Method and device for sealing a narrow tape to a heatsealable strip

摘要

The method and device for sealing a narrow tape (2) to a strip (3) of heatsealable material in cigarette packing machines, which produce packets of cigarettes protected by an external wrapper made of plastic which can be torn using the said tear tape; to avoid a thermal degradation in the sections of heatsealable strip adjacent to the sealing zone, the present invention envisages sealing the narrow tape (2) to the strip (3) by passing them through a sealing unit (15), in contact with one another, and joining them with an ultrasound sealer (5) which directs the ultrasound to at least a zone in which the narrow tape (2) and strip (3) overlap; the intensity of the heatsealing action of the ultrasound is controlled and adjusted by elements (6) which detect the feed speed of the narrow tape (2) and strip (3).