METHOD AND DEVICE FOR PRODUCING TEAR-OPEN LIDS

A method for manufacturing a tear-off lid (27). A lid blank (9) is punched with a punching tool (1, 5) having a die (6) and a cutting punch (2, 3) to form a lid ring (8) with a central removal opening (17) surrounded by a sealing flange (18). The edge of the removal opening (17) is then formed by drawing to a collar (20) projecting from the sealing flange (18) on the intended inside of the lid (underside), the collar (20) is rolled up at its free end and a tear-off foil (24) is sealed or glued onto the sealing flange (18) on the intended outside of the lid (upper side).In accordance with the invention, the die (6) is arranged on the inner side (bottom) of the lid and the cutting punch (2, 3) is moved into the die (6) from the outer side (top) of the lid while punching out a punched pad (16) and the punched pad (16) is conveyed by compressed air through the die (6) to a conveyor (33) by means of which it is removed from the tool area.It has been shown that by this measure the known and established processes and devices for the production of tear-off lids can be modified with very little effort in such a way that during the punching of the lid blank (9) the punching or cutting pad is produced on the intended inner side (underside) of the produced lid ring (8), which is desirable when producing lids with "re-verse curl".