Auto industry on the hunt for new lightweight materials

The auto industry is focusing on lightweighting, and this is igniting a race to find new materials that can meet ever-changing performance needs of the OEMs.

A materials innovation panel discussed the topic during Plastics News' 2015 Plastics in Automotive Conference, held Jan. 14 at the Westin Book Cadillac in Detroit.

The panel, moderated by Sandra McClelland, vice chairman of the American Chemistry Council's Automotive Division, included:

• Brian Baleno, global automotive business manager, Solvay Specialty Polymers.

• Dan McNary, vice president of sales, DLH Industries.

• Shawn Mealey, senior AETS specialist, Dow Corning.

• Brice Mulholland, global color technology manager, Celanese Corp.

Baleno led off the discussion, focusing on high performance polymers and reducing CO2 emissions by improving powertrain efficiency. He noted that there are two key areas where new materials can help plastics make inroads in vehicles — in air management systems and turbo exhaust hoses.

The auto industry's gravitation toward smaller, more fuel-efficient engines also is creating new opportunities.

“As you downsize the engine, you increase the thermal performance,” Baleno pointed out.

To that end, materials suppliers are investing money in research and development to create materials that can withstand higher temperatures.

Other changes are coming in transmissions, where Baleno noted a metal needle bearing replacement was replaced by a polymeric bearing by one manufacturer.

“The biggest advantage is space savings when you switch to the plastic,” Baleno said. “You can downsize the casting of the transmission, which results in additional weight savings. This translates to less energy used.”

Solvay continues to work on thermoplastic composites that can be used in a number of under-hood applications and in areas where temperatures can exceed 220° C.

“We are researching it,” he said. “We don't have anything that we are ready to talk about publicly.”

McNary touted the work DLH Industries is doing under the hood of vehicles including the latest incarnation of Chevrolet's iconic Corvette and the Cadillac CTS, Motor Trend's 2014 Car of the Year. The Canton, Ohio-based company specializes in air and fluid handling components and assemblies as well as precision molded and extruded plastic parts.

One advancement made, McNary noted, is the conversion of rubber hoses under the hood to thermoplastic options, which have resulted in weight savings. Housings that cover tie rods in the suspension of vehicles also has been converted from rubber to plastic.

McNary noted that these parts also are recyclable.

“These products are key to what we do, but they don't define us,” he said.

And when looking for lightweighting opportunities under the hood, it is important to understand the impact of temperatures the material will be subjected to.

“We have to have the correct materials and understand the environment,” McNary said.

The path to materials innovation isn't without its hurdles.

Dow Corning's Mealey noted that silicone is a viable option as it can be made to have a wide variety of functions. It offers long-term flexibility and works at a wide range of temperatures.

“There is really a finite range of known polymers,” he said. “The challenge is getting the known polymers to perform at a higher level.”

Silicone also can have a wide range of functions. They can be slippery or tacky. They can be made flexible or rigid.

“It is those attributes that we leverage in the materials we make that go into plastics,” Mealey said.

Those properties can be transferred to the plastics that silicone is added to. It can make the plastic a better product in the end.

Molded in-color trim is being used more frequently in today's vehicles and can help improve OEM brand equity and improve the scratch resistance of interior components.

The addition of silicone can help increase the performance of the plastic. Mealey added that “there is minimal to no change in the property of the plastic.”

Silicones also are naturally UV-resistant and won't break down with prolonged exposure to the sun. This makes the material a natural option for interior uses.

Celanese's Mulholland said as plastic uses increase and color variations are added, it eliminates paint from interiors.

“If we can do that, we can increase the recyclability at the end of life of the plastic parts,” he said. “The elimination of painting and plating ultimately leads to a greener solution.”

The challenge, Mulholland added, is to ensure that materials are not used in the interiors that are going to have a negative impact on the occupants.

“To that end, we are designing materials that offer low emissions of volatile organic compounds,” he said.