摘要 |
A method is provided for ironing a cup to a selected wall thickness, using a mandrel that pushes the cup through several ironing rings that are axially aligned with the central axis of the mandrel. The method includes selecting a wall thickness, providing a resistive heater associated with at least one of the punch, the ram and the ironing rings, and controlling a gap between the punch and the ironing rings, and thus the wall thickness of the ironed can body, by setting a temperature of at least one of the punch, the ram and the ironing rings. The temperature is set by controlling electrical current in the resistive heater to provide a controlled gap between the mandrel and ironing rings, to produce a wall thickness of the ironed can body equal to the selected wall thickness when the can body is pushed through the ironing rings by the mandrel. |