DISPOSITIVO DI SIGILLATURA AD AZIONE MULTIPLA DIFFERENZIATA PER MACCHINE CONFEZIONATRICI DI SACCHETTI-FILTRO BIUSO PER PRODOTTI DA INFUSIONE

摘要

A sealing device with multiple differential action is provided for machines producing dual-use filter sachets for infusion products. In such machines a continuously moving strip of thermally weldable filter paper, fed with equidistantly spaced fractional doses of the infusion product, is progressively folded longitudinally into a flattened tubular shape with adjacent folded-back longitudinal edges forming a longitudinal crest. The device is constituted by two blocks having respective pairs of mirror-image stepped overlapping edges extending to the opposite sides of the adjacent folded back edges of the strip forming the longitudinal crest. The mirror-image edges of the upper overlap have bores connected to a fluid-dynamic heat source. The mirror-image edges of the lower step have a lamellar structure.