CO2 reduction through the use of rasselstein® container steel

Andernach (Germany), 29.09.2022 – Germany’s only tinplate manufacturer, thyssenkrupp Rasselstein GmbH, is expanding its sustainability strategy and now offers more CO2 emission reduction products to its customers in the packaging industry. The company has included tinplate made from bluemint® steel in its portfolio, manufactured with reduced CO2 emissions. For the production of bluemint®, alternative materials to the steel manufacturing process are used. This reduces, above all, the use of coal for the reduction process in blast furnaces. The result is a real decrease in carbon dioxide emissions.

Using rasselstein® innovative packaging steel grades in the manufacture of “easy-open” closures for food cans and for aerosol can domes and bottoms enables additional savings in CO2 emissions. This is the result of a study conducted by Sphera Solutions on behalf of thyssenkrupp Rasselstein and complies with DIN ISO 14040 / 14044 standards. “On the basis of the reduced material thicknesses that rasselstein® Solidflex enables, significant CO2 reductions are achieved. This is of great interest to our customers who want to reduce their CO2 footprint,” says Carmen Tschage, Head of Communications and Market Development at thyssenkrupp Rasselstein GmbH. These data were confirmed within the framework of a critical review by the TÜV Süd testing institute.

CO2 reduction through the use of steel grades for innovative packaging. rasselstein® Solidflex is a grade of container steel that is both tough and especially formable. Therefore, rasselstein® Solidflex allows for thinner material thicknesses to produce the same stability in the can. With an elasticity of more than five percent and a yield strength of 600 MPa up to 750 MPa, the material is particularly suitable for applications that, in addition to good strength, also require high formability, such as “easy-open” closures for food cans or the domes and bottoms of aerosol cans. The extraordinary: if the material thicknesses of these components are reduced, the thicknesses of the can bodies can also be reduced. For this purpose, thyssenkrupp Rasselstein offers its customers special grades of container steels that are optimally matched to the complete system. thyssenkrupp Rasselstein’s Technical Customer Support staff will be happy to propose the various possibilities.

The study evaluated the equivalent CO2 savings for the use of tinplate in a food can with a filling volume of 425 milliliters. The innovative rasselstein® Solidflex packaging steel technology allows for reduced material thicknesses for “easy-open” closures. This results in a reduction of CO2 emissions. Thus, the thickness of an “easy open” fastener can be reduced from 0.18 mm to 0.16 mm. As a result, the weight of the can is reduced by 1.98 percent. Considering the impact on the carbon footprint, this measure represents a 2.14 percent cut in material use. That is 3.9 g of CO2 per cap.
The potential increases if, in addition to the rasselstein® Solidflex closure, optimized container steel grades are also used for the body and bottom. In this way, the weight of the food can allows a total savings of 13.52 percent and the carbon footprint drops by 13.52 percent. This represents a CO2 reduction due to the material of 18.4 g per can. Therefore, research shows that simply changing the grade of container steel used in favor of rasselstein® Solidflex results in perfectly quantifiable carbon dioxide reductions. Especially in combination with our other optimized materials, emissions are significantly reduced,” says Tschage.

In the case of the aerosol can, a clear savings potential is also achieved. In the manufacture of an aerosol can with a volume up to the rim of 378 milliliters, the weight of the can can be reduced by 14.34 percent. The reduction in CO2 emissions due to steel packaging means a decrease of 14.41 percent or 22.0 g per aerosol can. In this case, both the dome and the bottom would be made of rasselstein® Solidflex and the body would be made of a suitable container steel from the thyssenkrupp Rasselstein portfolio.

The first CO2-reduced tinplate can went into production in March.

Another important element in thyssenkrupp Rasselstein’s environmental sustainability strategy is bluemint® steel sheet. This steel, manufactured at thyssenkrupp Steel Europe AG, was used for the first time at the German tinplate manufacturer’s facility in the spring.

bluemint® steel is available as pure bluemint® and recycled bluemint®. The two variants do not differ from the classic steels in terms of material characteristics: except for their specific carbon dioxide emissions. The high quality of rasselstein® container steel is maintained. These products are the first transformation success story as part of thyssenkrupp Steel’s climate strategy. “In the coming years, we will invest heavily in innovation and technologies that bring our customers step by step closer to the common goal of climate neutrality and an environmentally friendly steel product,” according to Tschage.

One of the first customers for tinplate made from bluemint® steel is the well-known Swiss company Ricola. The herbal candy manufacturer will soon offer its Swiss herbal pearls in low-emission food cans. “Sustainability and innovation go hand in hand in our company. This also applies to the packaging of our herbal candies. As a result, we are the first company in our market to use cans made of reduced CO₂ steel. For the manufacture of bluemint® steel, thyssenkrupp Steel limits the use of carbon in the blast furnace reduction process. The collaboration with Hoffmann Neopac resulted in a package that has a much lower carbon footprint than a conventional can,” says Dr. Martin Messerli, Ricola’s Chief Operating Officer.

Zentis is also now using bluemint® steel tinplate for the closures of its natural fruit preserves. They are manufactured by a thyssenkrupp Rasselstein customer, Pano
Verschluss GmbH. thyssenkrupp Rasselstein wants to further promote sustainable product innovations in the future. For this purpose, a separate department has just been established at thyssenkrupp Rasselstein. “We want to deliver the usual high quality with our ideas and products. In addition, we are now evaluating the impact on CO2 emissions of our new developments and how best to reduce them during manufacturing. In this way we ensure that our customers receive the customary high quality of our products in line with the strictest sustainability criteria.” Tschage announces.