Within the automotive industry, plastics are helping improve vehicles through safety, performance and style. Because plastics are lightweight and versatile, they make up approximately 50% of the total material volume of new cars.1 Below are a few examples of how plastics are helping to innovate vehicle technology.
Keeping it Light.
Plastic vehicle components, from engine systems to interior and exterior materials, help to reduce overall vehicle weight, contributing to greater fuel efficiency. In fact, for every 10% reduction in weight of the total vehicle, fuel economy improves by 5-7%.1 This saves money at the gas pump by decreasing the number of times drivers need to fill up. Some examples of the role plastic can play in helping keep your vehicle light include:
- Front-end Composite Structures: Vehicles are structurally designed so that during a crash, the crush occurs in a relatively gradual, predictable way that absorbs much of the impact energy, keeping it away from the occupants in what is termed a “controlled crush.”2 By utilizing fiber-reinforced polymer composite materials (carbon fiber), the front-end structure can weigh as much as 50% less, and the carbon fibers in the composite can have four to five times higher energy absorption than steel or aluminum.3,4
- Lightweight Plastic Foams: Filling thin-walled, hollow structures in vehicles with rigid, plastic foam can improve the structural strength of the vehicle without adding significant weight.5 Plastic foam can be injected into hollow structures and remains intact for the life of the vehicle, enhancing structures like the support frames necessary to prevent roof crush. Current applications for structural plastic foam include body-side joints, sills, pillars, underbody cross-car structure, frame rails/longitudinal structure, door panels, engine cradles, lateral rails, and hydroformed reinforcements.6
- Interior Design: The interiors of commercial vehicles, from the dashboard to the door, are composed of about 50% plastic, including safety subsystems, door and seat assemblies.7 These components, which contribute to the overall lightweighting of commercial vehicles, include:
- Blow Molded Seatback – Reduces weight by 5 lbs per vehicle and saves costs. Used in 2007 Audi TT; System supplier: Lear Corporation; Material Supplier: Dow Automotive.
- Plastic Automotive Door Module – Reduces weight 40-
60% and lowers cost.
Made by Ticona Engineering Polymers, a Division of Celanese and used on Jeep Wrangler, Jaguar XJ. - Metallic-look Plastic Door Handle – Reduces weight
up to 50% and eliminates high energy/high emission
inputs associated with metal plating and painting processes. Recyclable.
Made by Ticona Engineering Polymers, a Division of Celanese and used on Honda Accord. - Rail-less Window Regulator – Reduces weight by 25%
and saves costs.
Used in 2007 Dodge Nitro;
System Supplier: Faurecia Interior Systems;
Material Supplier: St. Gobain/ExxonMobil. - Center Console Support: Polypropylene center console support produces the structure less the typical weight for the center console. Requires no metal reinforcements, integrates several parts into one, and achieves mass savings.
- Invisible Passenger-Side Airbag Door: This soft, seamless passenger airbag door is integrally molded into a hard instrument panel using a simultaneous-shot molding process and two grades of olefins: talc-filled PP for the IP and a TPO for the door itself. This system provides a simple, uncluttered appearance and color harmony while eliminating fit and finish issues and providing cold-temperature impact strength. Both design and materials optimization were required for success, and the final system – which is covered by seven tooling and materials patents – provides performance at reduced cost and 500g weight reduction, while significantly reducing molding and assembly operations.
- Plastics-Intensive Fuel Filter Module: This module filters and cools engine oil. This new housing saves 38% weight and lowers cost while reducing pressure losses for higher engine efficiency. A plastic hose replaces rubber for further savings.
Reducing Waste.
By utilizing recyclable plastics in automotive parts, auto manufacturers are increasingly able to meet their recycling and recovery targets for vehicles that are at the end of their lives. This means that much of the car you drive today may get recycled and live on in a new vehicle or other product, instead of in a landfill. Today, more and more manufacturers are using post-consumer recycled plastic in their vehicles. Some examples of recycled plastic parts include:
- Recycled Material Door-Trim: The Recycled Material Door-Trim door uses 100% post-industrial scrap, diverting 100,000 pounds of scrap from landfills, saves cost, and changes the industry spec to allow more than 20% regrind in a component.
- HDPE Tailgate Liner with Anti-Static Layer: This pickup tailgate liner is composed of two coextruded plastics. The liner prevents damage to the paint and metal when hauling heavy or bulky objects. It is made mostly from milk jug HDPE with a thin anti-static/antislip layer to dissipate static electricity for refueling containers on the tailgate. The HDPE was sourced from post-consumer recycled bottle scrap at half the cost while diverting 2 million pounds of material from landfills.
Helping to Protect You and Your Family during a Collision.
Plastics play an instrumental role in essential vehicle safety features from belts and air bags that immediately protect occupants to foam-filled bumpers and structural components that help cushion a collision and reduce interior noise. According to Deborah F. Mielewski, a plastics research technical leader at Ford, a single injection molded plastic part can do the job of many metal pieces welded together.8 Below are some examples of how plastics are helping to protect you on the road:
- Lowering the Center of Gravity: Reducing the weight of a vehicle above its center of gravity, which can be accomplished through the use of plastic components such as spoilers, shelf panels, intake manifolds, fenders, and truck boxes, can increase vehicle rollover resistance.9
- Crumple Zone Physics: Crumple zones are structural areas in the front and sometimes rear of a vehicle that are designed to absorb energy upon impact in a predictable way.10 Crash test results from the National Highway Traffic Safety Administration’s New Car Assessment Program (NCAP) indicate that occupant injury and fatality risk can be reduced by designing vehicles with softer front end structures resulting in larger “maximum crush,” provided there is no intrusion.11 When used in crumple zones, lightweight plastic components can help absorb energy and save vehicle weight at the same time. Located in the front crumple zone, the plastic fan/shroud reservoir of the 2000 Dodge Dakota and Durango saved 1.1 lbs./vehicle, while the plastic bumper beam of the Saturn VUE saved 2.5 lbs. in vehicle weight.12
- Energy Absorbing Steering Columns: Energy absorbing steering columns were first developed in the late 1960s to cushion the impact of the driver’s chest by absorbing much of his or her impact energy in frontend crashes and limit the rearward displacement of the steering column into the passenger compartment.13 While the column enhanced passenger safety, it also added to the overall vehicle weight. Some manufacturers have incorporated plastic into their structures, which has helped to reduce overall vehicle weight.
- Polycarbonate Headlight Lenses: The use of plastic in headlamp applications enables automakers to reduce weight and increase resistance to breakage without sacrificing optical performance.14 Glass headlamp lenses began to be replaced with polycarbonate ones in the 1980s15; today, virtually all glass lenses have been replaced by transparent, shatter-resistant polycarbonate plastics.16
- Plastic Fuel Tanks: Plastic fuel tanks have several advantages over traditional steel fuel tanks, which are prone to corrosion from fuel and exterior elements like dirt, salt, and road chemicals. A plastic fuel tank made of high-density polyethylene (HDPE) is inert to the corrosive environments inside and outside of the tank.17 A plastic fuel tank also has a key safety feature: since it can be manufactured as a single part without soldered seams, there are no seams to fail in a collision.8, 18
- Laminated Glass: Today, almost all windshields are made with laminated glass, which is a multilayer unit consisting of a thin plastic layer (currently polyvinyl butryal or PVB) layered between two sheets of glass.19 Due to the lightweight embedded plastic, laminated glass windshields can be both thinner and stronger than those made of tempered glass alone, resulting in a typical weight savings of 11%.20,21 Laminated glass is also less likely to shatter under impact, and if a laminated glass window or windshield does break, the shattered pieces tend to remain bound to the inner tear-resistant plastic layer – helping prevent injury, and the broken sheet remains transparent, helping maintain visibility.22
Citations:
Mark Fisher, Michael PhD. “Enhancing Future Automotive Safety With Plastics.” Paper Number 17-0451
2 Ashley, Steven. “Composite car structures pass the crash test.” Mechanical Engineering, December 1996.
http://www.memagazine.org/backissues/december96/features/crash/crash.html (accessed April 20, 2006).
3 Diem, William. “Still Too Exotic.” Ward’s AutoWorld, November 1, 2004. http://wardsautoworld.com/ar/auto_exotic/ (accessed May 2, 2006).
4 Serious Wheels. “Mercedes SLR McLaren.” http://www.seriouswheels.com/top-Mercedes-SLR-McLaren.htm (accessed May 2, 2006).
5 Lilley, K. and A. Mani. “Roof-Crush Strength Improvement Using Rigid Polyurethane Foam.” Journal of Materials Engineering and Performance 7, no. 4 (August 1998): 511-514.
6 Dow Automotive. BETAFOAM Structural Foams. (Auburn Hills, MI: The Dow Chemical Company, 2006), a brochure, available at http://www.dow.com/PublishedLiterature/dh_0550/09002f13805508e3.pdf?filepath=automotive/pdfs/noreg/299-50613.pdf&fromPage=GetDoc (accessed May 4, 2006).
7 Fisher, Michael. “Enhancing Future Automotive Safety with Plastics.” American Chemistry Council. Paper Number 07-0451. 4.
8 Tullo, Alexander H. “Driving Efficiency.” Chemical & Engineering News 84, no. 24, June 12, 2006: 12-18.
http://pubs.acs.org/cen/coverstory/84/8424plastics.html (accessed March 15, 2007).
9 Van Auken, R.M and J.W. Zellner. Supplemental Results on the Independent Effects of Curb Weight, Wheelbase, and Track on Fatality Risk in 1995-1998 Model Year Passenger Cars and 1985-1997 Model Year LTVs. Torrance, CA: Dynamic Research, Inc., May 2005.
10 K-12 school Web pages in Newfoundland and Labrador. “Crumple Zones.” Sourced through the American Institute of Physics.
http://www.k12.nf.ca/gc/Science/Physics3204/Projects2003/SlotA/ProjectA2/link20.htm (accessed April 28, 2006).
11 Van Auken, R.M and J.W. Zellner. Supplemental Results on the Independent Effects of Curb Weight, Wheelbase, and Track on Fatality Risk in 1995-1998 Model Year
Passenger Cars and 1985-1997 Model Year LTVs. Torrance, CA: Dynamic Research, Inc., May 2005.
12 American Plastics Council. Automotive Learning Center. Plastics: Your Key to Fuel and Cost Savings. Arlington, VA: American Plastics Council, 2001. A brochure. Available at http://www.plastics-car.com/fuel_economy/Default.html (accessed April 28, 2005).
13 National Highway Traffic and Safety Administration. Lives Saved by the Federal Motor Vehicle Safety Standards and Other Vehicle Safety Technologies, 1960-2002:
Passenger Cars and Light Trucks With a Review of 19 FMVSS and their Effectiveness in Reducing Fatalities, Injuries and Crashes. Washington, DC: U.S. Department of Transportation, October 2004. DOT HS 809 833. http://www.nhtsa.dot.gov/cars/rules/regrev/Evaluate/pdf/809833Part1.pdf (accessed November 29, 2006).
14 UK Optical Plastic Ltd. “Luminaires: Overview of Plastic Optics and Luminaires.”
http://www.ukopticalplastics.com/luminaires.html (accessed March 15, 2007)
15 Tullo, Alexander H. “Driving Efficiency.” Chemical & Engineering News 84, no. 24, June 12, 2006: 12-18.
http://pubs.acs.org/cen/coverstory/84/8424plastics.html (accessed March 20, 2007).
16 Automotive Learning Center. “Plastics & Today’s Automobiles: Car Lighting Systems.” American Chemistry Council. http://www.plastics-car.com/s_plasticscar/doc.asp?CID=418&DID=1417 (accessed March 19, 2007).
17 The State University of New York, University of Buffalo, Department of Chemical and Biological Engineering. Plastics Metal Automobiles Report. Buffalo, NY: The State University of New York, University of Buffalo, Department of Chemical and Biological Engineering, 2004. http://www.eng.buffalo.edu/Courses/ce435/2001ZGu/Plastics_Metals_Automobiles/PlasticsMetalAutomobilesReport.htm (accessed May 31, 2006).
18 Alvarado, Peter J. “Steel vs. Plastics: The Competition for Light-Vehicle Fuel Tanks.” Journal of Materials 48, no 7 (1996): 22-25. http://www.tms.org/pubs/journals/JOM/9607/Alvarado-9607.html (accessed May 31, 2006).
19 Parsons, Glenn G. An Evaluation of the Effects of Glass-Plastic Windshield Glazing in Passenger Cars. Washington, DC: National Highway Traffic Safety Administration, November 1993. Excerpts from NHTSA Report Number DOT HS 808 062.
20 Terry Cressy (Director of Marketing, Automotive Safety Systems, DuPont Automotive), in email correspondence with Robert Krebs (Director, Public Affairs, American Plastics Council), April 26, 2006.
21 Michael L. Sanders (Global Director – Automotive Safety, DuPont Automotive), in email correspondence with Robert Krebs (American Plastics Council), May 2, 2006.
22 How Products Are Made. “Automobile Windshields.” Thomson Gale. http://www.madehow.com/Volume-1/Automobile-Windshield.html (accessed April 21, 2006).
