WO2009131496A1

WO2009131496A1 - Inside creasing on a packaging laminate, a packaging container made from the packaging laminate, and a method for producing the packaging laminate

Info

Publication number: WO2009131496A1
Application number: PCT/SE2008/000275
Authority: WO
Inventors: Nelcio Carlos Do Amaral
Original assignee: Tetra Laval Holdings & Finance S.A.
Priority date: 2008-04-21
Filing date: 2008-04-21
Publication date: 2009-10-29
Also published as: PE20100031A1; TW200944366A; CL2009000933A1; CN101827754A; AR071211A1

Abstract

A packaging laminate for forming packaging containers has a core of paper or cardboard, and a first side forming the outside of a packaging container and a second side forming the inside of the packaging container. The packaging laminate is provided with crease lines defining folding locations usable during forming of the packaging containers, and each crease line defines a linear protrusion on one side of the laminate and a corresponding linear depression on the opposite side of the laminate. The packaging laminate is characterized in that at least one crease line, which forms a corner edge of the packaging container, has its linear protrusion on the first side of the packaging laminate.

Description

Inside "creasing on a packaging laminate, a packaging container made from the packaging laminate, and a method for producing the packaging laminate

Technical field

The present disclosure relates to packaging technology for packaging containers made from folded flexible material, such as a sheet or web material, in the form of a packaging laminate. More specifically, this disclosure relates to a packaging laminate for such packaging containers and a method of producing such a packaging laminate.

Background

Liquid foodstuff, such as milk and yoghurt, as well as semi-liquid foodstuff, such as soup, is typically sold in small volume consumer packaging containers. The packaging containers serve to protect the foodstuff throughout the value chain during transport and handling. Apart from protecting the product the container may carry information about its content and also act as a display surface to promote the product to the consumer.

Many different types of consumer packaging containers are known, such as plastic bottles, glass bottles and containers made from a paper based packaging laminate. Costs and environmental impact may influence the choice of packaging container.

A common choice of packaging container for liquid or semi-liquid foodstuff is a container made of a paper-based packaging laminate. Such a container is inexpensive to produce, has low environmental impact and can be stacked for efficient transport and handling.

Current packaging containers are made of a paper based packaging laminate with a paper fiber core surrounded by one or more layers of barrier material, such as a polymer coating and/or metal film, resulting in a packaging laminate. The barrier materials serve to protect the core material from the contained product and also protect the product from gases and moisture surrounding the packaging container. When producing such a container, the packaging laminate is folded and then glued and/or welded to form the con- tainer. This is a high-speed process, which is usually performed in connection to the filling of the containers. In order to make it easier to fold the packaging laminate in the correct places the packaging laminate is prepared by adding one or more crease lines. A crease line is created by letting the paper core pass under controlled pressure between two or more opposing crease rolls. The crease rolls are provided with substantially linear protrusions and/or depressions. The perimeter surfaces of the opposing rolls are very close to each other, and a protrusion of one roll corresponds to a matching depression in another roll, leaving some room for the paper core in-between.

The crease lines for the vertical corner edges of the resulting packaging container, extending from the container base towards the container top, of current packaging containers are oriented so that the depression is made in what is to become the outer surface of a packaging container, thus making it easy to fold those corner edges in the correct positions and thus making the corner edge "bulge" inwards, towards the center of the packaging container.

Often, several packaging containers are transported together on a special load carrier, such as a roller cage, from a filler unit to a point of sale. When arranging the containers on a load carrier they are typically stacked on top of each other in a regular, layer- based pattern. The containers should therefore preferably be rigid enough to allow for several layers of filled packaging containers to be stacked in said manner.

One way to reduce the cost and environmental impact of a packaging container is to reduce the amount of material used to produce it, and the most direct way to reduce the amount of material without lowering the container volume is to reduce the thickness of the material. However, reducing the thickness of the container material potentially also reduces its rigidity and, with that, its stackability.

Hence, a packaging container with maintained rigidity, in particular in relation to loads occurring during stacking of containers, and lowered material usage would be advantageous. Note that this objective also covers a packaging container with increased rigidity and maintained material usage.

During formation of the packages the packaging laminate may be subjected to great stresses. Particularly, folding of the packaging laminate can give rise to stresses in the material. Due to the rigidity of the core layer, the thermoplastic layer which in relation to the folding is located on the "outside" of the fold is subjected to elongation, i.e. tensile stresses, whereas the thermoplastic layer which in relation to the fold is located on the "inside" of the fold is pressed together and usually wrinkled along the fold line. Generally, the wrinkles are concentrated to and guided by any crease line present in laminate. Owing to the great extensibility of the thermoplastic material, folding only rarely leads to damages in the form of cracks in the outer plastic layers. However, in some cases when the packaging laminate comprises an aluminium foil there may be a risk that the foil, due to its low extensibility, tends to crack.

During formation of for example parallelepipedic packages from a tube formed of a packaging laminate web, the tube is filled with a product and transversally sealed along sealing zones, the zones being located at distances from each other, to form individual packages, which packages are separated from the tube through cutting in the sealing zones. The sealing fin located in the bottom end of the package, which fin is having a thickness corresponding to the thickness of two packaging laminates, is then folded towards the bottom surface of the package. Next, the triangular side flaps created at the sides of the package, which flaps also have a double material thickness, are folded towards the bottom surface of the package. This means that there are fold lines intersecting other fold lines, i.e. the packaging laminate is first folded about a first fold line and thereafter folded again about a second fold line intersecting the first one. In the intersection between the folds parts of the material are subjected to great tensile stresses, and/or elongation, because of the large total material thickness about which it is folded the second time. The presence of wrinkles at crease lines in the fold lines, which wrinkles create a thickening or bulge in the material, further increases the elongation in the outer layers of the laminate located on the "outside" of the fold.

One way of reducing the tensile stresses is to make the first fold sharp and well- defined, so that the second fold, which is made over the first fold, does not give rise to any unnecessary elongation in the outer layers of the packaging laminate being located on the "outside" of the second fold. The document EP-Al-O 027 668 discloses a packaging laminate, adapted to first being folded along a first fold line, and then along a second fold line intersecting the first one, where the first fold is made sharp by reducing the amount of wrinkles at the fold line. The packaging laminate is provided with crease lines along the first and second intersecting fold lines. In the intersection between the fold lines these crease lines are interrupted and the first crease line, along the first fold line, is being replaced by two auxiliary crease lines situated on either side of the fold line and being substantially parallel thereof. After folding the fold line extends between said auxiliary crease lines without coinciding with them. Thus, the wrinkles being formed on the "inside" of the fold are concentrated to the auxiliary crease lines and not to the fold line. Thereby, the first fold will be sharper and the material thickness about which the second fold is to be made is less. Thus, the elongation of the packaging laminate on the "outside" of the second fold is reduced. However, it has been found that the auxiliary creases disclosed in EP-Al-O 027 668 in some cases, for example for some types of laminates, laminate thicknesses or package volumes, may not be totally satisfactory. For example, some packaging laminates are not suited to be folded with a sharp first fold.

Summary

The present invention aims at providing a new packaging container meeting the above criteria, that is, a container with an increased ratio between rigidity and material usage.

This object has been achieved by a packaging laminate and a method of producing such a packaging laminate.

The packaging laminate comprises a core of paper or cardboard and has a first side forming the outside of a packaging container and a second side forming the inside of the packaging container and the material is often referred to as packaging laminate. Further, the material is provided with crease lines defining folding locations usable during forming of the packaging containers. Each crease line defines a linear protrusion on one side of the material and a corresponding linear depression on the opposite side of the material. The packaging laminate is characterized in that at least one crease line, which forms a corner edge of the packaging container, has its linear protrusion on the first side of the packaging laminate.

The method of producing the packaging laminate comprises: imprinting the packaging laminate with one or more crease lines with the help of using two or more corresponding crease rolls together defining a pattern of one or more crease lines, each crease line defining a linear protrusion and a corresponding linear depression. The method is characterized in that at least one of the one or more crease lines positioned for forming a corner edge of the packaging container has the linear protrusion on the first side of the packaging laminate.

The inventive creasing results in several advantages, all emanating from the fact that it is easier to fold the packaging container when using the invention. Since it easier to fold, the crease line does not have to be so deep, and thus the effect on the strength and stiffness of the packaging laminate is not affected as much. With prior art methods the crease lines have to be so deep that there is a risk of cutting the material along the crease line, when creasing. This results in a narrow production window in terms of creasing pressure. When using the invention the creasing pressure may be reduced, resulting in a broadened production window, less wear on crease plates (the plates arranged on the crease rolls), and thus a more economic production. Since it is easier to fold the packag- ing container when using the invention, the final folding of the packaging container, which is performed after filling of the packaging container, is facilitated and the production speed may be increased.

Another aspect of the present invention is also to provide a packaging laminate provided with crease lines arranged for reducing the risk of cracks arising in the packaging laminate at fold lines intersecting each other.

This aspect has been achieved by a packaging laminate comprising first and second intersecting fold lines about which said packaging laminate is adapted to be folded in order to form a package, the laminate being adapted to first being folded along the first fold line, and then along the second fold line, the laminate further comprising corresponding first and second crease lines along said first and second fold lines respectively, which crease lines are adapted to facilitate folding of the package, wherein said second crease line having an interruption along said second fold line, or an end, in an area where the first and second fold lines intersect, the interruption or end being provided with auxiliary crease lines, which auxiliary crease lines being substantially parallel with the second fold line, and the first crease line having an interruption or end adapted to accommodate the auxiliary crease lines. In this way folding along the first fold line is made in a conventional way not preventing wrinkles at the fold line, whereas the second folding along the second fold line is made in a smooth way that distributes the stresses in an even way and reduces the creation of wrinkles at the fold line, which wrinkles would give rise to increased elongation in the outer layers of the packaging laminate at the "outside" of the fold. Thus, the risk of cracks in the outer layers of the packaging laminate is reduced. By replacing a portion of the second crease line with two auxiliary crease lines the second fold can more easily and gently follow over the first fold. The configuration can for example be used for packaging laminates sensitive to sharp folds, and can therefore be used as an alternative to the prior known crease line configuration. These auxiliary crease lines comprise a linear depression on first side of the packaging laminate. A significant effect of the present invention as compared to the discussed prior art is that the auxiliary crease lines provides a predictable fold, looking essentially the same each time, while the prior art method is more random. This is believed to be the case since the prior art method aims at delaminating the packaging laminate, so that the various layers may fold independently, and thereby avoid tension, and thus cracking, while the present invention provides well defined crease lines, along which a fold will be created.

In a preferred embodiment of the invention the area where the auxiliary crease lines are provided and where the first and second fold lines intersect is delimited by the end points of the interruption in, or the end point of, the first crease line and the end points of the interruption in, or the end point of, the second crease line. It is in the area of the interruption in, or the end of, the crease lines that the auxiliary crease lines can have effect. If the auxiliary crease lines coincide with other crease lines the material tends to be too softened and a satisfactory guidance of the fold lines cannot be achieved.

Preferably, the auxiliary crease lines are situated on either side of the second fold line and at such a distance therefrom that the second fold line after folding of the packaging laminate extends between said auxiliary crease lines without coinciding with them. A too short distance between the auxiliary crease lines and the fold line may lead to a softening of the packaging laminate so that the fold line is not given a satisfactory guidance in the space between the two auxiliary crease lines. In this way it can be avoided that the fold line upon folding will instead be guided by the auxiliary crease lines and tend to follow either of the two.

Advantageously, the distance between any end point or end points of the second crease line and the nearest end point thereto of the respective auxiliary crease lines is such that the second fold line after folding of the packaging laminate extends between said auxiliary crease lines without coinciding with them, hi this way it can be avoided that the fold line upon folding will instead tend to follow any of the auxiliary crease lines. A too short distance, as mentioned before, may lead to a softening of the packaging laminate so that the fold line is not given a satisfactory guidance.

In another preferred embodiment the auxiliary crease lines are mutually parallel and located symmetrically in relation to the second fold line. Thereby, the wrinkles created nearby the crease lines are more evenly distributed on both sides of the fold line, i.e. the two sides will be formed substantially equal.

As mentioned preferably, substantially all of the crease lines are formed from the side of the packaging laminate being the inside of the package after forming of the package. It has been shown that forming the crease lines in this way is particularly favourable for some types of packaging laminates, laminate thicknesses or for example package volumes.

In yet another preferred embodiment a third crease line is provided along a third fold line, said third fold line being substantially parallel with the second fold line, which third crease line having an interruption or end in an area adapted to coincide with the auxiliary crease lines when the packaging laminate is folded about a fourth line arranged substantially in parallel with and at substantially equal distances from the second and third fold lines. Since the wrinkle formation is well guided in one area of the packaging laminate, there is no need to guide it further in another area coinciding with the first area upon folding. Generally, it is better to let the packaging laminate in that area smoothly follow the first area to reduce the risk of unnecessary elongation of the packaging laminate.

The invention also relates to a package made from packaging laminate comprising first and second intersecting fold lines about which said packaging laminate is folded in order to form the package, folds being provided first along the first fold line, and then along the second fold line, the package further comprising corresponding first and second crease lines along said first and second fold lines respectively, which crease lines are adapted to facilitate folding of the package, wherein said second crease line having an interruption along said second fold line, or an end, in an area where the first and second fold lines intersect, the interruption or end being provided with auxiliary crease lines, which auxiliary crease lines being substantially parallel with the second fold line and defined by a linear depression on the first side of the packaging laminate, forming the inner side of the packaging container. The first crease line having an interruption or end adapted to accommodate the auxiliary crease lines, hi this way folding along the first fold line is made in a conventional way not preventing wrinkles at the fold line, whereas folding along the second fold line is made in a smooth way that distributes the stresses in an even way and reduces the creation of wrinkles at the fold line, which wrinkles would give rise to increased elongation in the outer layers of the packaging laminate at the "outside" of the fold of the package. Thus, the risk of cracks in the outer layers of the packaging laminate, from which the package is made, is reduced. By replacing a portion of the second crease line with two auxiliary crease lines the second fold can more easily and gently follow over the first fold. The configuration can for example be used for forming packages of packaging laminates sensitive to sharp folds. Preferably, the package can be formed in accordance with the features defined in the dependent claims of the packaging laminate.

Description of drawings

Fig. 1 illustrates, schematically, creasing of a paper web.

Fig. 2 is a sectional packaging laminate with crease lines according to the invention.

Fig. 3 shows a corner edge of a packaging container according to the invention.

Fig. 4A and B are photographs comparing a corner of a packaging container formed according to the invention and a corner of a prior art packaging container, respectively.

Fig. 5 schematically shows a portion of the packaging laminate according to the invention, Fig. 6 schematically shows a parallelepipedic package, the bottom of which is being formed by a first folding along a first fold line, and

Fig. 7 schematically shows the package from Fig. 6, after a second folding along a second fold line, the second fold line intersecting the first fold line.

Fig. 8 shows a schematic cross section of two layers of packaging laminate, where the inner is provided with crease lines according to one embodiment of the invention.

Detailed description of embodiments

Referring to Fig. 1 , the inventive method according to one embodiment is performed in a creasing machine or rather in a creasing unit 2 of a converting machine, where paper core is printed, provided with crease lines and provided with barrier material, thereby forming a packaging laminate 4. In the creasing unit the paper is passed between two opposing crease rolls, a first roll 6 having protrusions and a second roll 8 having depressions. The depressions and the protrusions are in register, so as to form corresponding protrusions 10 and depressions 12 on the packaging laminate 4, see Fig. 2. The crease rolls 6, 8 are usually made of metal, but it should be understood that they could also be made of other materials, as long as they withstand the stress from the creasing operation, and have the necessary durability.

According to a first embodiment of the invention, a packaging laminate 4 is provided for forming packaging containers. The packaging laminate comprises a core 14 of paper or cardboard and is provided with one or more layers of barrier material, such as a laminated polymer film and/or metal film. The barrier materials serve to protect the core material 14 from the contained product and also protects the product from gases and liquids surrounding the packaging container. The packaging laminate has a first side 16 forming the outside of a packaging container and a second side 18 forming the inside of the packaging container. The packaging laminate 4 may also be any other type of fold- able material or combination of materials fulfilling the requirements of the packaging container. Any laminated barrier material is usually applied after creasing. A common procedure is to laminate a polyethylene (PE) film onto one or both of the sides of the paper core 14. If a metal foil is used as a further barrier material this is arranged after creasing. A PE layer is used as an adhesive to "glue" the metal foil to the core material, and generally two layers of PE are laminated on top of the metal foil, to act as barrier material and be used when sealing the packaging container.

When producing a parallelepipedic packaging container, the packaging laminate 4 is folded and then glued or welded to form a container. This is a high-speed process, which usually is performed in connection to the filling of the containers. The crease lines 20 are arranged in order to make it easier to fold the packaging laminate 4 in the correct place.

According to the first embodiment of the invention, one or more of the one or more crease lines 20 are formed so that the geometry of the one or more crease lines 20 when folded smoothly follows the natural bend curve of the corresponding fold edge. Especially, the crease lines 20 for the corner edges 22 of the packaging container (see Fig. 3) are formed this way. This means that substantial deformation of the second (inner) side 18 of the packaging laminate 4 along the one or more corner edge 22 crease lines is avoided, since both the protrusion 10 and the depression 12 is in the direction of the corner edge 22. For a vertical corner edge 22 that means that the one or more depressions 12 of the one or more crease lines 20 are formed in what is to become the inner surface of the packaging container. When one or more of the corner edge 22 crease lines 20 are arranged like this, it is possible to achieve a more rigid container and hence it is possible to use a less thick, hence more environmental friendly, packaging laminate 4 than what would have been needed for a container using prior art crease lines.

Surprisingly the invention results in an increased rigidity of the packages. The reason may be that delamination of coating from the paper core 2 is reduced. The reason may also be that the paper fibres in the core 2 are affected less by the inventive way of forming crease lines, in relation to prior art techniques. Fig. 4A and B are comparing photographs of a real example of inside creasing according to the invention (Fig. 4A), and regular creasing according to prior art (Fig. 4B). The photographs have been digitally enhanced to increase clarity. The same packaging laminate is used in both examples. It is apparent from the pictures that the outside corner is more well-defined for inside creasing, while the regularly creased packaging laminate displays a corner with two bends. Further, as the packaging laminate is bent, the length of the inner layer (the layer facing the inside of the packaging container) remains unaltered, which means that it has to fold or wrinkle. For inside creasing the inner layer will be urged to form a bulge towards the core of the packaging laminate, thus compacting it, and supposedly make it more rigid. This should be compared to the situation for outside creasing, where the inner layer will be urged, to form a bulge away from the core of the packaging laminate. Thus, as is evident from Fig. 4B, the bond between fibres constituting the core will be negatively affected, resulting in that the packaging laminate will be less rigid.

Fig. 5 schematically shows a portion of a packaging laminate, as a whole denoted with the reference numeral 110 in the figures. The packaging laminate 110 may comprise a core layer of fibrous material, such as for instance paper or board, which is provided with outer layers of polymers, preferably a thermoplastic material. Further, the packaging laminate 110 can also comprise additional layers, for example a gas barrier layer of metal foil, for instance aluminium foil.

The packaging laminate 110 comprises a first fold line A and a second fold line Bl about which said packaging laminate is adapted to be folded in order to form a package 112, see Figs. 6 and 7. As can be seen in Fig. 5 the first and second fold lines A, Bl intersect each other. The fold lines are only geometrical lines and are marked with dashed lines. Further, to facilitate forming of the package 112 the laminate 110 comprises corresponding first and second crease lines 114, 116 along the first and second fold lines A, Bl respectively. The use of crease lines to facilitate folding of a package is common and the manufacturing of crease lines onto a laminate is made using conventional technique, which will not be further discussed.

Along the second fold line Bl , the second crease line 116 has an interruption or end 18. Said interruption or end 118 is being located in the area where the first and second fold lines A, Bl intersect. The area is marked as a rectangle in Fig. 5. At the interruption or end 118 the crease line 116 is replaced by auxiliary crease lines 120. Said auxiliary crease lines 120 are substantially parallel with the second fold line Bl and are defined by a linear depression on the side of the packaging laminate forming the inside of the package 112. Moreover, the first crease line A has an interruption 122 or end adapted to accommodate the auxiliary crease lines 120. That is, the interruption 122 or end is located in the area where the first and second fold lines A, Bl intersect. As can be seen from Fig. 5, the first crease line 114 is interrupted, i.e. it continues after the intersection area accommodating the auxiliary crease lines 120, whereas the second crease line 116 ends at the intersection area. The intersection area where the auxiliary crease lines 120 are provided and where the first and second fold lines A, B 1 intersect is delimited by the end points of the interruption 122 in the first crease line 114, i.e. the ends of the crease line where the interruption 122 starts, and the end 118 of the second crease line 116. In a preferred embodiment the auxiliary crease lines 120 are not situated outside the marked rectangle, i.e. the auxiliary crease lines 120 are not situated so that they intersect with the first crease line 114 or situated so that they overlap the second crease line 116. Preferably, the auxiliary crease lines 120 are situated on either side of the second fold line Bl and at such a distance therefrom that the second fold line Bl after folding of the packaging laminate 110 extends between said auxiliary crease lines 120 without coinciding with them. Further, the longitudinal distance between the end point 118 of the second crease line 116 and the nearest end point thereto of the respective auxiliary crease lines 120 is such that the second fold line Bl after folding of the packaging laminate 110 extends be- tween said auxiliary crease lines 120 without coinciding with them. With longitudinal distances is meant distances directed along the second fold line Bl.

The auxiliary crease lines 120 are mutually parallel and located symmetrically in relation to the second fold line Bl. As is apparent from Fig. 5, the distance between the end point 118 of the second crease line 116 and the nearest end point of each respective auxiliary crease lines 120 is approximately of the same magnitude as the distance between the two auxiliary crease lines 120. Further, the width, or thickness, of the auxiliary crease lines 120 is larger than the width of the first and second crease lines 114, 116. Moreover, the distance between the auxiliary crease lines 120 are preferably larger than the distances from the auxiliary crease lines 120 to the end points of the interruption 122 of the first crease line 114. Further, the length of the auxiliary crease lines 120 is approximately less or equal to the interruption of the crease line 16. In the shown example there is no interruption but an end 118 of the crease line 116 and the length of the auxiliary crease lines 120 is approximately of the magnitude half the length of the distance from the end 118 of the crease line 116 to the nearest transversal edge of the packaging laminate 110. Additionally, the distance between the end 118 of the crease line 116 and the nearest end point of each respective auxiliary crease lines 120 is approximately of the same magnitude as the distance from the aforementioned packaging laminate edge and the auxiliary crease line end points being located nearest said edge. However, more or less all the distances are dependent on for example the quality and thickness of the packaging laminate 110, the volume of the package 112 etc.

Moreover, the packaging laminate comprises a third crease line 24 along a third fold line C 1. Said third fold line C 1 is substantially parallel with the second fold line B 1. The third crease line 124 has an interruption or end 126 in an area adapted to coincide with the auxiliary crease lines 120 when the packaging laminate 110 is folded about a fourth line D arranged substantially in parallel with and at substantially equal distances from the second and third fold lines Bl and Cl. As is apparent from Fig. 5, the third crease line has an end 126, although the crease line actually continues with two auxiliary crease lines 128 extending from the first fold line A to the transversal edge of the packaging laminate 110.

Substantially all of the aforementioned crease lines 114, 116, 120 are formed from the side of the packaging laminate 110 being the inside of the package after forming thereof. However, it should be understood that the crease lines may as well be formed from the opposite side. Which way is favorable depends on for example the quality and thickness of the packaging laminate 110, the volume of the package 112 etc. The invention also relates to a package 112 formed from the described packaging laminate and in the following, with reference to Figs. 6 and 7, the formation of the bottom of the package 112 will be described. The package as such is a parallelepipedic package sold by the applicant under the trademark Tetra Brik and will not be discussed in detail. The bottom of the package, see Fig. 6, comprises a transversal seal in the form of a fin 130. Before sealing the packaging laminate 10 is "folded" about the fourth line D (Fig. 1) so that the fold lines Bl and Cl coincide with each other. Then the package 112 is formed by means of crease lines 132 along fold lines B2 and C2 so that it presents a rectangular cross section. The package 112 is also being folded a first time about the first fold line A. Thereby, the fin 130 is being folded towards a bottom surface being formed and onto which the fin 130 will bear after folding. Preferably, the fin 30 is folded in a direction away from a longitudinal seal 136 of the package 112. Upon folding triangular side flaps 34 are also formed. Next, a second fold is formed along the second fold line Bl. During the second folding, and as is apparent from Fig. 7, the triangular side flaps 134 are folded towards the bottom of the package 112. Hence, a second fold about the second fold line B 1 has been made over an intersecting first fold about the first fold line A. Since the focus of this application is generally related to folding twice about two intersecting fold lines the description focuses on the intersection area between the first fold line A and the second fold line B 1. However, in the shown package embodiment the second fold is in fact made about a fold line comprising both fold lines Bl and Cl . Upon sealing of the fin 130, the second fold line Bl and the second fold line Cl will coincide, that is, when folding the second time, i.e. when folding the triangular side flaps towards the package bottom, one portion of the flap is folded about Bl, whereas another portion is folded about Cl. Also, one portion of the fin 130 is folded about Bl and another portion of the fin 130 is folded about Cl.

Fig. 8, which is a cross section of a fold using the auxiliary crease lines 120, may well represent a partial cross section of Fig. 7. Fig. 8 illustrates two layers of packaging laminate, of which the inner has been provided with crease lines 120, with the depression from the inside. The crease lines 120, as well as the fold lines Bl and Cl (indicated by filled circles), extends in a direction orthogonal to the paper surface. The mushroom shape of the inner laminate is typical for the inventive creasing, and is a repetitive shape ensuring a consistent and predictable quality of the fold. During folding the inner layer will experience a pressure from the outer layer (coming from the right in Fig. 8) and as a result it will fold along the crease lines 120, instead of in an arbitrary position, hi this context it should be noted that Fig. 8 is an illustration only, and does not constitute a photorealistic representation. The auxiliary crease lines 120 may be used to improve packaging containers other than those provided with the inventive creasing of the corners of the package.

Although the present invention has been described with respect to a presently preferred embodiment, it is to be understood that various modifications and changes may be made without departing from the object and scope of the invention as defined in the appended claims.

Claims

1. A packaging laminate for forming packaging containers, said laminate comprising a core of paper or cardboard, wherein the laminate has a first side forming the outside of a packaging container and a second side forming the inside of the packaging container, and is provided with crease lines defining folding locations usable during forming of the packaging containers, each crease line defining a linear protrusion on one side of the packaging laminate and a corresponding linear depression on the opposite side of the packaging laminate, characterized in that at least one crease line, which will form a corner edge of the packaging container, has its linear protrusion on the first side of the packaging laminate.

2. The packaging laminate of claim 1, wherein the core of paper is coated on one or both sides with a polymer film and/or a metal foil.

3. A packaging laminate (110) according to claim 1 or 2, further comprising first and second intersecting fold lines (A, Bl) about which said packaging laminate (110) is adapted to be folded in order to form a package (112), the laminate (110) being adapted to first being folded along the first fold line (A), and then along the second fold line (Bl), the laminate (110) further comprising corresponding first and second crease lines (14, 16) along said first and second fold lines (A, Bl) respectively, which crease lines (114, 116) are adapted to facilitate folding of the package (112), wherein said second crease line (116) having an interruption along said second fold line (Bl), or an end (118), in an area where the first and second fold lines (A, Bl), intersect, the interruption or end (118) being provided with auxiliary crease lines (120), which auxiliary crease lines (120) being substantially parallel with the second fold line (Bl), and the first crease line (114) having an interruption (122) or end adapted to accommodate the auxiliary crease lines (120).

4. Packaging laminate (10) according to claim 3, wherein the area where the auxiliary crease lines (20) are provided and where the first and second fold lines (A, Bl) intersect is delimited by the end points of the interruption (22) in, or the end point of, the first crease line (14) and the end points of the interruption in, or the end point (18) of, the second crease line (16).

5. Packaging laminate (10) according to any of claims 3-4, wherein the auxiliary crease lines (20) are situated on either side of the second fold line (Bl) and at such a dis- tance therefrom that the second fold line (Bl) after folding of the packaging laminate (10) extends between said auxiliary crease lines (20) without coinciding with them.

6. Packaging laminate (10) according to any of claims 3-5, wherein the longitudinal distance between any end point or end points of the second crease line (16) and the nearest end point thereto of the respective auxiliary crease lines (20) is such that the second fold line (Bl) after folding of the packaging laminate (10) extends between said auxiliary crease lines (20) without coinciding with them.

7. Packaging laminate (10) according to any of claims 3-6, wherein the auxiliary crease lines (20) are mutually parallel and located symmetrically in relation to the second fold line (Bl).

8. Packaging laminate (10) to any of claims 3-7, wherein substantially all of the crease lines (14, 16, 20) are formed from the side of the packaging laminate (10) being the inside of the package (12) after forming of the package (12).

9. Packaging laminate (10) according to any of claims 3-8, wherein it comprises a third crease line (24) along a third fold line (Cl), said third fold line (Cl) being substantially parallel with the second fold line (Bl), which third crease line (24) having an interruption or end (26) in an area adapted to coincide with the auxiliary crease lines (20) when the packaging laminate (10) is folded about a fourth line (D) arranged substantially in parallel with and at substantially equal distances from the second and third fold lines (Bl, Cl).

10. Packaging container (12) made from packaging laminate (10) comprising the packaging laminate of claim 1, further comprising first and second intersecting fold lines (A, Bl) about which said packaging laminate (10) is folded in order to form the package (12), folds being provided first along the first fold line (A), and then along the second fold line (Bl), the package (12) further comprising corresponding first and second crease lines (14, 16) along said first and second fold lines (A, Bl) respectively, which crease lines (14, 16) are adapted to facilitate folding of the package (12), wherein said second crease line (16) having an interruption along said second fold line (Bl), or an end (18), in an area where the first and second fold lines (A, Bl) intersect, the interruption or end (18) being provided with auxiliary crease lines (20), which auxiliary crease lines (20) being substantially parallel with the second fold line (Bl), and the first crease line (14) having an interruption (22) or end adapted to accommodate the auxiliary crease lines (20).

11. A method for producing a packaging laminate for forming packaging containers, wherein the packaging laminate comprises a core of paper or cardboard and one or more barrier layers of polymers or metal foil, wherein the packaging laminate has a first side forming the outside of a packaging container and a second side forming the inside of a packaging container, said method comprising the step of imprinting the core with one or more crease lines by using two or more opposing crease rolls together defining a pattern of one or more crease lines, each crease line defining a linear protrusion and a corresponding linear depression, characterized in that at least one of the one or more crease lines positioned for forming a corner edge of the packaging container has the linear protrusion on the first side of the packaging laminate.

12. The method of claim 11, adapted for producing a packaging laminate according to any of claims 1-10