Patent ID: 8365570
Filing Date: 2013-02-05
Classification: B21D,B32B,B65D

Abstract:
1. A method of manufacturing a can body for a two-piece can with multistage forming of a circular laminated steel sheet having a radius of R 0 , comprising: producing at least two forms by stepwise drawing a laminated steel sheet coated with a polyester resin, which has a plane orientation coefficient of 0.06 or less such that height h, maximum radius r, and minimum radius d of the form satisfy 0.2≦d/R≦0.5, and 1.5≦h/(R−r) ≦2.5, where R represents radius of the laminated steel sheet having a weight equivalent to the weight of a final form; an intermediate forming stage comprising heat-treating the resulting forms after each drawing at a temperature of 150° C. or higher, and lower than or equal to the melting point of the polyester resin; and working the heat-treated form into a form satisfying d≦r, 0.1≦d/R≦0.25, and 1.5≦h/(R−r)≦4, wherein the polyester resin is a resin in which primary components of polymerization are terephthalic acid and at least one diol selected from the group consisting of ethylene glycol and butylene glycol and wherein the polyester resin further comprises an incompatible resin having a glass transition point of 5° C. or lower as a subphase.