Solvents (volatile organic compounds or VOCs) in particular are released during vehicle production. In addition sulfur dioxide (SO2), carbon monoxide (CO), nitrogen oxides (NOx), and particulates are also emitted into the atmosphere. Damaging substances have only been emitted into the ozone layer in negligible residual amounts since we introduced the almost exclusive use of refrigerants that are not damaging to the ozone layer. As a trailblazer in the introduction of largely solvent-free paint systems, we have already achieved a drastic reduction in solvent emissions over the last decades; in particular at Mercedes-Benz Cars we are benchmark in the competitive comparison. We are also unlocking further reduction potential through the use of state-of-the-art technologies, primarily in the painting of commercial vehicles and major components.
Absolute VOC, CO, SO2, NOX emissions
Avoidance of emissions in the foundry
New process prevents emissions
In the aluminum foundry, sand cores are used in addition to the solid outer molds. When the metal has solidified they are removed from the mold to create the required cavities inside the casting. To produce such a core, previously it was customary to mix sand with an organic binder and harden the mixture with a catalyst – a process with side-effects. The organic binders give rise to emissions with an unpleasant odor both during core production and casting. Extensive systems are required to clean the exhaust air to protect the workers and neighbors.
This no longer applies at the foundry in Esslingen-Mettingen, where an inorganic binder system based on sodium silicate has been in use since 2013. The cores are no longer hardened using a chemical reaction but by drying. The result: Virtually no organic pollutants are produced, since the emissions during core manufacturing have declined by 99 percent and by 96 percent during casting.
The foundry is now further expediting the conversion to the innovative process with each new product. This calls for extensive investments in new equipment. For example, heated molds will be required for core production in the future, and the equipment needed for core removal and sand regeneration must also be modified with considerable effort and expense. On the other hand, after the complete changeover the previously required exhaust cleaning systems will become unnecessary, and the volume of exhaust air – from which only dust will have to be removed with dry filters – will be reduced to less than half. This will lead to substantial savings in energy, water, waste, and maintenance effort.
Most of all, the workers and neighbors of the plant will benefit in the future: The foundry odors, which are sometimes still perceptible today despite sophisticated filtering technology, will then be a thing of the past.