Europe: Ford Focuses on Sustainable Mouldings
By David Vink
Ford Forschungszentrum says it is close to using polypropylene reinforced with 30% sisal fibres for injection moulding.
Ford's Maira Magnani was speaking at Kassel University's 8th Global WPC and Natural Fibre Composites congress and exhibition last month, held for the first time in Stuttgart-Fellbach.
The 30% sisal fibre reinforced parts have already passed FMC crash and head impact test requirements. A centre console made using the material weighs 20% less than talc filled PP. Other advantages include a 20% lower melt temperature and a 10% faster cycle time.
However, further work is needed on the sisal material, Magnani advised, as there are issues to be solved in terms of odour, colour matching with parts made with non-natural fibres, mould flow input data, crash simulation and natural fibre simulation modules.
The sisal reinforced PP was developed by Ford Motor Company (FMC) which has over the last few years developed natural fibre reinforced composites for injection moulding, for example the 50% kenaf fibre reinforced PP used in Ford Mondeo, Focus and Fiesta door panels.
Ford is also looking at using 30% hemp fibre reinforced PP made in the USA and Brazil in electrical/electronic housings and engine compartment applications. Material and component tests also indicated that this type of material is also “close to implementation”, says Ford.
The company faces the same problems with the hemp material as with the sisal, but an ecological comparison of glass fibre and hemp reinforced battery trays showed that the global warming potential (GWP) over 100 years is 45% lower in terms of the equivalent weight of carbon dioxide. Part weight is also lower.
Another successful use of a sustainable material is Ford’s use of AgriPlas BF20H-31 wheat straw reinforced PP compound from Schulman for the quarter trim bin and inner lid of the storage bins of Ford’s 2010 Flex car.
This application alone has cut fuel consumption by 9 tonnes/year and CO2 emissions by around 15 tonnes/year, said Magnani.
At the conference, Magnani also talked about FMC’s three-year ‘liquid wood’ project that began in 2009, aimed at improving the quality of injection mouldable WPC. Banbury-type internal mixing is more effective at compounding the material than twin-screw extruders as it ensures complete enclosure of the fibres within the polymer. This eliminates the need to pre-treat wood fibres, as well as reducing both water absorption and odour, FMC has found.
Moulding trials revealed the liquid wood has low viscosity but only minor processing modifications are needed in terms of temperature, for example. It can be moulded into complex shapes and cut-outs and while draft angles have to be adjusted to allow for low shrinkage, this could be an advantage for tool design, Magnani concluded.
Remaining challenges for liquid wood include optimisation for cost effective industrial production, stable supply, colour management and development of simulation input data and tools, Magnani concluded.
The Ford Motor Company hopes that its use of biomaterials will help it meet its target of cutting carbon dioxide emissions from its vehicles by 30% between 2006 and 2020.