Sheet packaging material for producing sealed packages for liquid foods

Abstract

A sheet packaging material for making a sealed package (101) containing a food product, the sealed package (101) including fold lines having sections angled towards each other so that at least two side panels (153, 154) of the sealed package are given a trapezoidal shape.

Description

[Technical field]

[0001] The present invention relates to a sheet packaging material for producing a sealed package containing a liquid food product. It also relates to a sealed package made of the sheet packaging material and containing a liquid food product. [Background technology]

[0002] As is commonly known, many liquid foods, such as fruit juices, pasteurized milk, UHT (ultra-high temperature treated) milk, yogurt and other fermented dairy products, wine, tomato sauce, soup, etc., are sold in different types of packages, some of which are made of sterilized packaging material.

[0003] A typical example of a package is the package for liquids or pourable foods known as Tetra Brik Aseptic®, which is made by folding, sealing and cutting a web of laminated packaging material. In particular, the packaging material has a multi-layer structure, including a base layer, for example paper, covered on both sides with a layer of heat-sealable plastic material, such as polyethylene. In the case of aseptic packages for long-term storage products such as UHT milk, the packaging material also includes a layer of oxygen barrier material, such as aluminum foil, superimposed on the layer of heat-sealable plastic material, which in turn is covered with another layer of heat-sealable plastic material that ultimately forms the inner surface of the package that contacts the food.

[0004] This type of package is usually produced by a fully automatic packaging machine in which a continuous tube is formed from the web of wound packaging material, and the web of packaging material is often sterilized on-board the packaging machine by applying a chemical sterilant, e.g. hydrogen peroxide, which is removed from the surface of the packaging material once sterilization is complete and evaporated, e.g. by heating. The so-sterilized web is then kept in a closed, sterile environment and folded longitudinally into a vertically fed tube and sealed.

[0005] To complete the forming operation, the tubes are filled with liquid food, which may be sterilized if applicable, sealed along the evenly spaced cross sections and subsequently cut, so that pillow packs are obtained which are then mechanically folded to form the respective finished packages in a final folder.

[0006] To allow folding of the web packaging material both during formation and final folding, fold lines, or lines of weakness, are formed in the packaging material by creasing tools at the manufacturing plant, which in effect define the fold lines along which the pillow pack is folded to obtain the desired final configuration.

[0007] Alternatively, the packaging material can be cut into blanks, which are folded into packages upon spindle formation. The resulting packages are then filled with food product and sealed. An example of this type of package is the so-called "gable top" package known from Tetra Rex®.

[0008] To open the above mentioned packages, they may be provided with a removable part, which is partially separated by an opening device from the remainder of the packaging material to release a pouring opening for pouring out the product.

[0009] A removable portion is formed on the wrapping material before the wrapping material is folded and sealed to form the finished package.

[0010] The removable portion may include a "pre-laminated" hole, i.e., a circular hole formed through a base layer made of packaging material only and covered with a layer of heat seal plastic material and shielding material that are bonded together at the hole when the materials are laminated.

[0011] Each package of the above type, cut from a tube of packaging material or formed on a forming spindle, is obtained from an elementary unit of packaging material having a given fold line.

[0012] In other words, the basic unit above represents the exact length of packaging material used to produce one single package.

[0013] In the case of packages made from a tube of packaging material, the original web comprises a plurality of elementary units joined together, whereas in the case of packages made on a forming spindle, the elementary units are defined by blanks cut from the web before the forming and sealing operation begins.

[0014] The basic unit typically has a rectangular or square configuration with two boundary edges parallel to the longitudinal direction and two other boundary edges parallel to the transverse direction perpendicular to the longitudinal direction.

[0015] When the elementary units are folded and sealed to form the finished package, the longitudinal direction is the direction which defines the overall height of the package itself, and the longitudinal direction also represents the main direction of extension of the web from which the elementary units are derived.

[0016] The basic unit typically includes at least two transverse fold lines that extend transversely to the longitudinal direction and divide the basic unit into a bottom region that includes a bottom fold line pattern and is configured to form the bottom of the finished package, a top region that includes a top fold line pattern and is configured to form the top of the finished package, and a middle region that is interposed between the bottom and top regions and is typically included between the transverse fold lines having a plurality of longitudinal fold lines designed to form the lateral edges of the plurality of side walls of the finished package. Depending on the package orientation, the middle region of the basic unit may instead form the top, bottom and two opposite sides of the package, while the bottom and top regions of the basic unit form the two remaining opposite sides of the package.

[0017] The bottom of the finished package typically includes a flat, horizontal bottom panel that defines the resting surface of the package itself.

[0018] The top of the finished package may include a flat, horizontal top panel parallel to the bottom panel. For some types of packages, inclined top panels are advantageously used in combination with an opening device, since they are wider than the corresponding flat top panels of parallelepiped or rectangular packages, thus allowing the application of larger opening devices, for example provided with a screw cap. Opening devices and principles other than those mentioned are also often used.

[0019] As is known, after their production, the packages are transported to the point of sale by being placed on transport pallets having a predetermined size, therefore the need to maintain an attractive appearance of such packages whilst optimizing the filling of the transport pallets with the finished packages is particularly felt in the packaging field.

[0020] Different sizes and shapes of packages are often desirable depending on the product and intended application area of ​​the package, and sometimes how the package is intended to be opened. Summary of the Invention [Problem to be solved by the invention]

[0021] It is therefore an object of the present invention to provide a sheet packaging material and a sealed package containing a liquid food product that can meet the above needs and desires in a simple and cost-effective manner. [Means for solving the problem]

[0022] To solve these objects, sheet packaging materials and packages according to the appended claims are provided. The sheet packaging materials and packages are advantageous in that they provide a package having a shape similar to a cup, with a base narrower than its top, i.e. the area of ​​the bottom of the package is smaller than the area of ​​the top of the package. This makes it easier to dispense the product from the package, especially when spooning the product from the package.

[0023] Other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description and drawings.

[0024] Embodiments of the present invention will now be described, by way of example, with reference to the accompanying schematic drawings. [Brief description of the drawings]

[0025] [Figure 1a] FIG. 2 is a top view of a sheet packaging material for producing a sealed package according to the first embodiment. [Figure 1b] FIG. 1b is a perspective view of a package made from the sheet packaging material shown in FIG. 1a. [Figure 1c] FIG. 1b is a side view of a package made from the sheet packaging material shown in FIG. 1a. [Figure 1d]FIG. 1b is a bottom view of a package made from the sheet packaging material shown in FIG. 1a. [Figure 2a] FIG. 11 is a top view of a sheet packaging material for producing a sealed package according to a second embodiment. [Figure 2b] FIG. 2b is a perspective view of a package made from the sheet packaging material shown in FIG. 2a. [Figure 2c] FIG. 2b is a side view of a package made from the sheet packaging material shown in FIG. 2a. [Figure 2d] FIG. 2b is a bottom view of a package made from the sheet packaging material shown in FIG. 2a. [Figure 3a] FIG. 10 is a top view of a sheet packaging material for producing a sealed package according to a third embodiment. [Figure 3b] FIG. 3b is a perspective view of a package made from the sheet packaging material shown in FIG. 3a. [Figure 3c] FIG. 3b is a side view of a package made from the sheet packaging material shown in FIG. 3a. [Figure 3d] FIG. 3b is a bottom view of a package made from the sheet packaging material shown in FIG. 3a. [Figure 4a] FIG. 3b is a top view of the sheet packaging material shown in FIG. 3a, also showing the aperture structure. [Figure 4b] FIG. 4b is a perspective view of a package made from the sheet packaging material shown in FIG. 4a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] With reference to Figures la-ld, a sheet packaging material 100 for producing a sealed package 101 containing a food product is shown. The sheet packaging material 100 corresponds to the "basic unit" referred to above. It is made of a web of laminated packaging material having a multi-layer structure including a base layer, for example of paper, covered on both sides with layers of heat-sealable plastic material, such as polyethylene. It may also have a layer of oxygen barrier material, such as aluminium foil, superimposed on the layer of heat-sealable plastic material and thus covered with another layer of heat-sealable plastic material, which ultimately forms the inner surface of the package that contacts the food product.

[0027] In order to fold the sheet packaging material 100 into the package 101, it has several fold lines, i.e. lines of weakness, formed on the packaging material by a creasing tool in the manufacturing plant. The folding of the sheet packaging material 100 to form the package 101 is performed along these fold lines. The production of the web of laminated packaging material from which the sheet packaging material 100 is made is accomplished by any suitable and commonly available technique per se. Also, any suitable and commonly available technique may be used to create the fold lines on the sheet packaging material 100. Known techniques may also be used to fold the sheet packaging material 100 into the sealed package 101 for filling with the liquid food product and for performing the final sealing to form the sealed package 101 containing the product. The invention herein is particularly concerned with the particular configuration of the fold lines and thus the final shape of the sealed package 101.

[0028] In particular, the sheet packaging material 100 has four edges. A first edge 1 and a second edge 2 are two opposite parallel edges. A third edge 3 and a fourth edge 4 are two opposite parallel edges. The third and fourth edges 3, 4 are connected to the first and second edges 1, 2, thereby making the sheet packaging material 100 rectangular.

[0029] The first fold line 11 and the second fold line 12 extend parallel between the first and second edges 1, 2 from the first edge 1 to the second edge 2. The third fold line 13 and the fourth fold line 14 extend parallel between the first and second edges 1, 2 and are between the first and second fold lines 11, 12. The third fold line 13 and the fourth fold line 14 are therefore closer to the center of the sheet packaging material 100 than the first fold line 11 and the second fold line 12. The fifth fold line 15 and the sixth fold line 16 extend between the first and second fold lines 11, 12. The seventh fold line 17 and the eighth fold line 18 extend between the first and second fold lines 11, 12 and are between the fifth and sixth fold lines 15, 16. The seventh fold line 17 and the eighth fold line 18 are therefore closer to the center of the sheet packaging material 100 than the fifth fold line 15 and the sixth fold line 16.

[0030] Fold lines 11-18 divide sheet packaging material 100 into seven sections: a central section 50, a first side section 51, a second side section 52, a third side section 53, a fourth side section 54 and two end sections 55a, 55b.

[0031] The central portion 50 has a rectangular shape and forms a top panel 150 of the sealed package 101, see FIG. 1b. The first side portion 51 and the second side portion 52 are adjacent to the central portion 51 and opposite each other, forming the first side panel 151 and the second side panel 152 of the sealed package 101. The third side portion 53 and the fourth side portion 54 are adjacent to the central portion 51 and opposite each other, forming the third side panel 153 and the fourth side panel 154 of the sealed package 101. The two ends 55a, 55b are adjacent two of the side portions 53, 54, more specifically and in the illustrated embodiment adjacent the third side portion 53 and the fourth side portion 54. The ends 55a, 55b are arranged to be joined to each other to form the bottom panel 155 of the sealed package 101 when the sheet packaging material 100 is folded into the sealed package 101. The ends 55a, 55b overlap at a line indicated by reference number 6.

[0032] The seventh and eighth fold lines 17, 18 have a first pair of fold sections 17a, 18a that define two opposite sides of the first side portion 51. The first pair of fold sections 17a, 18a are angled towards each other such that the first side portion 51 has a trapezoidal shape.

[0033] The seventh and eighth fold lines 17, 18 also have a second pair of fold sections 17b, 18b that define two opposite sides of the second side portion 52. The second pair of fold sections 17b, 18b are angled toward each other such that the second side portion 52 also has a trapezoidal shape.

[0034] The resulting trapezoids, when folded from the sheet packaging material 100, give the sealed package 101 side panels that also have a trapezoidal shape, see two panels 153 and 154 in Figures 1b-1d and four panels 151-154 in Figures 2b-2d and 3b-3d, respectively. More specifically, the trapezoidal panels have an isosceles trapezoidal shape. As a result, the area of ​​the bottom panel 155 is smaller than the area of ​​the top panel 150. This makes it easier to dispense the product from the package, especially when spooning the product from the sealed package 101. Some examples of products that may be contained in the sealed package 101 are yogurt and other fermented dairy products.

[0035] The first pair of fold sections 17a, 18a are positioned opposite the second pair of fold sections 17b, 18b when viewed relative to the central portion 50. The distance D between the angled fold sections of the first fold sections 17a, 18a and the second fold sections 17b, 18b decreases with distance from the central portion 50. This gives the top 150 of the sealed package 101 an area that is greater than the area of ​​the bottom 155 of the sealed package 101.

[0036] The first pair of folding sections 17a, 18a may be inclined towards each other at the same angle such that the first side portion 51 has the shape of an isosceles trapezoid. A corresponding situation may apply for the second pair of folding sections 17b, 18b, i.e. they may be inclined towards each other at the same angle such that the second side portion 52 has the shape of an isosceles trapezoid.

[0037] To fold the packaging material 100 into the sealed package 101, it may have fold lines 11-18 dividing the sheet packaging material 100 into again four flap portions 61-64, with the first flap portion 61 and the second flap portion 62 adjacent to and on the opposite side of the first side portion 51 to form first and second flaps folded at the first side panel 151 of the sealed package 101. The third and fourth flap portions 63 and 64 adjacent to and on the opposite side of the second side portion 52 to form third and fourth flaps 158 and 159 folded at the second panel 152 of the sealed package 101. The fifth and sixth fold lines 15, 16 have a third pair of folding sections 15a, 16a which together with the first pair of folding sections 17a, 18a define the sides of the first and second flap portions 61, 62. The third pair of fold sections 17a, 18a are angled towards each other such that the first and second flap portions 61, 62 have a quadrilateral shape. The fifth and sixth fold lines 15, 16 also have a fourth pair of fold sections 15b, 16b which together with the second pair of fold sections 17b, 18b define the sides of the third and fourth flap portions 63, 64. The fourth pair of fold sections 15b, 16b are angled towards each other such that the third and fourth flap portions 63, 62 have a quadrilateral shape. In some embodiments, the flap portions 61-64 have a parallelogram shape (FIGS. 1a-1d), while in other embodiments they have a quadrilateral shape (FIGS. 2a-2d and 3a-3d).

[0038] The first flap portion 61 may have a respective pair of fold lines 22a, 22b that divide the first flap portion 61 into three sections 61a, 61b, 61c each having a triangular shape. The first fold line 22a of the fold line pair 22a, 22b is longer and located further away from a center line A1 that extends through the centers of the first and second side portions 51, 52 compared to the second fold line 22b of the fold line pair 22a, 22b. Another center line A2 is perpendicular to the center line A1 and extends through the centers of the third and fourth side portions 53, 54.

[0039] The second, third and fourth flap portions 62-64 may have corresponding pairs of fold lines 19a, 19b, 21a, 21b, 20a, 20b that divide the second, third and fourth flap portions 62-64 into three respective sections 62a-62c, 63a-63c and 64a-64c, each having a triangular shape.

[0040] 2a-2d and 3a-3d, the third and fourth fold lines 13, 14 may have a fifth pair of fold sections 13a, 14a that define two opposite sides of the third side portion 53. The fifth pair of fold sections 13a, 14a are angled towards each other such that the third side portion 53 has a trapezoidal shape. In a corresponding manner, the third and fourth fold lines 13, 14 may include a sixth pair of fold sections 13b, 14b that define two opposite sides of the fourth side portion 54. The sixth pair of fold sections 13b, 14b are angled towards each other such that the fourth side portion 54 has a trapezoidal shape. From the fifth pair of fold sections 13a, 14a and the sixth pair of fold sections 13b, 14b, the fold lines 13, 14 have end sections 13c, 14c and 13d, 14d extending parallel to the third and fourth edges 3, 4 to the first and second edges 1, 2, respectively.

[0041] The distance between the angled fold sections of the fifth fold section 13a, 14a and the sixth fold section 13b, 14b decreases with distance from the central portion 50. As a result, the area of ​​the top 150 of the sealed package 101 is much larger than the area of ​​the bottom 155 of the sealed package 101.

[0042] The fifth pair of folding sections 13a, 14a may be inclined toward one another at the same angle such that the third side portion 53 has the shape of an isosceles trapezoid. The sixth pair of folding sections 13b, 13b may also be inclined toward one another at the same angle such that the fourth side portion 54 has the shape of an isosceles trapezoid.

[0043] 3a-3d, the four flap portions 61-64 and their respective fold lines 22a, 22b may be shaped and proportioned such that the flaps do not overlap when folded toward one another on the sealed package 101 as shown, see particularly FIG. 3b.

[0044] With reference to Figures 4a and 4b, the sheet packaging material 100 may have an opening structure 200 extending along at least three sides of the central portion 50. This allows the top panel 150 to be released so that the sealed package 101 can be opened. An example of an opening structure is a conventional plastic steering ribbon that is partially made up of the relevant edge of the central portion 50. A pull-tab system that tears the package along the edge of the central portion may also be used. Alternatively or additionally, the opening structure 200 may be a weakened edge that allows the consumer to push through the package so that it breaks open along the weakened edge. In one embodiment, the package does not have an opening structure, in which case it may be opened with, for example, a knife or a pair of sharp scissors. Other shapes of opening structures different from the one shown may be used. For example, it may have the shape of a cross located on the top panel 150.

[0045] By using the described sheet packaging material 100, a sealed package 101 may be produced that can be sealed to contain a liquid food product enclosed within the sealed package 101.

[0046] From the above description, while various embodiments of the present invention have been described and illustrated, the present invention is not limited thereto but may be embodied in other ways within the scope of the subject matter defined in the following claims.

Claims

1. A sheet packaging material (100) for making a sealed package (101) containing a food product, said sheet packaging material (100) comprising: a first edge (1), a second edge (2) parallel to the first edge (1), a third edge (3), and a fourth edge (4) parallel to the third edge (3), the third and fourth edges (3, 4) connecting the first and second edges (1, 2) such that the sheet packaging material (100) has a rectangular shape; a first fold line (11) and a second fold line (12) extending parallel between the first and second edges (1, 2); a third fold line (13) and a fourth fold line (14) extending parallel between the first and second edges (1, 2) and between the first and second fold lines (11, 12); a fifth fold line (15) and a sixth fold line (16) extending between the first and second fold lines (11, 12); a seventh fold line (17) and an eighth fold line (18) extending between the first and second fold lines (11, 12) and between the fifth and sixth fold lines (15, 16); Including, The folding lines (11 to 18) form the sheet packaging material (100). - a rectangular central portion (50) adapted to form the top panel (150) of said sealed package (101); - a first side portion (51) and a second side portion (52) adjacent said central portion (50) and on opposite sides thereof, configured to form a first side panel (151) and a second side panel (152) of said sealed package (101); - a third side portion (53) and a fourth side portion (54) adjacent to said central portion (50) and on opposite sides thereof, configured to form a third side panel (153) and a fourth side panel (154) of said sealed package (101); - two ends (55a, 55b) adjacent two of said side portions (53, 54) and adapted to be joined together to form a bottom panel (155) of said sealed package (101); In a sheet packaging material (100), the seventh and eighth fold lines (17, 18) include a first pair of folding sections (17a, 18a) defining two opposite sides of the first side portion (51), the first pair of folding sections (17a, 18a) being angled towards each other such that the first side portion (51) has a trapezoidal shape; the seventh and eighth fold lines (17, 18) include a second pair of fold sections (17b, 18b) defining two opposite sides of the second side portion (52), the second pair of fold sections (17b, 18b) being angled towards each other such that the second side portion (52) has a trapezoidal shape; a distance (D) between the angled fold sections of the first pair of fold sections (17a, 18a) and the second pair of fold sections (17b, 18b) decreases with distance from a central portion (50) such that an area of ​​the top panel (150) of the sealed package (101) is greater than an area of ​​the bottom panel (155) of the sealed package (101); A sheet packaging material (100).

2. 2. The sheet packaging material (100) of claim 1, wherein the first pair of fold sections (17a, 18a) are located opposite the second pair of fold sections (17b, 18b) when viewed relative to the central portion (50).

3. A sheet packaging material (100) for making a sealed package (101) containing a food product, the sheet packaging material (100) comprising: a first edge (1), a second edge (2) parallel to the first edge (1), a third edge (3), and a fourth edge (4) parallel to the third edge (3), the third and fourth edges (3, 4) connecting the first and second edges (1, 2) such that the sheet packaging material (100) has a rectangular shape; a first fold line (11) and a second fold line (12) extending parallel between the first and second edges (1, 2); a third fold line (13) and a fourth fold line (14) extending parallel between the first and second edges (1, 2) and between the first and second fold lines (11, 12); a fifth fold line (15) and a sixth fold line (16) extending between the first and second fold lines (11, 12); a seventh fold line (17) and an eighth fold line (18) extending between the first and second fold lines (11, 12) and between the fifth and sixth fold lines (15, 16); Including, The folding lines (11 to 18) form the sheet packaging material (100). - a rectangular central portion (50) adapted to form the top panel (150) of said sealed package (101); - a first side portion (51) and a second side portion (52) adjacent said central portion (50) and on opposite sides thereof, configured to form a first side panel (151) and a second side panel (152) of said sealed package (101); - a third side portion (53) and a fourth side portion (54) adjacent to said central portion (50) and on opposite sides thereof, configured to form a third side panel (153) and a fourth side panel (154) of said sealed package (101); - two ends (55a, 55b) adjacent two of said side portions (53, 54) and adapted to be joined together to form a bottom panel (155) of said sealed package (101); In a sheet packaging material (100), the seventh and eighth fold lines (17, 18) include a first pair of folding sections (17a, 18a) defining two opposite sides of the first side portion (51), the first pair of folding sections (17a, 18a) being angled towards each other such that the first side portion (51) has a trapezoidal shape; the seventh and eighth fold lines (17, 18) include a second pair of fold sections (17b, 18b) defining two opposite sides of the second side portion (52), the second pair of fold sections (17b, 18b) being angled towards each other such that the second side portion (52) has a trapezoidal shape; the sheet packaging material (100) includes an opening structure (200) extending along at least three sides of the central portion (50) to allow the top panel (150) to be released so that the sealed package (101) can be opened; A sheet packaging material (100).

4. a first pair of said folding sections (17a, 18a) inclined towards each other at the same angle such that said first side portion (51) has the shape of an isosceles trapezoid; a second pair of said folded sections (17b, 18b) inclined towards each other at the same angle such that said second side portion (52) has the shape of an isosceles trapezoid; A sheet packaging material (100) according to any one of claims 1 to 3.

5. A sheet packaging material (100) for making a sealed package (101) containing a food product, said sheet packaging material (100) comprising: a first edge (1), a second edge (2) parallel to the first edge (1), a third edge (3), and a fourth edge (4) parallel to the third edge (3), the third and fourth edges (3, 4) connecting the first and second edges (1, 2) such that the sheet packaging material (100) has a rectangular shape; a first fold line (11) and a second fold line (12) extending parallel between the first and second edges (1, 2); a third fold line (13) and a fourth fold line (14) extending parallel between the first and second edges (1, 2) and between the first and second fold lines (11, 12); a fifth fold line (15) and a sixth fold line (16) extending between the first and second fold lines (11, 12); a seventh fold line (17) and an eighth fold line (18) extending between the first and second fold lines (11, 12) and between the fifth and sixth fold lines (15, 16); Including, The folding lines (11 to 18) form the sheet packaging material (100). - a rectangular central portion (50) adapted to form the top panel (150) of said sealed package (101); - a first side portion (51) and a second side portion (52) adjacent said central portion (50) and on opposite sides thereof, configured to form a first side panel (151) and a second side panel (152) of said sealed package (101); - a third side portion (53) and a fourth side portion (54) adjacent to said central portion (50) and on opposite sides thereof, configured to form a third side panel (153) and a fourth side panel (154) of said sealed package (101); - two ends (55a, 55b) adjacent two of said side portions (53, 54) and adapted to be joined together to form a bottom panel (155) of said sealed package (101); In a sheet packaging material (100), the seventh and eighth fold lines (17, 18) include a first pair of folding sections (17a, 18a) defining two opposite sides of the first side portion (51), the first pair of folding sections (17a, 18a) being angled towards each other such that the first side portion (51) has a trapezoidal shape; the seventh and eighth fold lines (17, 18) include a second pair of fold sections (17b, 18b) defining two opposite sides of the second side portion (52), the second pair of fold sections (17b, 18b) being angled towards each other such that the second side portion (52) has a trapezoidal shape; The fold lines (11-18) form the sheet packaging material (100), a first flap portion (61) and a second flap portion (62) adjacent to said first side portion (51) and on an opposite side of said first side portion (51), the first flap portion (61) and the second flap portion (62) being configured to form first and second flaps to be folded over said first side panel (151) of said sealed package (101); a third flap portion (63) and a fourth flap portion (64) adjacent to and on an opposite side of the second side portion (52) and configured to form a third flap (158) and a fourth flap (159) that are folded over the second side panel (152) of the sealed package (101); Divide into the fifth and sixth fold lines (15, 16) include a third pair of folding sections (15a, 16a) which together with the first pair of folding sections (17a, 18a) define sides of the first and second flap portions (61, 62), the third pair of folding sections (17a, 18a) being angled towards each other such that the first and second flap portions (61, 62) have the shape of a parallelogram; the fifth and sixth fold lines (15, 16) include a fourth pair of folding sections (15b, 16b) which together with the second pair of folding sections (17b, 18b) define sides of the third and fourth flap portions (63, 64), the fourth pair of folding sections (15b, 16b) being angled towards each other such that the third and fourth flap portions (63, 64) have the shape of a parallelogram; A sheet packaging material (100).

6. Each flap portion (61) includes a respective pair (22a, 22b) of fold lines that divide the flap portion (61) into three sections (61a, 61b, 61c) each having a triangular shape, and the first fold line (22a) of the pair (22a, 22b) of fold lines is compared to the second fold line (22b) of the pair (22a, 22b) such that - Longer, - located further away from a centre line (A1) extending through the centres of said first and second side portions (51, 52); The sheet packaging material (100) of claim 5.

7. the third and fourth fold lines (13, 14) include a fifth pair of fold sections (13a, 14a) defining two opposite sides of the third side portion (53), the fifth pair of fold sections (13a, 14a) being angled towards each other such that the third side portion (53) has a trapezoidal shape; 7. The sheet packaging material (100) of any one of claims 1 to 6, wherein the third and fourth fold lines (13, 14) include a sixth pair of fold sections (13b, 14b) defining two opposite sides of the fourth side portion (54), the sixth pair of fold sections (13b, 14b) being angled towards each other such that the fourth side portion (54) has a trapezoidal shape.

8. 8. The sheet packaging material (100) of claim 7, wherein a distance between the angled fold sections of the fifth pair of fold sections (13a, 14a) and the sixth pair of fold sections (13b, 14b) decreases with distance from a central portion (50) such that an area of ​​the top panel (150) of the sealed package (101) is greater than an area of ​​the bottom panel (155) of the sealed package (101).

9. a fifth pair (13a, 14a) of said folded sections incline towards each other at the same angle such that said third side portion (53) has the shape of an isosceles trapezoid; 9. The sheet packaging material (100) of claim 7 or 8, wherein the sixth pair (13b, 13b) of folded sections are inclined towards each other at the same angle such that the fourth side portion (54) has the shape of an isosceles trapezoid.

10. 2. The sheet packaging material (100) of claim 1, wherein the sheet packaging material (100) includes an opening structure (200) extending along at least three sides of the central portion (50) to allow the top panel (150) to be released so that the sealed package (101) can be opened.

11. A sealed package (101) made of the sheet packaging material (100) according to any one of claims 1 to 10, comprising a liquid food product contained within said sealed package (101).

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