Process for preparation of thickness-reduced deep-draw-formed can

A process for the preparation of a thickness-reduced deep-draw-formed can, which comprises the steps of

• laminating a crystalline thermoplastic resin film on a metal plate,
• heating the laminated metal plate at a temperature T.sub.1 higher than the glass transition point (Tg) of the termoplastic resin, and lower than the heat crystallization temperature of the thermoplastic resin.
• draw-forming the laminated metal plate at said temperature T.sub.1, at a draw ratio of from 1.2 to 1.9 to form a shallow-draw-formed cup, said draw ration being defined by the following formula:
• draw-ratio=diameter of blank/diameter of shallow-draw-formed can.
• reheating the obtained preliminarily drawn cup at a temperature T.sub.2 higher than the glass transition temperature (Tg) of the termosplastic resin, and lower than the heat crystallization temperature of the thermoplastic resin,
• holding the reheated shallow-draw-formed cup by an annular holding member and a redrawing die arranged coaxially with the annular holding member and a redrawing punch, said redrawing die having a working corner, the working corner having a radius of curvature from 1 to 2.9 times the thickness t.sub.B of the metal plate, and
• relatively moving the redrawing die and the redrawing punch to redraw the shallow-draw-formed cup into a deep-draw-formed cup having a diameter smaller than the diameter of the shallow-draw-formed cup at said temperature T.sub.2 so that the entire side wall of the cup is bent and pulled substantially vertically to the axial direction by the working corner of the redrawing die at a bend-pulling speed of at least 1 m/min. and the thickness reduction ratio of the side wall of the can is 5 to 45%.