Synthetic mineral fiber compound plays its part in vehicle lightweighting

French automotive plastics component producer Mecaplast (Monaco) reports that it can make significant weight reductions in injection molded TPO parts by partially replacing talc filler with Hyperform HPR-803i, a synthetic mineral-based reinforcing fiber from Milliken (Spartanburg, SC).

Prototype B-pillar with mineral fiber filler weighs 7% less than talc-filled version.

Demonstrating this, Mecaplast has adopted a TPO compound containing a mix of talc and Hyperform HPR-803i (total additive content around 10 percent by weight) to mold prototype B-pillar covers that it normally supplies in a conventional 20 percent talc-filled TPO (elastomer-modified polypropylene) compound. The prototype parts weighed 524 g, seven percent less than the commercial parts. The compound has a density of 0.98 g/cm³, which compares with 1.04 g/cm³ for a 20 percent talc-filled TPO with similar mechanical properties.

Nathalie Samson-Maguet, Mecaplast's Research & Innovation Manager, says its final product costs are exactly the same: Hyperform HPR-803i costs more than talc, but this is cancelled out by the reduced total material requirement. The compound is produced by Inno-Comp (Tiszaújváros, Hungary).

Car drivers will benefit because they will use less fuel. The savings achievable by using Hyperform HPR-803i in B-pillar covers will be relatively small, but Samson-Maguet says Hyperform HPR-803i can also be used to reduce weight in larger parts such as C-pillars and sill panels. Mecaplast plans to use compounds containing Hyperform HPR-803i for these kinds of parts. Further savings could be achieved with the use of such compounds in the production of larger parts, such as instrument panels, which Mecaplast does not produce. Hyperform-containing compounds are also being employed in rear tail gates in Japanese vehicles.

The European Union recently set new standards for CO₂ emissions for cars. It has set a maximum of 120 g/km on average by the end of this year, with a further reduction to 95 g/km on average by 2020. Lightweighting will be an important weapon for auto makers in helping them achieve these targets.

Mecaplast is aiming to go into production with TPO parts reinforced with Hyperform HPR-803i within the next two years. The company makes parts for several major car companies, including BMW, Citroen, General Motors, Peugeot, Renault, Toyota, and Volkswagen. According to Samson-Maguet, Mecaplast is also developing a new process, still confidential, that will yield Hyperform-reinforced TPO interior and exterior parts between 35 and 40 percent lighter than current versions.

In addition to reducing part weight, Hyperform HPR-803i improves scratch resistance. This is important as the B-pillar covers are normally installed in the car unpainted, and are colored using masterbatch.

Milliken will present Hyperform HPR-803i reinforcing agent, as well as other additives that improve performance in automotive parts, on its stand at the Plastics in Automotive Engineering conference and exhibition organized by the Association of German Engineers (VDI) in Mannheim on March 21 and 22.-[email protected]