Multilayer sheet packaging material for sealed packages

Abstract

The packaging material (M) includes at least one base layer (10) for providing rigidity, a plurality of laminate layers (11) covering both sides of the base layer (10), a pre-laminate opening (12) formed by a through slot provided in the base layer (10) and covered by one or more of the laminate layers (11), the pre-laminate opening (12) configured to receive an opening device for dispensing the food product, and 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), the pre-laminate opening (12) not being intersected by any one of the fold lines (15), and an outer peripheral edge formed in an arc and configured to define a first portion of a first perimeter.

Description

[Technical Field]

[0001] The present invention relates to a multi-layer sheet 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 illustrates a cross section 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 4C] FIG. 4C shows an enlarged detail of FIG. 4B. [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 5C] FIG. 5C shows an enlarged detail of FIG. 5B. [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 6C] FIG. 6C shows an enlarged detail of FIG. 6B. [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. 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] Referring to Figures 2A, 3A, 4A, 5A and 6A, package 1 comprises a quadrilateral (particularly rectangular or square) top wall 5, a quadrilateral (particularly rectangular or square) bottom wall 6 and four side walls 7 extending between top wall 5 and bottom wall 6. An opening device is configured to be applied to top wall 5. Preferably, package 1 comprises 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 comprises a longitudinal seal line 9 perpendicular to the transverse seal line 8.

[0019] 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.

[0020] In the illustrated example, laminate layer 11 includes layer 11a containing an oxygen barrier material, such as 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Preferably, the plurality of laminate layers 11 includes a first laminate layer applied to a first surface of the base layer 10 and a second laminate layer 11 applied to a second surface of the base layer 10. For example, the first laminate layer may include an oxygen barrier layer 11a and / or a heat-sealable plastic material layer 11b, and the second laminate layer may include another heat-sealable plastic material layer 11b. The first and second laminate layers are sealed to each other at a pre-laminate opening 12.

[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 packages 1. In the second case, a web of packaging material containing successive basic units is folded into a cylindrical shape to form a longitudinal 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 packaging material M comprises a plurality of fold lines (or score lines) 15 arranged to define the boundaries of two adjacent walls of the sealed package 1. In particular, each basic unit of the packaging material M is formed with a pattern of fold lines (or score lines) 15 (crease pattern) for folding the packaging material M to form the finished package 1. Preferably, the fold lines 15 are formed by compressing the base layer 10 with a pair of tools to locally deform the base 10 before bonding the base layer 10 with the laminate layer 11.

[0028] In the illustrated example, the crease pattern includes a first crease line extending horizontally, a second crease line extending vertically (i.e., perpendicular to the first crease line), and a third crease line inclined at an acute angle to the first and second crease lines. The crease lines 15 define the edges between the various walls of the formed package 1 in a known manner.

[0029] Packaging material M further comprises a pre-laminate opening 12 formed by a through slot in base layer 10 and covered by one or more of laminate layers 11. This pre-laminate opening 12 is configured to receive an opening device (particularly a reusable opening device) for dispensing food product from package 1. Pre-laminate opening 12 is configured to be broken by a cutting tool of the opening device, thereby defining a pouring spout. In particular, action of a cutter in the opening device partially separates a removable portion from the remainder of packaging material M, thereby defining a pouring spout.

[0030] Preferably, prelaminate opening 12 is formed in packaging material M before packaging material M is folded and sealed to form package 1. Preferably, prelaminate opening 12 does not intersect any of fold lines 15. That is, fold lines 15 are spaced apart from prelaminate opening 12. As a result, in the formed package 1, prelaminate opening 12 is completely contained within top wall 5 and does not extend into any of side walls 7.

[0031] Preferably, the prelaminate opening 12 includes a peripheral edge 120 extending between a first end 120a and a second end 120b spaced from the first end 120a. The peripheral edge 120 is arcuate (or curved) to define a first portion C11 of the first perimeter C1.

[0032] The curved arc shape of the outer peripheral edge of the prelaminate opening helps guide the rotation of the cutting blade of the opening device and define the injection opening as the opening device is inserted through the opening. This cutter rotation precisely controls the rupture of the prelaminate opening, tightly adhering the opening device to the packaging material M. Furthermore, the fact that the first end 120a is spaced from the second end 120b and the outer peripheral edge defines only a partial circumference prevents small portions of the packaging material M from falling into the container when the opening device is inserted.

[0033] 2C, 3C, 4C, 5C, 6C, and 10, in one or more embodiments, the first end 120a and the second end 120b of the outer periphery 120 are disposed along the first perimeter C1. Thus, a first periphery C11 of the first periphery C1 is defined (or extends) between the first end 120a and the second end 120b of the outer periphery 120 (i.e., from the first end 120a to the second end 120b of the outer periphery 120).

[0034] In other embodiments, the first end 120a and / or the second end 120b of the outer perimeter 120 are located outside the first perimeter C1, as shown in Figures 7, 8, and 9. In these cases, the outer perimeter 120 extends partially along the first perimeter C1 and partially outside the first perimeter C1.

[0035] Preferably, the multi-layer sheet M of packaging material has a line of weakness 13 in the base layer 10. Preferably, the line of weakness 13 extends from the prelaminate opening 12. In particular, the line of weakness 13 extends from a first end 120a and / or a second end 120b of the outer periphery 120 of the prelaminate opening 12.

[0036] Preferably, the line of weakness 13 extends at least partially along the second portion C12 of the first perimeter C1. Preferably, the first portion C11 of the first perimeter C1 (including the outer peripheral edge 120) does not overlap the second portion C12 of the first perimeter C1 (including the line of weakness 13).

[0037] In one embodiment, a first portion C11 of the first perimeter C1 (including the outer peripheral edge 120) is longer than a second portion C12 of the first perimeter C1 (including the line of weakness 13). In other embodiments, the first portion C11 of the first perimeter C1 (including the outer peripheral edge 120) is shorter than a second portion C12 of the first perimeter C1 (including the line of weakness 13).

[0038] In some non-limiting embodiments, the first perimeter C1 includes a first portion C11 (having the outer peripheral edge 120 of the prelaminate opening 12), a second portion (having the weakened line 13), and a third portion (a portion not included in either the outer peripheral edge 120 of the prelaminate opening 12 or the weakened line 13).

[0039] 2C and 6C, the base layer 10 is at least partially cut along the lines of weakness 13. In particular, the lines of weakness 13 extend to a depth in the base layer 10 that is less than the thickness of the base layer 10. In particular, the base layer 10 is cut in a dotted line along the lines of weakness 13.

[0040] 3C, 7, and 9, the base layer 10 is creased along the lines of weakness 13. Preferably, the crease lines defining the lines of weakness 13 are obtained by clamping the base layer 10 between a pair of tools to locally deform it prior to bonding the base layer 10 with the lamination layer 11.

[0041] 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.

[0042] 2C, 3C, 4C, 5C, 6C, 7, 8, and 9, the prelaminate opening 12 includes an arcuate inner perimeter that extends along a second perimeter C2. The second perimeter C2 is smaller than the first perimeter C1. The prelaminate opening 12 is bounded at least in part by the inner edge of the second perimeter C2 and the outer edge 120 of the first perimeter C1.

[0043] Preferably, the first perimeter C1 and the second perimeter C2 have a common center, such that the inner perimeter of the second perimeter C2 and the outer perimeter 120 of the first perimeter C1 are parallel to each other. In other embodiments, the first perimeter C1 and the second perimeter C2 have different centers, such that the inner perimeter of the second perimeter C2 and the outer perimeter 120 of the first perimeter C1 are not parallel to each other.

[0044] In particular, in these embodiments, the prelaminate opening 12 is C-shaped. As such, the prelaminate opening 12 is positioned to partially surround the center of the base layer. This C-shape is particularly useful for improving the impact resistance of the prelaminate opening 12 to prevent accidental rupture during shipping.

[0045] 10, the prelaminate opening 12 is bounded by an arcuate outer peripheral edge 120 extending from a first end 120a to a second end 120b along a first portion C11 of the first perimeter C1 and is bounded by a straight line connecting the first end 120a and the second end 120b inside the first perimeter C1. Preferably, the line of weakness 13 extends along a second portion C12 of the first perimeter C1 that does not have the outer peripheral edge 120.

[0046] 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.

[0047] In the embodiment shown in FIG. 8 , packaging material M includes an additional prelaminate opening 16 formed by a further through slot in base layer 10 and covered by one or more laminate layers 11. Additionally, additional prelaminate opening 16 is positioned in cooperation with prelaminate opening 12 to surround a central portion of base layer 10 (which helps improve the impact resistance of prelaminate opening 12). Preferably, prelaminate opening 12 and additional prelaminate opening 16 are positioned in areas of the sheet not intersected by fold line 15. As a result, prelaminate opening 12 and additional prelaminate opening 16 are both contained in top wall 5 of formed package 1. Additionally, additional prelaminate opening 16 can be provided in combination with or in addition to an additional prelaminate opening configured to receive a straw.

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 plurality of fold lines (15) configured to define an edge between two adjacent walls of a sealed package formed by folding and sealing said packaging material (M), wherein said prelaminate opening (12) is not crossed by any one of said fold lines (15); The pre-laminate opening (12) includes a peripheral edge (120) extending between a first end (120a) and a second end (120b) spaced from the first end (120a), the peripheral edge (120) being arcuate and configured to define a first portion (C11) of a first perimeter (C1). Multilayer sheet of packaging material (M).

2. The first end (120a) and the second end (120b) of the outer peripheral edge (120) are arranged along the first perimeter, and the portion of the outer peripheral edge (120) from the first end (120a) to the second end (120b) constitutes part of the first perimeter. A multilayer sheet (M) of packaging material according to claim 1.

3. The base layer (10) further comprises a line of weakness (13), the line of weakness (13) extending from the prelaminate opening (12). A multilayer sheet (M) of packaging material according to claim 1 or 2.

4. the weakened line (13) extends from the first end (120a) and / or the second end (120b) of the outer periphery (120) of the prelaminate opening (12); A multilayer sheet (M) of packaging material according to claim 3.

5. the weakened line (13) extends along a second portion (C12) of the first periphery (C1); A multilayer sheet (M) of packaging material according to claim 3 or 4.

6. The first portion (C11) of the first periphery (C1) is the same length as or longer than the second portion (C12) of the first periphery (C1). A multilayer sheet (M) of packaging material according to claim 5.

7. The first periphery (C1) comprises a first periphery (C11) having the first periphery (C1), a second periphery (C12) having the second periphery (C12), and a third periphery that is free from both the periphery (120) of the first periphery (C1) and the periphery (120) of the second periphery (C12) and the weakened lines (13) of the second periphery (C12), A multilayer sheet (M) of packaging material according to claim 5 or 6.

8. The base layer (10) is at least partially cut along the weakened line (13). A multilayer sheet (M) of packaging material according to any one of claims 3 to 7.

9. the depth of the weakened line (13) in the base layer (10) is less than the thickness of the base layer (10); A multilayer sheet (M) of packaging material according to claim 8.

10. The base layer (10) is cut in a dotted line along the weakened line (13). A multilayer sheet (M) of packaging material according to claim 8 or 9.

11. The base layer (10) is folded along the lines of weakness (13). A multilayer sheet (M) of packaging material according to any one of claims 3 to 10.

12. The prelaminate opening (12) includes an arcuate inner edge extending along the second perimeter, the second perimeter being smaller than the first perimeter. A multilayer sheet (M) of packaging material according to any one of claims 1 to 11.

13. The prelaminate opening (12) is C-shaped. A multilayer sheet (M) of packaging material according to claim 12.

14. The plurality of laminate layers (11) comprises 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), and the first laminate layer and the second laminate layer are sealed in the pre-laminate opening (12). A multilayer sheet (M) of packaging material according to any one of claims 1 to 13.

15. A sealed package (1) for a pourable food product formed by folding and sealing the packaging material (M) according to any one of claims 1 to 14, wherein the sealed package 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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