Multilayer sheets of packaging material for sealed packages

Abstract

A multi-layer sheet (M) of packaging material for producing a sealed package (1) with a spout for food comprises at least one base layer (10) for providing rigidity, a plurality of laminate layers (11) applied to the base layer (10) and covering both sides of the base layer (10), a pre-laminate opening (12) configured to receive an opening device for dispensing the food, and lines of weakness (13) in the base layer (10).

Description

[Technical Field]

[0001] The present invention relates to a multi-layer sheet of packaging material for producing sealed packages of poured food products. [Background technology]

[0002] As is well known, many pourable foods, such as fruit juice, UHT (ultra-high temperature processed) milk, wine, and tomato sauce, are sold in packages made from sterile packaging materials. A typical example is the parallelepiped-shaped package for liquid or pourable foods known as Tetra Brik Aseptic®, which is made by folding and sealing a laminated strip of packaging material. This packaging material has a multi-layer structure, for example, a base layer of paper covered on both sides with layers of heat-sealable plastic, such as polyethylene. In the case of aseptic packages for long-life products such as UHT milk, the packaging material also includes a layer of oxygen barrier material, such as aluminum foil, which is laminated with a layer of heat-sealable plastic and then covered with another layer of heat-sealable plastic, ultimately forming the inner surface of the package that comes into contact with the food. This type of package is usually produced on fully automatic packaging machines, where a continuous tube is formed from the web of packaging material. The web of packaging material is sterilized on the packaging machine by applying a chemical sterilant, such as aqueous hydrogen peroxide, which, once sterilization is complete, is removed from the surface of the packaging material, e.g., by evaporation via heating. The sterilized web is then maintained in a closed, sterile environment and folded lengthwise and sealed to form a longitudinally fed tube. To complete the forming operation, the tube is filled with pasteurized or aseptically processed food, sealed, and then cut along evenly spaced cross sections. This results in pillow packs, which are mechanically folded to form individual finished packages. Alternatively, the packaging material may be cut into blanks, which are formed into packages on forming spindles, filled with food, and sealed. One example of this type of package is the so-called "gable-top" package known by the trade name Tetra Rex®.

[0003] To open such packages, the packaging material is typically provided with a removable portion that is partially separated from the remainder of the packaging material by an opening device to release a spout for pouring the product, and this removable portion is formed in the packaging material before the packaging material is folded and sealed to form the finished package.

[0004] This removable portion is usually provided with a so-called "prelaminate" hole, i.e. a hole that passes only through the base layer of the packaging material, which is covered with a layer of heat-sealable plastic material and barrier material that is glued at the hole when the material is laminated. The prelaminate hole is usually circular, although other shapes are also possible, as disclosed in European Patent Applications EP 2 287 082 A1 and EP 3 260 386 A1 in the name of Tetra Laval.

[0005] Typically, the package comprises an opening device including a frame defining a spout and mounted about a removable portion of the package, a removable cap screwed onto the outside of the frame to close the spout, and a substantially tubular-cylindrical cutter screwed onto the inside of the frame and configured to rupture the removable portion upon initial opening of the package. Typically, such opening devices are made of a plastic material. Summary of the Invention [Problem to be solved by the invention]

[0006] Recently, research has focused on reducing plastic consumption to make packaging more sustainable.

[0007] In particular, research has focused on providing reusable opening devices that can be used multiple times on multiple packages, where the opening device is not attached to the package itself, and the end consumer must first apply the opening device to the package, then pour in the liquid product, and then remove the opening device once the package is empty and reuse it on another package.

[0008] Accordingly, a need is felt to provide a package suitable for receiving a reusable opening device, and in particular a package having a pre-laminated opening that can securely receive a reusable opening device and that will not allow liquid product to drip down the package during the flow of the liquid product.

[0009] Additionally, a need is felt to provide a package having a pre-laminate opening for receiving a reusable opening device, which pre-laminate opening can be cleanly cut with the cutter of the opening device and will not fray to interfere with pouring of the food product.

[0010] Additionally, a need is felt to provide a package having a pre-laminate opening for receiving a reusable opening device, wherein the pre-laminate opening will not be inadvertently ruptured during storage and transport of the package. [Means for solving the problem]

[0011] It is therefore an object of the present invention to provide a multi-layer sheet of packaging material for producing a sealed package with a spout for food products that overcomes one or more of the above-mentioned drawbacks.It is also an object of the present invention to provide a sealed package that overcomes one or more of the above-mentioned drawbacks.

[0012] These objects are fully achieved by the multi-layer sheet of packaging material and the sealed package as claimed in the appended claims.

[0013] Two non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 shows a cross-sectional view of a multi-layer sheet of packaging material according to the present disclosure. [Figure 2A] 1 illustrates a sealed package according to an embodiment of the present disclosure. [Figure 2B] 2B shows a multi-layer sheet of packaging material for producing the sealed package of FIG. 2A. [Figure 2C] FIG. 2C shows an enlarged detail of FIG. 2B. [Figure 3A] 1 illustrates a sealed package according to an embodiment of the present disclosure. [Figure 3B] 3B shows a multi-layer sheet of packaging material for producing the sealed package of FIG. 3A. [Figure 3C] FIG. 3C shows an enlarged detail of FIG. 3B. [Figure 4A] 1 illustrates a sealed package according to an embodiment of the present disclosure. [Figure 4B] 4B shows a multi-layer sheet of packaging material for producing the sealed package of FIG. 4A. [Figure 5A] 1 illustrates a sealed package according to an embodiment of the present disclosure. [Figure 5B] 5B shows a multi-layer sheet of packaging material for producing the sealed package of FIG. 5A. [Figure 6A] 1 illustrates a sealed package according to an embodiment of the present disclosure. [Figure 6B] 6B shows a multi-layer sheet of packaging material for producing the sealed package of FIG. 6A. [Figure 7] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. [Figure 8] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. [Figure 9] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. [Figure 10] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. [Figure 11] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. [Figure 12] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. [Figure 13] 10A-10C show details of each of the multi-layer sheets of packaging material according to further embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Number 1 generally designates a sealed package for a pourable food product made from multi-layer sheet packaging material M and designed to receive an opening device for dispensing the pourable food product. In particular, the sealed package 1 is designed to receive a reusable opening device on the top or top wall of the package 1. Preferably, the opening device comprises a cutter configured to rupture a pre-laminate opening 12 to define a pour spout.

[0016] In a non-limiting example, the opening device is of the type described in European Patent Application Publication EP 3260386 A1. It should be noted that other opening devices may also be used, in particular reusable opening devices that are applied to the sealed package by the end consumer and are removable so that they can be applied to another package once the package is emptied.

[0017] Package 1 can be a parallelepiped or prismatic package, or a "gable-top" package. According to a non-limiting embodiment, package 1 has a parallelepiped shape as described in International Patent Application Publication WO 2015 / 169656 A1.

[0018] 2A, 3A, 4A, 5A, and 6A, the package 1 comprises a quadrilateral (in the illustrated example, rectangular or square) top wall 5, a quadrilateral (in the illustrated example, rectangular or square) bottom wall 6, and four side walls 7 extending between the top wall 5 and the bottom wall 6. The opening device is configured to be applied to the top wall 5.

[0019] Preferably, package 1 includes a transverse seal line 8 across top wall 5 and a further transverse seal line, not visible in the figures, across bottom wall 6. Preferably, package 1 includes a longitudinal seal line 9 perpendicular to transverse seal line 8.

[0020] The packaging material M for producing the sealed package 1 has a multi-layer structure including at least one base layer 10, for example made of paper, configured to impart rigidity, and multiple laminate layers 11 applied to and covering both sides of the base layer 10.

[0021] In the illustrated example, laminate layer 11 includes layer 11a containing an oxygen barrier material, for example aluminum foil, and multiple layers 11b of heat-sealable plastic material covering both sides of base layer 10 and layer 11a. In other words, the packaging material includes, in succession from the side that will ultimately form the interior of package 1, layer 11b of heat-sealable plastic material, layer 11a of oxygen barrier material, another layer 11b of heat-sealable plastic material, base layer 10, and another layer 11b of heat-sealable plastic material.

[0022] The inner layer 11b of heat sealable plastic material which contacts the food product, in use, may be made, for example, of high strength, particularly high stretch, metallocene catalyzed low linear density (LLD) polyethylene.

[0023] Typically, the layer 11b of heat-sealable plastic material is laminated to the base layer 10 and / or the oxygen barrier material layer 11a in a molten state and then cooled.

[0024] As a possible alternative, at least the inner layer of plastic material 11b may be provided as a prefabricated film which is laminated to the base layer 10 and / or the oxygen barrier material layer 11a. In this way, the risk of holes or cracks forming in or around the removable portion during the forming operation to produce the sealed package 1 may be reduced.

[0025] 2B, 3B, 4B, 5B and 6B show basic units of packaging material M for producing package 1, which may be pre-cut blanks or portions of a web of packaging material M comprising continuous units.

[0026] In the first case, the basic units are folded on a known folding spindle (not shown), filled with food and sealed at the top to form the package 1. In the second case, a web of packaging material containing successive basic units is folded into a cylindrical shape to form an elongated tube, successively filled with food, sealed transversely and cut into basic units, and then each basic unit is folded to form a respective package 1.

[0027] The basic unit of packaging material M has a number of fold lines 15 that define a fold pattern, i.e., respective fold lines along which packaging material M is folded to form the finished package 1 .

[0028] In the illustrated example, the fold pattern comprises a first fold line extending horizontally, a second fold line extending vertically (i.e., perpendicular to the first fold line), and a third fold line inclined (at an acute angle) to the first and second fold lines. The fold lines define, in a known manner, the edges between the various walls of the formed package 1.

[0029] The packaging material M further comprises a pre-laminate opening 12 formed by a through slot in the base layer 10 and covered by one or more of the laminate layers 11. The pre-laminate opening 12 is configured to receive an opening device (particularly a reusable opening device) for pouring the pourable food product from the package 1. In particular, the action of a cutter in the opening device partially cuts the removable portion from the remainder of the packaging material M to define a pour spout.

[0030] Preferably, the pre-laminate opening 12 is formed in the packaging material M before the packaging material M is folded and sealed to form the package 1 .

[0031] Preferably, the packaging material M further comprises a line of weakness 13 in the base layer 10. In other words, the base layer 10 has the line of weakness 13. In a preferred embodiment, the line of weakness 13 is defined by a cut in the base layer 10. In particular, in a preferred embodiment, in an unbroken state of the prelaminate opening 12, the prelaminate opening 12 is completely covered by one or more laminate layers 11, and the base layer 10 is at least partially cut along the line of weakness 13. Preferably, the base layer 10 is cut in a dotted line along the line of weakness 13. Preferably, the line of weakness 13 has a depth in the base layer 10 that is smaller than the thickness of the base layer. In other words, the line of weakness 13 is preferably defined by a cut that does not penetrate the base layer 10. It should be noted that the line of weakness 13 is preferably obtained by cutting the base layer 10 before bonding the base layer 10 to the laminate layer 11.

[0032] The lines of weakness 13 guide the opening device during the initial opening of the package 1. In particular, the opening device is inserted through the prelaminate opening 12 and breaks the laminate layer 11 covering the prelaminate opening 12 to form a spout. The spout is then enlarged by also breaking the base layer 10 along the lines of weakness 13. In this manner, the formation of the spout is precisely controlled, and the final size and shape of the spout is precisely predictable. As a result, the opening device adheres tightly to the packaging material M.

[0033] Preferably, the plurality of laminate layers 11 includes at least a first laminate layer applied to a first surface of the base layer 10 and a second laminate layer 12 applied to a second surface of the base layer 11. For example, the first laminate layer may include an oxygen barrier layer 11a and / or one heat-sealable plastic material layer 11b. The second laminate layer may include another heat-sealable plastic material layer 11b. At the pre-laminate opening 12, the first laminate layer and the second laminate layer are sealed together.

[0034] Preferably, the line of weakness 13 includes at least a portion that, in plan view, extends from the boundary of the prelaminate opening 12 to an area of ​​the sheet outside the prelaminate opening 12. In this context, plan view means the planar sheet of packaging material viewed perpendicular to the plane defined by the planar sheet. In other words, the at least a portion extends parallel to the plane defined by the sheet of packaging material. In particular, the at least a portion of the line of weakness 13 has a first end closer to (and in particular overlapping with) the boundary of the prelaminate opening 12 and a second end opposite the first end and further from the prelaminate opening 12.

[0035] According to one or more embodiments, the line of weakness 13 includes at least a first portion 131 and a second portion 132. The first portion 131 and the second portion 132 define at least a portion of the line of weakness. The first portion 131 and the second portion 132 extend (preferably in opposite directions) from the prelaminate opening 12, with the prelaminate opening 12 being interposed between the first portion 131 and the second portion 132. Preferably, the first portion 131 and the second portion 132 each extend from a boundary of the prelaminate opening 12 to a respective region of the sheet remote from the prelaminate opening 12.

[0036] The line of weakness 13 may further include a third portion 133 extending from the prelaminate opening 12. The line of weakness 13 may further include a fourth portion 134 extending from the prelaminate opening 12. In this case, preferably, the prelaminate opening 12 is further interposed between the third portion 133 and the fourth portion 134. In particular, the first portion 131, the second portion 132, the third portion 133, and the fourth portion 134 (if present) are angularly spaced apart from one another around the prelaminate opening 12.

[0037] According to some embodiments of the present disclosure, shown in Figures 2A-2C, 3A-3C, 4A-4B, 5A-5B, 6A-6B, 7, 8, 9, 12, and 13, the line of weakness 13 includes four portions arranged in an X-shape. In these embodiments, the first portion 131 and the second portion 132 of the line of weakness 13 are aligned along a first straight line, and the third portion 133 and the fourth portion 134 of the line of weakness 13 are aligned along a second straight line. The first and second straight lines are incident on each other, and the prelaminate opening 12 is located at the intersection of the first and second straight lines.

[0038] 10, the line of weakness 13 includes three portions (to be precise) arranged in a Y-shape. In this embodiment, the first portion 131, the second portion 132, and the third portion 133 each extend along a corresponding straight line, the straight lines of the first portion 131, the second portion 132, and the third portion 133 are incident on each other, and the prelaminate opening 12 is located at the intersection between them.

[0039] According to the embodiment of the present disclosure shown in FIG. 11, the line of weakness 13 starts from the prelaminate opening 12 (to be precise) and includes six portions, each positioned diagonally relative to the others.

[0040] According to one or more embodiments, the prelaminate opening 12 is circular (i.e., has a circular or circular shape). Preferably, the length of each of the first portion 131 and the second portion 132 is equal to or greater than the diameter of the circular prelaminate opening 12. Preferably, if the line of weakness 13 also includes a third portion 133 and / or a fourth portion 134, the length of the third portion 133 and / or the fourth portion 134 is also equal to or greater than the diameter of the circular prelaminate opening 12.

[0041] According to one or more embodiments, the prelaminate opening 12 has an X-shape or a Y-shape. In particular, the prelaminate opening 12 may include a central portion 120 and a plurality of peripheral portions extending from the central portion and angularly spaced apart from one another. More particularly, the prelaminate opening 12 may include a first peripheral portion 121, a second peripheral portion 122, a third peripheral portion 123, and optionally a fourth peripheral portion 124 angularly spaced apart from one another. Each of the first peripheral portion 121, the second peripheral portion 122, the third peripheral portion 123, and, if present, the fourth peripheral portion 124, extends from the central portion 120. Preferably, a first portion 131 of the line of weakness 13 extends from a first peripheral portion 121 of the laminate opening 12, a second portion 132 of the line of weakness 13 extends from a second peripheral portion 122 of the laminate opening 12, and a third portion 133 of the line of weakness 13 extends from a third peripheral portion 123 of the laminate opening 12 (and, if present, a fourth portion 134 of the line of weakness 13 extends from a fourth peripheral portion 124 of the laminate opening 12).

[0042] Preferably, the length of the first portion 131 of the weakened line 13 is less than the length of the first peripheral portion 121 of the prelaminate opening 12, the length of the second portion 132 of the weakened line 13 is less than the length of the second peripheral portion 122 of the prelaminate opening 12, the length of the third portion 133 of the weakened line 13 is less than the length of the third peripheral portion 123 of the prelaminate opening 12, and the length of the fourth portion 134 of the weakened line 13 (if present) is less than the length of the fourth peripheral portion 124 of the prelaminate opening 12 (if present).

[0043] According to one or more embodiments, the packaging material M includes a plurality of fold lines 15. The fold lines 15 are configured to define edges between two adjacent walls of a sealed package formed by folding the packaging material M and sealing the packaging material M. In particular, the package 1 is obtained by folding the packaging material M along the fold lines 15. Preferably, the fold lines 15 are obtained by pressing the base layer 10 between a pair of tools so that the base layer 10 is locally deformed before bonding the base layer 10 with the laminate layer 11. Preferably, the prelaminate opening 12 does not intersect any of the fold lines 15. In other words, the fold lines 15 are located away from the prelaminate opening 12. As a result, in the formed package 1, the prelaminate opening 12 is completely contained within the top wall 5 and does not extend into any of the side walls 7.

[0044] According to one or more embodiments, the packaging material M includes an additional prelaminate opening 14 formed by an additional through slot in the base layer 10 and covered by one or more laminate layers 11. The additional prelaminate opening 14 is configured to receive a straw connected to an opening device. The straw is configured to allow air to escape from the package when the liquid food is poured through the prelaminate hole and the associated opening device. Preferably, the additional prelaminate opening 14 is circular. Preferably, the prelaminate opening 12 and the additional prelaminate opening 14 are located in an area of ​​the sheet that is not crossed by the fold line 15. As a result, the prelaminate opening 12 and the additional prelaminate opening 14 are both contained in the top wall 5 of the formed package 1.

Claims

1. A multi-layer sheet (M) of packaging material for producing a sealed package (1) for a pourable food product, said multi-layer sheet (M) of packaging material comprising: At least one base layer (10) for providing stiffness; a plurality of laminate layers (11) covering both sides of the base layer (10); a prelaminate opening (12) formed by a through slot in the base layer (10) and covered by one or more of the laminate layers (11), the prelaminate opening (12) being configured to receive an opening device for dispensing the food product; a line of weakness (13) in the base layer (10), such that in an unbroken state of the prelaminate opening (12), the prelaminate opening (12) is completely covered by the laminate layer (11) and the base layer (10) is at least partially cut along the line of weakness (13). Multilayer sheet of packaging material (M).

2. The plurality of laminate layers (11) includes a first laminate layer applied to a first side of the base layer (10) and a second laminate layer applied to a second side of the base layer (11), and the first laminate layer and the second laminate layer are sealed together at the pre-lamination opening (12). A multilayer sheet (M) of packaging material according to claim 1.

3. the weakened line (13) includes a first portion (131) and a second portion (132) extending from the prelaminate opening (12), the prelaminate opening (12) being interposed between the first portion (131) and the second portion (132); A multilayer sheet (M) of packaging material according to claim 1 or 2.

4. the sheet of packaging material (M) extends in a plane, the first portion (131) and the second portion (132) being elongated along the plane; A multilayer sheet (M) of packaging material according to claim 3.

5. the weakened line (13) includes a third portion (133) extending from the prelaminate opening (12), and / or the weakened line (13) includes a fourth portion (134) extending from the prelaminate opening (12), and the prelaminate opening (12) is further interposed between the third portion (133) and the fourth portion (134); A multilayer sheet (M) of packaging material according to claim 3.

6. the first portion (131) and the second portion (132) of the line of weakness (13) are aligned along a first straight line, the third portion (133) and the fourth portion (134) of the line of weakness (13) are aligned along a second straight line, the first straight line and the second straight line are incident on each other, and the prelaminate opening (12) is located at the intersection between the first straight line and the second straight line. A multilayer sheet (M) of packaging material according to claim 5.

7. The prelaminate opening (12) is circular. A multilayer sheet (M) of packaging material according to any one of claims 3 to 6.

8. The length of each of the first portion (131) and the second portion (132) is equal to or greater than the diameter of the circular prelaminate opening (12); A multilayer sheet (M) of packaging material according to claim 7.

9. the weakened line (13) includes a third portion (133) and / or a fourth portion (134) extending from the prelaminate opening (12), and the length of the third portion (133) and / or the fourth portion (134) is equal to or greater than the diameter of the circular prelaminate opening (12); A multilayer sheet (M) of packaging material according to claim 8.

10. The pre-laminate opening (12) is a central portion (120); a first peripheral portion (121), a second peripheral portion (122), and a third peripheral portion (123) angularly spaced apart from one another, each of the first peripheral portion (121), the second peripheral portion (122), and the third peripheral portion (123) extending from the central portion (120); A multilayer sheet (M) of packaging material according to any one of claims 1 to 6.

11. the weakened line (13) comprises a first portion (131), a second portion (132), and a third portion (133); the first portion (131) of the line of weakness (13) extends from the first peripheral portion (121) of the prelaminate opening (12); the second portion (132) of the line of weakness (13) extends from the second peripheral portion (122) of the prelaminate opening (12); the third portion (133) of the line of weakness (13) extends from the third peripheral portion (123) of the prelaminate opening (12); A multilayer sheet (M) of packaging material according to claim 10.

12. the prelaminate opening (12) further includes a fourth peripheral portion (124) extending from the central portion (120) and angularly spaced apart from each of the first peripheral portion (121), the second peripheral portion (122), and the third peripheral portion (123), and the fourth peripheral portion (124) of the line of weakness (13) extends from the fourth portion (134) of the prelaminate opening (12); A multilayer sheet (M) of packaging material according to claim 10 or 11.

13. a plurality of fold lines (15) configured to define an edge between two adjacent walls of a sealed package formed by folding and sealing the packaging material (M), wherein the prelaminate opening (12) is not crossed by any one of the fold lines (15); A multilayer sheet (M) of packaging material according to any one of claims 1 to 12.

14. The base layer (10) is cut along the weakened lines (13) with dotted lines. A multilayer sheet (M) of packaging material according to any one of claims 1 to 13.

15. the lines of weakness (13) have a depth in the base layer (10) that is less than the thickness of the base layer (10); A multilayer sheet (M) of packaging material according to any one of claims 1 to 14.

16. and additional pre-laminate openings (14) formed by additional through slots in the base layer (10) and covered by one or more of the laminate layers (11). A multilayer sheet (M) of packaging material according to any one of claims 1 to 15.

17. the weakened line (13) includes at least a portion extending parallel to a plane defined by the sheet (M) of packaging material from a first end to a second end opposite the first end, the first end being closer to the prelaminate opening (12) than the second end, and the second end being farther from the prelaminate opening (12); A multilayer sheet (M) of packaging material according to any one of claims 1 to 16.

18. A sealed package (1) for a pourable food product formed by folding and sealing a multilayer sheet of packaging material (M) according to any one of claims 1 to 17, wherein the sealed package (1) is configured to receive an opening device for pouring the pourable food product, and the pre-laminate opening (12) is configured to be broken by a cutter of the opening device to define a pouring opening.

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