Abstract: A web of heat-sealable film is advanced in overlying relation with filled cups to a sealing station where both the web and the cups dwell momentarily. During the dwell period, sealing heads advance downwardly and seal the web to the upper end portions of the cups. The heads are advanced downwardly with a two-step stroke, the heads first advancing in unision with a carriage and then being individually advanced by individual pneumatic actuators which are mounted on the carriage. After being sealed, the cups are indexed to a cutting station where annular knives are advanced downwardly to cut through the web and leave each cup with a circular sealing membrane. The knives are advanced with a two-step stroke similar to that of the sealing head.