Patent ID: 9174262
Filing Date: 2015-11-03
Classification: B21D,B65D

Abstract:
1. A method for manufacture of a metal cup for the production of a two-piece food container, the method comprising the following operations: i. a stretching operation performed on a metal sheet, the operation comprising clamping an annular region on the sheet to define an enclosed portion and a clamped portion, and deforming and stretching all or part of the enclosed portion to thereby increase the surface area and reduce the thickness of the enclosed portion, the annular clamping adapted to restrict metal flow from the clamped portion into the enclosed portion during the stretching operation; ii. a drawing operation for drawing the metal sheet into a cup having a sidewall and an integral base, wherein the base comprises material from the stretched and thinned enclosed portion, the drawing operation adapted to pull and transfer outwardly material of the stretched and thinned enclosed portion; wherein the drawing operation is adapted such that material of the stretched and thinned enclosed portion is pulled and transferred into the sidewall.