Multi-recycling – a strong argument for tinplate packaging

Sustainability is the driving factor in the packaging industry, due
to consumers’ increased environmental awareness: In a representative survey
commissioned by tinplate manufacturer thyssenkrupp Rasselstein in Germany in 2020, 41%
of consumers reported the sustainability of packaging to be a major influence on their
purchasing decisions. This is where packaging recyclability comes into play: Material that
can be recycled after use and does not have to be newly produced saves both energy and
resources. This is especially true for the food can made of packaging steel because CO2
emissions can be significantly reduced by the way tinplate products are recycled into new
high-quality steel products – the keyword is multi-recycling. In practice, this means that
even recycled packaging steel can be recycled over and over again. “Tinplate is a permanent
material in a closed cycle that is almost 100% recyclable. And it can be recycled almost
infinitely and without downcycling, thus without any reduction in quality,” said Andreas
Knein, Managing Director of DWR - Deutsche Gesellschaft für Weißblechrecycling mbH, a
subsidiary of tinplate manufacturer thyssenkrupp Rasselstein GmbH.

Compared to primary production, resources and CO2 are saved with each cycle of tinplate
recycling. After seven recycling processes, 4.6 tons of steel products have been produced
from the original one ton of steel. The recycling of one ton of steel and iron scrap saves 1.6
tons of iron ore, 0.65 tons of coal, and 0.3 tons of limestone. “By using scrap in steel
production, we are also using 70% less energy compared to primary production. The
emissions of a product made from tinplate are therefore falling with each recycling process,
as significantly less energy is used than if the steel were produced purely from iron ore.
After just the sixth cycle, emissions have more than halved,” Knein explained.

Material cycle closes in the steel mill
During the recycling process, it is continually attempted to make tinplate recycling even
more sustainable. The consistent separation of waste and raw materials such as tinplate is
an important step in this direction. In Germany, emptied tinplate packaging is collected by
way of the dual systems from consumers and is subsequently sorted. Thanks to its inherent
properties – in this case magnetism – tinplate is easily separated from waste in the sorting
facilities. For further processing, tinplate scrap is then taken to processing centers where
the material is shredded by machines and separated from residual contents, labels, or other
impurities. To optimally condition the raw material for further use, the material is pressed
into scrap bundles. The now very clean tinplate scrap is transported to the steel mill, where
it is melted down without loss of quality and processed with pig iron from the blast furnace
to produce crude steel. After several product-specific processing steps, it is recycled into a
new high-quality steel product, from car sheet to steel beams to new packaging. Every steel
mill can therefore also be considered a recycling plant. The material cycle is closed.

The route via processing plant to steel mill ensures that no undesirable materials are burnt
along with the steel scrap when it is melted down so that no unnecessary emissions are
caused. The separated mostly organic residues are used to generate energy. This upstream
treatment step is not only common in Germany. Disruptive materials such as plastics are
also removed in other EU member states. “At EU level, we are observing a trend towards
higher steel qualities, even if it means accepting another intermediate step on the way to
recycling. Be it through further processing plants or through additional manual steps in
sorting plants as is often the case in other European countries,” said Andreas Knein.

Tinplate is the recycling leader in Europe
Since tinplate has excellent recyclability, consumers, manufacturers, and retailers in the
packaging sector can contribute to protecting the environment and reducing CO2 by
choosing packaging steel, a material with a closed material cycle. At a current recycling rate
of 84% in Europe, tinplate is the front-runner among all packaging materials. To further
increase the overall rate, however, more consumer education is needed. Above all, waste
separation is a topic that still needs addressing. “All those involved – from manufacturers
to retailers, from the dual systems to the recycling industry – must offer better information
to the public on waste separation. This is the only way to guarantee that products such as
food cans end up in the right bin and that important resources are available to the recycling
loop. In this way, it is possible to further improve both multi-recycling and the ecological
performance of tinplate packaging,” said Andreas Knein.

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