Multilayer sheet-like packaging material for producing sealed packages

Abstract

A multilayer sheet-like packaging material (M) for producing sealed packages (1) of pourable food products comprises: at least one base layer (10) for imparting stiffness; a plurality of laminate layers (11) applied to both sides of the base layer (10) and covering both sides of the base layer (10); a pre-laminated opening (12) configured to receive an opening device for pouring the pourable food product; and a line of weakness (13) in the base layer (10).

Description

TECHNICAL FIELD

[0001] The present invention relates to a multi-layer packaging material for producing a hermetically sealed package for pourable foods.

[0002] As is well known, many pourable foods, such as fruit juices, UHT (ultra-high temperature treated) milk, wine, tomato ketchup, etc., are sold in packages made of sterilizable packaging materials. A typical example is the parallelepiped-shaped package for liquid or pourable foods called Tetra Brik Aseptic (registered trademark), which is made by folding and sealing a laminated strip of packaging material. The packaging material has a multi-layer structure, including a base layer (such as paper) covered on both sides with layers of heat-sealable plastic material (such as polyethylene). For aseptic packaging for long-term storage of products (such as UHT milk), the packaging material also includes a layer of oxygen barrier material, such as aluminum foil, which is superimposed on the heat-sealable plastic material layer and is in turn covered by another heat-sealable plastic material layer that forms the inner surface of the package that finally contacts the food. Such packaging is usually produced on a fully automatic packaging machine, where a continuous tube is formed from a roll-fed packaging material; the roll of packaging material is sterilized on the packaging machine, for example, by applying a chemical sterilizing agent (such as hydrogen peroxide solution), which is removed from the surface of the packaging material after sterilization is completed, for example, by heating and evaporation; then the so-sterilized roll is kept in a closed aseptic environment and longitudinally folded and sealed to form a tube, which is fed vertically. To complete the forming operation, the sterilized or aseptically treated food is loaded into the tube, which is then sealed and subsequently cut along equidistant cross-sections; thus obtained are pillow-shaped packages, which are then mechanically folded to form the corresponding finished packages. Alternatively, the packaging material can be cut into blanks, formed into packages on a forming mandrel, and then the food is loaded into the packages and sealed. An example of such a package is the so-called "gable-top" package, which is commercially known as Tetra Rex (registered trademark).

[0003] To open the above-mentioned packages, these packages are usually provided with a detachable part that is partially separated from the rest of the packaging material by an opening device to release a pouring opening through which the product is poured out. The detachable part is formed on the packaging material before folding and sealing the packaging material to form the finished package.

[0004] The detachable part usually includes a so-called "pre-laminated" hole, i.e., a hole formed only in the base layer of the packaging material, which is covered by the heat-sealable plastic material layer and the barrier material layer when the material is laminated, and the heat-sealable plastic material layer and the barrier material layer adhere to each other at the hole. The "pre-laminated" holes are usually circular, but other shapes can be envisaged, such as those disclosed in patent documents EP2287082A1 and EP3260386A1 under the trade name Tetra Laval.

[0005] Typically, the package includes an opening device, which includes: a frame that defines a nozzle and is mounted around a detachable part of the package; a detachable lid that is screwed onto the outside of the frame to close the nozzle; and a generally tubular cylindrical cutter that is screwed inside the frame and is configured to tear the detachable part during the first opening of the package. Typically, such an opening device is made of plastic material.

[0006] Recently, the focus of research has been on reducing plastic consumption to improve the sustainability of packaging.

[0007] Specifically, the focus of research has been on providing a reusable opening device that can be used multiple times for several packages. In this case, the package does not come with an opening device applied to it. The end consumer needs to first apply the opening device to the package and then pour out the liquid product. Once the package is empty, the opening device is removed to be used again for another package.

[0008] Therefore, there is a need to provide a package suitable for receiving a reusable opening device. Specifically, there is a need to provide a package with a pre-laminated opening that allows the reusable opening device to be received tightly so that during the pouring of the liquid product, no liquid product drips onto the package.

[0009] In addition, there is a need to provide a package with a pre-laminated opening for receiving a reusable opening device, where the pre-laminated opening can be cleanly cut by the cutter of the opening device without fraying that interferes with the pouring of the food product.

[0010] In addition, there is a need to provide a package with a pre-laminated opening for receiving a reusable opening device, where the pre-laminated opening does not accidentally break during the storage and transportation of the package. Summary of the Invention

[0011] Therefore, an object of the present invention is to provide a multi-layer sheet packaging material for producing a sealed package for pourable food products, which overcomes one or more of the above disadvantages. In addition, an object of the present invention is to provide a sealed package for pourable food products, which overcomes one or more of the above disadvantages.

[0012] These objects are fully achieved by the multi-layer sheet packaging material and the sealed package according to the appended claims. Brief Description of the Drawings

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

[0014] Figure 1 A cross-sectional view of a multi-layer sheet packaging material according to the present disclosure is shown;

[0015] Figure 2A shows a sealed package according to an embodiment of the present disclosure;

[0016] Figure 2B shows a multilayer sheet packaging material for producing Figure 2A the sealed package;

[0017] Figure 2C shows Figure 2B an enlarged detail;

[0018] Figure 3A shows a sealed package according to an embodiment of the present disclosure;

[0019] Figure 3B shows a multilayer sheet packaging material for producing Figure 3A the sealed package;

[0020] Figure 3C shows Figure 3B an enlarged detail;

[0021] Figure 4A shows a sealed package according to an embodiment of the present disclosure;

[0022] Figure 4B shows a multilayer sheet packaging material for producing Figure 4A the sealed package;

[0023] Figure 5A shows a sealed package according to an embodiment of the present disclosure;

[0024] Figure 5B shows a multilayer sheet packaging material for producing Figure 5A the sealed package;

[0025] Figure 6A shows a sealed package according to an embodiment of the present disclosure;

[0026] Figure 6B shows a multilayer sheet packaging material for producing Figure 6A the sealed package;

[0027] Figures 7 - 13 shows corresponding details of the multilayer sheet packaging material according to a further embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] The numeral 1 denotes a sealed package for pourable foodstuffs in general, made of a multi-layer sheet packaging material M and designed to receive an opening device for pouring the pourable foodstuffs. Specifically, 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 includes a cutter configured to tear a pre-laminated opening 12 to define a pouring opening.

[0029] In a non-limiting example, the opening device is of the type described in EP3260386A1. It should also be noted that other opening devices can be used. Specifically, a reusable opening device can be used, which can be applied by the end consumer to the sealed package and removed once the package is empty for application to another package.

[0030] The package 1 can be a parallelepiped or prismatic package, or a "gable top" package. According to a non-limiting embodiment, the package 1 has the parallelepiped shape described in WO2015 / 169656A1.

[0031] Reference Figure 2A 、 3A 、4A, 5A, 6A, the package 1 includes a quadrilateral (rectangular or square in the example shown) top wall 5, a quadrilateral (rectangular or square in the example shown) 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.

[0032] Preferably, the package 1 includes a transverse seal line 8 across the top wall 5 and another transverse seal line (not visible in the figure) across the bottom wall 6. Preferably, the package 1 includes a longitudinal seal line 9 perpendicular to the transverse seal line 8.

[0033] The packaging material M for producing the sealed package 1 has a multi-layer structure, which includes at least one base layer 10 (made of paper, for example) configured to impart stiffness, and a plurality of laminated layers 11 are applied to both sides of the base layer 10 and cover both sides of the base layer 10.

[0034] In the example shown, the laminated layer 11 includes a layer 11a made of an oxygen barrier material (such as aluminum foil), and a plurality of heat-sealable plastic layers 11b covering both sides of the base layer 10 and the layer 11a. In other words, the packaging material includes, starting from the side that will ultimately form the inside of the package 1, a heat-sealable plastic layer 11b, an oxygen barrier material layer 11a, another heat-sealable plastic layer 11b, the base layer 10, and another heat-sealable plastic layer 11b in sequence.

[0035] In use, the inner heat-sealable plastic material layer 11b in contact with the food can be made of, for example, a sturdy, particularly highly stretchable, metallocene-catalyzed, low linear density (LLD) polyethylene.

[0036] Typically, the heat-sealable plastic material layer 11b is laminated to the base layer 10 and / or the oxygen barrier material layer 11a in a molten state and then cooled.

[0037] As a possible alternative, at least the inner plastic material layer 11b can be provided as preformed films that are laminated onto the base layer 10 and / or the oxygen barrier material layer 11a; this technique allows reducing any risk of forming holes or cracks at or around the removable part during the forming operation for producing the sealed package 1.

[0038] Figure 2B 、 3B Figures 4A, 4B, 5B, 6B show the basic units of the packaging material M for producing the package 1, which can be pre-cut blanks or part of a roll of packaging material M comprising continuous units.

[0039] 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 roll of packaging material comprising continuous basic units is folded into a cylinder to form a vertical tube; continuously filled with food; transversely sealed and cut into basic units, and then folded to form the corresponding package 1.

[0040] The basic units of the packaging material M have a crease pattern, i.e., a plurality of crease lines 15 that define the corresponding folding lines along which the packaging material M is folded to form the finished package 1.

[0041] In the example shown, the crease pattern includes a first folding line extending horizontally, a second folding line extending vertically (i.e., perpendicular to the first folding line), and a third folding line inclined (at an acute angle) with respect to the first and second folding lines. The folding lines define the edges between the respective walls of the formed package 1 in a known manner.

[0042] The packaging material M further includes a pre-laminated opening 12 formed by a through slot provided in the base layer 10 and covered by one or more of the laminated layers 11 of the laminated layer 11. The pre-laminated opening 12 is configured to receive an opening device (especially a reusable opening device) for pouring out the pourable food from the package 1. In particular, under the action of the cutter of the opening device, the removable part can be partially separated from the rest of the packaging material M, thus defining a pourable opening.

[0043] Preferably, the pre-laminated opening 12 is formed on the packaging material M before folding and sealing the packaging material M to form the package 1.

[0044] Preferably, the packaging material M further includes the score line 13 in the base layer 10. In other words, the base layer 10 has the score line 13. In a preferred embodiment, the score line 13 is defined by a cut in the base layer 10. Specifically, in a preferred embodiment, in a state where the pre-laminated opening 12 is not ruptured, the pre-laminated opening 12 is completely covered by the one or more laminated layers 11, and the base layer 10 is at least partially cut along the score line 13. Preferably, along the score line 13, the base layer 10 is cut in a dotted pattern. Preferably, the depth of the score line 13 in the base layer 10 is less than the thickness of the base layer. In other words, the score line 13 is preferably defined by a non-penetrating cut in the base layer 10. It should be noted that, preferably, the score line 13 is obtained by cutting the base layer 10 before coupling the base layer 10 with the laminated layer 11.

[0045] The score line 13 provides guidance for the opening device when the package 1 is opened for the first time. Specifically, the opening device is inserted through the pre-laminated opening 12 such that the laminated layer 11 covering the pre-laminated opening 12 is ruptured, thereby forming a pouring hole. In addition, the pouring hole is also enlarged by rupturing the base layer 10 along the score line 13. In this way, the formation of the pouring hole is finely controlled, and the final size and shape of the pouring hole are precisely predictable. Therefore, the opening device will adhere tightly to the packaging material M.

[0046] Preferably, the plurality of laminated layers 11 includes at least a first laminated layer applied to the first side of the base layer 10 and a second laminated layer 12 applied to the second side of the base layer 11. For example, the first laminated layer may include the oxygen barrier layer 11a and / or a heat-sealable plastic material layer 11b; the second laminated layer may include another heat-sealable plastic material layer 11b. At the pre-laminated opening 12, the first laminated layer and the second laminated layer are sealed together.

[0047] Preferably, the score line 13 includes at least a portion that extends from the boundary of the pre-laminated opening 12 to a region of the sheet material outside the pre-laminated opening 12 in a top view. Herein, the top view refers to observing the planar sheet packaging material from a direction perpendicular to the plane defined by the planar sheet material. In other words, the at least a portion extends parallel to the plane defined by the sheet packaging material. Specifically, at least a portion of the score line 13 has a first end near the boundary of the pre-laminated opening 12 (specifically, overlapping with the boundary of the pre-laminated opening 12) and a second end opposite to the first end, and the second end is away from the pre-laminated opening 12.

[0048] According to one or more embodiments, the weakening line 13 includes at least a first part 131 and a second part 132. The first part 131 and the second part 132 define at least a portion of the weakening line. The first part 131 and the second part 132 extend from the pre-lamination opening 12 (preferably, in opposite directions), wherein the pre-lamination opening 12 is between the first part 131 and the second part 132. Preferably, each of the first part 131 and the second part 132 extends from the boundary of the pre-lamination opening 12 to a corresponding area of the sheet material away from the pre-lamination opening 12.

[0049] The weakening line 13 may further include a third part 133 extending from the pre-lamination opening 12. The weakening line 13 may further include a fourth part 134 extending from the pre-lamination opening 12. In this case, preferably, the pre-lamination opening 12 is also between the third part 133 and the fourth part 134. Specifically, the first part 131, the second part 132, the third part 133, and the fourth part 134 (if present) are angularly spaced apart from each other around the pre-lamination opening 12.

[0050] According to some embodiments of the present disclosure, as Figures 2A - 2C shown in FIGS. 3A - 3C, 4A - 4B, 5A - 5B, 6A - 6B, 7, 8, 9, 12, 13, the weakening line 13 includes four parts positioned in an X configuration. In these embodiments, the first part 131 and the second part 132 of the weakening line 13 are aligned along a first straight line, and the third part 133 and the fourth part 134 of the weakening line 13 are aligned along a second straight line. The first straight line and the second straight line intersect (incident) with each other, and the pre-lamination opening 12 is located at the intersection between the first straight line and the second straight line.

[0051] According to Figure 10 the embodiment of the present invention shown in FIGS., the weakening line 13 includes (exactly) three parts in a Y configuration. In this embodiment, each of the first part 131, the second part 132, and the third part 133 extends along a corresponding straight line; the straight lines of the first part 131, the second part 132, and the third part 133 intersect (incident) with each other, and the pre-lamination opening 12 is located at the intersection between them.

[0052] According to Figure 11 the embodiment of the present invention shown in FIGS., the weakening line 13 includes (exactly) six parts that deviate from the pre-lamination opening 12 and are arranged at an angle to each other.

[0053] According to one or more embodiments, the shape of the pre-laminating opening 12 is circular (i.e., having a circular or round shape). Preferably, the lengths of both the first part 131 and the second part 132 are equal to or greater than the diameter of the circular pre-laminating opening 12. Preferably, in the case where the weakened line 13 further includes a third part 133 and / or a fourth part 134, the lengths of the third part 133 and / or the fourth part 134 are also equal to or greater than the diameter of the circular pre-laminating opening 12.

[0054] According to one or more embodiments, the pre-laminating opening 12 has an X or Y shape. Specifically, the pre-laminating opening 12 may include a central portion 120 and a plurality of peripheral portions extending from the central portion and angularly spaced from each other. More specifically, the pre-laminating opening 12 may include a first peripheral portion 121, a second peripheral portion 122, a third peripheral portion 123, and possibly a fourth peripheral portion 124 that are angularly spaced from each other. The first peripheral portion 121, the second peripheral portion 122, the third peripheral portion 123, and the fourth peripheral portion 124 (if present) all extend from the central portion 120. Preferably, the first part 131 of the weakened line 13 extends from the first peripheral portion 121 of the pre-laminating opening 12, the second part 132 of the weakened line 13 extends from the second peripheral portion 122 of the pre-laminating opening 12, and the third part 133 of the weakened line 13 extends from the third peripheral portion 123 of the pre-laminating opening 12 (and if present, the fourth part 134 of the weakened line 13 extends from the fourth peripheral portion 124 of the pre-laminating opening 12).

[0055] Preferably, the length of the first part 131 of the weakened line 13 is less than the length of the first peripheral portion 121 of the pre-laminating opening 12; the length of the second part 132 of the weakened line 13 is less than the length of the second peripheral portion 122 of the pre-laminating opening 12; the length of the third part 133 of the weakened line 13 is less than the length of the third peripheral portion 123 of the pre-laminating opening 12; the length of the fourth part 134 (if present) of the weakened line 13 is less than the length of the fourth peripheral portion 124 (if present) of the pre-laminating opening 12.

[0056] According to one or more embodiments, the packaging material M includes a plurality of crease lines 15. The crease lines 15 are configured to define an edge between two adjacent walls of a sealed package formed by folding and sealing the packaging material M. Specifically, the package 1 is obtained by folding the packaging material M along the crease lines 15. Preferably, the crease lines 15 are obtained by pressing the base layer 10 between pairs of tools such that the base layer 10 is locally deformed and then coupling the base layer 10 with the laminate layer 11. Preferably, the pre-laminated opening 12 does not intersect any of the crease lines 15. In other words, the crease lines 15 are spaced apart from the pre-laminated opening 12. Thus, in the formed package 1, the pre-laminated opening 12 is completely contained within the top wall 5 and does not extend into any of the side walls 7.

[0057] According to one or more embodiments, the packaging material M includes additional pre-laminated openings 14 formed by additional through slots provided in the base layer 10 and covered by one or more of the laminate layers 11. The additional pre-laminated openings 14 are configured to receive a straw connected to an opening device. The straw is configured to allow air to leave the package during pouring of a liquid food through the pre-laminated hole and an opening device connected to the pre-laminated hole. Preferably, the additional pre-laminated openings 14 are circular in shape. Preferably, the pre-laminated opening 12 and the additional pre-laminated openings 14 are located in a region of the sheet material not traversed by any of the crease lines 15; thus, both the pre-laminated opening 12 and the additional pre-laminated openings 14 will be contained within the top wall 5 of the formed package 1.

Claims

1. A multi-layer sheet packaging material (M) for producing a sealed package (1) for pourable food, said packaging material (M) comprising: At least one base layer (10) for imparting stiffness; A plurality of laminated layers (11) applied to both sides of said base layer (10) and covering both sides of said base layer (10); A pre-laminated opening (12) formed by a through slot provided in said base layer (10) and covered by one or more of said laminated layers (11), wherein said pre-laminated opening (12) is configured to receive an opening device for pouring out said pourable food; Characterized in that it further comprises a weakening line (13) in said base layer (10), wherein, in a state where said pre-laminated opening (12) is not ruptured, said pre-laminated opening (12) is completely covered by said one or more laminated layers (11), and said base layer (10) is at least partially cut along said weakening line (13).

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

3. The multi-layer sheet packaging material (M) according to claim 1 or 2, wherein said weakening line (13) comprises a first portion (131) and a second portion (132) extending from said pre-laminated opening (12), and wherein said pre-laminated opening (12) is between said first portion (131) and said second portion (132).

4. The multi-layer sheet packaging material (M) according to claim 3, wherein said sheet packaging material (M) extends in a plane, and wherein said first portion (131) and said second portion (132) extend along said plane.

5. The multi-layer sheet packaging material (M) according to claim 3, wherein said weakening line (13) comprises a third portion (133) extending from said pre-laminated opening (12), and / or wherein said weakening line (13) comprises a fourth portion (134) extending from said pre-laminated opening (12), and wherein said pre-laminated opening (12) is further between said third portion (133) and said fourth portion (134).

6. The multi-layer sheet packaging material (M) according to claim 5, wherein said first portion (131) and said second portion (132) of said weakening line (13) are aligned along a first straight line, and said third portion (133) and said fourth portion (134) of said weakening line (13) are aligned along a second straight line, wherein said first straight line and said second straight line intersect each other, and wherein said pre-laminated opening (12) is located at the intersection of said first straight line and said second straight line.

7. The multi-layer sheet packaging material (M) according to any one of claims 3 to 6, wherein said pre-laminated opening (12) is circular in shape.

8. The multi-layer sheet packaging material (M) according to claim 7, wherein the length of each of said first portion (131) and said second portion (132) is equal to or greater than the diameter of said circular pre-laminated opening (12).

9. The multi-layer sheet packaging material (M) according to claim 8, wherein the weakening line (13) includes a third portion (133) and / or a fourth portion (134) extending from the pre-laminating 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 pre-laminating opening (12).

10. The multi-layer sheet packaging material (M) according to any one of the preceding claims 1 to 6, wherein the pre-laminating opening (12) includes: a central portion (120); a first peripheral portion (121), a second peripheral portion (122), and a third peripheral portion (123) that are angularly spaced from each other, and each of the first peripheral portion (121), the second peripheral portion (122), and the third peripheral portion (123) extends from the central portion (120).

11. The multi-layer sheet packaging material (M) according to claim 10, wherein the weakening line (13) includes a first portion (131), a second portion (132), and a third portion (133), wherein the first portion (131) of the weakening line (13) extends from the first peripheral portion (121) of the pre-laminating opening (12), the second portion (132) of the weakening line (13) extends from the second peripheral portion (122) of the pre-laminating opening (12), the third portion (133) of the weakening line (13) extends from the third peripheral portion (123) of the pre-laminating opening (12).

12. The multi-layer sheet packaging material (M) according to claim 10 or 11, wherein the pre-laminating opening (12) further includes a fourth peripheral portion (124) extending from the central portion (120) and angularly spaced from each of the first peripheral portion (121), the second peripheral portion (122), and the third peripheral portion (123), and the weakening line (13) includes a fourth portion (134) extending from the fourth peripheral portion (124) of the pre-laminating opening (12).

13. The multi-layer sheet packaging material (M) according to any one of the preceding claims, which includes a plurality of crease lines (15) configured to define an edge between two adjacent walls of a sealed package formed by folding and sealing the packaging material (M), and the pre-laminating opening (12) does not intersect any of the crease lines (15).

14. The multi-layer sheet packaging material (M) according to any one of the preceding claims, wherein the base layer (10) is dot-cut along the weakening line (13).

15. The multi-layer sheet packaging material (M) according to any one of the preceding claims, wherein the depth of the weakening line (13) in the base layer (10) is less than the thickness of the base layer (10).

16. The multi-layer sheet packaging material (M) according to any one of the preceding claims, comprising an additional pre-laminated opening (14), said additional pre-laminated opening (14) being formed by an additional through slot provided in the base layer (10) and covered by one or more of the laminating layers (11) in the laminating layer (11).

17. The multi-layer sheet packaging material (M) according to any one of the preceding claims, wherein the weakening line (13) comprises at least a portion that extends parallel to the plane defined by the sheet packaging material (M) from a first end to a second end opposite the first end, wherein the first end is closer to the pre-laminated opening (12) than the second end, and the second end is remote from the pre-laminated opening (12).

18. A sealed package (1) for a pourable food product, formed by folding and sealing a multi-layer sheet packaging material (M) according to any one of the preceding claims, said sealed package (1) being configured to receive an opening device for pouring the pourable food product, wherein the pre-laminated opening (12) is configured to be torn by a cutter of the opening device, thereby defining a pouring opening.

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