New Smart cars share common features

ForTwo

In this feature for Plastics News Europe David Vink discovers that earlier setbacks have not deterred Daimler's Smart brand from launching new two- and four-passenger versions of its plastics-panelled city car.

The first plastic-bodied two-passenger Smart car, built around a metal “tridion” safety frame, was introduced in October 1998, as the City coupe at the time. There had been a delay due to a redesign for increased stability following the “elk test” collision issues with another small car, the Mercedes-Benz A-Class.

It was a bold step to set up a new car plant on a greenfield plant in Hambach (“Smartville”), France near Saarbrücken in Germany, but this new start meant there were no inhibitions in producing a volume sales car with injection moulded body panels rather than using existing sheet steel capacity.

Daimler also brought in major suppliers to establish their own plants within the facility: Magna for the chassis and door panels, Dynamit Nobel for the plastic body panels. The latter were in through-coloured Xenoy PC/PBT from GE Plastics (now Sabic), saving expensive painting procedures, even though dust attraction to plastic panels required washing and drying stages prior to protective hard coat lacquering.

The body panels changed to a Borealis PP material, Daplen ED 230HP 20% mineral filled grade of EPDM elastomer modified PP copolymer, in 2007 with other changes applied to the second generation ForTwo. This change with 20% weight reduction qualified the application for a 2007 SPE Central Europe innovation award, as the first moulded-in colour (MIC) exterior body panel to be produced in PP with a single-layer protective clear lacquer coating.

Plastal had acquired Dynamit Nobel and thereby also the Hambach moulding facilities, which were subsequently acquired by Faurecia in 2012, in a move to strengthen its exteriors business activities. Faurecia says it presently supplies cowl vent grilles, door panels, engine air intakes, front and rear bumpers, fuel flaps, headlamp bezels, hoods, spoilers, tailgates, wheel arches and wings for the new Smart ForTwo.

In November 2014, Daimler said at the introduction of the new, more comfortable third generation Smart ForTwo and a reborn new ForFour model in Europe, that Smart ForTwo sales had accumulated since the 1998 launch to 1.6 million units, with annual sales having reached a stable level of 100,000/year.

China became the second largest market for the ForTwo car in 2014, after Germany and Italy, Daimler states. The new ForTwo was launched in China in August 2015 and the ForFour follows in “early 2016”.

Plastics News Europe recalls a Daimler press conference at one of the IAA automotive fairs when the chairman of DaimlerChrysler at that time, Jürgen Schrempp, suggested dropping the Smart brand if it did not achieve sales of at least 80,000 units/year. The IHS consultancy estimated production volumes would be 98,000 ForTwos and 63,000 ForFours in 2015.

The four-passenger, higher performance Smart ForFour has had a more chequered history than the ForTwo. It was first developed together with Mitsubishi and produced alongside the Colt, with which it shared some components, at around only 2,000 units/year at NedCar in The Netherlands, as from 2005 as the Smart Roadster. But the Roadster was dropped in 2006, with the Smart division having problems with profitability. These financial issues led to plans for ForMore (SUV) and Crossblade (Roadster) versions being dropped, and also led to full incorporation of Smart operations into DaimlerChrysler (now Daimler).

But the ForFour is back, now having the same exterior body design as the ForTwo, but simply with the tridion frame and body panels extended 800mm to allow for two more doors. The two models are “as clearly recognisable as members of the same family”, as Daimler puts it, adding that they retain the traditional colour contrast between the tridion cell and body panels. Both models benefit from newer technologies such as LED daytime driving lights.

As they share the same interiors and powertrain as the Renault Twingo, it is the exterior that distinguishes today’s Smarts from the Twingo. While the ForTwo is still produced in Hambach, the ForFour is produced at Renault’s plant in Novo Mesto, Slovenia. They both have rear engines made by Renault, while the previous Roadster preceding today’s ForFour had a front engine. So there are production efficiencies here too. A For-Two diesel engine option has been dropped with the new ForTwo, as the extra cost would require the car to be driven 17,500 km/year, while Smart owners drive just 8,000 km/year, Automotive News Europe has reported.

The honeycomb grille pattern on the new Smarts is something Daimler showed earlier when Plastics News Europe attended a future ForVision electric drive Smart presentation, although existing “electric drive conversion” Smart’s have yet not adopted other features from the ForVision concept. The honeycomb pattern also appears in the black cooling air opening in the bumper, as well as featuring “in the clear glass over the indicators and reversing lights in the middle of the lamps, and in the integrated loudspeaker and tweeter in the mirror triangle”. The same pattern was also seen at IAA 2015 in Frankfurt in September within the front headlamp units and in the quilted seat pattern on models customised by Brabus.

New at IAA 2015 was the world premiere of a new Smart ForTwo cabrio with a sliding and folding canvas roof, for launch in Spring 2016, and further customised ForTwo versions by Brabus.

Smart chief Dr Annett Winkler said of the new cabrio: “I am sure we will delight our 220,000 cabrio customers to date and win lots of fans with this lifestyle icon”. Winkler pointed out that Smart sales of 11,329 vehicles in the month of June 2015 was 54.5% higher than for June 2014, while sales in 1H 2015 of 62,164 vehicles were up 32.8% over 1H 2014.

Daimler says of the body panels on the new Smarts “as previously, the door is lined with a panel in high?quality lightweight plastic, allowing shrugging off of knocks and bumps from other road users”.

Webasto has moulded the 4.5mm thick fixed polycarbonate panoramic roof of the second-generation ForTwo since introduction of PC glazing on Pulse and Passion models at the 2007 Auto Salon in Geneva. The size of the roof panel has increased from 1.2 square metres to a new record size of 1.3 square metres, and its weight has increased from 7.6kg to 8kg on the new third generation ForTwo, advanced engineering manager Steffen Galle told Plastics News Europe on the Webasto stand at IAA 2015. He said this is due to the new ForTwo being 100mm wider than before.

Another new feature is the first ever use on the new ForTwo of the Makrolon AG2677 grade of polycarbonate from Covestro, which keeps the interior cooler through incorporation of infrared additives in the polycarbonate, and also through use of the 771079 heat-absorbing colour tint in the transparent material. Webasto had spoken already in 2007 of 60% of the sun’s energy being reflected and 100% of UV radiation blocked just by the slight tinted colour, with a polyester sunblind providing additional protection.

As previously, two-component injection-compression moulding is used on the new ForTwo roof panel, applying Covestro’s Bayblend T95 MF grade of PC/ABS as the secondary component for opaque black edges and integration of features such as screw bosses on the lower side of the roof panel.

At the JEC 2015 composites and Utech 2015 polyurethane fairs, polyurethane machinery producer Hennecke revealed that it supplied the machinery to make the opaque roof used on other versions of the Smart ForTwo car. This involves the PUR composite spray moulding (CSM) process applying polyurethane to a combination of a paper honeycomb core and upper and lower glass fibre mats. The sandwich obtained in this way is finished with application of a Senotop grain textured, black through-coloured thermoplastic film from Senoplast in Austria in a heated compression moulding tool. The part has a Class A surface quality, although texturing means it is not a smooth high gloss one.

The PUR CSM paper honeycomb cored roof is 30% lighter than the preceding roof and is produced by Webasto and FS Fehrer Composites Components in Gro?langheim with use of low density thermally activated Elastoflex E 3532 polyurethane from BASF, which has been formulated to allow thin wetting of the glass fibre mats, yet without drop formation. BASF says the PU can be applied with spraying time up to 120 seconds on such large surface area parts before onset of cure, yet demoulding of the finished roof takes place within 60 seconds.

Fehrer showed the sandwich roof on the stand of its automotive foam seating and textile solutions parent company Aunde (Achter und Ebels) at IAA 2015. In December 2014, Fehrer claimed the application as the “lightest car roof construction in the market”. It pointed out that the roof is used on the standard ForTwo, representing 40% of the various ForTwo models, adding that it is the first exterior large series production part to be produced by Fehrer. The application took fourth place in the 2015 SPE Central Europe exteriors awards.

At Fakuma 2015, Michael D?britz, managing director of ?tisheim, Germany based plastics processor Varioplast Konrad D?britz showed PNE how the company has started production of plastic parts for instruments on the new Smart ForTwo and ForFour cars.

This involves a fully automatic production cell equipped with two injection moulding machines that moulds the PC/ABS housing, polycarbonate ring, PMMA “glass” and PMMA pointer for the instruments.