A tag to be fixed to a connecting thread to a filter bag for infusion products has a flat body delimited by a perimeter edge; a first slit, starting from a first point of a side of the perimeter edge; a second slit and a third slit, starting from respective points of such side of the perimeter edge arranged on opposite sides with respect to the first starting point of the first slit. At least one of the second and third slits exhibits, starting from the respective starting point on said side, a progression and a development directed towards a point of a straight line in the plane of the body of the tag and perpendicular to said side at the first starting point of the first slit; the first slit, the second slit and the third slit being such as to enable passage there-through of a connecting thread, for fixing the tag to the thread.

A tag to be fixed to a connecting thread to a filter bag for infusion products has a flat body delimited by a perimeter edge; a first slit, starting from a first point of a side of the perimeter edge; a second slit and a third slit, starting from respective points of such side of the perimeter edge arranged on opposite sides with respect to the first starting point of the first slit. At least one of the second and third slits exhibits, starting from the respective starting point on said side, a progression and a development directed towards a point of a straight line in the plane of the body of the tag and perpendicular to said side at the first starting point of the first slit; the first slit, the second slit and the third slit being such as to enable passage there-through of a connecting thread, for fixing the tag to the thread.

A unit for over-wrapping filter bags includes a carousel rotating about a first axis with first and second grippers along a closed circular trajectory. A forming station for forming single sheets of over-wrapping material is arranged near the trajectory and includes a feeding device for feeding the sheets in a U-shape, synchronized with the first grippers. A first drum transports formed bags, rotates about a second axis and has grippers receiving the bags from a preceding station and releasing the bags from the first grippers with the U-shaped sheets in synchronization. A closing station includes a sealing gripper movable from a first position near the carousel, for picking the bag with the sheet the first gripper, to a second away position for closing the sheet and, lastly, to a third position near the carousel, for release of the enclosed bag to the second gripper.

A unit for over-wrapping filter bags includes a carousel rotating about a first axis with first and second grippers along a closed circular trajectory. A forming station for forming single sheets of over-wrapping material is arranged near the trajectory and includes a feeding device for feeding the sheets in a U-shape, synchronized with the first grippers. A first drum transports formed bags, rotates about a second axis and has grippers receiving the bags from a preceding station and releasing the bags from the first grippers with the U-shaped sheets in synchronization. A closing station includes a sealing gripper movable from a first position near the carousel, for picking the bag with the sheet the first gripper, to a second away position for closing the sheet and, lastly, to a third position near the carousel, for release of the enclosed bag to the second gripper.

A tag to be fixed to a connecting thread to a filter bag for infusion products has a flat body delimited by a perimeter edge; a first slit, starting from a first point of a side of the perimeter edge; a second slit and a third slit, starting from respective points of such side of the perimeter edge arranged on opposite sides with respect to the first starting point of the first slit. At least one of the second and third slits exhibits, starting from the respective starting point on said side, a progression and a development directed towards a point of a straight line in the plane of the body of the tag and perpendicular to said side at the first starting point of the first slit; the first slit, the second slit and the third slit being such as to enable passage there-through of a connecting thread, for fixing the tag to the thread.

A tag to be fixed to a connecting thread to a filter bag for infusion products has a flat body delimited by a perimeter edge; a first slit, starting from a first point of a side of the perimeter edge; a second slit and a third slit, starting from respective points of such side of the perimeter edge arranged on opposite sides with respect to the first starting point of the first slit. At least one of the second and third slits exhibits, starting from the respective starting point on said side, a progression and a development directed towards a point of a straight line in the plane of the body of the tag and perpendicular to said side at the first starting point of the first slit; the first slit, the second slit and the third slit being such as to enable passage there-through of a connecting thread, for fixing the tag to the thread.

A machine for making filter bags of different shapes for infusion products includes: a wheel defining a work surface and rotating about a relative axis; feed stations for placing tags on the work surface, a continuous thread, along a weave path, and a strip of filter material superposing the weave of thread and the tag. A sealing device is located downstream of the feed stations for sealing between the thread, tag and strip of filter material. A feed device moving the strip along a feed line is positioned downstream of the wheel. A station introduces a dose of infusion product in bag and closes the bag. The feed device has two feed rollers, for unwinding the strip, controlled by a control system for adjusting the speed of rotation of the feed rollers as a function of the length of the filter material needed to form the bag.

A machine for making filter bags of different shapes for infusion products includes: a wheel defining a work surface and rotating about a relative axis; feed stations for placing tags on the work surface, a continuous thread, along a weave path, and a strip of filter material superposing the weave of thread and the tag. A sealing device is located downstream of the feed stations for sealing between the thread, tag and strip of filter material. A feed device moving the strip along a feed line is positioned downstream of the wheel. A station introduces a dose of infusion product in bag and closes the bag. The feed device has two feed rollers, for unwinding the strip, controlled by a control system for adjusting the speed of rotation of the feed rollers as a function of the length of the filter material needed to form the bag.

A machine for forming filter bags for infusion products starting from pieces of filter material each containing a dose of infusion product and having, the pieces, a corresponding longitudinal axis of extension, including a carousel rotating about a main axis of rotation and including gripping elements movable in rotation about the main axis along a closed circular trajectory; each gripping element configured to receive and retain a piece of filter material along an operating path; an operating station configured to perform an operation on the piece of filter material retained by a corresponding gripping element; each gripping element including an articulation device configured for obtaining a further rotation about a secondary axis of rotation, transversal to the main axis of rotation, to rotate and position the corresponding piece of filter material with its longitudinal axis of extension parallel to the main axis of rotation at the operating station.

A machine for forming filter bags for infusion products starting from pieces of filter material each containing a dose of infusion product and having, the pieces, a corresponding longitudinal axis of extension, including a carousel rotating about a main axis of rotation and including gripping elements movable in rotation about the main axis along a closed circular trajectory; each gripping element configured to receive and retain a piece of filter material along an operating path; an operating station configured to perform an operation on the piece of filter material retained by a corresponding gripping element; each gripping element including an articulation device configured for obtaining a further rotation about a secondary axis of rotation, transversal to the main axis of rotation, to rotate and position the corresponding piece of filter material with its longitudinal axis of extension parallel to the main axis of rotation at the operating station.