Packaging machine and method for producing sealed packages

Abstract

A packaging machine (1) is described, comprising a conveying device (5) for advancing a web (4) of packaging material along a web advancement path (P) to at least a tube forming station (6) where the web (4) of packaging material is formed into a tube (3), and for advancing the tube (3) along a tube advancement path (Q), a tube forming and sealing device (10) configured to form the tube (3) in the tube forming station (6) and to seal the tube (3) longitudinally, a tensioning device (32) configured to control the tension in the web (4) of packaging material and / or the tube (3), and a control unit (13) configured to control the operation of the packaging machine (1). The tensioning device (32) includes at least one tensioning assembly (33) having at least a first drive roller (34), a second drive roller (35), a first drive motor coupled to the first drive roller (34) and configured to actuate rotation of the first drive roller, and a second drive motor (37) coupled to the second drive roller (35) and configured to actuate rotation of the second drive roller (35) about a second axis of rotation (B). The control unit (13) is configured to control the first drive motor and the second drive motor (37) so that, in use, a free loop (38) of the web of packaging material (4) expands and / or advances between the first drive roller (34) and the second drive roller (35).

Description

[Technical field]

[0001] The present invention relates to a packaging machine for producing sealed packages of pourable products, in particular pourable food products.

[0002] The present invention also relates to a method for producing a sealed package of a pourable product, in particular a pourable food product. [Background technology]

[0003] As is known, many liquid or pourable food products, such as fruit juice, UHT (ultra-high temperature treated) milk, wine, tomato sauce, etc., are sold in packages made from sterilized packaging materials.

[0004] A typical example is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic®, which is made by sealing and folding laminated strip packaging material. The packaging material has a multi-layer structure including a base layer, e.g. paper, covered on both sides with a layer of heat-sealed plastic material, e.g. polyethylene. In the case of aseptic packages for long-term storage products such as UHT milk, the packaging material also includes a layer of oxygen barrier material (oxygen barrier layer), e.g. aluminum foil, which is superimposed on the layer of heat-sealed plastic material and then covered with another layer of heat-sealed plastic material that finally forms the inner surface of the package that contacts the food product.

[0005] This type of package is typically produced on a fully automatic packaging machine which advances a web of packaging material through a sterilizer to an isolation chamber (closed sterile environment) for sterilizing the web of packaging material at a sterilization station, and the sterilized web of packaging material is maintained and advanced within the isolation chamber. During the advancement of the web of packaging material through the isolation chamber, the web of packaging material is folded and longitudinally sealed at a tube forming station to form a tube having a longitudinal seam, and the tube is fed further along the vertical advance direction.

[0006] To complete the forming operation, the tube is filled with a sterilized or pasteurized pourable product, in particular a pourable food product, transversely sealed and then cut along equally spaced transverse cross sections within a package forming unit of the packaging machine as it advances along a vertical advance direction.

[0007] Pillow packages are thus obtained in the packaging machine, each pillow package having a longitudinal seal strip, a top lateral seal strip and a bottom lateral seal strip.

[0008] A typical packaging machine includes a conveying device for advancing a web of packaging material along a web advancement path and a tube formed from the web of packaging material along a tube advancement path, a sterilization apparatus for sterilizing the web of packaging material before it is formed into a tube, a tube forming and sealing device disposed at least partially within the isolation chamber and configured to form a tube from the advancing web of packaging material and seal the tube longitudinally, a filling device for filling the tube with a pourable product, and a package forming unit adapted to form, transversely seal and cut single packages from the tube of packaging material.

[0009] A typical packaging machine also includes a tensioning device configured to control the tension in the web and / or tube of packaging material.

[0010] In particular, the tensioning device includes at least one tensioning assembly for controlling the tension in a portion of the web of packaging material and / or in a tube immediately downstream of the tensioning assembly itself.

[0011] Specifically, it is known to position a tensioning assembly between the sterilization station and the tube forming station to at least control the tension in the tube.

[0012] A typical tensioning assembly includes at least one first roller rotatable about a first axis of rotation, one first counter roller adjacent to the first roller, one second roller rotatable about a second axis of rotation and disposed downstream of the first roller, one second counter roller adjacent to the second roller, and a drive motor associated with the second roller for actuating rotation of the second roller about the second axis of rotation.

[0013] A typical tensioning assembly further includes a pendulum roller sandwiched between the first roller and the second roller and configured to tension a portion of the web of packaging material expanding between the first roller and the second roller.

[0014] It should be noted that operation of the package forming unit is cyclical resulting in a cyclical force which changes the forward speed of the tube.

[0015] Thus, a tensioning assembly located between the tube forming station and the sterilization station is controlled such that the drive motor controls a constant rotational speed of the second roller which corresponds to the average forward speed of the tube, and the operation of the pendulum roller compensates for the difference between the forward speed of the web resulting from the rotation of the second roller and the forward speed of the tube.

[0016] Applicant has discovered that while control of the tension in the web and / or tube of packaging material can be sufficiently good to allow reliable production of packages, the tension in the web and / or tube of packaging material can vary in part in an uncontrolled manner.

[0017] It would therefore be desirable to improve known tensioning devices and methods of producing packages so as to improve the accuracy and / or reliability of tension control. Summary of the Invention [Problem to be solved by the invention]

[0018] It is therefore an object of the present invention to provide a packaging machine to overcome in a simple manner at least one of the above mentioned drawbacks.

[0019] Specifically, it is an object of the present invention to provide a packaging machine with improved tension control.

[0020] It is a further object of the present invention to provide a method for producing a sealed package, in order to overcome in a simple manner at least one of the aforementioned drawbacks.

[0021] In particular, it is an object of the present invention to provide a method with improved tension control. [Means for solving the problem]

[0022] According to the present invention there is provided a packaging machine and a method for producing a sealed package as claimed in the independent claims.

[0023] Preferred embodiments are claimed in the dependent claims.

[0024] Non-limiting embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic diagram, with parts removed for clarity, of a packaging machine according to the present invention; FIG. [Diagram 2] FIG. 2 is a schematic diagram of a portion of the packaging machine of FIG. 1 with parts removed for clarity. [Diagram 3] FIG. 2 is a perspective view of a detail of the packaging machine of FIG. 1 with parts removed for clarity. [Figure 4] FIG. 4 is an enlarged perspective view of some of the details of FIG. 3 with parts removed for clarity; [Diagram 5] FIG. 4 is a perspective view of a detail of FIG. 3 from a different perspective, with parts removed for clarity; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Number 1 generally indicates a packaging machine for producing sealed packages 2 of pourable product, in particular pourable food products such as pasteurized milk, fruit juice, wine, tomato sauce, etc., from a tube 3 of a web 4 of packaging material. In particular, in use, the tube 3 extends along a longitudinal axis which preferably has a vertical orientation.

[0027] The web 4 of packaging material has a multi-layer structure (not shown) and includes at least one layer of fibrous material, such as a paper or paperboard layer, and at least two layers of heat-sealable plastic material, such as polyethylene, sandwiching the layer of fibrous material between each other, one of these two layers of heat-sealable plastic material defining the inner surface of the package 2 that will ultimately contact the pourable product.

[0028] Preferably, but not necessarily, the web 4 also includes a layer of gas and light blocking material, such as aluminum foil or ethylene vinyl alcohol (EVOH) film, specifically disposed between one of the layers of heat-sealable plastic material and the layer of fibrous material. Preferably, but not necessarily, the web 4 also includes a further layer of heat-sealable plastic material sandwiched between the layer of gas and light blocking material and the layer of fibrous material.

[0029] According to a preferred, non-limiting embodiment, web 4 includes a first side and a second side, specifically the first side is the side of web 4 that forms the inner surface of the formed package 2 that will ultimately contact the filled pourable food product.

[0030] According to a preferred, non-limiting embodiment, a typical package 2 obtained by the packaging machine 1 includes a longitudinal seam and a pair of lateral sealing strips, specifically a lateral top sealing strip and a lateral bottom sealing strip.

[0031] With specific reference to FIG. 1 , packaging machine 1 is configured to advance web 4 along a web advancement path P, preferably sterilize web 4 while advancing along path P, to form and longitudinally seal a tube 3 from web 4, preferably fill tube 3 with a pourable product, and preferably form a single package 2 from the filled tube 3.

[0032] With particular reference to Figures 1 and 2, the packaging machine 1 includes: a conveying device 5 configured to advance the web 4 along a web advancement path P to at least a tube forming station 6 where the web 4 is, in use, formed into a tube 3, for advancing the tube 3 along a tube advancement path Q; an isolation chamber 7 having an internal (sterile) environment 8 and extending along a longitudinal axis, preferably but not necessarily having a vertical orientation; a tube forming and sealing device 9 disposed at least partially within the isolated chamber 7 and configured to form and longitudinally seal the tube 3 at the tube forming station 6, specifically within at least a portion of the isolated chamber 7, and even more specifically within the internal environment 8; In particular a filling device 10 for filling the tube 3 with a pourable product; and a package forming unit 11 adapted (configured) to at least form and laterally seal the tube 3, and preferably also to laterally cut the tube 3, between successive packages 2, in particular while advancing the tube 3 along the tube advancement path Q, in order to form the package 2 itself.

[0033] According to a preferred, non-limiting embodiment, the packaging machine 1 further includes a sterilization device for sterilizing at least a portion of the web 4, preferably at least a first side, and even more preferably the first and second sides, in particular at a sterilization station located upstream of the tube forming station 6 along the web advancement path P.

[0034] According to a preferred, non-limiting embodiment, the packaging machine 1 also includes a control unit 13 for controlling the operation of the packaging machine 1 itself.

[0035] According to a preferred, non-limiting embodiment, the packaging machine 1 also includes a sealing strip application device 17 configured to apply a sealing strip (not explicitly shown) of a heat-sealable material, in particular a heat-sealable plastic material, to at least one lateral edge of the web 4 along the web advancement path P, in particular at a strip application station 18 arranged upstream of the tube forming station 6, and in particular also at a sterilization station.

[0036] According to a preferred, non-limiting embodiment, the packaging machine 1 also includes a magazine unit adapted to host and present the web 4 at the host station. In particular, the conveying device 5 is configured to advance the web 4 from the host station to the tube forming station 6.

[0037] In particular, the package forming unit 11 is disposed along path Q downstream of the isolated chamber 7 and the tube forming and sealing device 9 .

[0038] Preferably, but not necessarily, the conveying device 5 is adapted to advance the tube 3 and any intermediate part of the tube 3 in a known manner, such as along a path Q, in particular from the tube forming station 6 through the isolation chamber 7, in particular towards and at least partially through the package forming unit 11. Any configuration of the web 4, in particular with an intermediate part of the tube 3, is meant before obtaining a tube structure as well as after the tube forming and sealing device 9 has started folding the web 4. In other words, the intermediate part of the tube 3 is the result of a gradual folding of the web 4 to obtain the tube 3, in particular by overlapping the opposing lateral edges of the web 4 on one another.

[0039] According to a preferred, non-limiting embodiment, the sterilization device is configured to sterilize the web 4, particularly the first side, and even more particularly the second side, by physical sterilization, such as sterilizing radiation, particularly electromagnetic radiation, and even more particularly electron beam irradiation.

[0040] Alternatively or additionally, the sterilization device may be configured to sterilize the web 4, particularly the first side and even more particularly the second side, by chemical sterilization, particularly by hydrogen peroxide.

[0041] According to a preferred, non-limiting embodiment, the isolation chamber 7 separates an internal environment 8 from an external environment, and specifically allows the tube 3 to be formed and filled within a controlled environment. Specifically, the internal environment 8 contains a sterile gas.

[0042] 1 and 2, the filling device 10 includes at least a filling pipe 19 in fluid communication with a storage tank of pourable product (not shown, but known as such) and extending partially into the isolated chamber 7, specifically the internal environment 8. Specifically, in use, the filling pipe 19 is located partially within the tube 3 for delivering the pourable product into the tube 3 which advances in use.

[0043] With specific reference to FIG. 1 , the tube forming and sealing device 9 includes at least a tube forming assembly 20 configured to form a tube 3 from a web 4, specifically by overlapping respective lateral edges of the web 4, and at least a sealing head 21 configured to seal the tube 3 longitudinally, specifically along a portion of the tube 3 obtained by overlapping the lateral edges of the web 4.

[0044] Preferably, but not necessarily, the tube forming assembly 20 and sealing head 21 are disposed within the isolated chamber 7 , specifically within the interior environment 8 .

[0045] Preferably, but not necessarily, the tube forming assembly 20 includes at least a plurality, in the illustrated embodiment two, of forming ring assemblies 22 adapted to gradually fold the web 4 into the tube 3. Specifically, the forming ring assemblies 22 are arranged in parallel spaced apart planes, specifically perpendicular to the longitudinal axis of the isolation chamber 7, and even more specifically have a substantially horizontal orientation.

[0046] Preferably, but not necessarily, the tube forming and sealing device 9 also includes a pressure assembly configured to apply a mechanical force to the tube 3, particularly to improve longitudinal sealing of the tube 3. Specifically, the pressure assembly is associated with a forming ring assembly 22 that is disposed downstream of the other forming ring assembly 22 along the web advancement path P and / or the tube advancement path Q.

[0047] According to a preferred, non-limiting embodiment, the package forming unit 11 includes a plurality of pairs of at least one respective actuating assembly 23 (only one shown) and at least one counter actuating assembly 24 (only one shown); Specifically, it includes a transport unit (not shown, and known as such) adapted to advance a pair of respective actuating assemblies 23 and respective counter-actuating assemblies 24 along respective transport paths.

[0048] Preferably, but not necessarily, each actuating assembly 23 is adapted to cooperate in use with a respective counter actuating assembly 24 of a respective pair to form a respective package 2 from the tube 3. In particular, each actuating assembly 23 and each counter actuating assembly 24 is configured to shape, transversely seal and preferably, but not necessarily, also transversely cut the tube 3 to form a package 2 as it advances along a respective actuating portion of a respective conveying path in use.

[0049] Preferably, but not necessarily, each actuating assembly 23 and each counter actuating assembly 24 are adapted to cooperate with each other to form a respective package 2 from the tube 3 as it advances along its respective actuating portion of the respective conveying path.

[0050] Preferably, but not necessarily, each actuating assembly 23 and each counter actuating assembly 24 is configured to contact tube 3 as it advances along its respective actuating portion of its respective transport path, specifically when it begins to contact tube 3 at a (fixed) hit position.

[0051] Preferably, but not necessarily, each actuation assembly 23 and counter actuation assembly 24 comprises: a half shell 25 adapted to contact the tube 3 and to at least partially define the shape of the package 2; one of a sealing element 26 and a counterseal element 27 adapted to laterally seal the tube 3 between adjacent packages 2 in a known manner; Preferably, but not necessarily, it includes one of a cutting element (not shown, but known as such) and an anti-cutting element (not shown, but known as such) for cutting the tube 3 transversely between adjacent packages 2 in a manner known as such.

[0052] Preferably, but not necessarily, each half-shell 25 is adapted to be controlled between a working position and a rest position by means of a drive assembly (not shown), in particular each half-shell 25 is adapted to be controlled in the working position by a respective actuating assembly 23 or a respective counter-actuating assembly 24 which, in use, advances along a respective actuating section.

[0053] Preferably, but not necessarily, each sealing element 26 and each counterseal element 27 is adapted to be controlled between an actuated sealing position in which the sealing element 26 and each counterseal element 27 are adapted to contact and laterally seal with the tube 3, and a rest position in which the sealing element 26 and each counterseal element 27 are separated from the tube 3. In particular, each sealing element 26 and each counterseal element 27 is adapted to be controlled in the sealing position by the respective actuating assembly 23 or the respective counter actuating assembly 24 which, in use, advances along the respective actuating portion.

[0054] Preferably, but not necessarily, each half-shell 25 is configured to be controlled in a respective working position, with the respective sealing element 26 and counter-seal element 27 being controlled in the respective working position.

[0055] Preferably, but not necessarily, each actuating assembly 23 and each counter-actuating assembly 24 is configured to exert a traction force on the tube 3 in order to advance the tube 3 along the tube advancement path Q in cooperation with the transport unit.

[0056] Preferably, but not necessarily, the actuation assembly 23 , the counter actuation assembly 24 and the transport unit can be considered to form part of the transport device 5 .

[0057] It should be noted that the forces acting on the tube 3 and resulting from the interaction with the actuating assembly 23 and the counter-actuating assembly 24 depend on the various steps of forming the package 2. The forces acting on the tube 3 vary, for example, due to the sealing element 26 and the counter-seal element 27 contacting the tube 3 when they are controlled in their respective actuating positions and / or when the half-shells 25 are controlled in their respective working positions, and / or due to the traction of the tube 3 caused by the advancement of the actuating assembly 23 and the counter-actuating assembly 24 along their respective conveying paths.

[0058] In particular, during the process of forming the package 2 (using the package forming unit 11), there is a complex cyclical behavior of the acting forces.

[0059] According to a preferred, non-limiting embodiment, the sealing strip application device 17 comprises: a positioning unit (not shown in detail, but known as such) adapted (configured) to position a first longitudinal portion of the sealing strip on one lateral edge of the web 4; and a strip sealing unit (not shown in detail and known as such) adapted to seal a first longitudinal portion of the sealing strip to the web 4, in particular to the lateral edges of the web 4.

[0060] In particular, the tube forming and sealing device 9 is configured to form the tube 3 such that a sealing strip applied to the web 4 covers lateral edges of the web 4 that are arranged on the inside of the tube 3 (and thus on the inside of the package 2). Even more particularly, the sealing strip contacts a portion of the first side of the web 4.

[0061] 1 and 2, the packaging machine 1 also includes at least one tensioning device 32 configured to control the tension of at least the web 4 and / or the tube 3. Specifically, the tensioning device 32 is configured to locally and selectively control the tension of the web 4 and / or the tube 3.

[0062] Advantageously, the tensioning device 32 includes at least one tensioning assembly 33, and preferably but not necessarily a plurality of tensioning assemblies 33, configured to control the tension in the web 4 and / or tube 3. In particular, each tensioning assembly 33 is configured to selectively locally control the tension in a respective downstream portion of the web 4 and / or tube 3 along the web advancement path P and / or tube advancement path Q.

[0063] Specifically, each tension assembly 33 is positioned along the web advancement path P upstream of a tube forming station 6 .

[0064] According to a preferred, non-limiting embodiment, each tensioning assembly 33 is configured to operate independently of the other tensioning assemblies 33 .

[0065] Advantageously, the control unit 13 is configured to selectively control the operation of each tensioning assembly 33. In particular, the control unit 13 is configured to control each tensioning assembly 33 independently of the other tensioning assemblies 33.

[0066] With specific reference to FIGS. 1 and 2, the tensioning device 32 comprises at least one tensioning assembly 33 arranged upstream of the tube forming station 6 and / or the tube forming and sealing device 9 and specifically downstream of the sterilization station and / or the sterilization device, configured to control the tension of at least a portion of the tube 3 and / or web 4 extending between the tensioning assembly 33 and the tube forming station 6 and / or the tube forming and sealing device 9; and / or one tensioning assembly 33 arranged along the web advancement path P upstream of the strip applying station 18 and / or the sealing strip applying device 17 and configured to control the tension of the web 4 at the strip applying station 18 and / or during application of the sealing strip and / or during operation of the sealing strip applying device 17 in use; and / or It includes one tension assembly 33 located downstream of the strip applying station 18 and / or sealing strip applying device 17 and upstream of the sterilization station and / or sterilization device along the web advancement path P.

[0067] 1-5, each tensioning assembly 33 includes at least a first drive roller 34 rotatable about a first rotation axis A; a second drive roller 35 rotatable about a second rotation axis B; a first drive motor, specifically a first servo motor, coupled to the first drive roller 34 and configured to actuate and / or control the rotation of the first drive roller 34 about a rotation axis A; and a second drive motor 37, specifically a servo motor, coupled to the second drive roller 35 and configured to actuate rotation of the second drive roller 35 about the rotation axis B.

[0068] It should be noted that Figures 3 and 5 show a first portion of each tensioning assembly 33, having a respective second drive roller 35 and a respective second drive motor 37. A second portion of each tensioning assembly 33, having a respective first drive roller 34 and a respective first drive motor, is not explicitly shown, as the second portion is substantially identical to the first portion.

[0069] According to a preferred, non-limiting embodiment, each first drive roller 34 and each second drive roller 35 of each tension assembly 33 are spaced apart along the web advancement path P, specifically, each first drive roller 34 is positioned upstream of each second drive roller 35.

[0070] Conveniently, the control unit 13 is configured to control the respective first drive motors and the respective second drive motors 37 of the respective tension assemblies 33 so that the free loop 38 of the web 4 expands and / or advances between the respective first drive rollers 34 and the respective second drive rollers 35 in use.

[0071] In the context of the present invention, the term free loop 38 indicates that the portion of web 4 that expands and / or advances between the respective first drive roller 34 and the respective second drive roller 35 and that defines and / or forms the free loop 38 is not subjected to any tension, i.e., the portion of web 4 that defines and / or forms the free loop 38 is not exposed to and / or is free from any tension. In other words, each free loop 38 is a tension-free portion of web 4.

[0072] According to a preferred, non-limiting embodiment, each tensioning assembly 33 comprises at least a first counter roller 39 rotatable about a central axis C and disposed adjacent to the first drive roller 34, specifically adjacent to the first drive roller 34 in the circumferential direction, and more specifically in contact with the first drive roller 34; The second drive roller 35 further includes a second counter roller 40 rotatable about a central axis E and disposed adjacent to the second drive roller 35, specifically adjacent to the second drive roller 35 in the circumferential direction, and even more specifically in contact with the second drive roller 35.

[0073] According to a preferred non-limiting embodiment, and in accordance with the arrangement of each first drive roller 34 and each second drive roller 35, each first counter roller 39 is positioned upstream of each second counter roller 40 along the web advancement path P.

[0074] Specifically, in use, the web 4 is clamped and / or advanced between the respective first counter rollers 39 and the respective first drive rollers 34, and between the respective second counter rollers 40 and the respective second drive rollers 35. In other words, while the web 4 is advanced in use, the web 4 advances between the respective first drive rollers 34 and the respective first counter rollers 39, and between the respective second drive rollers 35 and the respective second counter rollers 40.

[0075] According to a preferred, non-limiting embodiment, the control unit 13 is configured to control each second drive motor 37 such that the angular velocity and / or angular acceleration of each second drive roller 35 is controlled and / or varied to thus control the tension in the web 4 and / or tube 3.

[0076] Preferably, but not necessarily, the control unit 13 is configured to control each first drive motor such that the angular velocity of each first drive roller 34 thus maintains and / or controls, specifically the extension of each free loop 38 expanding and / or advancing between each first drive roller 34 and each second drive roller 35.

[0077] Specifically, in use, the angular velocity of each first drive roller 34 substantially controls the extension of each free loop 38, while the angular velocity and / or angular acceleration of each second drive roller 35 substantially controls the tension in the web 4 and / or tube 3, specifically the portion of the web 4 and / or tube 3 downstream of each second drive roller 35 along the web advancement path P.

[0078] Preferably, but not necessarily, the control unit 13 is configured to selectively control each first drive motor such that the angular velocity of each first drive roller 34 is substantially constant. In particular, substantially constant means that possible changes in the angular velocity of each first drive roller 34 occur at a lower rate than changes in the angular velocity of each second drive roller 35.

[0079] According to a preferred, non-limiting embodiment, the control unit 13 is configured to control each first drive motor and, accordingly, each second drive roller 35 depending on the operation and / or control of each second drive motor 37 and / or the angular velocity and / or angular acceleration of each second drive roller 35.

[0080] According to a preferred, non-limiting embodiment, the control unit 13 is configured to control each second drive motor 37 such that the angular velocity of each second drive roller 35 varies according to at least one predefined and / or predetermined velocity profile and / or acceleration profile. In particular, such one and / or several velocity profiles and / or such one and / or several acceleration profiles are determined and / or defined as a function of the type and / or format of the package 2, and / or the advancement speed of the web 4 and / or the tube 3, and / or the advancement speed of the actuation assembly 23 and the counter actuation assembly 24, and / or the type of pourable product. In particular, the respective velocity profile and / or the respective acceleration profile are determined and / or measured at factory settings.

[0081] Preferably, but not necessarily, the control unit 13 stores one or more speed profiles and / or acceleration profiles which can be selected in use for control of one or more tension assemblies 33, in particular at least each second drive motor 37.

[0082] Preferably, but not necessarily, the control unit 13 controls and / or operates each tensioning assembly 33 with the same velocity profile and / or the same acceleration profile, and / or different velocity profiles and / or acceleration profiles.

[0083] According to a preferred, non-limiting embodiment, the control unit 13 is configured to control each tension assembly 33 depending on its position along the forward path P and / or its specific function.

[0084] According to a preferred, non-limiting embodiment, the control unit 13 is configured to control the respective second drive motors 37 of the tensioning assemblies 33 sandwiched between the tube forming station 6 and the sterilization station such that the angular velocity and / or the angular acceleration of the respective second drive rollers 35 are modified and / or controlled as a function of the operation of the package forming unit 11 and / or as a function of the package forming cycle and / or the forces acting on the tube 3 and / or the operation of the filling device 10 and filling the tube 3. In particular, as described above, the forces acting on the tube 3 result from the interaction of the actuating assembly 23 and the counter-actuating assembly 24 with the tube 3, and the various steps of forming the package 2 are controlled in particular due to the respective sealing element 26 and the counter-sealing element 27 in the respective sealing position and / or the respective half-shells 25 in the working position and / or the actuating assembly 23 and the counter-actuating assembly 24 advancing along the respective working parts of the conveying path and / or the pourable product being introduced into the tube 3 through the filling pipe 19.

[0085] Preferably, but not necessarily, such (complex) behavior is determined and / or measured before the packaging machine 1 and / or the package forming unit 11 and / or the filling device 11 are operated and encoded in the respective speed profile and / or acceleration profile of each second drive roller 35.

[0086] According to a preferred, non-limiting embodiment, each tension assembly 33 also includes at least one sensor element 41 configured to determine and / or measure the extension and / or level of a respective free loop 38 (i.e., the longitudinal length of a portion of web 4) that expands and / or extends between a respective first drive roller 34 and a respective second drive roller 35 in use.

[0087] Preferably, but not necessarily, each sensor element 41 is configured to determine and / or measure the position of an apex 42 of each free loop 38 as an indication of the extension and / or level of each free loop 38 .

[0088] According to a preferred, non-limiting embodiment, each tension assembly 33 further includes an actuation group 46 configured to (locally) control the orientation and / or advancement direction of the web 4, in particular to modify and / or control the relative orientation between the respective central axis C and the respective rotation axis A, and / or to modify and / or control the relative orientation between the respective central axis E and the respective rotation axis B.

[0089] Preferably, but not necessarily, the actuation group 46 is coupled and / or connected to the respective first counter roller 39 and / or second counter roller 40 and configured to control and / or vary the orientation of the respective corresponding central axis C and the respective corresponding central axis E relative to the respective corresponding axis of rotation A and the respective corresponding axis of rotation B in order to locally control the advancement direction and / or orientation and / or alignment of the web 4. In particular, locally controlled means that the advancement direction and / or orientation and / or alignment of the web 4 is controlled immediately downstream and / or at the exit of the respective tensioning assembly 33 along the advancement path P.

[0090] For example, tensioning assembly 33, located downstream of strip applying station 18, is configured to control (with respective actuators 46) the advancement direction and / or orientation and / or alignment of web 4 at strip applying station 18 and / or during operation of sealing strip applying device 17 and / or during application of a sealing strip to web 4. In particular, tensioning assembly 33 is also configured to align web 4 with respect to sealing strip applying device 17 such that the sealing strip is properly applied to the lateral edges of web 4, in particular with actuators 46.

[0091] 3-5, each tension assembly 33 includes a support structure 47 that carries and / or supports a corresponding first drive roller 34 and a corresponding first drive motor, as well as a corresponding second drive roller 35 and a corresponding second drive motor 37.

[0092] Preferably, but not necessarily, the respective support structure 47 also carries and / or supports the respective first counter roller 39 or second counter roller 40 and / or the respective working group 46 .

[0093] According to a preferred, non-limiting embodiment, each support structure 47 includes at least one support bar 48 which supports (at least indirectly) the respective first counter roller 39 or the respective second counter roller 40 and extends along the central axis F, specifically parallel to each of the relative rotation axes A and B.

[0094] Preferably, but not necessarily, each support bar 48 is rotatable about its respective central axis F, in order to control the relative distance between each first counter roller 39 and each first drive roller 34, or between each second counter roller 40 and each second drive roller 35.

[0095] It should be noted that FIGS. 3 and 5 show a first part of the respective tensioning assembly 33 , i.e. the support bar 48 shown carries (at least indirectly) the second counter roller 40 .

[0096] Since the construction of the second portion of each tensioning assembly 33 is similar to the construction of the first portion, only the first portion will be described below with reference to FIGS.

[0097] For the structure of the second part, reference is made to the description of the first part as follows: Specifically, when considering the structure of the second part, the references can simply be replaced such that the first drive roller 34 replaces the second drive roller 35, and the first counter roller 39 replaces the second counter roller 40.

[0098] In particular, each support structure 47 pivots about a pivot axis G on a support bar 48 and includes at least one coupling element 49 which is connected to and directly carries the respective first counter roller 39 or the respective second counter roller 40 .

[0099] According to a preferred, non-limiting embodiment, each actuation group 46 is configured to control the angular position of a respective coupling element 49 about a respective pivot axis G to control the relative position of the central axis C with respect to the respective rotation axis A or the relative position of the central axis E with respect to the respective rotation axis B.

[0100] Preferably, but not necessarily, each actuation group 46 includes at least a control bar 50 rotatable about a respective axis of rotation I, in particular parallel to a respective central axis F, and configured to interact with a respective coupling element 49; and an electric motor 51 configured to control the angular position of a control bar 50 about a rotation axis I for controlling the angular position of the coupling element 49 about the pivot axis G.

[0101] Specifically, when in use, modifying the angular position of each control bar 50 about its respective rotation axis I causes each coupling element 49 to pivot about its respective pivot axis G, which in turn modifies the orientation of each central axis C or each central axis E.

[0102] Preferably, but not necessarily, each control bar 50 includes an interaction portion 52, particularly in the form of a cam, configured to interact with an interaction member 53 of the respective coupling element 49, particularly defining a cam follower, to couple the angular position of the respective control bar 50 to the angular position of the respective coupling element 49.

[0103] According to a preferred, non-limiting embodiment, each tension assembly 33 also includes at least one actuation assembly 56 configured to control the angular position of at least one respective support bar 48 about a respective central axis F to move each first counter roller 39 toward or away from a respective first drive roller 34, or to move each second counter roller 40 toward or away from a respective second drive roller 35.

[0104] According to the non-limiting embodiment shown, each actuation assembly 56 includes a linear actuator 57 and at least one bar element 58 coupled to the linear actuator 57 and to a respective support bar 48 .

[0105] Preferably, but not necessarily, each bar element 58 is perpendicular to the respective support bar 48 and the piston 59 of the respective linear actuator 57 .

[0106] According to an alternative embodiment not shown, each actuation assembly 57 can include at least one motor, e.g., a stepper motor, coupled to a respective support bar 48 and configured to control the angular position of the respective support bar 48.

[0107] In use, the packaging machine 1 forms a package 2 filled with a pourable product.

[0108] More specifically, the main production cycle includes at least the following steps: advancing the web 4 along an advancing path P; folding the web 4 into a tube 3 in a tube forming station 6, specifically in an isolated chamber 7; - advancing the tube 3 along a tube advancement path Q, in particular towards and at least partially through the package forming unit 11; and controlling the tension in the web 4 and / or the tube 3 using the tensioning device 32.

[0109] Preferably, but not necessarily, the method comprises the following steps: Sealing the tube 3 longitudinally, in particular in the isolation chamber 7, and / or Filling the tube 3 with a pourable product, and / or forming single packages 2 from the tube 3 by forming the tube 3, sealing the tube 3 transversely between successive packages 2, and in particular cutting the tube 3 transversely between successive packages 2, in order to obtain single packages 2 while advancing the tube 3 along the tube advancement path Q; and / or sterilizing the web 4 in a sterilization station 8, and / or applying at least one sealing strip to one lateral edge of the web 4 at a strip application station 18; and / or It also includes controlling and / or modifying the orientation of web 4, during which web 4 is specifically selectively locally oriented and / or aligned.

[0110] According to a preferred, non-limiting embodiment, during the step of advancing the web 4 , the transport device 5 advances the web 4 along a web advancement path P.

[0111] According to a preferred, non-limiting embodiment, during the step of folding the tube 3, the tube forming and sealing device 9 gradually overlaps the opposing lateral edges of the web 4 onto one another to form a longitudinal seam.

[0112] According to a preferred, non-limiting embodiment, during the step of longitudinally sealing the tube 3, the tube forming and sealing device 9 seals the longitudinal seam by directing heat onto the longitudinal seam.

[0113] According to a preferred, non-limiting embodiment, during the step of advancing the tube 3, the conveying device 5 advances the tube 3 (and any intermediate bodies of the tube 3), in particular through the isolated chamber 7 along path Q into and partially through the package forming unit 11.

[0114] According to a preferred, non-limiting embodiment, during the step of filling the tube 3, the filling device 10 fills the injectable product into the longitudinally sealed tube 3. In particular, the injectable product is directed into the tube 3 through a filling pipe 19.

[0115] According to a preferred, non-limiting embodiment, during the step of sterilizing the web 4, at least the first side, in particular the second side, of the web 4 is also sterilized.

[0116] Preferably, but not necessarily, during the step of sterilizing web 4, sterilizing radiation, particularly electromagnetic radiation, even more particularly electron beam radiation, is directed onto at least a first surface of web 4, and preferably also onto a second surface.

[0117] According to a preferred, non-limiting embodiment, the sterilizing step is performed before the folding step.

[0118] According to a preferred, non-limiting embodiment, during the step of applying at least one sealing strip, the sealing strip applying device 17 applies a sealing strip to one lateral edge of the web 4 .

[0119] According to a preferred, non-limiting embodiment, during the step of forming a single package 2, the package forming unit 11 forms and transversely seals a tube 3 between consecutive packages 2, and preferably also cuts the tube 3 transversely between consecutive packages 2.

[0120] Preferably, but not necessarily, during the step of forming the single packages 2, the actuating assembly 23 and the counter-actuating assembly 24 advance along their respective conveying paths and cyclically form and transversely seal, and in particular also transversely cut, the tube 3 to obtain the packages 2. In particular, the sealing element 26 and the counter-seal element 27 move from their respective rest positions to their respective sealing positions to transversely seal the tube 3 between successive packages 2, and the half-shells 25 move from their respective rest positions to their respective working positions to form the tube 3.

[0121] According to a preferred, non-limiting embodiment, during the step of controlling the tension, the control unit 13 controls each tension assembly 33 independently of the other tension assemblies.

[0122] According to a preferred, non-limiting embodiment, during the tension controlling step, a tensioning assembly 33 sandwiched between the tube forming station 6 and the sterilization station controls at least the tension and / or tension profile of the tube 3 .

[0123] According to a preferred, non-limiting embodiment, during the step of controlling the tension, a tensioning assembly 33 located upstream of the strip applying station 18 along the web advancement path P controls the tension of the web 4 at the strip applying station 18 and / or during the actuation of the sealing strip applying device 17 and / or during the step of applying the sealing strip.

[0124] According to a preferred, non-limiting embodiment, during the tension controlling step, each of the first drive rollers 34 and each of the second drive rollers 35 rotates about a respective relative rotation axis A and a respective relative rotation axis B such that each of the free loops 38 expands and / or advances between each of the first drive rollers 34 and each of the second drive rollers 35.

[0125] Preferably, but not necessarily, during the step of controlling tension, the control unit 13 selectively and independently controls each of the first drive motors 34 and each of the second drive motors 37 to control the respective rotations of each of the first drive rollers 34 and each of the second drive rollers 35.

[0126] Preferably, but not necessarily, the angular velocity and / or angular acceleration of each second drive roller 35 is controlled and / or varied to control the tension in the web 4 and / or tube 3 .

[0127] Preferably, but not necessarily, the angular velocity and / or angular acceleration of each second drive roller 35 is selectively varied according to a respective predefined and / or predetermined velocity profile and / or acceleration profile. In particular, the applied velocity profile and / or acceleration profile may be changed from one second drive roller 35 to another second drive roller 35.

[0128] According to a preferred, non-limiting embodiment, during the tension controlling step, the angular velocity and / or angular acceleration of each second drive roller 35 of the tensioning assembly 33, which is clamped between the tube forming station 6 and the sterilization station, is varied and / or controlled as a function of the operation of the package forming unit 11 and / or the filling device 10, and / or the type and / or format of the package 2. In particular, in this way the tension of the tube 3 is controlled.

[0129] According to a preferred, non-limiting embodiment, during the step of controlling tension, the angular velocity of each first drive roller 34 should maintain the respective free loop 38 expanding and / or advancing between each first drive roller 34 and each second drive roller 35. In particular, the angular velocity of each first drive roller 34 may be different from the angular velocity of the other first drive rollers 34.

[0130] Preferably, but not necessarily, the angular velocity of each first drive roller 34 is substantially constant.

[0131] According to a preferred, non-limiting embodiment, the step of controlling and / or modifying includes the sub-step of controlling and / or modifying the relative orientation between at least one central axis C and the respective rotation axis A, and / or the relative orientation between at least one central axis E and the respective rotation axis B, specifically using the respective actuation groups 46.

[0132] Preferably, but not necessarily, during the controlling and / or correcting sub-step, the orientation of at least one central axis E is controlled and / or corrected relative to each rotational axis B in order to control the advancement direction and / or orientation of the web 4, specifically using each actuation group 46.

[0133] Preferably, but not necessarily, during the controlling and / or correcting sub-step, the angular position of each control bar 50 is controlled and / or corrected by a respective electric motor 51 in order to pivot each coupling element 49 about a respective pivot axis G in order to control and / or correct the orientation of each first counter roller 39 or each second counter roller 40.

[0134] According to a preferred, non-limiting embodiment, the controlling and / or modifying step includes the sub-step of modifying the relative distance between each first counter roller 39 and each first drive roller 34, or between each second counter roller 40 and each second drive roller 35, by operating each actuating assembly 56.

[0135] The advantages of the packaging machine 1 according to the invention will become apparent from the above description.

[0136] The tensioning device 32, in particular having at least one tensioning assembly 33, provides improved and even more precise control of the tension of the web 4 and / or tube 3. This is achieved by the presence of a respective tensioning assembly 33 having two drive rollers, i.e. a respective first drive roller 34 and a respective second drive roller 35, each coupled to a respective drive motor, i.e. a first drive motor and a second drive motor 37, and a untensioned portion of the web 4, i.e. a free loop 38, which advances in use between the respective first drive roller 34 and the respective second drive roller 35.

[0137] A further advantage resides in controlling the at least one second drive roller 35 according to a predefined and / or predetermined velocity profile and / or acceleration profile.

[0138] A still further advantage is that by controlling the relative orientation between at least one first drive roller 34 and each first counter roller 39, and / or at least one second drive roller 35 and each second counter roller 40, the alignment and / or orientation and / or advance direction of the web 4 can be controlled.

[0139] Obviously, modifications may be made to the packaging machine 1 and method as described herein, but without departing from the scope of protection as defined in the appended claims.

Claims

1. A packaging machine (1) for producing sealed packages (2) of pourable products from a web (4) of packaging material, comprising: a conveying device (5) for advancing said web of packaging material (4) along a web advancement path (P) to at least a tube forming station (6) where said web of packaging material (4) is formed, in use, into a tube (3), and for advancing said tube (3) along a tube advancement path (Q); a tube forming and sealing device (9) configured to form the tube (3) at the tube forming station (6) and to longitudinally seal the tube (3); a filling device (10) configured to fill the tube (3) with the injectable product; a package forming unit (11) adapted in use to at least form and transversely seal said tube (3) during advancement of said tube (3) along said tube advancement path (Q); a tensioning device (32) configured to control the tension of the web of packaging material (4) and / or the tube (3); a control unit (13) configured to control the operation of the packaging machine (1); The tensioning device (32) is disposed along the web advancement path (P) upstream of the tube forming station (6) and includes at least a first drive roller (34) rotatable about a first axis of rotation (A); a second drive roller (35) rotatable about a second axis of rotation (B); a first drive motor coupled to the first drive roller (34) and configured to actuate rotation of the first drive roller (34) about the first axis of rotation (A); and a second drive motor (37) coupled to the second drive roller (35) and configured to actuate rotation of the second drive roller (35) about the second axis of rotation (B); said control unit (13) being configured to control said first drive motor (37) and said second drive motor (37) such that a free loop (38) of said web of packaging material (4) expands and / or advances between said first drive roller (34) and said second drive roller (35) in use; the first drive roller (34) is disposed upstream of the second drive roller (35) along the web advancement path (P); the control unit (13) is configured to control the second drive roller (37) such that the angular velocity and / or the angular acceleration of the second drive roller (35) is controlled and / or varied as a function of the operation of the package forming unit (11) and / or the filling device (10) and / or the type and / or format of the package (2). Packaging machine (1).

2. 2. The packaging machine of claim 1, wherein the control unit (13) is configured to control the first drive motor such that the angular velocity of the first drive roller (34) maintains the free loop of the web of packaging material (4) in use.

3. 3. The packaging machine of claim 2, wherein the control unit (13) is configured to control the first drive motor (34) such that the angular velocity of the first drive roller (34) is substantially constant.

4. 4. The packaging machine according to claim 1, wherein the control unit (13) is configured to control the second drive motor (37) such that the angular velocity and / or the angular acceleration of the second drive roller (35) are varied according to a predefined and / or predetermined velocity profile and / or acceleration profile, respectively.

5. a sterilization device configured to sterilize the web of packaging material (4) at a sterilization station upstream of the tube forming station (6) along the web advancement path (P); The tensioning assembly (33) is sandwiched between the sterilization station and the tube forming station (6); A packaging machine according to any one of claims 1 to 4, wherein the first drive roller (34) and the second drive roller (35) are actuated to thus control at least the tension in the tube (3).

6. a sealing strip applying device (17) configured to apply at least one sealing strip to one lateral edge of said web of packaging material (4) at a strip applying station (18); 6. A packaging machine according to any one of claims 1 to 5, wherein the tensioning assembly (33) is arranged along the web (4) advancement path upstream of the strip applying station (18) and configured to control the tension in the web of packaging material (4) during application of the sealing strip and / or during operation of the sealing strip applying device (17).

7. The tension assembly (33) also includes a first counter roller (39) and a second counter roller (40); the first counter roller (39) is disposed adjacent to the first drive roller (34), and the second counter roller (40) is disposed adjacent to the second drive roller (35); In use, the web of packaging material (4) is pinched and / or advanced between the first counter roller (39) and the first drive roller (34) and between the second counter roller (40) and the second drive roller (35); 7. The packaging machine according to claim 1, wherein the tensioning assembly (33) comprises an actuation group (46) configured to control and / or modify a relative orientation between a first central axis (C) of the first counter roller (39) and the first axis of rotation (A) of the first drive roller (34) and / or to control and / or modify a relative orientation between a second central axis (E) of the second counter roller (40) and the second axis of rotation (B) of the second drive roller (35).

8. the second drive roller (35) and the second counter roller (40) are disposed downstream of the first drive roller (34) and the first counter roller (39) along the web advancement path (P); 8. The packaging machine of claim 7, wherein the actuator group (49) is coupled and / or connected to the second counter roller (40) and configured to control and / or vary the orientation of the second central axis (E) relative to the second axis of rotation (B) in order to control the advancement direction and / or orientation of the web of packaging material (4).

9. 1. A method for producing a sealed package (2) of a pourable product from a web (4) of packaging material, comprising the steps of: At least the following steps: advancing said web of packaging material (4) along a web advancement path (P) to at least a tube forming station (6); forming said web of packaging material (4) into a tube (3) at said tube forming station (6); advancing the tube (3) along a tube advancement path (Q); filling said tube (3) with said pourable product; forming said package (2) by at least forming and transversely sealing said tube (3) during advancement of said tube (3) along said tube advancement path (Q); and controlling the tension of said web of packaging material (4) and / or said tube (3) by a tensioning device (32), the tensioning device (32) is disposed along the web advancement path (P) upstream of the tube forming station (6) and includes at least one tensioning assembly (33) having at least a first drive roller (34) and a second drive roller (35); During the tension controlling step, the first drive roller (34) and the second drive roller (35) rotate about a first axis of rotation (A) and a second axis of rotation (B), respectively, such that a free loop (38) of the web of packaging material (4) expands and / or advances between the first drive roller (34) and the second drive roller (35); the first drive roller (34) is disposed upstream of the second drive roller (35) along the web advancement path (P); During the tension control step, the angular velocity and / or the angular acceleration of the second drive roller (35) is controlled and / or varied as a function of the step of filling and / or forming the package (2) and / or the type and / or format of the package (2). method.

10. 10. The method of claim 9, wherein during the step of controlling tension, the angular velocity of the first drive roller (34) maintains the free loop (38) of the web of packaging material (4).

11. The method of claim 10, wherein the angular velocity of the first drive roller (34) is substantially constant.

12. The method according to any one of claims 9 to 11, wherein the angular velocity and / or the angular acceleration of the second drive roller (35) is controlled and / or varied according to a predefined and / or predetermined velocity profile and / or acceleration profile, respectively.

13. sterilizing the web of packaging material (4) at a sterilization station upstream of the tube forming station (6) along the web advancement path (P); The tensioning assembly (33) is sandwiched between the sterilization station and the tube forming station (6); The method according to any one of claims 9 to 12, wherein during the step of controlling the tension, at least the tension in the tube (3) is controlled.

14. applying at least one sealing strip to one lateral edge of said web of packaging material (4) at a strip application station (18) upstream of said tube forming station (6) along said web advancement path (P); The method according to any one of claims 9 to 13, wherein during the step of controlling tension, the tensioning assembly (33) controls the tension of the web advancement path (P) during application of the sealing strip.

15. The tension assembly (33) also includes a first counter roller (39) and a second counter roller (40); the first counter roller (39) is disposed adjacent to the first drive roller (34), and the second counter roller (40) is disposed adjacent to the second drive roller (35); During the step of advancing the web of packaging material (4), the web of packaging material (4) advances between the first counter roller (39) and the first drive roller (34) and between the second counter roller (40) and the second drive roller (35); 15. The method according to any one of claims 9 to 14, further comprising controlling and / or modifying a relative orientation between a first central axis (C) of the first counter roller (39) and the first rotational axis (A) of the first drive roller (34) and / or a relative orientation between a second central axis (E) of the second counter roller (40) and the second rotational axis (B) of the second drive roller (35).

16. the second drive roller (35) and the second counter roller (40) are disposed downstream of the first drive roller (34) and the first counter roller (39) along the web advancement path (P); 16. The method according to claim 15, wherein during the controlling and / or correcting step, the orientation of the second central axis (E) is controlled and / or corrected relative to the second axis of rotation (B) for an advancement direction and / or orientation and / or alignment of the web of packaging material (4).

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