Cycle times decrease approximately 10%, which translates to the same in increased productivity.
BMW’s Landshut plant outside of Munich will become the world’s first foundry with emission-free sand core production, the German company announced today. The light-alloy foundry is introducing a new production method for gravity die-casting.
Instead of conventional organic binders long in use in castings, newly developed inorganic binders will be used, which generate virtually no pollutants during the process.
BMW claims the plant’s emissions from combustion residues will be reduced by 98%. As a result, the plant will completely decommission its current waste air treatment systems by 2010.
The new method could be of enormous significance in the business as automobile makers continue to shift into lighter weight aluminum and magnesium materials to increase fuel economy and decrease emissions of carbon dioxide.
Landshut foundry’s 1,300 employees currently produce around 1.8 million aluminum and magnesium castings a year, with a total weight of 45,000 tons. The product range includes engine components, such as cylinder heads and crankcases, structural components, chassis parts, tailgate frames, corner castings and casting nodes for front and rear axles.
About half the castings produced are gravity die-cast using sand cores. The light-alloy foundry uses some 120 tons of sand daily in sand core production, and 90% is recycled. Following an initial pilot operation phase, BMW is now poised to become the world’s first manufacturer to use inorganic sand cores in volume production of all engine core components. The inorganic binders used are based on water-soluble alkali silicates (a water/silica sand solution), resulting in significantly reduced resource consumption.
“Inorganic sand core production positions us at the forefront of the foundry industry,” says Dr Wolfgang Blümlhuber, head of the light-alloy foundry. “We see inorganic sand core production as key to competitive operation, particularly in highly industrialized countries with stringent environmental regulations, where manufacturing costs are correspondingly high.”
The light-alloy foundry first introduced this reduced-emission process for use in the manufacturing of aluminum crankcases and cylinder heads for six-cylinder diesel engines. Now inorganic sand core production is gradually being extended to the foundry’s entire product range.
The process also has economic and ergonomic benefits. The strength of the resulting light-alloy components is enhanced by the improved, faster solidification of the liquid aluminum during the casting process, as it cools from a temperature of approximately 750º C. BMW Group is using this light-but-strong design potential as a way of producing energy-saving, fuel-efficient engines capable of higher peak cylinder pressures and increased power density.
The foundry’s employees benefit as well, says BMW, due to substantially enhanced working conditions. Until now, the casting tools had to be blasted with dry ice after every use in order to remove combustion residues. This energy-intensive process will be eliminated.
To accompany the introduction of inorganic sand core production, the light-alloy foundry developed new core shooting tools and equipment. The casting equipment has become less complex, since the previously required venting systems are gone. Maintenance costs are halved. In addition, the cooling intensity during the casting process can be increased, thus reducing manufacturing cycle times by around 10%, which translates to the same in increased productivity. The simulation technology used in the process and tool development was developed at the Landshut plant as well.
“We will be able to fully amortize the investment in tools and equipment, along with our development costs, in the space of just a few years, at most, thanks to increased productivity, and thanks to savings on tool maintenance, tool and workshop air extraction systems and waste air treatment systems,” says Blümlhuber.