When the first patent for the “self-spray can” was granted in 1927, it was still expensive to produce and had thick walls. Today, however, aerosol cans are part and parcel of people’s everyday lives - and thanks to thyssenkrupp Rasselstein GmbH lighter than ever before. After all, thyssenkrupp Rasselstein GmbH is one of the world’s leading suppliers of packaging steel for aerosol cans and aerosol can components and is constantly driving innovation forward.
One such innovation is rasselstein® Solidflex - a material that’s hard but at the same time formable. rasselstein® Solidflex has more than 5% elongation in tensile tests and has a tensile yield strength ranging from 600 MPa to 750 MPa, making it perfect for applications requiring not only high material strengths but also tremendous forming potential—such as aerosol can tops and bottoms. The key secret here is that the use of this leading-edge packaging steel makes it possible to reduce the thickness of the entire aerosol can and thereby significantly increase its efficiency.
Germany’s only tinplate manufacturer provides a stunning example of this in practice. The company cooperated with experts from the Lanico Group and MAIKO Engineering GmbH and produced prototypes with a standard 52 mm diameter in order to meet typical pressure resistance requirements. The result: by using rasselstein® Solidflex to make tops and bottoms for aerosol cans, they were able to achieve a thinner material thickness for the can bodies. All in all, the prototypes were 14 percent lighter on average.
“rasselstein® Solidflex is an extremely thin, strong yet flexible material. The challenge for us here was to develop special closure tools for this material while also considering the product’s geometric and physical requirements to allow for wrinkle-free finishing. Achieving identical pressure stability of the components but with a much thinner material was our main focus. Our experience with rasselstein® Solidflex had shown us that this material can be optimally processed. Using existing tools for the new material achieves excellent results when they’ve been retrofitted with the right technological innovations by MAIKO,” explains Martin Ruhnke, Project Manager Mechanical Engineering at MAIKO Engineering GmbH, who accompanied the trials.
Jürgen Krone, Head of Sales and Marketing at Lanico Group, adds: “Our latest generation of can formers is designed for extremely thin material and is thus ideal for ultrathin body materials. The machine is designed so that it extremely quickly neck, flange and also seam packaging steel with a thickness of up to 0.13 mm. Up to 500 cans per minute can be made. One of this project’s greatest challenges was the wrinkle-free flanging and sealing of the can without causing any damage to it. Achieving the 0.13 mm thickness was a big challenge from a technical point of view, but we were able to master it by working with thyssenkrupp Rasselstein GmbH.”
thyssenkrupp Rasselstein GmbH also has a very positive view of the joint project. “We were able to produce an extremely lightweight aerosol can in our technology network. In comparison to a conventional 52 mm diameter can, which complies with EU standards, rasselstein® Solidflex was not only able to reduce the thickness of the aerosol can top by more than 14 percent, with an buckle pressure of 20 bar, but also the aerosol can bottom thickness by over 19 percent with a burst pressure of 20 bar. We also reduced the thickness of the aerosol can body, which is made from a standard-diameter formable TH550 material, for example, by 13 percent, meaning more than 7 grams of weight can be saved on each can,” says Andreas Tschage, the development engineer who spearheaded the project and who works in the Application Technology division at thyssenkrupp Rasselstein GmbH.
Braunschweig-based MAIKO Engineering GmbH is an experienced developer and manufacturer of tools used in the metal packaging industry. The Lanico Group, which is also headquartered in Braunschweig, has many years of experience in the mechanical engineering field and has already delivered more than 1,000 aerosol can machine systems worldwide.
This innovation provides thyssenkrupp Rasselstein GmbH’s customers with the benefit of reduced weight and materials as well as improved environmental performance. In addition to the fact that tinplate cans are completely recyclable and part of a closed-loop material cycle, raw materials can also be saved by using thinner rasselstein® Solidflex. The aerosol cans are also easier to transport due to their lower weight.
rasselstein® Solidflex has already received thyssenkrupp Steel AG’s Steel Tomorrow award, which the company gives out every year for in-house developed innovations. Since the presentation of the trial results at the Rasselstein Future Symposium, numerous customers of thyssenkrupp Rasselstein GmbH have expressed interest in using rasselstein® Solidflex, whether for use in the aerosol can industry or for easy open end manufacturing. “The project is already a complete success. In the future, it should be possible to reduce the weight even further for other aerosol can designs,” says Tschage. thyssenkrupp in Andernach puts innovative thinking first - benefitting not only customers and consumers but also the environment.
thyssenkrupp Rasselstein GmbH will have a booth (D31) at the Aerosol & Dispensing Forum, taking place on September 17 and 18, 2019, in New York CIty, where its staff will be available to answer all of your questions regarding the use of rasselstein® Solidflex for aerosol can tops and bottoms, as well as about mounting cups and body material.