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EP-4741295-A2 - A METHOD AND MACHINE FOR THE PRODUCTION OF POUCHES CONTAINING A RESPECTIVE QUANTITY OF A LOOSE MATERIAL, IN PARTICULAR SNUS

EP4741295A2EP 4741295 A2EP4741295 A2EP 4741295A2EP-4741295-A2

Abstract

A machine (6) for the production of pouches (1) containing a respective quantity (2) of a loose material, in particular snus, is provided, comprising a forming station (13) configured to enclose each quantity (2) within a wrapping material band (11) comprising, in turn, a wrapping device (14) at which the wrapping material band (11) is wound to form a tubular wrap (8) having a longitudinal extension in which a first edge of the wrapping material band (11) partially overlaps a second edge of the wrapping material band (11) defining an overlapping area; a longitudinal sealing unit (15) configured to longitudinally seal the tubular wrap (8) at the overlapping area; and a transverse sealing unit (16) configured to make transverse seals (5) of the tubular wrap (8) so as to form a continuous succession of pouches (1) connected to each other at said transverse seals (5). The transverse sealing unit (16) configured to make an ultrasound transverse seal (5) of the tubular wrap (8) and comprises a sealing device (25) and a countering device (26), which cooperate to make the transverse seals (5); the sealing device (25) and the countering device (26) are both configured to follow a trajectory divided into a first straight segment, in which the transverse seals (5) are made and a second arc-shaped segment.

Inventors

  • GHIOTTI, ROBERTO
  • MANGIULLO, Antonio
  • PIERAGOSTINI, MAURO

Assignees

  • Sasib S.p.A.

Dates

Publication Date
20260513
Application Date
20251103

Claims (9)

  1. A machine (6) for the production of pouches (1) containing a quantity (2) of a loose material, in particular snus, comprising a forming station (13) configured to enclose each quantity (2) within a wrapping material band (11) comprising, in turn: - a wrapping device (14), in the area of which the wrapping material band (11) is rolled up so as to form a tubular wrap (8) having a longitudinal extension, wherein a first edge of the wrapping material band (11) partially overlaps a second edge of the wrapping material band (11), thus defining an overlapping area; - a longitudinal sealing unit (15) configured to longitudinally seal the tubular wrap (8) in the overlapping area; and - an ultrasound transverse sealing unit (16) configured to make transverse seals (5) of the tubular wrap (8) so as to form a continuous succession of pouches (1) connected to each other in the area of said transverse seals (5); the ultrasound sealing unit (16) comprises a sealing device (25) and a countering head (26), which cooperate to make the transverse seals (5); wherein the sealing device (25) and the countering device (26) are both configured to follow a trajectory divided into a first straight segment, in which they cooperate to make the transverse seals (5), and a second arc-shaped segment, preferably circular; the machine is characterized in that it comprises an adjustment device (38) configured to keep the sealing pressure constant during the first straight segment, and in which the adjustment device (38) is divided into a first, lower adjustment device (38*) connected to the first sealing device (25) and a second upper adjustment device (38**) connected to the second sealing device (26).
  2. The machine according to claim 1, wherein the sealing device (25) and the countering device (26) are configured to move along the first straight segment of the respective trajectories with even speeds.
  3. The machine according to claim 1 or 2, wherein the sealing device (25) and the countering device (26) are configured to move along the first straight segment of the respective trajectories with the same speed with which the tubular wrap (8) moves.
  4. The machine according to any one of the preceding claims, wherein: the first straight segment defines a sealing step, during which the sealing device (25) and the countering device (26) cooperate with the tubular wrap (8) to make the transverse seals (5) from a seal start point (A) to a seal end point (B); whereas the circular arc-shaped segment defines a return step from the seal end point (B) to the seal start point (A).
  5. The machine according to any one of the previous claims, wherein the adjustment device (38) comprises a number of adjustment elements (39) provided with respective axes (X, Y) parallel to one another and configured to translate along said axes (X, Y) in the area of a seal start point (A), where the sealing device (25) and the countering device (26) come into contact with the tubular wrap (8) to make the transverse seals (5), and of a seal end point (B), where the contact of the sealing device (25) and of the countering device (26) with the tubular wrap (8) is interrupted.
  6. The machine according to claim 5, wherein each adjustment element (39) comprises sleeves (41), which slide along respective pistons (40) coaxial to said axes (X, Y).
  7. The machine according to any one of the claims from 4 to 6, wherein the adjustment device (38) comprises a number of limit stop elements (44) configured to adjust the stroke of the adjustment elements (39) along the respective axes (X, Y).
  8. The machine according to any one of the preceding claims and comprising operating means (M) for operating the sealing device (25) and the countering device (26) comprising, in turn, an actuator device (34), preferably a brushless motor, configured to transmit the motion to a number of eccentric shafts (36), which control the motion of the sealing device (25) and of the countering device (26).
  9. A method for the production of pouches (1) containing a quantity (2) of a loose material, in particular snus, comprising in succession: - a step in which to wrap a wrapping material band (11) around a wrapping device (14) so as to form a tubular wrap (8) having a longitudinal extension, wherein a first edge of the wrapping material band (11) partially overlaps a second edge of the wrapping material band (11), thus defining an overlapping area; - a longitudinal sealing step, during which the tubular wrap (8) is longitudinally sealed in the overlapping area; and - an ultrasonic transverse sealing step of the tubular wrap (8) so as to form a continuous succession of pouches (1) connected to one another; wherein the ultrasonic transverse sealing step is carried out by means of an ultrasonic transverse sealing unit (16) having a sealing device (25) and a countering device (26) and comprising, in turn: a) a first sub-step, during which the sealing device (25) and the countering device (26) follow a first straight segment of a trajectory, in which they cooperate with one another to make the ultrasonic transverse seal; and wherein to keep the sealing pressure constant by means of an adjustment unit (38) divided into a first, lower adjustment device (38*) connected to the first sealing device (25) and a second, upper adjustment device (38**) connected to the countering device (26); and b) a second sub-step, during which the sealing device (25) and the countering device (26) follow a second arc-shaped segment, preferably circular, of the trajectory.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority from Italian patent application no. 102024000025446 filed on November 12, 2024, the entire disclosure of which is incorporated herein by reference. TECHNICAL FIELD This invention relates to a machine for the production of pouches (or sachets) containing a quantity of a loose product (that is, a non-compact product), in particular snus, and to a method for producing pouches containing a quantity of a loose product, in particular snus. This invention can be advantageously applied to the production of snus pouches (that is, permeable pouches for oral use that each contain a predetermined quantity of a loose, that is, non-compact product, that is more or less wet and, for example, nicotine-based), to which the discussion that follows will explicitly refer without any loss of generality thereby. PRIOR ART As is well known, a snus pouch is essentially rectangular in shape, is made from a wrapping sheet that is folded back on itself to form a closed shape around a quantity of powdered material, and is stabilised by means of a longitudinal seal and a pair of opposite, transverse seals. Typically, a wrapping machine for producing snus pouches comprises a conveyor device for conveying a wrapping material band along a packaging path, a wrapping station arranged along the packaging path, wherein the wrapping material band is wound to form a tubular wrap having a longitudinal extension around a wrapping duct, and a feeding device for the loose material that terminates at the inlet of the wrapping duct and is configured to successively feed the loose product quantities into the tubular wrap (around which the wrapping material is folded to form the tubular wrap) by means of compressed air. The wrapping machine also comprises a longitudinal sealing unit to longitudinally seal the tubular wrap at an overlapping area of the wrapping material band; a transverse sealing unit to transversely seal the tubular wrap so as to form an alternating succession of sealing areas and areas containing a quantity of loose product; and a cutting unit to transversely cut the tubular wrap at the transverse sealing areas so as to separate the individual snus pouches. Known transverse sealing units mostly perform heat sealing and comprise two opposing sealing rollers that cooperate together to press against each other (that is, pinch together) the tubular wrap, are rotatably mounted around two corresponding horizontal rotation axes, and are rotated by the same actuator device. In known transverse sealing units when the wrapping material band and/or powdered material come into contact with the sealing rollers at high temperatures they crystallise, leaving residues and impurities. Therefore, there is a need for solutions to limit the crystallisation of powdered materials and at the same time have a high productivity and quality of transverse seals. Patents WO2023228068, US5771660 and US2019210753 describe machines for producing pouches of a known type. DESCRIPTION OF THE INVENTION The purpose of this invention is, therefore, to provide a machine for the production of pouches containing a quantity of a loose material, in particular snus, that is free from the drawbacks of the state of the art and is also easy and inexpensive to manufacture. In accordance with this invention, a machine for the production of pouches containing a respective quantity of loose material, in particular snus, is provided, comprising a forming station configured to enclose each quantity within a wrapping material band comprising, in turn, a wrapping device at which the wrapping material band is wound to form a tubular wrap having a longitudinal extension wherein a first edge of the wrapping material band partially overlaps a second edge of the wrapping material band defining an overlapping area; a longitudinal sealing unit configured to longitudinally seal the tubular wrap at the overlapping area; and a transverse sealing unit configured to make transverse seals of the tubular wrap so as to form a continuous succession of pouches connected to each other at said transverse seals. In accordance with this invention, the transverse sealing unit is configured to perform ultrasonic sealing of the tubular wrapping and comprises a sealing device and a countering device that cooperate to make the transverse seals. The sealing device and the countering device are both configured to traverse a trajectory divided into a first straight segment in which they cooperate to make the transverse seals, and a second arc-shaped segment, preferably circular. According to a preferred embodiment, the sealing device and the countering device are configured to travel the first straight segment of their respective trajectories at uniform speeds. According to a preferred embodiment, the sealing device and the countering device are configured to travel the first straight segment of their respective trajectories with the sam