An apparatus for sealing a flattened tube of heat-sealable filter paper to make filter bags for infusion products

摘要

In a machine for making filter bags for infusion products, a flattened tube (34) is used which is made from a web (17) of filter paper that: is heat-sealable by thermal reactivation of a layer of glue; is fed continuously in the horizontal position; has individual charges (19) of the infusion product placed on its top surface at suitable intervals; and, lastly, is gradually folded onto itself until its longitudinal edges (18) are juxtaposed. An apparatus (250) for sealing the tube (34) comprises an operator block (94) bearing two rows (251) of emitters (96) designed to give off a gaseous fluid heated to a suitable temperature. The operator block (94), accommodated inside the tube (34) with the emitters (96) aligned and juxtaposed with the edges (18), directs the fluid against internal faces (97) of the tube (34) directly at the layer of glue on the web (17) which is simultaneously folded around the operator block (94) itself.