Multirecycling a strong argument for tinplate packaging

Sustainability is the driving factor in the packaging sector. This is primarily due to the increased environmental awareness of consumers: for 41 per cent of consumers in Germany, the sustainability of a package has a major influence on their purchasing decision. This is the result of a representative survey commissioned by the tinplate manufacturer thyssenkrupp Rasselstein in Germany in 2020. This is where the recyclability of packaging comes into play: material that is reused after use without having to be generated again saves energy and resources. The food can made of container steel stands out in this respect, as the way in which tinplate products are converted back into a high-quality steel article enables CO2 emissions to be reduced enormously – the key word is multi-recycling. In practice, this means that steel packaging material that has already been recycled can be reused repeatedly. %22Tinplate is a permanent material in a closed circuit, can be recycled almost one hundred percent, almost infinitely and often without under-recycling, i.e. without reducing its quality,%22 says Andreas Knein, Managing Director of DWR, Deutsche Gesellschaft für Weißblechrecycling mbH, a subsidiary of the tinplate manufacturer thyssenkrupp Rasselstein GmbH.

Each tinplate recycling cycle reduces resources and CO2 , as opposed to primary production, so that after seven recycling runs, 4.6 tonnes of steel will have been obtained from one tonne of steel. Consider that recycling one tonne of steel and iron scrap saves 1.6 tonnes of iron ore, 0.65 tonnes of coal and 0.3 tonnes of calcite. %22In addition, with the use of scrap, we spend 70 percent less energy in the generation of steel compared to primary production. The emissions of a tinplate product are therefore reduced with each recycling, as the energy expenditure is significantly lower than in the production of steel from pure iron ore. After the sixth cycle, emissions have been reduced by less than half,%22 says Knein.

The material cycle is closed in the steel mill.

During the recycling process, the effort to regenerate the tinplate in an even more sustainable way continues. An important step in this direction is the consistent separation of waste and raw materials such as tinplate. In Germany, used tinplate packaging is separated in the dual recycling systems and then sorted. Tinplate is easily separated in the sorting plant thanks to its inherent characteristics: the magnetism of steel. The tinplate scrap is then taken to the recycling centre, where it undergoes mechanised shredding and separation of waste such as labels and other contaminants. In order to optimally prepare the raw material for reuse, it is compacted into scrap blocks. The tinplate scrap, now very clean, is transferred to the steelworks, where it can be melted down without any loss of quality and, together with the pig iron from the blast furnaces, is converted into crude steel. After the product-specific processing steps, they will produce another high-quality steel part, from a car sheet to a steel beam to a new container, so that any steelworks could also be defined as a recycling plant. The material cycle is closed.

The circuit through the recycling plant ensures that no unwanted materials are burned during smelting causing unnecessary emissions. The pollutants removed, often organic, are used for energy generation. This pre-processing is not only common in Germany. Other EU countries are also concerned about the separation of pollutants such as plastic. %22We see a trend within the European Union towards higher steel grades, even if it means introducing an additional step in recovery. Either through additional recycling plants or through manual processes added in screening plants, as is the case in many other European countries,%22 explains Andreas Knein.

Tinplate leads recycling in Europe

Since tinplate is extremely recyclable, consumers, manufacturers and the trade can contribute to the reduction of CO2 for the benefit of the environment by choosing steel for packaging, as it is a raw material with a closed material loop. Because with a recycling rate of 84% in Europe, tinplate still leads all packaging materials. However, it is necessary to proceed with consumer awareness in order to increase the total share. Specifically, there is room for improvement in the area of waste separation. %22Everyone involved, from the manufacturer to the dual recycling systems to the circular economy, needs to better inform the public about waste separation. This is the only way to ensure that products such as food cans end up in the right container and provide important resources for the recycling loop. Both the multi-recycling and the environmental performance of tinplate packaging can be boosted in this way,%22 says Andreas Knein.