Method of manufacturing can body and manufacturing line of the same

Abstract

A method of manufacturing a can body includes: molding a preform of a can including: molding a dome part on a bottom of a bottomed cylindrical body, the dome part being concave into the bottomed cylindrical body; and molding as annular leg part projecting in a direction opposite to a direction in which the dome part is concave, the leg part including an inner peripheral section which is inclined from a ground point of the leg part toward a can axis in a vertical cross-sectional view taken along the can axis; painting at least one of an inner surface and an outer surface of the preform of the can; and bottom reforming to mold a molded can including a curved end around the dome part by pressing an inner surface of the dome part of the preform of the can painted by the painting.

1 . A method of manufacturing a can body, comprising:
 molding a preform of a can including:
 molding a dome part on a bottom of a bottomed cylindrical body, the dome part being concave into the bottomed cylindrical body; and 
 molding an annular leg part projecting in a direction opposite to a direction in which the dome part is concave, the leg part including an inner peripheral section which is inclined from a ground point of the leg part toward a can axis in a vertical cross-sectional view taken along the can axis; 
   painting at least one of an inner surface and an outer surface of the preform of the can; and   bottom reforming to mold a molded can including a curved end around the dome part by pressing an inner surface of the dome part of the preform of the can painted by the painting.   
     
     
         2 . The method of manufacturing a can body according to  claim 1 , wherein the inner surface of the preform of the can is painted with a spray device in the painting. 
     
     
         3 . The method of manufacturing a can body according to  claim 1 , wherein, in the molding of the preform of the can:
 the preform of the can is molded such that a maximum height of the preform of the can from a ground plane to the dome part is greater than a maximum height of the molded can from a ground plane to the dome part; and   in the vertical cross-sectional view taken along the can axis, a length of the inner peripheral section of the leg part is greater than a length of the curved end of the molded can.   
     
     
         4 . The method of manufacturing a can body according to  claim 1 , wherein, in the bottom reforming, by using a molding device including a press object inserted into the preform of the can to contact the inner surface of the dome part, and a shaping die to mold the curved end by pressing the press object, the inner surface of the dome part is pressed by the press object to mold the curved end fitting the shaping die around the dome part. 
     
     
         5 . A manufacturing line of a can body, comprising:
 molding a preform of a can including:
 molding a dome part on a bottom of a bottomed cylindrical body, the dome part being concave into the bottomed cylindrical body; and 
 molding an annular leg part projecting in a direction opposite to a direction in which the dome part is concave, the leg part having an inner peripheral section which is inclined from a ground point of the leg part toward a can axis in a vertical cross-sectional view taken along the can axis; 
   painting at least one of an inner surface and an outer surface of the preform of the can; and   bottom reforming to mold a molded can including a curved end around the dome part by pressing an inner surface of the dome part of the painted preform of the can.