IMPROVEMENTS TO THE BEVERAGE CAN REDRAW PROCESS USING LSDYNA

In the United States, in the year 2000, over 100 billion aluminum beverage cans were manufactured. Lightweighting of these aluminum D&I beverage cans has been a continuous process for more than 35 years. Aluminum beverage can "ends" have been made progressively smaller over the years in order to reduce costs. Likewise, cost control efforts have resulted in continuous reduction of the net metal requirements for the can body. To reduce the weight and cost of the "bodies", cans with thinner sidewalls, reduced neck diameters and smaller base diameters have been developed. The reduction in cost has been achieved while maintaining functionality, structural performance, and formability of the can. Today, the gauge of can body stock is as low as 0.0098 inches. With small base diameter cans and a sheet thickness that continues to decrease, the likelihood of profile wrinkling during can forming increases, particularly in the redraw process. Redraw wrinkling is influenced by many factors such as mechanical properties of the aluminum sheet, tooling geometry, contact conditions including the effects of lubrication, and process boundary conditions. These factors are readily handled using the finite element method. A numerical technique for calculating the severity of the redraw wrinkling or wrinkle factor from an LSDYNA finite element analysis is employed. Using this wrinkle factor, and a fully parametric input generator, improvements to the beverage can redraw process are developed.