A sealing and cutting device for forming bags containing products includes; a sonotrode for sealing a portion of a continuous tubular strip, feeding along a feed direction; a counterhead positioned facing the sonotrode; a movement system for moving the sonotrode and/or anvil between a first non-operating position, wherein the sonotrode and the anvil are apart, and a second operating position wherein the sonotrode and the anvil are in contact to simultaneously seal a head and bottom of respective bags. A cutting element includes a circular blade connected to a supporting and movement element which imparts a translational movement to the blade with a circular shape along a direction perpendicular to the feed direction of the strip. The anvil includes a slit from which the blade 6 protrudes, for cutting the strip, by contact with the sonotrode in the second operating position, to separate a bag formed from the remaining strip.

A machine for grouping filter bags for infusion products includes: a movement wheel rotating about a first axis; a rotary transfer wheel, rotating in a synchronised fashion with the movement wheel, about a second axis; a device for collecting the bags; a plurality of gripping elements positioned along a circumference of the transfer wheel and movable with it for picking up, in a first angular position, a bag from the movement wheel and a release configuration of the bag in the collecting device, in a second angular position and after an angular stretch of rotation. A sensor detects possible defects of the bags, and identifies the defective bags before they reach the second angular position. A rejection area receives the defective bags. A locking control controls the gripping element to prevent release of the bag in the second angular position, when detected to be defective by the sensor.

A method and a device for forming stacks of packages by stacking infusion bags is disclosed. In one example, the method includes removing an individual infusion bag from a conveying stretch, on which individual infusion bags are fed, to a removal station. The individual infusion bags, guided by a vertically movable push-in device in a stacking stroke of said push-in device, are transferred into a buffer storage chute of said stack holding device. In a transfer stroke of said push-in device, which is greater than said stacking stroke, an infusion bag completing said stack of packages is raised off of said conveying stretch and transferred into a cartridge storage chute of said stack holding device.

Described is a machine for making filter bags including: a rotary carousel having a plurality of grippers for retaining respective filtering chambers; each gripper is configured for moving the filtering chamber to a pick-up zone; a first reel of a first strip and a second reel of a second strip; a selector device including a first channel engaged by the first strip arriving from the first reel, and a second channel engaged by the second strip arriving from the second reel; the selector device has a shared outfeed at the pick-up zone; first and second movement means, positioned, respectively, along the first and the second channel for feeding, respectively, the first strip of tags and the second strip of tags, the first and second movement means are operated selectively in such a way as to feed alternately the first or the second strip.