At this year's VDI "Plastics in Automotive Engineering" conference on March 18 and 19 in Mannheim, Germany, PolyOne (Avon Lake, OH) announced the development of its new natural fiber-filled reSound NF reinforced materials. Developed for advanced applications in transportation, these materials contain a minimum of 30% biobased content, and are in current evaluations at several key automotive OEMs. Already, the feedback from these customers indicates that the new materials can offer a persuasive and lighter weight alternative to conventional solutions while providing the high performance required for challenging applications.

Lightweighting is a major issue in the automotive industry, as Marc Mézailles, Automotive Market Manager at PolyOne explained. "While in the United States and in the countries of Asia, car manufacturers are being offered incentives to increase fuel economy or to decrease carbon emissions, European Union legislation has set mandatory emission reduction targets for new cars, complete with penalties if manufacturers fail to comply."

In the EU, the fleet averages applying for all new cars are 130 grams per kilometer (g/km) by 2015—with the target phased in from 2012—and 95g/km of CO₂ by 2021, phased in from 2020. The penalties for exceeding these limits are stiff. If the average CO₂ emissions of a manufacturer's fleet exceed the limit value in any year from 2012, manufacturers must pay an excess emissions premium for each car registered amounting to €5 for the first excess g/km, €15 for the second, €25 for the third, and €95 for each subsequent g/km. From 2019, the penalty is €95 from the first excess gram up.

"Understandably, therefore, car makers are looking for solutions that work," said Mézailles.

Compared to other natural fiber–reinforced plastics, reSound NF materials will offer mechanical property improvements of more than 20% for tensile and flexural properties, 10° to 20°C higher heat deflection temperature, and an increase of more than 50% in impact strength. Testing at Fraunhofer ICT Institute in Pfinztal, Germany, has shown that a 40%-filled reSound NF formulation has equivalent performance to a 30%-filled short-glass-fiber-reinforced alternative, at a 7 to 8% lower density.

"These are numbers that grab the attention of the automotive industry," said Mézailles. "The improved mechanical properties, compared with conventional solutions using natural fibers, are due to the fact that these fibers, which are wood based, are engineered specifically for use in a thermoplastic matrix. PolyOne applies a specific coupling technology, which optimizes the bond between matrix and fiber, and extrusion technology to create natural-fiber reinforced materials with these excellent mechanical properties." He added: "It's a solution that can be combined with MuCell foaming technology, for additional lightweighting with the same mechanical properties. It's both compatible with and complementary to foaming technology."

The new reSound NF materials, which are based on polypropylene chemistry, can be processed on standard machinery and tooling at low injection molding temperatures and short cycle times, and will complement the advanced long- and short-fiber solutions in PolyOne's current portfolio.

PolyOne has identified more than 15 potential applications, including under-the-hood components, lighting systems, and semi-structural applications, and is actively collaborating on these and additional opportunities with customers.

"Applications are not restricted to the automotive industry," commented Mézailles. "The building and construction sector also holds huge potential."

Demonstration parts made with reSound NF reinforced materials will be on display at next week's NPE 2015 exhibition in Orlando, FL.