A device for joining filter bags for infusion products comprising at least two operating units (2, 3) located on opposite sides of a continuous tubular strip of filter material movable along a feed direction; each operating unit (2, 3) comprising: - a sealing head positioned facing the continuous tubular strip of filter material; - a supporting body, which supports the sealing head; - two kinematic units (6, 6') each having an eccentric rotary system (7, 8, 9, 7', 8', 9'); each kinematic unit (6, 6') being connected to a corresponding first and second axis of movement, of which at least one is motor-driven, and movable in rotation and in a synchronised fashion with the feeding of the continuous tubular strip of filter material; the two kinematic units (6, 6') being articulated to the supporting body in such a way as to move the supporting body along a first trajectory which is able to move the sealing head at least between an end operating position, in contact with the continuous tubular strip of filter material, and an end non-operating position, away from the continuous tubular strip of filter material, characterised in that each operating unit (2, 3) comprises: - a carriage associated with the sealing head; the carriage being slidably connected to the supporting body and configured in such a way as to translate, in both directions, relative to the supporting body, along a second trajectory, transversal to the feed direction; - a second kinematic unit articulated, at a first end, to a third axis of movement, and, at a second end, to the carriage; the second kinematic unit being configured for moving the carriage in a synchronised fashion with the supporting body, so as to obtain a movement of the sealing head along a third trajectory, resultant from the combination of the first trajectory and the second trajectory, having at least one active rectilinear stretch parallel to the feed direction of the continuous tubular strip, wherein the sealing head is in contact with the continuous tubular strip. - a sealing head positioned facing the continuous tubular strip of filter material; - a supporting body, which supports the sealing head; - two kinematic units (6, 6') each having an eccentric rotary system (7, 8, 9, 7', 8', 9'); each kinematic unit (6, 6') being connected to a corresponding first and second axis of movement, of which at least one is motor-driven, and movable in rotation and in a synchronised fashion with the feeding of the continuous tubular strip of filter material; the two kinematic units (6, 6') being articulated to the supporting body in such a way as to move the supporting body along a first trajectory which is able to move the sealing head at least between an end operating position, in contact with the continuous tubular strip of filter material, and an end non-operating position, away from the continuous tubular strip of filter material, - a carriage associated with the sealing head; the carriage being slidably connected to the supporting body and configured in such a way as to translate, in both directions, relative to the supporting body, along a second trajectory, transversal to the feed direction; - a second kinematic unit articulated, at a first end, to a third axis of movement, and, at a second end, to the carriage; the second kinematic unit being configured for moving the carriage in a synchronised fashion with the supporting body, so as to obtain a movement of the sealing head along a third trajectory, resultant from the combination of the first trajectory and the second trajectory, having at least one active rectilinear stretch parallel to the feed direction of the continuous tubular strip, wherein the sealing head is in contact with the continuous tubular strip.