Basic Knowledge The Metal Industry Does Not Harm the Environment
From exhaust regulations and flying taxes to a ban on plastic bags - the aspect of environmental protection has arrived in politics and society. But not only end consumers need to implement sustainable processes – foundries are also affected by this development.
Foundries are energy-intensive companies. As a result of ever stricter legal requirements, foundries need to deal with the aspects of resource efficiency and environmental protection. According to the Federal Association of the German Foundry Industry (BDG), the term sustainability does not only cover environmental issues, but also economic and social factors. Therefore, foundries have to take a wide range of challenges if they want to optimize their production processes.
How can Foundries Reduce Costs and Increase Efficiency?
The metal producing and processing industry accounts for around 10 % of all German production sectors. One of the most important resources of the metal industry is energy which is supplied in the form of electricity, gas or oil. Due to their high consumption requirements, the costs of these resources are an important factor for foundries. In order to save costs, companies have to make sure that resources are used efficiently. The keyword is "Digitalization".
In this context, it is worthwhile using a computer-aided energy management system certified according to DIN EN ISO 50001. This system allows to monitor the energy consumption of individual production facilities, helping to identify power-hungry sources and eliminate them in good time. In order to evaluate the effectiveness of possible efficiency improvement measures without interrupting the production process pressmetall Gunzenhausen GmbH, ZPF GmbH, Siegelsbach, and the BDG at the University of Ansbach developed a demonstrator for simulation-based analysis. The aim is to identify potential savings and to facilitate the implementation of energy efficiency measures.
In addition, the Fraunhofer Institute for Factory Operation and Automation IFF, together with other partners, has developed a new technology for light metal foundries that reduces energy costs by up to 60 % and CO2 emissions by 80 %. Their modular, expandable burner technology enables decentralized and automated melt supply. The gas used for heat generation is used to achieve a degree of control quality and homogeneity that was previously only known from electrically heated units. This means that the waste heat can be recycled efficiently. In the future, metal can be completely melted, transported and kept warm in mobile crucible ladles, thus eliminating the previously required multi-stage processes. A sensor system enables networked and automated process control.
Modernization and New Technologies as the Key to Efficient Utilization of Resources
The conversion of foundries to Industry 4.0 is also accompanied by modern technical equipment. Energy-efficient furnaces provide for better control of melting conditions, which increases the metal yield. With the new melting furnace StrikoMelter from StrikoWestofen, Hattori Diecast could reduce metal losses and cut costs in half. The latter was due to lower gas consumption. Apart from efficient die casting machines, modern peripheral devices such as markers, sprayers and robots can also save raw materials and energy. In this way, the entire die casting process can be optimized in terms of resource and energy efficiency.
Foundries can also use 3D printing as a cost-effective manufacturing technology. This method is used especially for fine and sand casting, offering the advantage of significant material savings, since the models are produced with a ratio of 1:1 based on CAD data. Furthermore, there is no need to manufacture tools, which additionally reduces material expenses and costs. In addition, the sand used in the manufacture of sand molds and castings can be almost completely recycled.
With regard to environmental protection, recycling is an important issue. With recycling, new cast parts can be created from melted parts or from old and new metal scrap. Recently, a new technology has been developed that is to facilitate the industrial separation of aluminum alloys. This technology is aimed at counteracting a potential oversupply of scrap. According to Magdalena Garczyńska, Director Recycling at European Aluminium, the export of scrap to third countries hampers the development of a circular economy in Europe. The International Aluminium Recycling Congress focuses on important recycling trends in the aluminum industry and was last held in February 2019. Aluminum scrap can also be recycled by means of remelting. For this purpose, the German recycling plant of TRIMET Aluminium SE has commissioned a rotary kiln with a capacity of around 40 tons. It is equipped with a self-regulating burner system that, depending on the requirements, alternates between oxygen and air for the production of the fuel mixture. This reduces energy consumption and increases the share of recycled metal.
The use of environmentally friendly materials also fosters sustainable production methods. For example, ASK Chemicals has developed inorganic binders that help to improve a founry’s environmental performance. The binder system (IOB) VX1000-S consists of a liquid binder based on a modified mixture of alkali silicates and an additional solid component. An advantage of inorganic materials is to only release water vapor during the casting process, which improves air quality. Inorganic bonding systems are especially important in aluminum casting and have already become firmly established in light metal gravity die casting.