Beverage can. New die necking process

Abstract

This new process of die necking for beverage cans consists in exploiting advantageously two properties of metal: the thickening during the shrinking and principally the decrease of the flow stress during the process, improving the metal formability. The increasing die necking process rates harmonize the diameter reduction of the consecutive stages with the aptitude of the can wall to be shrunk. This new kind of necking route with increasing rates makes possible to limit the number of stages especially to neck thinner cans, and to make the dies more tolerant towards the imperfections of the cans.