Basell compounds are being used to produce nearly all of the polypropylene (PP) components for General Motor’s European model, the Opel Corsa. Reinforced Hostacom and Hifax grades have been selected for a range of parts for the new model, including applications such as the bumper or the side cladding in exterior and interior components, as well as the instrument panel, glove box, door panel and center consoles. “This significant amount of resin used in the Opel Corsa further supports the continuing success story of PP in the automotive industry,” said Basell’s Ulrich Mende, Key Account Manager for Opel.
Polypropylene interior applications in the new Opel Corsa
Special reinforced Hostacom grades were selected for a variety of interior applications including the instrument panel, glove box, center console, door panel, pillar trim panel, seat covers and trunk trim. “Opel was looking for materials that met their requirements for mechanical and safety properties, long service life, cost/performance balance, and that provided a superior surface with low gloss,” points out Wolfgang Jonischkeit, Basell’s Customer Project Manager for Opel.
Due to a new additive package (stabilization) and talc filling, the Hostacom polypropylene compounds surpassed conventional polypropylene materials in terms of their scratch-resistance and surface properties. Scratch and mar resistance measured using GM’s testing method GME 60280 showed that the parts produced using Hostacom resins demonstrated nearly no difference in their surface appearance. Whereas competitive PP material contains about 20 percent of additives, Basell’s specially-developed resins showed an increased scratch-resistance with just 15 percent filler.
“The lower talc content also enables improved density performance, delivering lighter-weight parts while all of the other specifications required are still maintained,” explains Jonischkeit. “Hostacom compounds also provided good impact/stiffness balance and outstanding processability.”
One of the keys to the successful development of the PP interior and exterior components for the new Opel Corsa was the design and development service provided. “Through our ability to simulate all phases of the process, beginning with the filling and packing phase, continuing with the in-mould cooling process, and ending with post-extraction and warpage simulations, we achieved a level of finish and comfort in the interior that Opel’s customers expect, at a favourable cost-performance balance,” explains Jonischkeit.
Safety and colour-matching
Basell’s PP grades used in the new vehicle resisted splintering upon deployment of airbags within a temperature range of -30°C up to 85°C, especially instrument panel and door panel parts. Hostacom resin also delivered excellent colourability and colour matching – the finished parts retained the same colour and gloss specifications throughout all of the processing stages.
Polypropylene exterior applications
According to Basell’s automotive experts, as bumpers form an important part of the overall "look" of a vehicle, they are closely integrated into bodywork with painted-in body colours, and are incorporated into lighting assemblies and grills. Because the zero-gap bumper closely follows the lines of the body fascia, it requires special material characteristics. Specifically, the bumper's thermal expansion must be as low as possible to avoid problems with differential shrinkage.
Basell’s Hifax grades exhibited extremely low thermal expansion as well as excellent impact/stiffness balance in the new Opel’s exterior applications. For the grill, Opel used an UV-stabilised Hifax resin, which demonstrated mechanical performance with high rigidity and good impact resistance. Hifax resins also exhibited high melt flow characteristics, which is a key requirement for the processing of large, thin-walled components.
New Softell advanced polyolefins used in automotive components
Today’s automotive interior components require a more enhanced sensory experience. To address this requirement, Basell has developed a new generation of advanced polyolefins called Softell, which offers a wide range of tactile and visual options as an alternative to soft-painted technical polymers, traditional textiles and surface coverings. Softell resins provide good haptics with a matt surface. “Softell resins can improve the ‘touch-and-feel’ of automotive interior parts”, said Jonischkeit.
The Opel Corsa
Opel produces the new Opel Corsa for Europe in a quantity of nearly 400.000 units per year. The vehicle has been awarded with the prize of the German Association of Drivers for being the best car in its class. In addition the car has got five stars in terms of its interior safety of the Euro NCAP.