lightweighting is not the sole reason to use plastics in automobiles.
“The benefits of lightweighting are far-reaching,” said Thomas Apostolos, Asia-Pacific president of Magna Exteriors and Interiors. “But it's not just lightweighting, plastics can improve performance and reduce operating costs.”
Manufacturers face some hurdles to using more plastics, despite the materials' advantages.
“We are seeing an increasing amount of plastics in cars,” said Shi Rongbo, manager of the non-metal materials department at Chery Automobile Co. Ltd., one of China's largest domestic auto manufacturers. “But the requirements of automobiles are stringent — some materials need to withstand high temperatures, others to have a certain feel or look,” he said.
“Cars are complicated.”
Still, materials suppliers are working hard to come up with solutions. Umamaheswaran pointed to a thermoplastic polyolefin/nylon blend being used in the fenders of Mitsubishi's new ASX SUV. With features built in for energy absorption, the new fenders improve collision resistance at low speeds.
A steering-wheel application for plastics offered by Sabic can save automakers 20 percent of the cost compared with magnesium and offers a 10-30 percent weight savings. Using plastics also offers designers more flexibility — with plastics, designers can “stretch the imagination of steering wheels,” Umamaheswaran said.
Chery also is using more plastics. A polyphenylene oxide/polyphthal- amide resin fender will soon be launched in a Chery model, saving roughly 61/2 to 10 pounds on the front end of the car and improving the vehicle's performance.
Verity emphasized the uses of polyolefins in automobiles. Currently, 35 percent of all plastics used in cars are polypropylene.
“They offer a significant density advantage as well as cost advantage and recyclability,” Verity said. Thermoplastic polyolefins can be used for metal replacement on bumpers, interior trim and instrument panel retainers. Thermoplastic vulcanizates can be used to replace rubber in glass run channel systems, offering a 29 percent weight reduction.
Polyolefins also can help answer the next generation of automakers' challenges.
“Plastics allow multiple components to be combined into a single molded part,” Verity said. The design flexibility will allow for larger, bolder fascias and grille openings, improving aerodynamics and styling.
As automakers try to meet tight regulations on weight and safety, suppliers have an important role to play, according to Apostolos.
That is particularly true in emerging markets, he said, where suppliers can help lead new auto manufacturers to new solutions.
“Suppliers more than ever play an important role in determining where the market is going to land,” he said.