Apparatus for forming rolled lips on thermoplastic containers

A lip rolling apparatus for open-mouthed stacked thermoplastic containers is disclosed. One particular apparatus includes components for presenting a nested stack of containers having unrolled lips to a rim roller, engaging individual cups on a screw assembly, heating a supply of air in a heater to a desired temperature, discharging the supply of heated air toward the containers as they are engaged on the screw assembly, and rolling the lips of the containers in the screw assembly. The present invention may be designed to prevent the screw assembly from operating until the supply of air reaches the desired temperature. Additionally, the heater (e.g., a forced air heater) may be moved between an initial position proximate the nested stack of containers and a safety position in response to a signal. Such a signal may be generated in response to a temperature sensor, system error, or any other such triggering episode.