Sheet-like packaging material for producing sealed packages containing pourable products and packages obtained therefrom

Abstract

A sheet-like packaging material (1, 1', 1'', 1''') for producing a sealed packaging container (P) has two first boundary edges (3, 4) parallel to a longitudinal direction (A) and two second boundary edges (5, 6) parallel to a transverse direction (B) perpendicular to the longitudinal direction (A); the sheet-like packaging material (1, 1', 1'', 1''') has at least a bottom transverse fold line including a bottom central portion (7a, 7a'', 7a'''), at least one bottom end portion (7b, 7b'', 7b'''), and at least one bottom side portion (7c, 7c'', 7c'''). the sheet-like packaging material comprises at least one pair of inclined fold lines (20, 21; 20", 21") inclined with respect to both the longitudinal direction (A) and the transverse direction (B), the inclined fold lines (20, 21; 20", 21") having a first end pointing to one (5) of the second boundary edges (5, 6) and a second end pointing to a continuous line (C) that is parallel to the transverse direction (B) and includes the bottom central portion (7a, 7a", 7a'") and the at least one bottom end portion (7b, 7b", 7b'"); the inclined fold lines (20, 21; 20", 21") delimit flap regions (22) of the sheet-like packaging material (1, 1', 1", 1'") that are designed to form, together with the at least one bottom side portion (7c, 7c", 7c'"), at least a part of a side flap of the packaging container (P); the projection of each inclined fold line (20, 21; 20", 21") on the continuous line (C) along a respective direction parallel to the inclined fold lines (20, 21; 20", 21") forms one respective projection on the continuous line (C). a first point (Q1) of the sheet-like packaging material; the sheet-like packaging material further includes at least one pair of longitudinal fold lines (19a, 19b; 19a', 19b'; 19a'', 19b'') disposed on both sides of the flap region (22) with respect to the transverse direction (B) and together defining fold lines around which the side flaps are designed to be folded; each longitudinal fold line (19a, 19b; 19a', 19b') on the continuous line (C) along a respective direction parallel to the longitudinal fold lines (19a, 19b; 19a', 19b'; 19a'', 19b'');19a'', 19b'') identify one respective second point (Q2) on said continuous line (C), said second point (Q2) being located on one side of said flap region (22) and spaced apart along said lateral direction (B) by a lateral offset (T) from a corresponding first point (Q1) located on the same one side of said flap region (22);

Description

[Technical field]

[0001] The present invention relates to a sheet-like packaging material for producing sealed packages containing pourable products, especially pourable food products.

[0002] The present invention also relates to a sealed package containing a pourable product, in particular a pourable food product, obtained from the sheet-like packaging material described above. [Background technology]

[0003] As is known, many pourable food products, such as fruit juices, UHT (ultra-high temperature treated) milk, wine, tomato sauce, etc., are sold in packaging containers made of sterile packaging material.

[0004] A typical example is the parallelepiped packaging container for liquids or pourable foods known as Tetra Brik Aseptic®, which is made by folding, sealing and cutting a laminated web of packaging material. In particular, the packaging material has a multi-layer structure comprising a base layer, e.g. paper, covered on both sides with a layer of heat-sealable plastic material, e.g. polyethylene. In the case of aseptic packaging containers for long-storage products such as UHT milk, the packaging material also comprises a barrier layer of oxygen barrier material, e.g. aluminium foil, which is superimposed on a layer of heat-sealable plastic material and then covered with another layer of heat-sealable plastic material that finally forms the inner surface of the packaging container that comes into contact with the food.

[0005] Typically, packaging containers of this kind are produced in a fully automatic packaging machine, in which a continuous tube is formed from the packaging material fed in a web; the web of packaging material is sterilized in the packaging machine by application of a chemical sterilant, e.g. a hydrogen peroxide solution, 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 maintained in a closed, sterile environment and folded longitudinally and sealed to form a tube, which is fed vertically.

[0006] To complete the forming operation, the tube is filled with sterilized or pre-sterilized food, sealed and subsequently cut along equally spaced cross sections, the pillow packs thus obtained being then mechanically folded to form the respective finished packaging containers in a final folding machine.

[0007] To allow for folding of the web-like packaging material both during formation and during final folding, crease lines, or lines of weakness, are formed in the packaging material at the packaging material manufacturing plant by creasing rolls, which in effect define the fold lines along which the pillow pack will be folded into its intended final configuration.

[0008] Alternatively, the packaging material can be cut into blanks which are formed into packages on a forming spindle and then the resulting packages are filled with the food product and sealed. One example of this type of package is the so-called "gable top" package known under the trade name Tetra Rex®.

[0009] To open said packaging containers, they usually comprise a removable part, which is partially separated from the remaining packaging material by a reclosable opening device to release a pouring opening for pouring the product.

[0010] The removable portion is formed on the packaging material prior to folding and sealing the packaging material to form the finished package.

[0011] The removable portion typically comprises a so-called "pre-laminate" hole, i.e. a circular hole formed only through the base layer of the packaging material and covered with layers of heat-sealable plastic material and barrier material that adhere to each other at the hole when the materials are laminated.

[0012] Each packaging container of the above types is obtained from an elementary unit of packaging material which is either cut from a tube of packaging material or formed and scored on a forming spindle.

[0013] In other words, the basic unit above represents the exact length of packaging material used to produce a single packaging container.

[0014] In the case of a packaging container made from a tube of packaging material, the original web comprises a plurality of elementary units joined together, whereas in the case of a packaging container made on a forming spindle, the elementary units are defined by blanks.

[0015] The basic unit typically has a rectangular or square configuration with two first boundary edges parallel to the vertical direction and two second boundary edges parallel to the horizontal direction perpendicular to the vertical direction, so that the second boundary edges are perpendicular to the first boundary edges.

[0016] When the basic units are folded and sealed to form the respective finished packaging containers, the longitudinal direction is the direction in which the overall height of the packaging container is defined, and the longitudinal direction also represents the main extension direction of the web from which the basic units are obtained.

[0017] The basic unit typically includes at least two transverse fold lines extending transversely to the machine direction and dividing the basic unit into: - a bottom region including a bottom fold pattern and configured to form the bottom of a finished packaging container; - a top region including a top fold pattern and configured to form a top portion of a finished package; and - A middle region that is contained between the transverse fold lines and inserted between the bottom and top regions and is configured to form a lateral main portion of the finished package, and that typically has a middle fold pattern, i.e., a plurality of longitudinal fold lines designed to form the lateral edges of a plurality of side walls of the lateral main portion.

[0018] Alternatively, some types of packages are obtained by folding and sealing a basic unit of packaging material that has no longitudinal fold lines in the intermediate region.

[0019] In view of the above, the basic unit includes a top transverse fold line and a bottom transverse fold line, which also have an infinite configuration and are configured to define top and bottom peripheral edges, respectively, of the finished packaging container that separate the bottom and top, respectively, from the lateral main portions of the finished packaging container.

[0020] The bottom of the finished package typically includes a bottom panel that defines the resting surface of the package.

[0021] The top of the finished package may include a flat, horizontal top panel parallel to the bottom panel, or a gable-top portion or a sloping top is very conveniently used in combination with a reclosable opening device, since the sloping top panel is wider than the corresponding flat top panel of a parallelepiped or prismatic package, thus allowing the attachment of a larger opening device, e.g. with a screw cap or the like.

[0022] Generally, the top and bottom fold patterns include respective longitudinal crease lines that are parallel to the longitudinal direction and extend within the top or bottom regions, respectively.

[0023] More precisely, each of the top and bottom crease patterns includes four such longitudinal crease lines, two more lateral and two more medial relative to the first boundary edge of the base unit.

[0024] Between each pair of such longitudinal creases, i.e., between one inner longitudinal crease and a corresponding outer longitudinal crease, there are two inclined creases, which are inclined with respect to both the longitudinal and transverse directions.

[0025] In particular, each pair of inclined fold lines has a common end located on a further lateral fold line parallel to the top or bottom lateral fold line, respectively, and an opposite end located at the intersection between such top or bottom lateral fold line, respectively, and a longitudinal fold line of the same pair.

[0026] In this manner, each pair of angled crease lines delimits a triangle with a segment of the top or bottom transverse crease line contained between the opposite ends of such angled crease lines.

[0027] Each area between the longitudinal fold lines is configured to define a respective top or bottom side flap of one of the finished packages.

[0028] In particular, once formed, the two top side flaps are folded outwardly along their respective longitudinal fold lines toward the lateral main portion of the package, while the two bottom side flaps are folded inwardly along their respective longitudinal fold lines toward the bottom panel of the package.

[0029] It is known in the art that weakening of the sheet packaging material may occur during folding of the bottom side flaps of the packaging container, particularly along the aforementioned longitudinal fold lines.

[0030] More precisely, this weakening may occur due to the fact that the bottom side flaps need to be folded inwardly towards the interior of the packaging container at a complementary angle to the horizontal to ensure a proper planar or substantially dome-shaped configuration of the bottom edge on which the packaging container stands upright during use, thereby ensuring the stability of the packaging container.

[0031] Although the sheet-like packaging materials known in the art are structurally and functionally effective, there is still room for further improvement, in particular to avoid weakening of said sheet-like packaging materials during folding of the bottom side flaps and to avoid non-optimal formation of the packaging container, in particular at the corners of the packaging container. Summary of the Invention [Problem to be solved by the invention]

[0032] It is therefore an object of the present invention to provide a sheet-like packaging material designed to meet the above needs simply and at low cost. [Means for solving the problem]

[0033] This object is achieved by a sheet-like packaging material according to claim 1.

[0034] Four non-limiting embodiments of the present invention will now be described by way of example with reference to the accompanying drawings. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a front view of a basic unit of a sheet-type packaging material according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a partial elevational view, on a larger scale, of a detail of the sheet packaging material of FIG. 1; [Diagram 3] FIG. 11 is a front view of a basic unit of a sheet-type packaging material according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a partial elevational view, on a larger scale, of a detail of the sheet packaging material of FIG. 3. [Diagram 5] FIG. 11 is a front view of a basic unit of a sheet-type packaging material according to a third embodiment of the present invention. [Figure 6] FIG. 6 is a partial elevational view, on a larger scale, of a detail of the sheet packaging material of FIG. 5. [Figure 7] FIG. 10 is a front view of a basic unit of a sheet-type packaging material according to a fourth embodiment of the present invention. [Figure 8] FIG. 8 is a partial elevational view, on a larger scale, of a detail of the sheet packaging material of FIG. 7. [Figure 9] FIG. 2 is a perspective view of a packaging container obtained from the basic unit of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] With reference to FIG. 1, the number 1 indicates as a whole a basic unit of sheet-like packaging material 2 for producing a sealed packaging container P (FIG. 9) containing a pourable product, in particular a pourable food product such as fruit juice, UHT (ultra-high temperature treated) milk, wine, tomato sauce, etc.

[0037] In particular, the packaging material 2 has a known multi-layer structure (not shown) including a base layer, for example made of paper for rigidity, and a number of laminate layers covering both sides of the base layer.

[0038] Preferably, the laminate layer comprises one layer of oxygen barrier material, for example aluminium foil, and multiple layers of heat-sealing plastic material covering both sides of the base layer and both sides of the layer of oxygen barrier material. In other words, by proceeding from the side that will ultimately form the interior of the packaging container P, the packaging material 2 comprises one layer of heat-sealing plastic material, one layer of oxygen barrier material, another layer of heat-sealing plastic material, a base layer and one or more additional layers of heat-sealing plastic material.

[0039] As shown in FIG. 1, the basic unit 1 of the packaging material 2 is of rectangular configuration and is divided as follows: - two side boundary edges 3, 4 parallel to the longitudinal direction A, which coincides with the longitudinal direction of the basic unit 1 in its upright position; - a bottom boundary edge 5 parallel to a transverse direction B perpendicular to the longitudinal direction A, and - an upper boundary edge 6 parallel to the lateral direction B and to the bottom boundary edge 5;

[0040] In particular, the longitudinal direction A is the direction in which the overall height of the packaging container P is defined.

[0041] It is pointed out that in the present description and in the claims, the term "total height" means the height of the packaging container P, if the packaging container P has a constant height, or the maximum height of the packaging container P, if the packaging container P has a variable height.

[0042] The basic unit 1 may be a pre-cut blank or part of a web of packaging material 2 comprising a series of basic units 1 .

[0043] In the first case, the basic unit 1 is folded on a known forming spindle (not shown), filled with pourable product and sealed at the top to form a packaging container P.

[0044] In the second case, a web of packaging material 2 comprising a series of elementary units 1: - folded into a cylindrical shape and sealed longitudinally to form a vertical tube; - Continuously filled with pourable product; and - Transversely sealed and cut into elementary units 1 which are then folded to form the respective packaging containers P.

[0045] To enable the folding and forming of each packaging container P, each basic unit 1 of packaging material 2 includes a number of crease lines defining respective fold lines along which packaging material 2 is configured to be folded.

[0046] In particular, the elementary unit 1 of the packaging material 2 comprises a bottom transverse fold line 7 and a top transverse fold line 8 both extending parallel to the transverse direction B.

[0047] More specifically, the bottom transverse fold line 7 may be a continuous fold line or a broken (discontinuous) fold line.

[0048] A bottom transverse fold line 7 and a top transverse fold line 8 divide the basic unit 1 into: - a bottom region 10 including a bottom fold pattern 11 and configured to form a bottom 25 (Figure 9) of the packaging container including a bottom panel (not shown), preferably a flat and horizontal bottom panel having a quadrilateral, i.e. rectangular or square, profile (represented by a rectangle in this particular example) and defining a resting surface for the packaging container P; - an upper region 12 including an upper fold pattern 13 and configured to form an upper portion 26 of the packaging container including a top panel 27, preferably a flat, horizontal top panel having a quadrangular, i.e. rectangular or square, profile (represented by a rectangle in this particular example), or a slanted, i.e. inclined, top panel; and - an intermediate region 14, included with respect to the longitudinal direction A between the bottom transverse fold line 7 and the top transverse fold line 8, located between the bottom region 10 and the top region 12 and designed to form a main part 28 of the packaging container P having a plurality of side walls 29.

[0049] More specifically, bottom transverse fold line 7 extends parallel to bottom bounding edge 5 and top bounding edge 6 and is disposed closer to bottom bounding edge 5 than top transverse fold line 8. Bottom transverse fold line 7 is configured to define a bottom peripheral edge 30 of package P that divides main portion 28 from bottom 25.

[0050] In particular, the bottom transverse fold lines 7 include: - a bottom central portion 7a configured to define a bottom front edge 30a of the packaging container P; - two bottom end portions 7b arranged opposite the bottom central portion 7a and adjacent the respective side boundary edges 3, 4 and configured to define a bottom rear edge (not shown) of the packaging container P; and - two bottom side portions 7c adjacent to and opposite the bottom central portion 7a, each extending between the bottom central portion 7a and one respective bottom end portion 7b and designed to define two respective bottom side edges 30b (only one is shown in Figure 9) of the packaging container P.

[0051] Top transverse fold line 8 is disposed closer to top boundary edge 6 than bottom transverse fold line 7 and is configured to define a top peripheral edge 31 of package P that divides main portion 28 from top portion 26 .

[0052] In particular, the upper transverse fold lines 8 include: - an upper central portion 8a configured to define an upper front edge 31a of the packaging container P; - two upper end portions 8b arranged opposite the upper central portion 8a and adjacent the respective side boundary edges 3, 4 and configured to define an upper rear edge 31b of the packaging container P; and - two upper side portions 8c extending adjacent to opposite sides of the upper central portion 8a and each designed to connect the upper central portion 8a to one respective upper end portion 8b and to define two respective upper side edges 31c of the packaging container P.

[0053] The basic unit 1 includes two further transverse fold lines, namely a further bottom transverse fold line 15 and a further top transverse fold line 16, both extending parallel to the transverse direction B and located near the bottom boundary edge 5 and the top boundary edge 6, respectively.

[0054] In detail, the further bottom transverse fold line 15 and the further top transverse fold line 16 delimit respective bottom transverse seal areas 17 and top transverse seal areas 18 at the bottom boundary edge 5 and top boundary edge 6 which are configured to define respective bottom transverse seal strips and top transverse seal strips of the packaging container P, along which the vertical tubes of packaging material 2 are transversely sealed and cut during the formation operation of the packaging container P.

[0055] The bottom fold pattern 11 is designed to form a bottom panel and two substantially triangular bottom side flaps (not shown) that are folded inwardly toward and particularly onto the bottom panel of the packaging container P.

[0056] With reference to FIG. 1, the bottom fold pattern 11 is parallel to the longitudinal direction A and includes four longitudinal fold lines 19a, 19b extending within the bottom region 10, in particular between the bottom transverse fold line 7 and a further bottom transverse fold line 15.

[0057] More specifically, longitudinal fold line 19b is the innermost fold line, while longitudinal fold lines 19a are located near the opposite boundary edges 3 and 4, respectively, and the area between longitudinal fold lines 19b, as well as the area bounded by longitudinal fold line 19a and the respective side boundary edges 3, 4, are configured to define the bottom panel of packaging container P.

[0058] In each of the regions delimited between one longitudinal crease line 19a and a corresponding longitudinal crease line 19b, the bottom crease pattern 11 further comprises a pair of additional crease lines, in particular a pair of inclined crease lines 20, 21 which are inclined with respect to both the longitudinal direction A and the transverse direction B and extend within the bottom region 10, preferably extending between the bottom transverse crease line 7 and the further bottom transverse crease line 15.

[0059] In particular, the inclined fold lines 20, 21 have one common end located on the further bottom transverse fold line 15 and an opposite end pointing to a continuation line C that is parallel to the transverse direction B and includes a bottom central portion 7a and a bottom end portion 7b of the bottom transverse fold line 7. The inclined fold lines 20, 21 together with their respective bottom side portions 7c delimit a flap region, preferably a substantially triangular region 22.

[0060] According to this particular preferred embodiment, the bottom central portion 7a, bottom end portions 7b and bottom side portions 7c of the bottom transverse fold line 7 are aligned with each other and with the continuation line C (FIGS. 1 to 6).

[0061] According to an alternative embodiment (FIGS. 7 and 8), the bottom central portion 7a, the bottom end portions 7b and the bottom side portions 7c may not be aligned with each other and with the continuous line C. In particular, the bottom central portion 7a, the bottom end portions 7b and the bottom side portions 7c may be parallel to each other and with the continuous line C, but the bottom side portions 7c may be spaced apart from the continuous line C by a longitudinal offset along the longitudinal direction A.

[0062] In the embodiment shown in Figures 1 and 2, said opposite ends of the inclined crease lines 20, 21 are located on the continuous line C, in particular on the bottom transverse crease line 7. In this way, the inclined crease lines 20, 21 delimit respective triangular regions 22 together with the segment of the bottom transverse crease line 7 contained between the opposite ends of the inclined crease lines 20, 21 themselves.

[0063] More precisely, the latter segment is defined by a bottom side portion 7c of one of the bottom transverse fold lines 7. The bottom side portion 7c therefore defines the base of each such triangular region 22.

[0064] Each area contained between longitudinal fold lines 19a and 19b, including triangular area 22, is configured to define a respective bottom side flap (not shown) of one of the packages P.

[0065] Further, with reference to a single pair of longitudinal fold lines 19a, 19b, such pair of longitudinal fold lines 19a, 19b are disposed on opposite sides of respective triangular regions 22 relative to one another with respect to the transverse direction B and together define a fold line about which the relative bottom side flaps are designed to fold inwardly, as described above.

[0066] As shown in Figure 1, and on a larger scale in Figure 2, for only one inclined crease line 20, the projection of the inclined creases 20, 21 onto the continuous line C along respective directions parallel to the inclined creases 20, 21 identifies respective first points Q1 (only one is shown in Figure 2) on the continuous line C located on respective opposite sides of the relative triangular regions 22, i.e., intersects with the continuous line C at the respective first points Q1.

[0067] According to this particular embodiment, the inclined crease lines 20, 21 directly intersect the bottom transverse crease line 7 at a first point Q1, which therefore defines the intersection between each inclined crease line 20, 21 and the bottom transverse crease line 7, thereby delimiting the corresponding bottom side portion 7c.

[0068] More specifically, each first point Q1 defines a base vertex of a respective triangular region 22.

[0069] Advantageously, the projection of each pair of longitudinal crease lines 19a, 19b onto the continuous line C along the longitudinal direction A identifies on the continuous line C a respective second point Q2 (only one of which is shown in Figure 2), i.e. intersects with the continuous line C at a respective second point Q2, each of the second points Q2 being located on a respective side of the relative triangular area 22 bounded by that pair of longitudinal crease lines 19a, 19b and spaced apart along the transverse direction B by a transverse offset T (shown in Figure 2) from a corresponding first point Q1 located on the same one side of the relative triangular area 22.

[0070] According to this particular embodiment, the longitudinal fold lines 19a, 19b directly intersect the bottom transverse fold line 7 at a second point Q2, which therefore defines the intersection between each of the longitudinal fold lines 19a, 19b and the bottom transverse fold line 7.

[0071] As an example, the inclined fold 20 located adjacent to the side boundary edge 3 intersects the bottom transverse fold line 7 at one first point Q1, and the corresponding longitudinal fold line 19a, i.e. the longitudinal fold line 19a located adjacent to the side boundary edge 3, intersects the bottom transverse fold line 7 at one second point Q2 spaced apart from the latter first point Q1 by a lateral offset T (Figure 2).

[0072] Since the basic unit 1 includes four (two pairs) longitudinal crease lines 19a, 19b and four (two pairs) oblique crease lines 20, 21, four second points Q2 and four first points Q1 are identified on the basic unit 1.

[0073] Preferably, the two second points Q2 of each pair, located on opposite sides of one respective triangular region 22, are outside the segment bounded by the corresponding first point Q1, i.e. outside the corresponding bottom side portion 7c of the bottom transverse fold line 7. The latter feature is applicable to both pairs of second points Q2 of the basic unit 1.

[0074] Preferably, all second points Q2 of the basic unit 1 are spaced apart from the corresponding first points Q1, i.e., from the nearest first points Q1 located on the same side of the relative triangular area 22, by the same lateral offset T, respectively.

[0075] Preferably, the lateral offset T is in the range of 0.1 mm to 2 mm.

[0076] The upper fold pattern 13 is designed to create, in a known but not described in detail manner, a top panel 27 and two substantially triangular upper side flaps 32 (only one shown in FIG. 9 ) configured to fold outwardly toward and particularly over the main portion 28.

[0077] Additionally, the upper crease pattern 13 includes a removable portion 24 disposed in the area of ​​the upper region 12 .

[0078] Preferably, the removable portion 24 comprises a so-called "pre-laminate" hole, i.e. a circular hole formed only through the base layer of the packaging material 2 and covered with layers of heat-sealable plastic material and barrier material that adhere to each other at the hole when the materials are laminated.

[0079] Once the package P is fully folded, a known opening device 33 (FIG. 9) is attached to the top panel 27 over the removable portion 24 by a conventional bonding system such as an adhesive, or by micro-flame, electric current induction, ultrasonic, laser, or other heat sealing techniques.

[0080] According to this preferred, non-limiting embodiment shown, the intermediate region 14 includes an intermediate fold pattern 34 that includes: - two intermediate longitudinal fold lines 35 parallel to the longitudinal direction A and extending in the intermediate region 14, in particular between the bottom transverse fold line 7 and the top transverse fold line 8, configured to form respective longitudinal lateral edges 36 (FIG. 9) of the main portion 28; and - two pairs of intermediate curved fold lines 37 extending within the intermediate region 14, in particular between the bottom transverse fold line 7 and the top transverse fold line 8, and configured to form respective curved lateral edges 38 of the main portion 28 which delimit respective leaf portions 39 (Figure 9) of the packaging container P.

[0081] In particular, the intermediate curved fold line 37 extends substantially along the longitudinal direction A.

[0082] More specifically, a pair of intermediate curved fold lines 37 delimit lobe regions of main portion 28 and are common to one another and have their opposite ends pointing to top transverse fold line 8 and bottom transverse fold line 7, respectively.

[0083] More specifically, the projection of the intermediate longitudinal crease line 35 or the intermediate curved crease line 37 onto the continuous line C along the longitudinal direction A or along a direction parallel to the intermediate curved crease line 37, respectively, coincides with the respective first point Q1.

[0084] In this particular example described, both the intermediate longitudinal crease line 35 and the intermediate curved crease line 37 directly intersect the bottom transverse crease line 7 at their respective first points Q1, which therefore define the intersection points between each intermediate longitudinal crease line 35 or intermediate curved crease line 37 and the bottom transverse crease line 7, thereby delimiting the corresponding bottom side portions 7c on the bottom transverse crease line 7.

[0085] Number 1' in Figure 3 indicates as a whole a different embodiment of a basic unit of a sheet-like packaging material 2 according to the invention. Since basic unit 1' is similar to basic unit 1, the following description will be limited to those differences and, where possible, the same reference symbols will be used for identical or corresponding parts.

[0086] In particular, base unit 1 ′ differs from base unit 1 by including a bottom fold pattern 11 ′ that includes four longitudinal fold lines 19 a ′, 19 b ′ that do not intersect bottom transverse fold line 7 .

[0087] In other words, only the projection of each longitudinal line 19a', 19b' along the longitudinal direction A intersects the continuous line C, in particular the bottom transverse fold line 7, at the respective second point Q2, while the respective ends of each longitudinal line 19a', 19b' do not reach the bottom transverse fold line 7.

[0088] This can be seen in particular for the single longitudinal line 19a' of the bottom fold pattern 11' in FIG. 4, where such longitudinal fold line 19a' does not reach the bottom transverse fold line 7, but the projection of such longitudinal fold line 19a' along the longitudinal direction A does.

[0089] Number 1" in Figure 5 indicates as a whole a further embodiment of a basic unit of a sheet-like packaging material 2 according to the invention. Since basic unit 1" is similar to basic unit 1', the following description will be limited to the differences therebetween and, where possible, the same reference symbols will be used for identical or corresponding parts.

[0090] In particular, basic unit 1'' differs from basic unit 1' by having a bottom lateral fold line 7'' that is interrupted at least at a first point Q1, at a corresponding second point Q2, and between the first point Q1 and the corresponding second point Q2.

[0091] In reality, the bottom transverse fold line 7'' is not continuous but is interrupted in some parts thereof, as described above.

[0092] Additionally, basic unit 1 ″ differs from basic unit 1 ′ by including a bottom fold pattern 11 ″ that includes two pairs of inclined fold lines 20 ″, 21 ″ that do not intersect with continuity lines C, specifically bottom transverse fold line 7 .

[0093] In other words, only the projections of such inclined crease lines 20'', 21'' along respective directions parallel to the inclined crease lines 20'', 21'' intersect with the continuous line C at the respective first points Q1, and the respective ends of the inclined crease lines 20'', 21'' do not reach the continuous line C.

[0094] Additionally, like bottom crease pattern 11', bottom crease pattern 11'' includes four longitudinal crease lines 19a'', 19b'' that do not intersect with line of continuity C.

[0095] Furthermore, basic unit 1'' differs from basic unit 1' by including an intermediate fold pattern 34'' that includes two intermediate longitudinal fold lines 35'' and two pairs of intermediate curved fold lines 37'' that do not intersect the continuous lines C, in particular the bottom transverse fold line 7.

[0096] In other words, only the projection of the intermediate longitudinal crease line 35'' or the intermediate curved crease line 37'' onto the continuous line C along a direction parallel to the longitudinal direction A or the intermediate curved crease line 37'', respectively, intersects with the continuous line C at the respective first point Q1.

[0097] In view of the above, bottom crease pattern 11' and intermediate crease pattern 34'' include a plurality of void areas 40'' where no crease lines are present.

[0098] This can be seen in FIG. 6 for a single void portion 40''.

[0099] Number 1''' in Figure 7 indicates as a whole a further embodiment of a basic unit of a sheet-like packaging material 2 according to the invention. Since basic unit 1''' is similar to basic unit 1, the following description will be limited to the differences therebetween and, where possible, the same reference symbols will be used for identical or corresponding parts.

[0100] In particular, basic unit 1''' differs from basic unit 1 by including a bottom fold pattern 11''' having a bottom transverse fold line 7''' that includes a bottom central portion 7a''', two bottom end portions 7b''', and two bottom side portions 7c''' that are not aligned with each other and with continuity line C.

[0101] In particular, bottom central portion 7a''', bottom end portion 7b''', and bottom side portion 7c''', are parallel to each other and to continuous line C, but bottom side portion 7c''' is spaced from continuous line C by a longitudinal offset along longitudinal direction A.

[0102] More specifically, bottom side portion 7c''' is closer to bottom boundary edge 5 than bottom central portion 7a'''' and bottom end portion 7b''''.

[0103] Thus, bottom central portion 7a''' and bottom end portions 7b''' are closer to the upper lateral fold line 8 than bottom side portions 7c'''.

[0104] Therefore, according to this preferred embodiment, the triangular area 22 is smaller than the triangular area 22 according to the previous embodiment.

[0105] The advantages of the basic units 1, 1', 1'', 1''' of the packaging material 2 according to the invention will be apparent from the above description.

[0106] In particular, the lateral offset T makes it possible to compensate for the thickness of the packaging material 2 during the formation of the bottom 25, in particular during the folding of the bottom side flaps. This misaligned configuration of the longitudinal fold lines 19a, 19b, 19a', 19b', 19a'', 19b'' makes it possible to carry out such folding of the bottom side flaps while avoiding a weakening of the sheet-like packaging material 2, in particular along the longitudinal fold lines 19a, 19b, 19a', 19b', 19a'', 19b'', since said compensation reduces local stresses occurring at such fold lines.

[0107] Furthermore, in a configuration where the longitudinal fold lines 19a', 19b' do not converge to the bottom fold line 7, localized stresses during folding are further reduced.

[0108] This is much more accentuated thanks to bottom crease pattern 11'' and intermediate crease pattern 34''. Indeed, thanks to the presence of void portion 40'', local stresses applied at the convergence points of the various creases during folding are reduced since such convergence points are eliminated. Furthermore, the formation of package P is improved, especially at the corners of package P.

[0109] Obviously, modifications can be made to the basic units 1, 1', 1'', 1''' of the packaging material 2 described herein without departing from the scope of protection defined in the appended claims.

[0110] In particular, the bottom side fold portion 7c''' can be implemented in either of the basic units 1' and 1''.

Claims

1. A sheet-like packaging material (1, 1', 1'') having a rectangular or square configuration for producing a sealed packaging container (P) containing a pourable product, said sheet-like packaging material (1, 1', 1'') comprising two first boundary edges (3, 4) parallel to a longitudinal direction (A) and two second boundary edges (5, 6) parallel to a transverse direction (B) perpendicular to said longitudinal direction (A), The sheet-like packaging material (1, 1', 1'') comprises at least a bottom transverse fold line (7, 7'') and a top transverse fold line (8), said two fold lines forming the sheet-like packaging material (1, 1', 1'') in the following manner: a bottom region (10) including a bottom fold pattern (11, 11', 11'') and adapted to form a bottom portion (25) of said packaging container (P) including a bottom panel; - an upper region (12) including an upper fold pattern (13); - an intermediate region (14) contained, with respect to said longitudinal direction (A), between said bottom transverse fold line (7, 7'') and said top transverse fold line (8) and interposed between said bottom region (10) and said top region (12); The bottom transverse fold lines (7, 7'') a bottom central portion (7a, 7a″), at least one bottom end portion (7b, 7b'') arranged on one side of said bottom central portion (7a, 7a'') and adjacent one of said first boundary edges (3, 4); at least one bottom side portion (7c, 7c'') adjacent to one side of said bottom central portion (7a, 7a'') and extending between said bottom central portion (7a, 7a'') and said at least one bottom end portion (7b, 7b''), said bottom central portion (7a, 7a''), said bottom end portion (7b, 7b'') and said bottom side portion (7c, 7c'') being aligned in a continuous line (C) parallel to said transverse direction (B); said bottom fold pattern (11, 11', 11'') is inclined with respect to both said longitudinal direction (A) and said transverse direction (B) and comprises at least one pair of inclined fold lines (20, 21; 20'', 21'') extending within said bottom region (10); said inclined fold line (20, 21; 20", 21") has a first end close to one (5) of said second boundary edges (5, 6) and a second end close to said line of continuity (C), said inclined fold line (20, 21; 20", 21") delimiting a flap region (22) of said sheet-like packaging material (1, 1', 1") designed to form, together with said at least one bottom side portion (7c, 7c"), at least a part of a side flap of said packaging container (P), The inclined crease line intersects with the continuous line (C) at a first point (Q1), or if the second end of the inclined crease line does not reach the continuous line (C), a virtual straight line extending from the second end intersects with the continuous line (C) at the first point (Q1); said bottom fold pattern (11, 11', 11'') further comprises at least one pair of longitudinal fold lines (19a, 19b; 19a', 19b'; 19a'', 19b'') extending in said bottom region (10) and arranged on either side of said flap region (22) with respect to said transverse direction (B) and together defining fold lines around which said side flaps are designed to be folded inwardly towards said bottom panel, The longitudinal crease line intersects with the continuous line (C) at a second point (Q2), or, if the end of the longitudinal crease line does not reach the continuous line (C), a virtual straight line extending from the end of the longitudinal crease line intersects with the continuous line (C) at the second point (Q2); The sheet-like packaging material (1, 1', 1''), characterized in that the second point (Q2) is located on one side of the flap region (22) and is spaced apart along the lateral direction (B) by a lateral offset (T) from a corresponding first point (Q1) located on the same one side of the flap region (22).

2. 2. The sheet-like packaging material of claim 1, wherein each of the first points (Q1) is closer to the flap region (22) than the corresponding adjacent second point (Q2).

3. 3. The sheet-like packaging material according to claim 1 or 2, wherein said second points (Q2) are each spaced apart from said corresponding first points (Q1) by respective equal lateral offsets (T).

4. said intermediate region (14) comprising an intermediate fold pattern (34, 34'') including at least one intermediate fold line (35, 37; 35'', 37'') configured to form a lateral edge (36) of the main portion (28) of said packaging container (P); The sheet-like packaging material according to any one of claims 1 to 3, wherein the intermediate crease line intersects with the continuous line (C) at the first point (Q1), or, if an end of the intermediate crease line does not reach the continuous line (C), a virtual straight line extended from the end of the intermediate crease line intersects with the continuous line (C) at the first point (Q1).

5. 5. The sheet-like packaging material according to claim 4, wherein said intermediate fold lines (35, 37) intersect said bottom transverse fold line (7) at said one of said first points (Q1).

6. A sheet-like packaging material according to any one of claims 1 to 5, wherein the inclined fold lines (20, 21) intersect the bottom transverse fold line (7, 7''') at the first point (Q1).

7. 7. Sheet-like packaging material according to claim 5 or 6, wherein the longitudinal fold lines (19a, 19b) intersect the bottom transverse fold line (7, 7''') at the second point (Q2).

8. 8. The sheet-like packaging material according to any one of claims 1 to 7, wherein the bottom transverse fold line (7'') is interrupted at least at each of the first points (Q1), at the corresponding second points (Q2) and between each of the first points (Q1) and the corresponding second points (Q2).

9. said bottom fold pattern (11, 11', 11", 11''') comprises two pairs of said inclined fold lines (20, 21; 20", 21"), said bottom transverse fold lines (7, 7", 7'") comprise two bottom side portions (7c, 7c", 7c'") arranged on either side of said bottom central portion (7a, 7a", 7a'"), said inclined fold lines (20, 21; 20", 21") delimiting two respective said flap regions (22) designed to form, together with the corresponding bottom side portions (7c, 7c", 7c'"), at least a part of two respective said side flaps of said packaging container (P), said bottom fold pattern (11, 11', 11", 11''') comprises two pairs of said longitudinal fold lines (19a, 19b; 19a', 19b'; 19a", 19b") one for each pair of said inclined fold lines (20, 21; 20", 21"), each pair of said longitudinal fold lines (19a, 19b; 19a', 19b'; 19a'', 19b'') is disposed on either side of a respective flap region (22); The sheet-like packaging material according to any one of claims 1 to 8.

10. 10. The sheet-like packaging material according to any one of claims 1 to 9, wherein the bottom central portion (7a, 7a″), the at least one bottom end portion (7b, 7b″), and the at least one bottom side portion (7c, 7c″) of the bottom transverse fold line (7, 7″) are aligned with each other and with the line of continuity (C).

11. A sheet-like packaging material (1''') for producing a sealed packaging container (P) containing a pourable product, said sheet-like packaging material (1''') having two first boundary edges (3, 4) parallel to a longitudinal direction (A) and two second boundary edges (5, 6) parallel to a transverse direction (B) perpendicular to said longitudinal direction (A), The sheet-like packaging material (1''') comprises at least a bottom transverse fold line (7''') and a top transverse fold line (8), said two fold lines forming the sheet-like packaging material (1''') in the following manner: a bottom region (10) including a bottom fold pattern (11''') and adapted to form a bottom portion (25) of said packaging container (P) including a bottom panel; - an upper region (12) including an upper fold pattern (13); - an intermediate region (14) contained, with respect to said longitudinal direction (A), between said bottom transverse fold line (7''') and said top transverse fold line (8) and interposed between said bottom region (10) and said top region (12); The bottom transverse fold line (7''') a bottom central part (7a'''), at least one bottom end portion (7b''') arranged on one side of said bottom central portion (7a''') and adjacent one of said first boundary edges (3, 4); at least one bottom side portion (7c''') adjacent to one side of said bottom central portion (7a''') and extending between said bottom central portion (7a''') and said at least one bottom end portion (7b'''), said bottom central portion (7a''') and said bottom end portion (7b''') being aligned to a continuous line (C) parallel to said transverse direction (B), said bottom side portion (7c''') being spaced apart from said continuous line (C) by a longitudinal offset along said longitudinal direction (A); said bottom fold pattern (11''') is inclined with respect to both said longitudinal direction (A) and said transverse direction (B) and includes at least one pair of inclined fold lines (20, 21) extending within said bottom region (10); said inclined fold lines (20, 21) having a first end close to one (5) of said second boundary edges (5, 6) and a second end close to said line of continuity (C), said inclined fold lines (20, 21; 20", 21") delimiting a flap region (22) of said sheet-like packaging material (1"') which is designed to form, together with said at least one bottom side portion (7c"'), at least a part of a side flap of said packaging container (P); said inclined fold lines (20, 21) intersect with said continuous line (C) at a first point (Q1); said bottom fold pattern (11''') further comprises at least a pair of longitudinal fold lines (19a, 19b) extending in said bottom region (10) and arranged on either side of said flap region (22) with respect to said transverse direction (B) and together defining fold lines around which said side flaps are designed to be folded inwardly towards said bottom panel, The longitudinal fold lines (19a, 19b) intersect with the continuous line (C) at a second point (Q2); the second point (Q2) is located on one side of the flap region (22) and is spaced apart along the lateral direction (B) by a lateral offset (T) from a corresponding first point (Q1) located on the same one side of the flap region (22); the intermediate region (14) includes an intermediate fold pattern (34) including at least one intermediate fold line (35, 37) configured to form a lateral edge (36) of the main portion (28) of the packaging container (P), the intermediate fold line intersecting the continuous line (C) at the first point (Q1); A sheet-like packaging material (1'').

12. 12. The sheet-like packaging material of claim 11, wherein the bottom central portion (7a''') and the at least one bottom end portion (7b''') are closer to the upper transverse fold line (8) than the at least one bottom side portion (7c''').

13. A sealed packaging container (P) containing a pourable product obtained from the sheet-like packaging material (1, 1', 1'', 1''') according to any one of claims 1 to 12, said packaging container (P) comprising a bottom (25), a top (26) and a main part (28) arranged between said bottom (25) and said top (26) and comprising a plurality of side walls (29), said main part (28) being divided from said bottom (25) and said top (26) by a bottom peripheral edge (30) and a top peripheral edge (31), respectively, A sealed packaging container (P), wherein said bottom transverse fold line (7, 7'', 7''') defines said bottom peripheral edge (30) and said top transverse fold line (8) defines said top peripheral edge (31).

14. The sheet packaging material has a rectangular or square configuration; 13. The sheet-like packaging material according to claim 11 or 12.

15. A sheet-like packaging material (1,1',1'') for producing a sealed packaging container (P) containing a pourable product, said sheet-like packaging material (1,1',1'') having two first boundary edges (3,4) parallel to a longitudinal direction (A) and two second boundary edges (5,6) parallel to a transverse direction (B) perpendicular to said longitudinal direction (A), The sheet-like packaging material (1, 1', 1'') comprises at least a bottom transverse fold line (7, 7'') and a top transverse fold line (8), said two fold lines forming the sheet-like packaging material (1, 1', 1'') in the following manner: a bottom region (10) including a bottom fold pattern (11, 11', 11'') and adapted to form a bottom portion (25) of said packaging container (P) including a bottom panel; - an upper region (12) including an upper fold pattern (13); - an intermediate region (14) contained, with respect to said longitudinal direction (A), between said bottom transverse fold line (7, 7'') and said top transverse fold line (8) and interposed between said bottom region (10) and said top region (12); The bottom transverse fold lines (7, 7'') a bottom central portion (7a, 7a″), at least one bottom end portion (7b, 7b'') arranged on one side of said bottom central portion (7a, 7a'') and adjacent one of said first boundary edges (3, 4); at least one bottom side portion (7c, 7c'') adjacent to one side of said bottom central portion (7a, 7a'') and extending between said bottom central portion (7a, 7a'') and said at least one bottom end portion (7b, 7b''), said bottom central portion (7a, 7a''), said bottom end portion (7b, 7b'') and said bottom side portion (7c, 7c'') being aligned in a continuous line (C) parallel to said transverse direction (B); said bottom fold pattern (11, 11', 11'') is inclined with respect to both said longitudinal direction (A) and said transverse direction (B) and comprises at least one pair of inclined fold lines (20, 21; 20'', 21'') extending within said bottom region (10); said inclined fold line (20, 21; 20", 21") has a first end close to one (5) of said second boundary edges (5, 6) and a second end close to said line of continuity (C), said inclined fold line (20, 21; 20", 21") delimiting a flap region (22) of said sheet-like packaging material (1, 1', 1") designed to form, together with said at least one bottom side portion (7c, 7c"), at least a part of a side flap of said packaging container (P), The inclined crease line intersects with the continuous line (C) at a first point (Q1), or if the second end of the inclined crease line does not reach the continuous line (C), a virtual straight line extending from the second end intersects with the continuous line (C) at the first point (Q1); said bottom fold pattern (11, 11', 11'') further comprises at least one pair of longitudinal fold lines (19a, 19b; 19a', 19b'; 19a'', 19b'') extending in said bottom region (10) and arranged on either side of said flap region (22) with respect to said transverse direction (B) and together defining fold lines around which said side flaps are designed to be folded inwardly towards said bottom panel, The longitudinal crease line intersects with the continuous line (C) at a second point (Q2), or, if the end of the longitudinal crease line does not reach the continuous line (C), a virtual straight line extending from the end of the longitudinal crease line intersects with the continuous line (C) at the second point (Q2); the second point (Q2) is located on one side of the flap region (22) and is spaced apart along the lateral direction (B) by a lateral offset (T) from a corresponding first point (Q1) located on the same one side of the flap region (22); said intermediate region (14) comprising an intermediate fold pattern (34, 34'') including at least one intermediate fold line (35, 37; 35'', 37'') configured to form a lateral edge (36) of the main portion (28) of said packaging container (P); The intermediate crease line intersects with the continuous line (C) at the first point (Q1), or, if the end of the intermediate crease line does not reach the continuous line (C), a virtual straight line extended from the end of the intermediate crease line intersects with the continuous line (C) at the first point (Q1); A sheet-like packaging material (1, 1', 1'').

16. A sheet-like packaging material (1,1',1'') for producing a sealed packaging container (P) containing a pourable product, said sheet-like packaging material (1,1',1'') having two first boundary edges (3,4) parallel to a longitudinal direction (A) and two second boundary edges (5,6) parallel to a transverse direction (B) perpendicular to said longitudinal direction (A), The sheet-like packaging material (1, 1', 1'') comprises at least a bottom transverse fold line (7, 7'') and a top transverse fold line (8), said two fold lines forming the sheet-like packaging material (1, 1', 1'') in the following manner: a bottom region (10) including a bottom fold pattern (11, 11', 11'') and adapted to form a bottom portion (25) of said packaging container (P) including a bottom panel; - an upper region (12) including an upper fold pattern (13); - an intermediate region (14) contained, with respect to said longitudinal direction (A), between said bottom transverse fold line (7, 7'') and said top transverse fold line (8) and interposed between said bottom region (10) and said top region (12); The bottom transverse fold lines (7, 7'') a bottom central portion (7a, 7a″), at least one bottom end portion (7b, 7b'') arranged on one side of said bottom central portion (7a, 7a'') and adjacent one of said first boundary edges (3, 4); at least one bottom side portion (7c, 7c'') adjacent to one side of said bottom central portion (7a, 7a'') and extending between said bottom central portion (7a, 7a'') and said at least one bottom end portion (7b, 7b''), said bottom central portion (7a, 7a''), said bottom end portion (7b, 7b'') and said bottom side portion (7c, 7c'') being aligned in a continuous line (C) parallel to said transverse direction (B); said bottom fold pattern (11, 11', 11'') is inclined with respect to both said longitudinal direction (A) and said transverse direction (B) and comprises at least one pair of inclined fold lines (20, 21; 20'', 21'') extending within said bottom region (10); said inclined fold line (20, 21; 20", 21") has a first end close to one (5) of said second boundary edges (5, 6) and a second end close to said line of continuity (C), said inclined fold line (20, 21; 20", 21") delimiting a flap region (22) of said sheet-like packaging material (1, 1', 1") designed to form, together with said at least one bottom side portion (7c, 7c"), at least a part of a side flap of said packaging container (P), The inclined crease line intersects with the continuous line (C) at a first point (Q1), or if the second end of the inclined crease line does not reach the continuous line (C), a virtual straight line extending from the second end intersects with the continuous line (C) at the first point (Q1); said bottom fold pattern (11, 11', 11'') further comprises at least one pair of longitudinal fold lines (19a, 19b; 19a', 19b'; 19a'', 19b'') extending in said bottom region (10) and arranged on either side of said flap region (22) with respect to said transverse direction (B) and together defining fold lines around which said side flaps are designed to be folded inwardly towards said bottom panel, The longitudinal crease line intersects with the continuous line (C) at a second point (Q2), or, if the end of the longitudinal crease line does not reach the continuous line (C), a virtual straight line extending from the end of the longitudinal crease line intersects with the continuous line (C) at the second point (Q2); the second point (Q2) is located on one side of the flap region (22) and is spaced apart along the lateral direction (B) by a lateral offset (T) from a corresponding first point (Q1) located on the same one side of the flap region (22); said bottom transverse fold line (7'') is interrupted at least at each said first point (Q1), at the corresponding second point (Q2) and between each first point (Q1) and the corresponding second point (Q2); A sheet-like packaging material (1, 1', 1'').

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