Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B61/00—Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages
  • B65B61/18—Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages for making package-opening or unpacking elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B50/00—Making rigid or semi-rigid containers, e.g. boxes or cartons
  • B31B50/006—Controlling; Regulating; Measuring; Improving safety
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B50/00—Making rigid or semi-rigid containers, e.g. boxes or cartons
  • B31B50/02—Feeding or positioning sheets, blanks or webs
  • B31B50/10—Feeding or positioning webs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B50/00—Making rigid or semi-rigid containers, e.g. boxes or cartons
  • B31B50/74—Auxiliary operations
  • B31B50/81—Forming or attaching accessories, e.g. opening devices, closures or tear strings
  • B31B50/84—Forming or attaching means for filling or dispensing contents, e.g. valves or spouts

Definitions

• the present invention relates to a method for applying opening devices on a web of packaging material, in particular a web of packaging material for the production of sealed packages containing a pourable product, preferably a pourable food product.
• the present invention also relates to a unit for applying opening devices on a web of packaging material, in particular a web of packaging material for the production of sealed packages containing a pourable product, preferably a pourable food product.
• pourable food products such as fruit juice, UHT (ultra-high temperature-treated) milk, wine, tomato sauce, etc.
• UHT ultra-high temperature-treated milk
• wine tomato sauce
• etc. are sold in packages made of sterilized packaging material.
• a typical example is the parallelepiped-shaped package for pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by folding and sealing a laminated web of packaging material.
• the packaging material has a multilayer structure substantially comprising a base layer for stiffness and strength, which may be made of fibrous material, e.g. paper or mineral-filled polypropylene material, and a number of lamination layers made of heat-seal plastic material, e.g. polyethylene films, covering both sides of the base layer.
• the packaging material also comprises a layer of gas-barrier material, e.g.
• Packages of this sort are normally produced in fully automatic packaging machines, which form and fill the packages starting from a multilayer web of packaging material.
• a continuous tube is formed from the web which is initially wound in a reel and fed through a plurality of unwinding rollers.
• the web is typically fed through a sterilization unit for sterilizing the web by applying a chemical sterilization agent, which is then removed after sterilization is completed, e.g. evaporated by heating.
• a chemical sterilization agent e.g. evaporated by heating.
• the web is maintained in a closed, sterile environment and is folded and sealed longitudinally to form the tube.
• the tube is filled from above, by means of a pipe, with the pourable food product and is formed, sealed and subsequently cut along equally spaced transversal cross sections.
• Pillow packs are obtained thereby, which have a longitudinal sealing band, a top transversal sealing band and a bottom transversal sealing band, and which are then folded mechanically to form respective substantially parallelepiped-shaped finished packages.
• the web is initially provided with holes, or prelaminated holes (i.e. holes formed through the base layer only and covered by the aforementioned lamination layers and/or barrier layer and defining a pierceable or removable portion of the packaging material), and opening devices which are applied, at an application station, at such holes or prelaminated holes, respectively.
• prelaminated holes i.e. holes formed through the base layer only and covered by the aforementioned lamination layers and/or barrier layer and defining a pierceable or removable portion of the packaging material
• each hole or prelaminated hole defines a predetermined area of the web at which an opening device must be applied.
• each opening device is applied at the respective predetermined area of the web by injecting plastic material directly thereat.
• the application station is an injection molding station.
• the web is unwound from the aforementioned reel. Subsequently, the web is stepwise fed to the application station before the packaging material is folded to form the tube. In particular, the web is fed towards the application station along an advancing path (or advancing direction).
• the application of opening devices on the web requires that the predetermined areas are stopped in respective nominal positions with respect to the application station, for a correct application of each opening device.
• EP-A-2357138 discloses a unit for applying opening devices onto respective pre-laminated holes, which define the predetermined areas of the web.
• the unit comprises a molding station, which is stepwise (i.e. intermittently) fed with the web and is adapted to injection mold a plurality of opening devices on the web and at respective prelaminated holes of the web.
• the molding station comprises a plurality of molds, in particular three molds, arranged adjacent to one another along the advancing path and injecting the plastic material forming the opening devices on the web at respective prelaminated holes of the web.
• each portion of the web is fed along the advancing path and through the application station, each portion of the web comprising a number of prelaminated holes corresponding to the number of molds of the molding station, i.e. three in the case of EP-A-2357138 .
• each prelaminated hole must be centered at the respective mold, i.e. each prelaminated hole must be arranged in the respective nominal position.
• the intermediate prelaminated hole i.e. the central prelaminated hole of the three prelaminated holes
• the intermediate prelaminated hole is centered under the intermediate mold of the molding station, in particular on the basis of the actual position of the intermediate prelaminated hole detected by a sensor.
• the web is positioned along the advancing path on the basis of the difference between the actual (detected) position and the nominal position of only one prelaminated hole, namely the intermediate one.
• each of the remaining prelaminated holes may be arranged at a non-zero distance from its nominal position, measured along the advancing path, due to inherent and inevitable tolerance errors in the distances between homologous points, e.g. central axes, of the prelaminated holes on the web.
• EP-A-2848399 in the name of the same Applicant, shows a unit for applying opening devices onto respective prelaminated holes comprising two molding stations, namely an upstream molding station and a downstream molding station with respect to the advancing direction of the web, each one having three molds.
• EP-A-2848399 describes an independent centering of the intermediate prelaminated hole of each group with respect to the intermediate mold of the respective molding station.
• centering of the respective intermediate prelaminated hole is made on the basis of a signal of a position sensor.
• centering of the respective intermediate prelaminated hole is made by means of a roller actuator arranged between the upstream molding station and the downstream molding station and controllable for recovering an intentionally imparted offset between a preliminary position of such intermediate prelaminated hole and the nominal position at which such intermediate prelaminated hole should receive the opening device.
• number 1 indicates as a whole a non-limiting example of a unit for applying opening devices 2 (only schematically shown) at predetermined areas 3 of a web 4 of packaging material.
• web 4 is designed for the production of sealed packages (not shown) containing a pourable product, preferably a pourable food product, to which the present disclosure will refer without loss of generality.
• the packaging material has a multilayer structure (not shown) and comprises a layer of fibrous material, e.g. paper, covered on both sides with respective lamination layers of heat-seal plastic material, e.g. polyethylene.
• the packaging material also comprises a layer of gas-and-light barrier material, e.g. aluminum foil or ethylene vinyl alcohol (EVOH) film, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material, the latter forming the inner face of the package eventually contacting the pourable product.
• gas-and-light barrier material e.g. aluminum foil or ethylene vinyl alcohol (EVOH) film
• Such packages are formed by a packaging machine which includes unit 1 and is only partially shown.
• the packaging machine includes a storage unit, at which a reel of web 4 is arranged, unit 1 and downstream of unit 1 a package filling and forming unit for forming the packages containing the pourable product.
• the packages are formed starting from a tube (not shown) of packaging material.
• the tube is formed in a known manner downstream of unit 1 by longitudinally folding and sealing web 4.
• the tube of packaging material is then filled with the pourable product, and is sealed and cut along equally spaced cross sections to form a number of pillow packs (not shown), which are then transferred to a folding unit where they are folded mechanically to form respective packages, in a manner known and not described in detail.
• predetermined areas 3 are defined by pierceable portions of web 4.
• pierceable portions are defined by so-called prelaminated holes, i.e. holes (or openings) formed through the base layer only and covered by the lamination layers and/or the barrier layer of the packaging material, so that each hole is sealed by a respective sheet cover portion (known per se and neither shown nor described in detail).
• prelaminated holes i.e. holes (or openings) formed through the base layer only and covered by the lamination layers and/or the barrier layer of the packaging material, so that each hole is sealed by a respective sheet cover portion (known per se and neither shown nor described in detail).
• predetermined areas 3 are defined by through holes obtained (e.g. punched) in web 4.
• predetermined areas 3 are distributed along web 4 longitudinally, i.e. in a lengthwise direction of web 4, at a non-zero distance from one another.
• prelaminated areas 3 are arranged along web 4 in respective positions equally spaced from one another, except for some possible tolerance distance errors.
• the present disclosure will refer, without loss of generality, to a unit 1 defining a molding unit for molding, in particular for injection molding, a plurality of opening devices 2 onto respective prelaminated holes.
• predetermined area and “prelaminated hole” will be used interchangeably.
• Web 4 includes a plurality of web portions 4a.
• web 4 is defined by a sequence of web portions 4a longitudinally attached to one another.
• Unit 1 comprises a conveyor 5 (only schematically shown) configured to convey web 4 along an advancing path P.
• Unit 1 comprises an application station 6 including a plurality of applicator devices 7 arranged one after the other along advancing path P and each configured to apply an opening device 2 at a respective predetermined area 3.
• each applicator device 7 is preferably a molding device for injection molding an opening device 2 on a respective predetermined area 3.
• Unit 1 comprises a feeding device 8, such as a roller actuatable in rotation, configured to feed web 4 through application station 6 and to intermittently feed one web portion 4a at a time through application station 6.
• a feeding device 8 such as a roller actuatable in rotation
• feeding device 8 stepwise feeds, in use, web portions 4a of web 4 one after the other, each web portion 4a comprising a predetermined number of predetermined areas 3.
• feeding device 8 is configured to sequentially feed one web portion 4a at a time through application station 6.
• each web portion 4a includes a number of predetermined areas 3 corresponding to the number of applicator devices 7 in the application station 6.
• application station 6 includes six applicator devices 7.
• each web portion 4a includes six predetermined areas 3, i.e. six prelaminated holes, each configured to receive an opening device 2 molded by a respective applicator device 7.
• each web portion 4a includes a number of sections of web 4 (six in this preferred embodiment), each section having a prelaminated hole, i.e. a predetermined area 3, and each section being designed to define a respective package, once formed, sealed, cut from web 4 (in particular from the formed and sealed tube) and folded.
• Unit 1 further comprises a control unit 10.
• Control unit 10 is configured to drive conveyor 5 and feeding device 8 so as to control the stepwise feeding of web portions 4a through application station 6.
• control unit 10 is configured to drive applicator devices 7 once each web portion 4a is temporarily stopped at application station 6, thereby determining the application of opening devices 2 onto the respective predetermined areas 3.
• unit 1 includes two buffer portions 11 arranged respectively upstream of application station 6 and downstream of application station 6 and configured to ensure a smooth and continuous advancement of web 4 along advancing path P, while allowing the temporary stopping of web portions 4a, according to a manner known and not described in detail.
• the other sections are comprised between the first section and the second section along advancing path P.
• a first predetermined area 3a first entering application station 6 and a second predetermined area 3b last entering application station 6 can be identified ( Figure 3a ) .
• second predetermined area 3b is the sixth predetermined area entering application station 6, for each web portion 4a.
• the remaining predetermined areas 3 of each web portion 4a are comprised between first predetermined area 3a and second predetermined area 3b along advancing path P.
• each applicator device 7 has a central axis A arranged in a fixed position along advancing path P.
• central axes A are arranged at the same distance from one another along advancing path P.
• application station 6 includes at least a first applicator device 7a and a second applicator device 7b, respectively arranged first and last when considering said plurality of applicator devices 7 of application station 6 along advancing path P.
• first applicator device 7a is configured to apply an opening device 2 on the first predetermined area 3a and second applicator device 7b is configured to apply an opening device 2 on the second predetermined area 3b.
• Each predetermined area 3, i.e. each prelaminated hole, has a central axis B.
• feeding device 8 feeds web portion 4a so that each predetermined area 3 is arranged with its central axis B coaxial to a respective central axis A.
• Such nominal operative condition is shown in Figure 2 .
• tolerance errors in the distances between homologous points, i.e. the central axes B, of predetermined areas 3 inevitably occurs during manufacturing of web 4, thereby leading to non-nominal operative conditions.
• control unit 10 is configured to:
• calculated distance D1 corresponds to the real distance between the position of first predetermined area 3a (in particular central axis B thereof) and the position of second predetermined area 3b (in particular central axis B thereof) and depends on the aforementioned tolerance errors.
• control unit 10 is further configured to compare calculated distance D1 with a reference distance D2 correlated to a distance between a pre-set nominal position of first predetermined area 3a (for example, the one shown in Figure 2 ) and a pre-set nominal position of second predetermined area 3b (for example, the one shown in Figure 2 ), along advancing path P.
• reference distance D2 is defined by an average distance obtained as an average of a predetermined number of calculated distances D1 respectively calculated (detected) for a corresponding predetermined number of web portions 4a.
• control unit 10 calculates, in use, a number of calculated distances D1 between the position of first predetermined area 3a (in particular central axis B thereof) and the position of second predetermined area 3b (in particular central axis B thereof) for a predetermined number of web portions 4a. Then, control unit 10 calculates an average distance on the basis of such calculated distances D1. Then, control unit 10 determines the reference distance D2 as the calculated average distance.
• the aforementioned average distance is calculated on the basis of a predetermined number of calculated distances D1 last calculated (detected) by control unit 10.
• reference distance D2 is calculated as a moving average of the last calculated distances D1.
• reference distance D2 is calculated as the moving average of the last 20 calculated distances D1 which are calculated (detected) by control unit 10.
• reference distance D2 is updated at each web portion 4a fed through application station 6.
• reference distance D2 is correlated to, and in particular is defined by, the distance between central axis A of first applicator device 7a and central axis A of second applicator device 7b.
• Figure 3a schematically shows calculated distance D1 and reference distance D2.
• control unit 10 is further configured to calculate a distance offset value E ( Figure 3b ) as a function of the difference between calculated distance D1 and reference distance D2.
• distance offset value E is calculated as the absolute value of the mathematical difference between calculated distance D1 and reference distance D2.
• Figure 3b schematically depicts distance offset value E as a difference between calculated distance D1 and reference distance D2.
• distance offset value E defines a distance error between the position of first predetermined area 3a (in particular central axis B thereof) and the position of second predetermined area 3b (in particular central axis B thereof) with respect to reference distance D2, for web portion 4a.
• Control unit 10 is further configured to control the position of web portion 4a at application station 6 so that one predetermined area 3 (amongst predetermined areas 3 of web portion 4a) is arranged at a distance equal to a fraction E/k (with k being a predefined constant value) of distance offset value E from a reference position of such one predetermined area 3 along advancing path P.
• the reference position of such one predetermined area 3 is defined by the nominal position of such one predetermined area 3 along advancing path P, i.e. the position that such one predetermined area 3 should have during nominal operative conditions of unit 1.
• the nominal position is the position at which axis B of said one predetermined area is aligned, i.e. coincides, with axis A of the applicator device 7 configured to apply an opening device 2 at said one predetermined area 3.
• fraction E/k equals half of distance offset value E and, therefore, corresponds to E/2.
• the reference position is the position of first applicator device 7a, and more in particular the position of central axis A thereof.
• control unit 10 is configured to control the position of web portion 4a at application station 6 so that first predetermined area 3a is arranged at a distance equal to fraction E/k of distance offset value E, and more in particular at a distance equal to half distance offset value, i.e. E/2, from a reference position of first predetermined area 3a.
• reference position is a nominal position of first predetermined area 3a, i.e. a position that first predetermined area 3a should have during nominal operative conditions of unit 1).
• control unit 10 is further configured to control the position of web portion 4a at application station 6 so that second predetermined area 3b is arranged at a distance equal to a further fraction (E - E/k) of distance offset value E, and in particular at a distance equal to half distance offset value E, i.e. E/2, from a reference position of second predetermined area 3b.
• reference position is a nominal position of second predetermined area 3b, i.e. a position that second predetermined area 3b should have during nominal operative conditions of unit 1)
• control unit 10 is advantageously configured to control the position of web portion 4a so that first predetermined area 3a is arranged at a distance equal to fraction E/k of distance offset value E, and in particular at a distance equal to half distance offset value E, i.e. E/2, from central axis A of first applicator device 7a.
• control unit 10 is advantageously configured to control the position of web portion 4a so that second predetermined area 3b is arranged at a distance equal to further fraction (E - E/k of distance offset value E, and in particular at a distance equal to half distance offset value E from central axis A of second applicator device 7b.
• first predetermined area 3a and second predetermined area 3b are each arranged at a distance equal to E/2 from the respective nominal position, i.e. from central axis A of, respectively, first applicator device 7a and second applicator device 7b.
• the distance offset value E i.e. the distance error, is "distributed" amongst all the predetermined areas 3 of web portion 4a.
• unit 1 includes a sensor device 12 arranged upstream of application station 6, in particular arranged upstream of second applicator device 7b, along advancing path P.
• Sensor device 12 is configured to detect marks 13 on web 4 and to generate a signal correlated with the detection of marks 13 and to send the generated signal to the control unit 10.
• Each mark 13 is associated to one respective predetermined area 3. Each mark 13 is configured to provide information on the position of the respective predetermined area 3.
• each mark 13 includes a magnetic portion, such as a magnetic band, and sensor device 12 is a sensor of magnetic and/or electromagnetic type configured to detect such magnetic portions.
• each mark 13 includes an optically detectable reference band
• sensor device 12 is a sensor of optical type configured to detect such reference band.
• Sensor device 12 is advantageously configured to detect a first mark 13a on web portion 4a, such first mark 13a being correlated with the actual position of first predetermined area 3a along advancing path P.
• sensor device 12 is further configured to detect a second mark 13b on said respective web portion, such second mark 13b being correlated with the actual position of the second predetermined area 3b along advancing path P.
• control unit 10 is able to effectively detect the positions of at least first predetermined area 3a and second predetermined area 3b.
• calculation of distance offset value E is performed by control unit 10 while second predetermined area 3b travels from sensor device 12 to second applicator device 7b (in particular central axis A thereof).
• Such moment corresponds to a time interval during which web portion 4a slows down, preparing to temporarily stop at application station 6.
• reading of marks 13 by sensor device 12 is more effective, as reading errors are less probable when the advancing speed of web is low.
• control unit 10 is configured to:
• control unit 10 is configured to prevent the applicator devices 7 from applying opening devices 2 onto predetermined areas 3 of web portion 4a if the calculated distance offset value E is equal to, or above, said distance offset threshold value.
• control unit 10 is configured to detect the positions along advancing path P of all the predetermined areas 3 of the same web portion 4a.
• sensor device 12 is configured to detect the positions of all the marks 13 of web portion 4a, associated to the respective predetermined areas 3.
• control unit 10 is configured to:
• the corrective operations may include issuing a warning and/or controlling a discard of the respective web portion 4a and/or controlling a stop of unit 1.
• the aforementioned “distribution" of the distance offset value E i.e. of the distance error, can be better controlled for each predetermined area 3 of web portion 4a.
• each predetermined area 3 is in a position with a distance error within the desired tolerance range.
• unit 1 enables to implement a method for applying opening devices 2 on a web 4 of packaging material at predetermined areas 3 of said web 4 arranged at a non-zero distance from one another, the method comprising the steps of:
• the step g) of controlling comprises arranging the first predetermined area 3a at a distance equal to a fraction E/k of said distance offset value E from said reference position of the first predetermined area 3a.
• the step g) of controlling comprises arranging the first predetermined area 3a at a distance equal to half said distance offset value E, i.e. E/2, from said reference position of the first predetermined area 3a.
• the step g) of controlling comprises arranging the second predetermined area 3b at a distance equal to a further fraction (E - E/k) of said distance offset value E from said nominal position of the second predetermined area 3b.
• the step g) of controlling comprises arranging the second predetermined area 3b at a distance equal to half said distance offset value E, i.e. E/2, from said reference position of the second predetermined area 3b.
• the step g) of controlling comprises arranging central axis B of the first predetermined area 3a at a distance equal to half said distance offset value E from central axis A of the first applicator device 7a and/or arranging central axis B of the second predetermined area 3b at a distance equal to half said distance offset value E from central axis A of the second applicator device 7b.
• the step c) of detecting comprises detecting a first mark 13a on said respective web portion 4a, the first mark 13a being correlated with the first predetermined area 3a along the advancing path P, and/or the step d) of detecting comprises detecting a second mark 13b on said respective web portion 4a, the second mark 13b being correlated with the second predetermined area 3b along the advancing path P.
• the method further comprises the steps of:
• the method further comprises the steps of:
• the distance offset value E i.e. the distance error
• control unit 10 configured to perform the detections and calculations described above, allows for a simplification of architecture of unit 1.
• unit 1 is also increased, since the distance between two adjacent applicator devices 7 can be reduced, thanks to the fact that no roller actuator or sensor device 12 needs to be arranged between them.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Coating Apparatus (AREA)
• Controlling Rewinding, Feeding, Winding, Or Abnormalities Of Webs (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=91617174

Family Applications (1)

Country Status (2)

Citations (5)

• 2025
  • 2025-03-20 EP EP25164904.2A patent/EP4647249A1/de active Pending
  • 2025-03-20 WO PCT/EP2025/057568 patent/WO2025201999A1/en active Pending

Patent Citations (5)

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