Package for pourable food products

Abstract: A package (1) for pourable food products is formed by a four-sided top wall (2) having four top corners (8); by a four-sided bottom wall (3) having four bottom corners (9); by four lateral walls (4) extending between the top wall and the bottom wall; and by four corner walls (5), each extending between two consecutive lateral walls and between the top wall and the bottom wall. A pair of top diagonal crease lines (10a) extends diagonally downwards from each top corner (8), and defines a top portion of a respective corner wall (5); a pair of bottom diagonal crease lines (10b) extends diagonally upwards from each bottom corner (9), and defines a bottom portion of a respective corner wall (5); each pair of top diagonal crease lines (10a) is joined to a respective pair of bottom diagonal crease lines (10b) at two respective intersections (11) spaced apart; and the intersections (11) all lie in a single horizontal plane close to the top wall (2).

Description: The present invention relates to an improved-shape package for pourable food products. As is known, many pourable food products, such as fruit juice, pasteurized or long-storage UHT milk, wine, tomato sauce, etc., are sold in packages made of packaging material. The packaging material has a multilayer structure comprising a layer of fibrous material, e.g. paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene, and, in the case of aseptic packages for long-storage products, also has a layer of oxygen-barrier material, e.g. a sheet of aluminum. A typical example is the parallelepiped-shaped package for pourable food products known as Tetra Brik Aseptic™, which is formed from a continuous tube formed by longitudinally folding and sealing a web of sterilized packaging material. The tube is filled with the food product and then sealed and cut at equally spaced positions to form pillow packs, which are then folded mechanically to obtain the finished, substantially parallelepiped-shaped packages. To assist folding of the packaging material when forming the continuous tube and final folding, the packaging material is provided at the production stage with crease lines defining a so-called "crease pattern". Though widely used, parallelepiped-shaped packages of the above type have some drawbacks. Firstly, being perfectly parallelepiped-shaped, individual packages are difficult to remove from display rafts, by being packed tightly together with the lateral walls of adjacent packages contacting completely with no space in which to insert the fingers. Secondly, the package is awkward to grip laterally, especially when damp, which makes it slippery, or in the case of so-called "family-size" packages. This is obviously problematic, in particular after opening of the package, when the product is poured and risks to spill over the package in a not controlled way. Thirdly, parallelepiped-shaped packages also make it difficult to form a gas-filled "headspace", e.g. injected with nitrogen, advantageous to allow the product to be shaken before use and so to prevent the liquid from spraying when opening the package. Indeed, to obtain sufficient headspace, the height of the package would have to be increased considerably, thus increasing the amount of packaging material required, plus the cost of adapting the packaging machinery. In order to solve the above problems, a prismatic package has been designed, as described, for example, in US-A-5,938,107, to which the preamble of claim 1 refers. In one embodiment of the above US patent, the package is defined by a four-sided, e.g. square, top wall; a four-sided bottom wall; four lateral walls extending between the top and bottom walls; and four corner walls, each located between two lateral walls. The corner walls extend along a substantial portion of the height of the package, so that the middle cross section of the package is substantially in the form of a regular or irregular octagon. Triangular walls are interposed between each corner wall and the top and bottom walls, so that, vertically, the horizontal cross sections of the package go from the quadrangular or square shape of the top and bottom walls to an octagonal shape, with the diagonal sides gradually increasing in size to the constant octagonal shape of the middle portion. The above shape has been highly successful, by being not only more attractive but also easier to grip and cheaper to produce, by enabling a headspace to be formed cheaply and easily, and by reducing the amount of packaging material required for a given content. Nevertheless, it still leaves room for improvement, particularly as regards slippage when damp, and the tendency to buckle at the bottom due to hydrostatic pressure. It is an aim of the invention to improve the above prismatic package to fully exploit or even enhance its advantages, while at the same time providing an attractive new shape. According to the present invention, there is provided a sealed package for liquid food products, as defined in claim 1. Further, preferred embodiments are disclosed in dependent claims 2 to 15. A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, wherein: Figure 1 shows a perspective view of a first embodiment of a package for pourable food products according to a first embodiment of the invention; Figure 2 shows a side view of the package of Figure 1; Figure 3 shows a top plan view of the package of Figure 1; Figure 4 shows a perspective view of a second embodiment of a package for pourable food products in accordance with the invention; Figure 5 shows a side view of the package of Figure 4. Figures 1-3 show a first embodiment of a package 1 for pourable food products, containing a pourable food product such pasteurized or UHT milk, fruit juice, wine, etc. Package 1 comprises a four-sided (in the example shown, square) top wall 2; a four-sided (in this case, square) bottom wall 3; four lateral walls 4 extending between top wall 2 and bottom wall 3; and four corner walls 5, each located between a respective pair of adjacent lateral walls 4, and extending between top wall 2 and bottom wall 3. Top wall 2 is fitted in known manner with a cap 15. Each corner wall 5 is defined by a top corner portion 5a and a bottom corner portion 5b. Top and bottom corner portions 5a and 5b are in the form of triangles with equal, coincident bases 7, and with apexes 8, 9 coincident with the corners of top wall 2 and bottom wall 3 respectively. In other words, top corner portions 5a - which are triangular with the apexes facing upwards - are connected to respective bottom corner portions 5b - which are also triangular, but with the apexes facing downwards - at bases 7. Top corner portions 5a are much smaller in height than bottom corner portions 5b, so that bases 7 are much closer to top wall 2 than to bottom wall 3 (in the example shown, they are located at a point at roughly 9/10 of the total height of package 1). Each lateral wall 4 of package 1 is defined by a top lateral portion 4a and a bottom lateral portion 4b, both in the form of an isosceles trapezium with coincident minor bases 12. That is, top lateral portions 4a are connected to respective bottom lateral portions 4b at minor bases 12. Bottom lateral portions 4b have a much greater height than top lateral portions 4a; and minor bases 12 and bases 7 extend in the same horizontal plane substantially parallel to bottom wall 3. Lateral walls 4 and corner walls 5 are delimited to each other by top crease lines 10a and bottom crease lines 10b. Top crease lines 10a extend diagonally in pairs from corners 8 of top wall 2; and bottom crease lines 10b extend diagonally in pairs from corners 9 of bottom wall 3; the term "diagonally" here being intended to mean that top and bottom crease lines 10a, 10b extend transversely with respect to ideal lines joining each corner 8 of top wall 2 to a respective corner 9 of bottom wall 3. Top crease lines 10a are joined directly to respective bottom crease lines 10b at intersections 11 defining the ends of bases 7 and of minor bases 12. That is, there are no vertical lines between top crease lines 10a and respective bottom crease lines 10b. Preferably, bases 7 are only ideal lines connecting intersections 11 across corner walls 5, and top and bottom corner portions 5a, 5b are connected gradually by curved portions. Similarly, minor bases 12 are also only ideal lines connecting intersections 11 across lateral walls 4, and top and bottom lateral portions 4a, 4b are connected gradually by curved portions. By virtue of the shape of lateral walls 4 and corner walls 5, and the arrangement of crease lines 10a, 10b, lateral walls 4 project outwards, with respect to a parallelepiped-shaped package, from corresponding edges of top wall 2 and bottom wall 3, the maximum bulk portions coinciding with minor bases 12, so that, when packed on rafts, the packages only contact one another at minor bases 12, thus leaving a gap in which to insert the fingers for easy grip. Moreover, by virtue of the geometry, bases 7 are arranged slightly rearwardly with respect to apexes 8, 9, as shown in the top plan view in Figure 3, in which bases 7 are shown by the dash lines. In other words, top and bottom corner portions 5a, 5b extend slightly inwards of package 1 from respective apexes 8, 9. Consequently, since top and bottom lateral portions 4a, 4b extend outwards, the cross section of package 1, in the plane containing bases 7 and minor bases 12, is smaller than the overall size of package 1 shown in the plan view in Figure 3, thus making package 1 even easier to grip, and preventing it from slipping even when damp or wet. Package 1 is formed from a tube of packaging material provided with crease lines 10a, 10b, as well as conventional crease lines for forming top and bottom walls 2, 3 and sealing the top and bottom of the package. The packaging material has a multilayer structure as described previously, and the crease lines are formed using the same punches currently used for octagonal packages. Moreover, currently used packaging machines can also be employed, by simply making appropriate minor alterations to the jaws and final folding device. The advantages of the package described as regards easy, non-slip grip, and the need for only minor alterations to existing packaging machinery, will be clear from the foregoing description. In addition, the package described requires a smaller amount of packaging material for a given volume; is more rigid than octagonal packages; is less subject to deformation at the bottom as compared with the known octagonal solution; can be provided easily at the top with a gas-filled headspace; and can be fitted with known closing, sealing and tamperproof devices and optionals. Last but not least, the package described has an attractive new look for a discerning market in search of novelty even in the packaging of pourable food products. Clearly, changes may be made to the package as described and illustrated herein without, however, departing from the scope of the invention as defined in the accompanying claims. In particular, the plane containing the lines connecting the top and bottom portions of the lateral and corner walls may be located at a different height, e.g. closer to bottom wall 3 than to top wall 2, as shown in the Figure 4 and 5 embodiment. Also, the lines between the top and bottom portions of the lateral and corner walls (bases 7 and minor bases 12) may be sharp lines defined by creases formed beforehand or during folding.

Claims: A sealed package (1) for liquid food products, comprising a four-sided top wall (2) having four top corners (8); a four-sided bottom wall (3) having four bottom corners (9); four lateral walls (4) extending between said top wall and said bottom wall; four corner walls (5), each extending between two consecutive lateral walls and between said top wall and said bottom wall; four pairs of top diagonal crease lines (10a), each said pair of top diagonal crease lines (10a) being connected to a respective top corner (8), extending diagonally downwards, and delimiting a top portion of a respective corner wall (5); and four pairs of bottom diagonal crease lines (10b), each pair of bottom diagonal crease lines (10b) being connected to a respective bottom corner (9), extending diagonally upwards, and defining a bottom portion of a respective corner wall (5); characterized in that each pair of top diagonal crease lines (10a) is joined to a respective pair of bottom diagonal crease lines (10b) at two respective intersections (11) spaced to each other. A package as claimed in claim 1, wherein said top wall and said bottom wall (2, 3) each have four edges; and said lateral walls extend between corresponding edges of said top wall and said bottom wall. A package as claimed in claim 1 or 2, wherein said top wall and said bottom wall (2, 3) are identical. A package as claimed in any one of claims 1 to 3, wherein said intersections (11) of said pairs of top (10a) and bottom (10b) diagonal crease lines lie in a single plane. A package as claimed in claim 4, wherein said single plane is a horizontal plane. A package as claimed in claim 4 or 5, wherein said single plane is closer to said top wall (2) than to said bottom wall (3). A package as claimed in claim 4 or 5, wherein said single plane is closer to said bottom wall (3) than to said top wall (2). A package as claimed in any one of claims 4 to 7, wherein said intersections (11) delimit a smaller cross section than a lateral bulk of said package (1). A package as claimed in any one of claims 1 to 8, wherein each said corner wall (5) comprises a top corner portion (5a) and a bottom corner portion (5b), both substantially triangular; said top corner portion (5a) having an apex (8) facing a respective top corner, and a triangle base (7) coincident with a triangle base of said bottom corner portion (5b); and said bottom corner portion having an apex (9) facing a respective bottom corner. A package as claimed in claim 8, wherein each said top corner portion (5a) is connected gradually to a respective bottom corner portion (5b). A package as claimed in claim 9 or 10, wherein said top corner portions (5a) and said bottom corner portions (5b) extend inwards of said package (1) from respective top corners (8) and respective bottom corners (9) respectively. A package as claimed in claim 11, wherein each said lateral wall (4) comprises a top lateral portion (4a) and a bottom lateral portion (4b), both substantially trapezoidal; said top lateral portion (4a) having a minor base coincident with a minor base of said bottom lateral portion (4b). A package as claimed in claim 11 or 12, wherein said triangle bases (7) and said minor bases (12) extend in a single plane. A package as claimed in claim 12 or 13, wherein said top lateral portions (4a) and said bottom lateral portions (4b) extend outwards of said package (1) from respective edges of said top wall (2) and said bottom wall (3) respectively. A package as claimed in claim 14, wherein said triangle bases (7) and said minor bases (12) delimit a smaller area than a transverse bulk of said package (1) viewed from above.

Inventors: GUIDOTTI LORENZO, MORANDI MAURO, GUIDOTTI, LORENZO, MORANDI, MAURO
Applicants: TETRA LAVAL HOLDINGS & FINANCE, TETRA LAVAL HOLDINGS & FINANCE S.A.
Application year: 2001
Main classification: B65D5
IPC codes: B65D5