To provide a bottle can manufacturing method by which a skirt part of a bottle can is highly accurately formed, consequently a bottle can with a cap obtained by screwing the cap to the bottle can is satisfactorily unsealed and resealed, and to provide a bottle can.
The bottle can manufacturing method is provided by which an inner tool 101 is arranged inside a mouth part 4c of a bottle can body 1b, and an outer tool 102 is arranged on the outer side thereof, these tools 101, 102 are brought close to each other, and a male screw part and a skirt part swollen radially outwardly are formed on the mouth part 4c by turning the inner tool 101 and the outer tool 102 around the body axis of the bottle can body 1b while inner and outer circumferential surfaces of a part 5a on which a male screw is to be formed and part 6c on which a skirt is to be formed are held by the outer circumferential parts of the tools 101, 102. In the method, after the part 6c on which the skirt is to be formed is formed in a recessed curved surface which is recessed radially inwardly with respect to the part 5a on which the male screw is to be formed, the part 6c on which the skirt is to be formed is pressed radially outwardly to form the skirt part.
Tadashi Takahashi
Masakazu Aoyama
Yasuhiko Murayama
Noriko Yanai