On the occasion of the VDI “Plastics for Automotive Engineering”, Plastics spoke with Dagmar van Heur, Vice President Automotive at Styron about the trends that move the industry forward and the contribution of Styron in particular.
Dagmar Van Heur, Vice President Automotive, at Styron’s VDI booth
Styron brought the strategic areas of structural components and exteriors right into focus at this year’s VDI booth. “I believe that ten years from now, reinforced plastics will be a key material for structural parts. The parts will be made with endless glass and/or carbon fibres to have the required structural performance. Whether thermoset or thermoplastic, these will require the development of completely new processing technologies to obtain the necessary output,” says van Heur.
Thermoplastics liftgate
Amongst other developments, Styron presented the thermoplastics liftgate solution which was unveiled in the end of 2012 for the new Renault Clio. A liftgate is a complex application for several reasons: it needs to fit perfectly on to the car and has numerous functions that need to be hidden such as the hinges and the closing mechanism. Additionally, it is subjected to many external conditions such as exposure to high/low temperature in humid environments that can cause deformation issues and must then be addressed to guarantee water tightness. Furthermore, the development target of the liftgate itself for the Renault Clio contained a weight reduction of 10% but also boasted easy recyclability. After a joint development phase of three years carried out by Renault and Styron, the liftgate could be manufactured as a thermoplastic solution from three separate parts, a market first. The material of choice is a long glass fibre polypropylene resin (LGF-PP) which was set up to guarantee the required stiffness and durability of the structural part. In the selection of materials, the development team was confronted with several challenges due to the complexity of the part.
The Renault Clio’s thermoplastic liftgate (photo: Styron)
The final liftgate design consists of three parts. The inner skin is injection moulded using a talc filled PP compound and connects the structural part. The structural part is produced with a LGF-PP concentrate. This concentrate is diluted directly on the moulding machine with appropriate PP copolymer resin through dry-blend directly. The outer skin is made with Styron’s Inspire At-Press talc masterbatch concept which injection moulds by blending the different components (PP impact copolymer, specifically designed 70% talc masterbatch and the required colour concentrate), allowing for a tailored mechanical performance to meet the OEM specific application requirements. “One of the problems as far as this component was concerned was guaranteeing that the tailgate would open and close flawlessly at any temperature,” is how Dagmar van Heur explains challenges in the development process; “in the lower area of the component in particular this was difficult because of the gap dimensions. In a subsequent generation it might be possible to carry out further work on reducing the construction space, there is still potential for improvement.”
Integrated bracket for the Ford Fusion
Another exhibit was the integrated bracket for the Ford Fusion for which Styron was part of the multi-party collaboration that helped Ford to win the 2012 SPE Automotive Innovation Award in the Safety category. The use of reinforced plastic (in this case LGF PP Inspire LGF9301Z) allows the part to be tuned to break at a well defined force level during a wide range of impact situations, allowing the headlamp and the bumpstop to move down at impact, which reduces the forces on the pedestrians head during a collision. “This component used to be fabricated from several metal parts; today a one-part PP component combines the function of the bonnet bump stop and headlamp attachment, plus it meets the very strict new US PedPro safety regulations,” says van Heur happily.
Spoiler solutions as presented at the VDI show (yellow spoiler: Renault Clio, silver spoiler: Ford Edge)
Spoiler solutions
The company presented two spoiler solutions on its stand, the one for the new Renault Clio along with the spoiler for the Ford Edge. The Clio-spoiler is developed with the company’s Magnum 3416 SC, an ABS resin based on Styron’s Mass ABS technology that is said to combine heat resistance with good processability. “In the USA the requirements as regards temperature are higher than in Europe, given the sheer size and weight of the parts, and this is why the spoiler for the Ford Edge is manufactured in PC-ABS,” explains Van Heur. Pulse 2000EZ is claimed to offer resistance to heat distortion, impact strength and dimensional stability.
www.styron.com
