Heating device for heat-sealing top portions of containers

摘要

A heating device for heat-sealing the top portions of containers comprises a primary heater and a secondary heater arranged respectively at a first stop position and a second stop position of holders of an intermittently drivable container conveyor, the primary heater having a primary hot air nozzle in the form of a bottomed tube generally square to rectangular in horizontal section and movable into and out of a top forming portion of the container as held by the holder at halt in the first stop position, the secondary heater having a secondary hot air nozzle in the form of a bottomed tube generally square to rectangular in horizontal section and movable into and out of the top forming portion of the container as held by the holder at halt in the second stop position, the primary hot air nozzle and the secondary hot air nozzle being each formed in a side wall thereof with a plurality df orifices arranged in a specified pattern so as to correspond to the region to be heated of the top forming portion. The positions of the orifices of the primary hot air nozzle differ respectively from the positions of the orifices of the secondary hot air nozzle with respect to the container as held by the holder at halt in the corresponding stop position.