METHOD FOR FORMING RUGGEDNESS PATTERN TO SIDE WALL PART OF SEAMLESS CAN

摘要

PROBLEM TO BE SOLVED: To form a ruggedness pattern having large unevenness in a side wall part of a seamless can not subjected to annealing treatment. SOLUTION: By using a split die having ruggedness containing a projecting part having a diameter smaller than the outer diameter of a can barrel part 102 of a seamless can 1 before bulging on its barrel inner face and pressing the projecting part of in the inner face the die on the barrel part 102 of the seamless can 1, part of the can barrel part 102 is dented, successively, by filling a fluid and/or an elastic member inside can and pressurizing this member. A can side wall part is bulged to a die inner face side, a bulged shape projecting part 105 and a dented shape recessed part 106 are formed on the can side wall part.