PET-Hair Generating Mechanism of Laminated Steel in Forming Process of DI Can

• Published in: Tetsu-to-Hagane Vol. 100; no. 8; pp. 966 - 973
• Main Authors: Kai, Masahiro, Taya, Shinichi, Tomaru, Hidekazu
• Format: Journal Article
• Language: English; Japanese
• Published: The Iron and Steel Institute of Japan 2014
• Subjects: adhesion; beverage can; environment; ironing; laminated steel
• ISSN: 0021-1575; 1883-2954
• DOI: 10.2355/tetsutohagane.100.966

On application of polyethylene terephthalate (PET) film laminated steel to Drawn and Ironing (DI) process, it is necessary to control the PET-hair that we named shaving or breaking film at formed can edge due to no flange making in process. We previously reported the PET-hair was controllable with lower yield stress of steel substrate and stronger adhesion between PET film and the substrate. In this study, to demonstrate cause and mechanism of the PET-hair generation, we investigated the film adhesion to the substrate and the film peeled-off length at upper edge of formed can, and found a correlation between the two properties. The film peeled-off strength over 15N gets the film peeled-off length considerably shorten, resulting in difficulty in the PET-hair generation. Furthermore, we checked effects of ironing rate on the strain in the film during can-forming, and found the following mechanism. While ironing rate of 10% provides fracture strain in the film, strong adhesion could achieve no PET-hair generation even at the rate of over 10%. However, in case of the rate of over 15%, fracture of the film can’t be avoided, resulting in the PET-hair generation.