Thermal effects on polymer laminated steel formability in ironing

In the current manufacturing processes for can making, a time consuming and therefore expensive process involves spraying a food-contact safe polymer coating onto the can interior before filling. This process can be eliminate d by using a prelaminated metal workpiece as long as the polymer will survi ve the manufacturing operations involved in can making. The most demanding operation in can making is ironing because of the high pressures involved a s well as the necessary generation of new surface. Previous research [5] ha s demonstrated the feasibility of using a polymer coated steel sheet stock for can making. However, ironing is commonly performed with elevated toolin g temperatures which result from friction and plastic deformation in the wo rkpiece. As such, it is possible that the polymer could significantly softe n or melt during the ironing process when tooling/workpiece contact is most intimate. In this paper, the thermal effects of hot tooling on polymer coa ted steel formability are explored through both experiments and mathematica l models.