Patent attributes
A piston stopper (2) made substantially of rubber has a piston section (8) enclosed in cap-like manner by an inert film (9′) facing the contents of a syringe or carpule cylinder (1), the inert film (9′) being located adjacent to the syringe or carpule cylinder (1). Adjacent to the piston section (8), the piston stopper (2) has a non-coated sealing section (10). According to a device and method for producing one such piston stopper (2), a non-vulcanized rubber sheet (7) is inserted into a form tool, together with an inert film (9). Under the effect of pressure and heat, an entire piston stopper contour is formed from the layered arrangement, extending to a flange (16) which protrudes laterally beyond the piston stopper (2) in the region of the separating plane of the form tool. A receiving cavity (6) for a piston rod is created in the piston section (8). The wall area of the sealing section (10) surrounding the receiving cavity (6) is forced into the receiving cavity (6). The piston stopper (2) is subsequently separated from the flange (16) in a blanking process, whereby a peripheral sealing area (13), directly adjacent to the edge of the inert film (9′) enclosing the piston section (8), is formed in the sealing section (10).
