Automakers Moving Towards Plastic to Reduce Weight

Posted by Al Elger on Jan 22, 2013 12:00:00 PM

blank.pngAccording to the January 15 issue of US News and World Report, auto manufacturers are moving away from steel and more toward lighter-weight materials to meet fuel economy standards.

“Faced with increasingly stringent benchmarks—the government's new Corporate Average Fuel Economy (CAFÉ) standards require a passenger vehicle fleet that averages 54.5 miles per gallon by 2025—carmakers are taking another approach to achieving better fuel mileage: shaving weight off vehicles by experimenting with lighter materials,” writes reporter Meg Handley.

These include aluminum, plastic, and carbon-fiber composites.

“Right now, only select parts have been revamped with lighter materials including more flexible, shock-absorbing bumpers and roof frames, and manufactures are starting to use more plastic components to lighten heavy engine blocks,” she continues. “But that will likely change over the next several years as auto manufacturers try to take pounds off of heavier vehicles and improve fuel efficiency.”

Kaysun Corporation has helped several automotive clients with this transition. For example, Kaysun worked with Gates Corporation to replace its metal serpentine belt pulley with a durable plastic replacement to reduce weight and improve performance. The plastic pulley—with a tolerance of +/- 0.001 inch—met all required noise, vibration, and harshness specifications and reduced overall production costs for the company.

Plastics manufacturers continue to develop resins that are specially engineered to withstand temperatures in the 400 °F to 500 °F range and resist the corrosive environments in cars and trucks. For example, DuPont’s Zytel® is a strong, stiff, high-performance polyamide that can withstand high temperatures and long-life coolants. It is considered ideal for thermostat housings, water pumps, engine oil systems, brake systems, and transmission components. Scania AB became the first vehicle manufacturer in the world to use a thermoplastic oil pan module/pump made from 35 percent glass fiber-filled Zytel in its commercial truck line.

Another polyamide product is BASF’s Ultramid®, which is designed for continuous use (3,000 or more hours) at 428°F, with temporary temperature peaks as high as 464°F—making it suitable for components near the engine, particularly for the charge air (heat exchange) systems of turbocharged engines. Chrysler is using cam cover injection-molded from Ultramid.

As specifically-engineered resins continue to enter the automotive market and compete favorably with metal in terms of performance, longevity, and cost, automakers will rely more on injection-molded plastic parts in the coming years to improve performance, reduce costs, and save customers money at the pump.