thyssenkrupp Rasselstein accelerates the transition to chromium-free passivated tinplate
Image: thyssenkrupp Rasselstein
thyssenkrupp Rasselstein, Germany’s only tinplate manufacturer, intends to considerably increase the output of its modern chromium-free passivation rasselstein CFPA. The Andernach-based company aims to gradually develop its capacity beginning in mid-2024 to produce exclusively chrome-free passivated tinplate in the future. The move to the new passivation was required since the use of Chromium(VI) in the tinplate passivation process is no longer authorized in the EU/EEA under the REACH Regulation. thyssenkrupp Rasselstein has been granted a provisional permit until 21 October 2027.
The German company implemented the EU requirements early on and now offers its customers rasselstein CFPA, a modern and equivalent passivation that meets all legislation, standards, and quality demands. “As of mid-2024, the availability of the old chrome passivation will be significantly reduced. Tinplate packaging manufacturers are advised to switch to our chromium-free passivation now to gain experience with the material passivated with CFPA,” said Dr Heiner Schäfgen, head of technical customer service at thyssenkrupp Rasselstein.
CFPA was developed in a collaboration of the members of APEAL, the Association of European Producers of Steel for Packaging. Chromium-free passivation complies entirely with EU and FDA rules and is safe for contact with food. CFPA has been classified as a new passivation standard in European standard EN10202:2022; in addition, it has been listed as an alternative passivation for tinplate in the ASTM A624/A624M and ASTM A626/A626M standards since 2022. The passivation is free of chromium and is based on titanium and zirconium oxides. The protective layer stabilizes the tin oxide in a manner similar to chromium passivation, prevents surface oxidation, and provides the desired product performance. CFPA meets thyssenkrupp Rasselstein GmbH’s rigorous quality criteria; the tinplate manufacturer conducts comprehensive tests to verify that its new passivation offers the same functionality as chrome-based passivation systems.
CFPA is appropriate for use with the latest generations of BPA-NI coatings
For several years, the use of the innovative passivation has been widely tested: since 2019, can manufacturers have extensively tested CFPA on hundreds of packages in all product categories, such as food cans, general line, aerosol cans, and other types of packaging including closures. Customer feedback is consistent with the tinplate specialist’s own positive test results. thyssenkrupp Rasselstein conducted representative storage tests for its CFPA solution with the Parma-based SSICA Institute on two products frequently found in food cans (chickpea puree and diced tomatoes with basil). A three-year shelf life study demonstrates that there are no storage differences between rasselstein CFPA and the prior chrome-based standard 311. Corrosion resistance and sulphide staining resistance were both identical. Tinplate with rasselstein CFPA is suitable for contact with food without any restrictions. The results also offer information about the usability for other tinplate products: the packaging tests were successful.
Additionally, CFPA provides planning security for future lacquers and coatings that are now being created expressly for chromium-free passivation. Since it has a higher surface tension than chromium-based passivations, the coating has the best prerequisites for the transition to BPA-NI lacquers. Furthermore, CFPA provides tinplate with high-quality surface qualities that both maintain the tinplate’s brilliant appearance and allow for direct printability.
thyssenkrupp Rasselstein employs novel spray coating techniques
As one of the earliest producers of the new passivation, the Andernach-based company draws on vast expertise. “Right from the start, our goal was to provide our customers with a product that is up to all future challenges while also providing the familiar and safe handling that our customers were accustomed to in the previous application process. I am confident that we have met this objective,” Dr Schäfgen explained. While other manufacturers utilise rolling techniques to apply CFPA, thyssenkrupp Rasselstein uses a cutting-edge spray application. “Our passivation equipment is an innovative engineering feat with which we achieve extremely precise and stable process control with particularly homogeneous results,” Schäfgen said.