摘要 |
In a packaging machine, typically a cellophaner (1) for overwrapping packets of cigarettes, each of the packets (4) is enveloped by a wrapping unit (2) in a heat shrinkable wrapper (5) presenting at least two opposite faces (6-6; 7-7) disposed parallel one with another. The machine (1) also comprises a unit (28) by which heat is applied to the wrappers (5), equipped with a pair of belt conveyors (21, 22) that present two branches (26, 27), facing one another and set in motion in such a way as to transport the packets (4) by gripping the two opposite faces (6-6; 7-7) of each wrapper (5), and at least one heating head (29) associated with each transport branch (26, 27); the heating heads (29) are faced with a leaf (34) of lamellar graphite bonded to the head (29) on one side and offered in direct contact on the other to the respective branch (26, 27) of the corresponding belt conveyor, so as to minimize friction between the belt and the head (29). |