A SEALED PACKAGE CONTAINING A POURABLE FOOD PRODUCT AND A SHEET PACKAGING MATERIAL FOR PRODUCING A SEALED PACKAGE CONTAINING A POURABLE FOOD PRODUCT

Abstract

A sealed package containing a pourable food product and comprising a bottom portion, a top portion and a main portion interposed between the bottom portion and top portion and including a plurality of side wall portions; the main portion is divided from the bottom portion and said top portion respectively by a bottom peripheral outline and a top peripheral outline extending transversally with respect to a longitudinal direction; each of the bottom peripheral outline and the top peripheral outline has a broken-line shape and is formed by a plurality of contour edges joined to each other; the bottom portion comprises a quadrilateral bottom panel delimited by the bottom peripheral outline and extending orthogonal to the longitudinal direction; the top portion comprises a quadrilateral top panel delimited by the top peripheral outline and extending transversally to the longitudinal direction; the area of the bottom panel is different from the area of a top quadrilateral obtained by projecting, along the longitudinal direction, the top panel on a reference plane parallel to the bottom panel, crossing the package and containing at least one of the contour edges of the top peripheral outline.

Description

The present invention relates to a sealed package containing a pourable food product.

The present invention also relates to a sheet packaging material for producing a sealed package containing a pourable food product.

As commonly known, many pourable food products, such as fruit juice, UHT (ultra-high-temperature treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by folding, sealing and cutting a web of laminated packaging material. In particular, the packaging material has a multilayer structure comprising a base layer, e.g. of paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material, e.g. an aluminium foil, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

Packages of this sort are normally produced on fully automatic packaging machines, on which a continuous tube is formed from the web-fed packaging material; the web of packaging material is sterilized on the packaging machine, e.g. by applying a chemical sterilizing agent, such as a hydrogen peroxide solution, which, once sterilization is completed, is removed from the surfaces of the packaging material, e.g. evaporated by heating; the web so sterilized is then maintained in a closed, sterile environment, and is folded and sealed longitudinally to form a tube, which is fed vertically.

In order to complete the forming operations, the tube is filled with the sterilized or sterile-processed food product, and is sealed and subsequently cut along equally spaced cross sections; pillow packs are so obtained, which are then folded mechanically to form respective finished packages at a final folder.

To allow folding of the web packaging material both during forming and final folding, crease lines, i.e. weakening lines, are formed on the packaging material at the production plant by creasing tools. In practice, the crease lines define folding lines along which the pillow packs are folded to take the desired final configuration.

Alternatively, the packaging material may be cut into blanks, which are formed into packages on forming spindles, and the resulting packages are then filled with the food product and sealed. One example of this type of package is the so-called “gable-top” package known by the trade name Tetra Rex (registered trademark).

To open the above-described packages, these are normally provided with a removable portion, which is partly detached by an opening device from the rest of the packaging material to free a pour opening through which to pour out the product.

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

The removable portion normally comprises a so-called “prelaminated” hole, i.e. a circular hole formed through the base layer only of the packaging material and covered, when the material is laminated, with the layers of heat-seal plastic material and barrier material, which adhere to one another at the hole.

Each package of the above type, either cut from a tube of packaging material or formed on a forming spindle, is obtained from a basic unit of packaging material having given crease lines.

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

In the case of packages made from a tube of packaging material, the original web includes a plurality of basic units joined to each other; in the case of packages made on forming spindles, the basic unit is defined by the blank cut from the web prior to starting the forming and sealing operations.

The basic unit typically has a rectangular or square configuration with two boundary edges parallel to a longitudinal direction and two other boundary edges parallel to a transversal direction orthogonal to the longitudinal direction.

Once the basic unit is folded and sealed to form the respective finished package, the longitudinal direction becomes the direction along which the total height of the package itself is defined; the longitudinal direction also represents the main direction of extension of the web from which the basic unit is obtained.

The basic unit usually includes at least two transversal crease lines extending transversally to the longitudinal direction and dividing the basic unit itself into:

• • a bottom region containing a bottom crease pattern and configured to form a bottom portion of the finished package;
  • a top region containing a top crease pattern and configured to form a top portion of the finished package; and
  • an intermediate region contained between the transversal crease lines, interposed between the bottom region and the top region and usually having a plurality of longitudinal crease lines designed to form lateral edges of a plurality of side walls of the finished package.

The transversal crease lines are also configured to define a bottom peripheral outline and a top peripheral outline of the finished package having endless configurations and respectively dividing the bottom portion and the top portion from the main portion.

The bottom portion of the finished package normally includes a flat and horizontal bottom panel defining the resting surface of the package itself.

The top portion of the finished package may include a flat and horizontal top panel, parallel to the bottom panel; alternatively, slanted top panels are very conveniently used in combination with opening devices because they are wider than corresponding flat top panels of parallelepiped or prismatic packages and therefore allow the application of larger opening devices, e.g. provided with screw caps or the like.

As it is known, after their production, packages are transported to sale points by placing them on transport pallets, which have pre-determined sizes. A need is therefore particularly felt in the packaging field to optimize filling of the transport pallets with the finished packages while maintaining a pleasing appearance of such packages.

It is therefore an object of the present invention to provide a sealed package containing a pourable food produce, which allows meeting the above-mentioned need in a straightforward and low-cost manner.

This object is achieved by a sealed package as claimed in claim 1.

This object is also achieved by a sheet packaging material for producing a sealed package containing a pourable food product, as claimed in claim 13.

Four preferred, non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a sealed package according to the present invention;

FIG. 2 is a smaller-scale front view of the package of FIG. 1;

FIG. 3 is a smaller-scale side view of the package of FIG. 1;

FIG. 4 is a smaller-scale bottom view of the package of FIG. 1;

FIG. 5 is the projection, along a vertical direction, of a top panel of the package of FIG. 3 on a horizontal plane containing a top front edge of the top panel itself;

FIG. 6 is a front view of a basic unit of a sheet packaging material according to the present invention, from which the package of FIGS. 1 to 5 is obtained;

FIG. 7 is a perspective view of a sealed package according to a different embodiment of the present invention;

FIG. 8 is a front view of a basic unit of a sheet packaging material according to the present invention, from which the package of FIG. 7 is obtained;

FIG. 9 is a perspective view of a sealed package according to another embodiment of the present invention;

FIG. 10 is a front view of a basic unit of a sheet packaging material according to the present invention, from which the package of FIG. 9 is obtained;

FIG. 11 is a perspective view of a sealed package according to a further embodiment of the present invention; and

FIG. 12 is a front view of a basic unit of a sheet packaging material according to the present invention, from which the package of FIG. 11 is obtained.

Number 1 in FIGS. 1 to 5 indicates as a whole a sealed package according to the present invention, which contains a pourable food product and is obtained from a sheet packaging material 2 as shown in FIG. 6.

Package 1 comprises a bottom portion 3, a top portion 4 and a main portion 5 interposed between bottom portion 3 and top portion 4 and including a plurality of side wall portions 6, each one delimited by two opposite lateral edge zones 7.

Main portion 5 is divided from bottom portion 3 by a bottom peripheral outline 8 having an endless configuration defined by a broken line. In a completely analogous manner, main portion 5 is divided from top portion 4 by a top peripheral outline 9, also having an endless configuration defined by a broken line.

Bottom portion 3 includes a flat and horizontal bottom panel 10 having a quadrilateral, i.e. rectangular or square (in the example shown rectangular), profile and defining the resting surface of the package itself.

Bottom panel 10 is delimited by bottom peripheral outline 8 in turn formed by four segments or contour edges, i.e. a bottom front edge 8a, a bottom rear edge 8b parallel to bottom front edge 8a and two bottom side edges 8c, orthogonal to bottom front edge 8a and bottom rear edge 8b.

Due to the rectangular profile of bottom panel 10, bottom front edge 8a and bottom rear edge 8b have the same length; the same applies to bottom side edges 8c, which also have the same length.

Package 1 extends vertically along a longitudinal direction A, which is orthogonal to bottom panel 10 and along which the total height of the package 1 itself is defined. Longitudinal direction A is also orthogonal to bottom front edge 8a, bottom rear edge 8b and bottom side edges 8c of bottom peripheral outline 8.

It is pointed out that, in the present description and in the claims, the term “total height” means either the height of the package when the latter has a constant height or the maximum height of the package when the latter has a variable height.

Bottom portion 3 further includes two bottom lateral flaps 11 having substantially triangular configurations and folded in a known manner onto bottom panel 10 (FIG. 4).

Top portion 4 includes a flat and slanted top panel having a quadrilateral, i.e. a square or a rectangular, profile and having a sloping configuration forwards with respect to longitudinal direction A.

In the example shown in FIGS. 1 to 3, top panel 14 is a rectangle approximating a square.

Top panel 14 is delimited by top peripheral outline 9 in turn formed by four segments or contour edges, i.e. a top front edge 9a parallel to bottom front edge 8a and bottom rear edge 8b, a top rear edge 9b, parallel to top front edge 9a and arranged higher than the top front edge 9a itself, and two top side edges 9c, orthogonal to top front edge 9a and top rear edge 9b and inclined with respect to longitudinal direction A.

As a consequence, top peripheral outline 9 extends transversally with respect to longitudinal direction A.

Due to the rectangular profile of top panel 14, top front edge 9a and top rear edge 9b have the same length; the same applies to top side edges 9c, which also have the same length.

Top portion 4 further includes two top lateral flaps 15 having substantially triangular configurations and folded in a known manner onto two opposite side wall portions 6 of main portion 5.

As visible in FIGS. 1 to 3 and 5, top portion 4 is also provided with an opening device 16 of plastic material placed over and around a removable portion 17 (FIG. 6) of the packaging material 2. Opening device is applied onto top panel 14 by conventional fastening systems, such as adhesives, or by micro-flame, electric-current-induction, ultrasound, laser, injection moulding or other heat-sealing techniques.

In the example shown in FIGS. 1 to 5, main portion 5 of package 1 includes four side wall portions with different profiles and sizes; advantageously, lateral edge zones 7 delimiting side wall portions 6 have rounded configurations.

In particular, a first side wall portion 6, designed to define a front face of package 1, has a substantially rectangular configuration delimited, at bottom and top, by straight bottom front edge 8a and top front edge 9a, and at opposite sides, by respective rounded and convex lateral edge zones 7.

A second side wall portion 6, designed to define a rear face of package 1, also has a substantially rectangular configuration and is delimited, at bottom and top, by straight bottom rear edge 8b and top rear edge 9b, and at opposite sides, by respective rounded and convex lateral edge zones 7; this second side wall portion 6 faces the side wall portion 6 designed to define the front face of the package 1 and has a height, parallel to longitudinal direction A, greater than the height of this latter side wall portion 6.

Each of the other two side wall portions 6 has a profile substantially resembling a rectangular trapezium delimited:

• • at the bottom, by one respective horizontal bottom side edge 8c;
  • at the top, by one respective inclined top side edge 9c; and
  • at opposite sides, by respective rounded and convex lateral edge zones 7.

The two side wall portions 6 having the trapezoidal profiles receive the respective top lateral flaps 15 on their outer surfaces.

According to an important aspect of the present invention, the area of bottom panel 10 is different from the area of a top quadrilateral Q (FIG. 5) obtained by projecting, along longitudinal direction A, top panel 14 on a reference plane P (FIG. 3) parallel to the bottom panel 10, crossing package 1 and containing top front edge 9a of top peripheral outline 9.

In particular, the area of bottom panel 10 is smaller than the area of top quadrilateral Q.

According to another possible variant not shown, the area of bottom panel 10 may be bigger than the area of top quadrilateral Q.

Analogously to top panel 14, top quadrilateral Q is a square or a rectangle, in the examples shown a rectangle approximating a square.

With particular reference to FIG. 5, top quadrilateral Q includes a top front segment Q1, corresponding to bottom front edge 8a, a top rear segment Q2, corresponding to bottom rear edge 8b, and two top side segments Q3, respectively corresponding to bottom side edges 8c.

Preferably, top side segments Q3 have the same length, which is in turn different from the length of bottom side edges 9c. More specifically, in the example shown, the length of bottom side edges 9c is smaller than the length of top side segments Q3.

In a similar way, top front segment Q1 and top rear segment Q2 have the same length, which is in turn different from the length of bottom front edge 8a and bottom rear edge 8b.

More specifically, in the example shown, the length of bottom front edge 8a and bottom rear edge 8b is greater than the length of top front segment Q1 and top rear segment Q2.

The packaging material 2 from which package 1 is made is shown in FIG. 6 and has a known multilayer structure (not shown) comprising a base layer, e.g. of paper, for stiffness, and a number of lamination layers covering both sides of the base layer.

Preferably, the lamination layers comprise one layer of oxygen-barrier material, e.g. an aluminum foil, and a number of layers of heat-seal 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 eventually forming the inside of package 1, packaging material 2 comprises one layer of heat-seal plastic material, one layer of oxygen-barrier material, another layer of heat-seal plastic material, the base layer, and one or more additional layers of heat-seal plastic material.

The letter M in FIG. 6 indicates a basic unit of packaging material 2, by which to produce package 1, and which may be a precut blank, or a portion of a web of packaging material comprising a succession of basic units M.

In the first case, basic unit M is folded on a known forming spindle (not shown), is filled with the food product, and is sealed at the top to form the final package.

In the second case, described therein with reference to FIGS. 1 to 12, the web of packaging material 2, comprising a succession of basic units M, is:

• • folded into a cylinder and sealed longitudinally to form a vertical tube;
  • filled continuously with the food product; and
  • sealed transversely and cut into basic units M, which are then folded to form respective packages 1.

After completion of these operations, package 1 has:

• • a bottom transverse sealing band 18 (FIG. 5) crossing bottom panel 10 along a centre line thereof and extending parallel to front bottom edge 8a and rear bottom edge 8b;
  • a top transverse sealing band 19 (FIGS. 1 to 4) crossing top panel 14 parallel to, and between, front top edge 9a and rear top edge 9b; and
  • a longitudinal sealing band 20 extending perpendicularly between the bottom transverse sealing band 18 and the top transverse sealing band 19 along respective portions of bottom panel 10 and top panel 14 and along the side wall portion 6 defining the rear face of package 1.

More specifically, after package 1 is completely sealed and formed, bottom panel 10 is crossed by bottom transverse sealing band 18 and by an end portion 20a of longitudinal sealing band 20 extending perpendicularly from the bottom transverse sealing band 18.

In a completely analogous way, after package 1 is completely sealed and formed, top panel 14 is crossed by top transverse sealing band 19 and by an end portion 20b of longitudinal sealing band 20 extending perpendicularly from the top transverse sealing band 19 and opposite to end portion 20a; in greater detail, top transverse sealing band 19 divides top panel 14 into two zones 14a, 14b and end portion 20b of longitudinal sealing band 20 extends on one (14b) of such zones 14a, 14b from an intermediate portion of the top transverse sealing band 19.

During the forming operations to obtain package 1, top transverse sealing band 19 is folded on zone 14b and end portion 20b of longitudinal sealing band 20; in this way, zone 14a has a bigger area than zone 14b and is therefore more suitable for receiving removable portion 17 and opening device 16.

In the example shown in FIG. 6, removable portion 17 has a circular profile and is designed to be at least partly detached in use from the rest of the packaging material by opening device 16 to free a pour opening through which to pour out the product.

Removable portion 17 is formed on packaging material 2 prior to folding and sealing the packaging material 2 itself to form the finished package.

In the present case, removable portion 17 comprises a so-called “prelaminated” hole, i.e. a circular hole formed through the base layer only of packaging material 2 and covered, when the packaging material 2 itself is laminated, with the layers of heat-seal plastic material and oxygen-barrier material, which adhere to one another at the hole.

With particular reference to FIG. 6, basic unit M of packaging material 2 has a rectangular configuration and is delimited by:

• • two side boundary edges 22 parallel to a longitudinal direction coinciding with longitudinal direction A in an upright condition of basic unit M;
  • a bottom boundary edge 23 parallel to a transversal direction B orthogonal to longitudinal direction A; and
  • a top boundary edge 24 parallel to transversal direction B and to bottom boundary edge 23.

Basic unit M of packaging material 2 comprises a number of crease lines defining respective fold lines, along which the packaging material 2 itself is folded to form the finished package 1.

More specifically, basic unit M comprises two transversal crease lines 25, 26 extending transversally with respect to longitudinal direction A and dividing the basic unit M itself into:

• • a bottom region 27 containing a bottom crease pattern 28 and configured to form bottom portion 3 of package 1;
  • a top region 29 containing a top crease pattern 30 and configured to form top portion 4 of package 1; and
  • an intermediate region 31 contained between transversal crease lines 25, 26, interposed between bottom region 27 and top region 29 and designed to form side wall portions 6 of package 1.

Transversal crease line 25 extends parallel to bottom boundary edge 23 and top boundary edge 24 and is arranged closer to bottom boundary edge 23 than transversal crease line 26. Transversal crease line 25 is configured to define bottom peripheral outline 8 of package 1.

In particular, transversal crease line 25 includes:

• • a bottom central portion 25a configured to define bottom front edge 8a of package 1;
  • two bottom end portions 25b arranged on opposite sides of bottom central portion 25a, located adjacent to respective side boundary edges 22 and configured to define bottom rear edge 8b of package 1; and
  • two bottom side portions 25c, extending adjacent to opposite sides of bottom central portion 25a, connecting the central portion 25a itself to the respective end portions 25b and designed to define respective bottom side edges 8c of package 1.

Transversal crease line 26 is arranged closer to top boundary edge 24 than transversal crease line 25 and is configured to define top peripheral outline 9 of package 1. In particular, transversal crease line 26 has a broken-line shape with:

• • a top central portion 26a parallel to transversal direction B and configured to define top front edge 9a of package 1;
  • two top end portions 26b parallel to transversal direction B, arranged closer to top boundary edge 24 than top central portion 26a and configured to define top rear edge 9b of package 1; and
  • two inclined top side portions 26c, having slanted configurations with respect to longitudinal direction A and transversal direction B and each one connecting top central portion 26a to respective top end portions 26b.

As visible in FIG. 6, top side portions 26c converge towards top central portion 26a.

Basic unit M includes two further transversal crease lines 32, 33 extending parallel to direction B and placed near bottom boundary edge 23 and top boundary edge 24, respectively; transversal crease lines 32, 33 delimit with bottom boundary edge 23 and top boundary edge 24 respective bottom transversal sealing area 34 and top transversal sealing area 35 configured to define bottom transversal sealing band 18 and top transversal sealing band 19 of package 1.

Bottom crease pattern 28 is designed to produce bottom panel 10 and bottom lateral flaps 11 of package 1. In particular, bottom crease pattern 28 includes, in a known manner, four longitudinal crease lines 36a, 36b parallel to longitudinal direction A and extending between transversal crease lines 25 and 32.

Longitudinal crease lines 36b are the most internal ones, whilst longitudinal crease lines 36a are located near opposite side boundary edges 22; the area between longitudinal crease lines 36b as well as the areas delimited by longitudinal crease lines 36a with the respective side boundary edges 22 are configured to define bottom panel 10 of package 1.

In each of the areas delimited between longitudinal crease lines 36a and 36b, bottom crease pattern 28 further includes two additional crease lines 37, 38 inclined with respect to both longitudinal direction A and transversal direction B.

In particular, the additional crease lines 37, 38 of each pair have one end in common located on transversal crease line 32 and opposite ends located at the intersection points between transversal crease line and longitudinal crease lines 36a and 36b, respectively. In this way, each pair of additional crease lines 37, 38 delimits a triangle 39 with the segment of transversal crease line 25 comprised between the additional crease lines 37, 38 themselves.

Each area between longitudinal crease lines 36a and 36b is configured to define one respective bottom lateral flap 11 of package 1.

Top crease pattern 30 is designed to produce top panel 14 and top lateral flaps 15 of package 1. In particular, top crease pattern 30 includes four longitudinal crease lines 40a, 40b parallel to longitudinal direction A and extending between transversal crease lines 26 and 33.

Longitudinal crease lines 40b are the most internal ones, whilst longitudinal crease lines 40a are located near opposite side boundary edges 22; the area between longitudinal crease lines 40b as well as the areas delimited by longitudinal crease lines 40a with the respective side boundary edges 22 are configured to define top panel 14 of package 1. Removable portion 17 is formed in the area of top region 29 comprised between longitudinal crease lines 40b.

In each of the areas delimited between longitudinal crease lines 40a and 40b, top crease pattern 30 further includes two additional crease lines 41, 42 inclined with respect to both longitudinal direction A and transversal direction B.

In particular, the additional crease lines 41, 42 of each pair have one end in common located on transversal crease line 33 and opposite ends located at, or adjacent to, the opposite ends of the respective inclined top side portion 26c of transversal crease line 26.

In this way, each pair of additional crease lines 41, 42 delimits a triangle 43 with the respective top side portion 26c of transversal creased line 26.

Each area between longitudinal crease lines 40a and 40b is configured to define one respective top lateral flap 15 of package 1.

According to an important aspect of the present invention, the length of top central portion 26a of transversal crease line 26 is different from the length of bottom central portion 25a of transversal crease line 25; in addition, the length of each of bottom side portions 25c of transversal crease line 25 is also different from the length of the projection R, parallel to longitudinal direction A, of each of top side portions 26c of transversal crease line 26 on a reference line S parallel to transversal crease line 25 and containing top central portion 26a.

In particular, the length of top central portion 26a is smaller than the length of bottom central portion 25a; in a different manner, the length of each projection R is greater than the length of the corresponding bottom side portion 25c.

As visible in FIG. 6, the length of bottom central portion 25a corresponds to the length of the segment of transversal crease line 32 comprised between longitudinal crease lines 36b; in a completely analogous manner, the length of top central portion 26a corresponds to the length of the segment of transversal crease line 33 comprised between longitudinal crease lines 40b.

The same applies to bottom side portions 25c, whose lengths correspond to the lengths of the respective segments of transversal crease line 32 comprised between each pair of longitudinal crease lines 36a and 36b. Analogously, the lengths of projections R correspond to the lengths of the respective segments of transversal crease line 33 comprised between each pair of longitudinal crease lines 40a and 40b.

It is important to note that the length of top front segment Q1 and top rear segment Q2 of top quadrilateral Q corresponds to the length of top central portion 26a; in an analogous manner, the length of top side segments Q3 of top quadrilateral Q corresponds to the length of projections R.

In the embodiment shown in FIG. 6, intermediate region 31 includes a central transversal band 44 having a uniform structure, i.e. lacking any creasing or weakening, and crossing the areas of the intermediate region 31 itself designed to form the respective lateral edge zones 7 of side wall portions 6 of package 1.

Preferably, intermediate region 31 of basic unit M further comprises a plurality of V-shaped crease lines 45 having respective vertices 46 located on or adjacent to the transversal crease lines 25, 26 and at given points thereof designed to define the opposite ends of respective lateral edge zones 7 delimiting the side wall portions 6 of package 1; each V-shaped crease line 45 extends from and in proximity of the respective transversal crease line 25, 26 up to central transversal band 44 and comprises two legs 47 diverging from the respective vertex 46.

In particular, each V-shaped crease line 45 extends from the respective transversal crease line 25, 26 towards the other transversal crease line 26, 25 and has a size, parallel to longitudinal direction A, greater than zero and smaller than one fourth, preferably smaller than one tenth, of the total height of intermediate region 31 measured parallel to the longitudinal direction A itself.

It is pointed out that, in the present description and in the claims, the term “total height of intermediate region 31” corresponds to the total height of the package.

In practice, each V-shaped crease line 45 extending from transversal crease line 25 and the corresponding V-shaped crease line 45 extending from transversal crease line 26 are spaced apart parallel to longitudinal direction A.

Preferably, each V-shaped crease line 45 has a size, parallel to longitudinal direction A, smaller than the maximum height of bottom region 27 or top region 29 measured parallel to the longitudinal direction A itself.

More preferably, each leg of the V-shaped crease lines 45 has a length smaller than the maximum length of the heights of triangles 39, 43 with reference to their bases on respective transversal crease lines 25, 26.

In the example shown, each V-shaped crease line 45 has a size, parallel to longitudinal direction A, substantially equal to one fourteenth of the total height of intermediate region 31 measured parallel to the longitudinal direction A itself.

As visible in FIGS. 1 to 4, V-shaped crease lines are the only crease lines present in intermediate region 31 at the areas designed to define lateral edge zones 7 between side wall portions 6 of package 1.

Due to the absence of continuous longitudinal crease lines between transversal crease lines 25, 26, the resulting package 1 presents a round configuration along lateral edge zones 7. V-shaped crease lines 45 perform the function of easing folding of the packaging material 2 at the corners between lateral edge zones 7 of side wall portions 6 and bottom peripheral outline 8 and top peripheral outline 9 without affecting the round configuration of lateral edge zones 7.

In the example shown, legs 47 of each V-shaped crease line 45 are rectilinear or straight; as a possible alternative not shown, legs 47 of each V-shaped crease line 45 may also be curved, preferably with their concavities facing one another.

Preferably, legs 47 of each V-shaped crease line 45 delimit an angle comprised between 45° and 90°.

Number 1′ in FIG. 7 indicates as a whole a different embodiment of a sealed package according to the present invention and obtained by a basic unit M′ (FIG. 8) of sheet packaging material 2. Package 1′ being similar to package 1, the following description is limited to the differences between them, and using the same references, where possible, for identical or corresponding parts; the same applies for basic units M′ and M.

In particular, package 1′ differs from package 1 only in that lateral edge zones 7 between side wall portions 6 are defined by respective longitudinal crease lines 50 extending between transversal crease lines 25 and 26. Longitudinal crease lines 50 are slightly slanted with respect to longitudinal direction A due to the different lengths between bottom central portion 25a and top central portions 26a of transversal crease lines 25, 26 as well as between bottom side portions 25c of transversal crease line 25 and respective projections R on reference line S.

In this case, there is no need for V-shaped crease lines, which are therefore absent.

Number 1″ in FIG. 9 indicates as a whole a different embodiment of a sealed package according to the present invention and obtained by a basic unit M″ (FIG. 10) of sheet packaging material 2. Package 1″ being similar to package 1, the following description is limited to the differences between them, and using the same references, where possible, for identical or corresponding parts; the same applies for basic units M″ and M.

In particular, package 1″ differs from package 1 only by having a top panel 14″ that extends horizontally and parallel to bottom panel 10.

In greater details, top panel 14″ is delimited by a top peripheral outline 9″ (formed by edges 9a″, 9b″, 9c″) parallel to bottom peripheral outline 8 and deriving by a transversal crease line 26″ also parallel to transversal crease line 25 and to transversal direction B.

In this case, top panel 14″ extends entirely on reference plane P and therefore the projection of top panel 14″ on this latter plane, i.e. top quadrilateral Q, coincides with the top panel 14″ itself.

The same applies to the projections R of top side portions 26c″ of transversal crease line 26″ on reference line S, which coincide with the top side portions 26c″ themselves; in fact, in this case, reference line S coincides with top transversal crease line 26″.

Number 1″′ in FIG. 11 indicates as a whole a different embodiment of a sealed package according to the present invention and obtained by a basic unit M″′ (FIG. 12) of sheet packaging material 2. Package 1″′ being similar to package 1″, the following description is limited to the differences between them, and using the same references, where possible, for identical or corresponding parts; the same applies for basic units M″′ and M″.

In particular, package 1″′ differs from package 1″ only in that lateral edge zones 7 between side wall portions 6 are defined by respective longitudinal crease lines 50 extending between transversal crease lines 25 and 26. Even in this case, longitudinal crease lines 50 are slightly slanted with respect to longitudinal direction A due to the different lengths between bottom central portion 25a and top central portion 26a″ of transversal crease lines 25, 26″ as well as between bottom side portions 25c and top side portion 26c″ of the same transversal crease lines 25, 26″.

Thanks to the presence of longitudinal crease lines 50, there is no need for V-shaped crease lines, which are therefore absent.

The advantages of packages 1, 1′, 1″, 1″′ and basic units M, M′, M″, M″′ of packaging material 2 according to the present invention will be clear from the above description.

In particular, all the solutions of packages 1, 1′, 1″, 1″′ described present bottom portions 3 slightly different from the top portions 4. In this way, it is possible to optimize filling of the transport pallets with the finished packages 1, 1′, 1″, 1″′, which present high flexibility in their dimensions without imparting relevant changes in their appearance. For instance, a slimmer bottom portion 3 than the top portion 4 permits to compensate the bulging effect produced by gravity on the pourable product contained in the package when placed in the upright position, which product tends to accumulate in the bottom portion of the package 1, 1′, 1″, 1″′, 1″″ itself.

Clearly, changes may be made to packages 1, 1′, 1″, 1″′ and basic units M, m′, M″, M″′ of packaging material 2 as described and illustrated herein without, however, departing from the scope of protection defined in the accompanying claims.

Claims

1. A sealed package containing a pourable food product and comprising a bottom portion, a top portion and a main portion interposed between said bottom portion and said top portion and including a plurality of side wall portions; wherein said main portion is divided from said bottom portion and said top portion respectively by a bottom peripheral outline and a top peripheral outline, each having an endless configuration and extending transversally with respect to a longitudinal direction, along which the total height of the package is defined;wherein each of said bottom peripheral outline and said top peripheral outline has a broken-line shape and is formed by a plurality of contour edges joined to each other;wherein said bottom portion comprises a quadrilateral bottom panel delimited by said bottom peripheral outline and extending orthogonal to said longitudinal direction; andwherein said top portion comprises a quadrilateral top panel delimited by said top peripheral outline and extending transversally to said longitudinal direction-;wherein the area of the bottom panel is different from the area of a top quadrilateral obtained by projecting, along said longitudinal direction, said top panel on a reference plane parallel to said bottom panel, crossing the package and containing at least one of the contour edges of said top peripheral outline.

2. The package as claimed in claim 1, wherein said reference plane contains at least a top front edge of the contour edges of said top peripheral outline.

3. The package as claimed in claim 1, wherein the area of said bottom panel is smaller than the area of said top quadrilateral.

4. The package as claimed in claim 1, wherein said contour edges of said bottom peripheral outline include a bottom front edge, a bottom rear edge and two bottom side edges and wherein said top quadrilateral includes a top front segment, corresponding to said bottom front edge, a top rear segment, corresponding to said bottom rear edge, and two top side segments, respectively corresponding to said bottom side edges.

5. The package as claimed in claim 4, wherein said bottom side edges have the same length and said top side segments have the same length; and wherein the length of said bottom side edges is different from the length of said top side segments.

6. The package as claimed in claim 5, wherein said length of said bottom side edges is smaller than said length of said top side segments.

7. The package as claimed in claim 4, wherein said bottom front edge and said bottom rear edge have the same length and said top front segment and said top rear segment have the same length; and wherein the length of said bottom front edge and said bottom rear edge is different from the length of said top front segment and said top rear segment.

8. The package as claimed in claim 7, wherein said length of said bottom front edge and said bottom rear edge is greater than said length of said top front segment and said top rear segment.

9. The package as claimed in claim 1, wherein said top panel is slanted with respect to said bottom panel, said reference plane and said longitudinal direction.

10. The package as claimed in claim 1, wherein said top panel is parallel to said bottom panel and wherein said top quadrilateral coincides with said top panel.

11. The package as claimed in claim 1, wherein each of said side wall portions is delimited by two rounded lateral edge zones convex outward.

12. The package as claimed in claim 1, wherein each of said side wall portions is delimited by two straight lateral edge zones.

13. A sheet packaging material for producing a sealed package containing a pourable food product, said packaging material having a rectangular or square configuration with two boundary edges parallel to a longitudinal direction and two other boundary edges parallel to a transversal direction orthogonal to said longitudinal direction; said packaging material comprising at least a bottom transversal crease line and a top transversal crease line extending transversally to said longitudinal direction and dividing the packaging material into: a bottom region containing a bottom crease pattern and configured to form a bottom portion of said package;a top region containing a top crease pattern and configured to form a top portion of said package; andan intermediate region contained between said bottom transversal crease line and said top transversal crease line, interposed between said bottom region and said top region and designed to form a main portion of said package having a plurality of side wall portions;wherein said bottom transversal crease line and said top transversal crease line are configured to define a bottom peripheral outline and a top peripheral outline of said package respectively dividing said bottom portion and said top portion from said main portion;wherein said bottom transversal crease line extends parallel to said transversal direction and includes a bottom central portion, designed to define a bottom front edge of said package, and two bottom side portions. extending on opposite sides of said bottom central portion and designed to define respective bottom side edges of said package;wherein said top transversal crease line includes a top central portion, designed to define a top front edge of said package, and two top side portions, extending on opposite sides of said top central portion and designed to define respective top side edges of said package;wherein said bottom crease pattern is configured to define a quadrilateral bottom panel of said package and said top crease pattern is configured to define a quadrilateral top panel of said package;wherein the length of said top central portion of said top transversal crease line is different from the length of said bottom central portion of said bottom transversal crease line.

14. The packaging material as claimed in claim 13, wherein the length of each of said bottom side portions of said bottom transversal crease line is different from the length of the projection, parallel to said longitudinal direction, of each of said top side portions of said top transversal crease line on a reference line parallel to said bottom transversal crease line and containing at least said top central portion.

15. The packaging material as claimed in claim 14, wherein said length of each of said bottom side portions is smaller than said length of the corresponding said projection.

16. The packaging material as claimed in claim 13, wherein said length of said bottom central portion of said bottom transversal crease line is greater than said length of said top central portion of said top transversal crease line.

17. The packaging material as claimed in claim 13, wherein said top side portions of said top transversal crease line are inclined with respect to both said longitudinal direction and said transversal direction and converge towards said top central portion.

18. The packaging material as claimed in claim 13, wherein said top transversal crease line is parallel to said bottom transversal crease line and coincides with said reference line, and wherein said projections of said top side portions on said reference line coincide with said top side portions.

19. The packaging material as claimed in claim 13, further comprising a plurality of longitudinal crease lines extending between said bottom transversal crease line and said top transversal crease line and configured to define respective lateral edge zones of the side wall portions of said package.

20. The packaging material as claimed in claim 19, wherein said longitudinal crease lines are slightly slanted with respect to said longitudinal direction.