BMW Clears the Air (at a Foundry)
Although when people think “auto” and “emissions” the first thing that undoubtedly comes to mind is the tailpipe. But that’s not the only place where things can get into the atmosphere.
Consider. . .foundries. Enough said, right?
BMW is transforming its Landshut, Germany, casting plant to become what is said to be the “world’s first foundry with emission-free sand core production.”
The plant produces aluminum and magnesium castings, about 1.8 million of them per year. Cylinder heads, crankcases, suspension strut supports, tailgate frames, corner castings, and axle corner castings, among them.
To produce about half of the castings gravity die casting with sand cores is used. This requires about 132 tons of sand per day, of which 90% is recycled.
But the step that will make the emissions change is the use of inorganic sand cores. The inorganic binders are based on water-soluble alkali silicates.
Reduce emissions aren’t the only advantage. The new cores allow aluminum to solidify faster, which enhances the strength of the components. Faster cooling reduces cycle time about 10%.
Conventional casting tools required blasting with dry ice after every use to eliminate combustion residues; this isn’t necessary with the new process.
The venting systems required for the previous core shooting tools and equipment are eliminated, thereby simplifying them. Tool maintenance costs are expected to fall by half.
“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 Dr. Wolfgang Blümlhuber, head of the BMW light-alloy foundry.