| 摘要 |
A packaging machine for bonding a sheet to opposite walls and over the articles therein. One embodiment has a conveyor which moves the trays down a predetermined path, during which a film sheet is disposed over the tops of the articles in each of the trays, and flight bars traveling about an orbital path interpose the sheet between the trailing and leading walls of each of the successive trays and press the sheet against the adjacent trailing and leading walls. Heating elements associated with each of the flight bars heat the sheet, while compressed, to form a bond between the film sheet and the tray walls. The heating elements are controlled by an improved electrical circuit. Three independently movable sets of flight bars are provided for placing each of the trays in compression whereby the apparatus is adjustable as required to accommodate trays of different sizes over a range within the limits of the machine. Improved cutting means separate the sheet between adjacent trays after the bonding process, and the trays then proceed to a heating tunnel if heat shrinking of the film is desired.
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