阅读说明：本技术 用于生产包装材料的方法 (Method for producing packaging material ) 是由 卢卡·朗切蒂 安德里亚·吉米佩里 马尔塞洛·巴尔别里 达维德·莫尔恰诺 于 2019-07-09 设计创作，主要内容包括：提供了一种包装材料(100),其包含芯材料层(140)和层压到其上的至少一个聚合物层(142,145,147)。芯材料层(140)设置有至少一个区域(C1,C2,C3,C4),其被构造成有助于将包装材料(100)折叠成待形成的包装(10)的底端拐角(PC1,PC2,PC3,PC4),其中,包装材料(100)包含被设计成形成包装(10)的底端(BP)的第一组折痕线(132)和被设计成形成包装(10)的主体(MB)的第二组折痕线(134)。至少一个区域(C1,C2,C3,C4)包括多条折痕线(BC,LCB)的交点(IX),多条折痕线(BC,LCB)中的每一条具有三角形的横截面,而第一组折痕线(132)中的多条折痕线(LCC,DC,BC’)被终止,使得其终结在与交点(IX)相隔距离(D)处,多条折痕线(LCC,DC,BC’)中的每一条具有三角形横截面并且具有穿过交点(IX)的虚拟延伸部。(A packaging material (100) is provided comprising a layer of core material (140) and at least one polymer layer (142, 145, 147) laminated thereto. The layer of core material (140) is provided with at least one area (C1, C2, C3, C4) configured to facilitate folding of the packaging material (100) into a bottom end corner (PC1, PC2, PC3, PC4) of a package (10) to be formed, wherein the packaging material (100) comprises a first set of crease lines (132) designed to form a bottom end (BP) of the package (10) and a second set of crease lines (134) designed to form a body (MB) of the package (10). The at least one region (C1, C2, C3, C4) comprises an intersection point (IX) of a plurality of crease lines (BC, LCB), each of the plurality of crease lines (BC, LCB) having a triangular cross-section, whereas the plurality of crease lines (LCC, DC, BC ') of the first set of crease lines (132) are terminated such that they end at a distance (D) from the intersection point (IX), each of the plurality of crease lines (LCC, DC, BC') having a triangular cross-section and having a virtual extension through the intersection point (IX).)

1. A packaging material (100) comprising a layer of core material (140) and at least one polymer layer (142, 145, 147) laminated thereto,

wherein the core material layer (140) is provided with at least one region (C1-C4), the at least one region (C1-C4) being configured to facilitate folding of the packaging material (100) into a bottom end corner (PC1, PC2, PC3, PC4) of a package (10) to be formed,

wherein the packaging material (100) comprises a first set of crease lines (132) designed to form a bottom end (BP) of the package (10) and a second set of crease lines (134) designed to form a Main Body (MB) of the package (10),

characterized in that said at least one region (C1, C2, C3, C4) comprises an intersection point (IX) of a plurality of crease lines (BC, LCB), each of said plurality of crease lines (BC, LCB) having a triangular cross section, whereas a plurality of crease lines (LCC, DC, BC ') of said first set of crease lines (132) is terminated such that it ends at a distance (D) from said intersection point (IX), each of said plurality of crease lines (LCC, DC, BC') having a triangular cross section and having a virtual extension passing through said intersection point (IX).

2. The packaging material of claim 1, wherein an imaginary extension of a terminating crease Line (LCC) of the first set of crease lines (132) substantially coincides with an intersecting crease Line (LCB) of one of the second set of crease lines (134).

3. The packaging material according to claim 1 or 2, wherein said terminal crease line (LCC, DC, BC ') of said at least one region (C1, C2, C3, C4) comprises one transverse crease line (BC'), one longitudinal crease Line (LCC) and one diagonal crease line (DC).

4. The packaging material according to any one of the preceding claims, wherein the intersecting crease lines (BC, LCB) are arranged perpendicular to each other.

5. The packaging material according to any one of the preceding claims, wherein the distance (D) is from 1 to 10mm, such as from 1.5 to 5mm, preferably from 1.5 to 3 mm.

6. The packaging material of any one of the preceding claims, comprising two regions (C1, C4), said two regions (C1, C4) being configured to form two rear bottom corners (PC1, PC4) of a package (10), wherein each region (C1, C4) comprises an intersection point (IX) of a plurality of crease lines (BC, LCB), each of said plurality of crease lines (BC, LCB) having a triangular cross-section, whereas a plurality of crease lines (LCC, DC, BC ') of said first set of crease lines (132) is terminated such that it terminates at a distance (D) from said intersection point (IX), each of said plurality of crease lines (LCC, DC, BC') having a triangular cross-section and having a virtual extension through said intersection point (IX).

7. The packaging material of claim 6, wherein the area (C1, C4) is configured to form bottom corners (PC1, PC4) arranged on opposite sides of a Longitudinal Sealing Area (LSA).

8. The packaging material of any one of the preceding claims, comprising four regions (C1, C2, C3, C4) configured to form four bottom corners (PC1, PC2, PC3, PC4) of a package (10), wherein each region (C1, C2, C3, C4) comprises an intersection point (IX) of a plurality of crease lines (BC, LCB), each of said plurality of crease lines (BC, LCB) having a triangular cross-section, whereas a plurality of crease lines (LCC, DC, BC ') of said first set of crease lines (132) are terminated such that they terminate at a distance (D) from said intersection point (IX), each of said plurality of crease lines (LCC, DC, BC') having a triangular cross-section and having a virtual extension through said intersection point (IX).

9. The packaging material according to any one of the preceding claims, wherein the cross section of the triangular crease line (BC, LCB, LCC, DC, BC') is asymmetric.

10. A package (10) produced by sealing and shaping a packaging material (100), said package (10) comprising at least one bottom corner (PC1, PC2, PC3, PC4), said at least one bottom corner (PC1, PC2, PC3, PC4) being shaped by folding the packaging material (100) in a relevant area (C1, C2, C3, C4),

characterized in that said at least one bottom corner (PC1, PC2, PC3, PC4) is defined by an intersection point (IX) of a plurality of crease lines (BC, LCB), each of said plurality of crease lines (BC, LCB) having a triangular cross section, whereas a plurality of crease lines (LCC, DC, BC ') are terminated such that they end at a distance (D) from said intersection point (IX), each of said plurality of crease lines (LCC, DC, BC') having a triangular cross section and having a virtual extension passing through said intersection point (IX).

11. A method for producing a packaging material, comprising:

providing a core material layer (140) having at least one region (C1, C2, C3, C4), said at least one region (C1, C2, C3, C4) being configured to facilitate folding of said packaging material (100) into a bottom end corner (PC1, PC2, PC3, PC4) of a package (10) to be formed, and

providing a first set of crease lines (132) designed to form a bottom end (TP) of the package (10) and a second set of crease lines (134) designed to form a body (MB) of the package (10), such that the at least one region (C1, C2, C3, C4) comprises an intersection point (IX) of a plurality of crease lines (BC, LCB), each of the plurality of crease lines (BC, LCB) having a triangular cross-section, whereas a plurality of crease lines (LCC, DC, BC ') of the first set of crease lines (134) is terminated such that it terminates at a distance (D) from the intersection point (IX), each of the plurality of crease lines (LCC, DC, BC') having a triangular cross-section and having a virtual extension through the intersection point (IX).

12. A panel (220) of a pressing tool (200) for providing a crease line (130) in a core material layer (140) of a packaging material (100), said panel (220) comprising at least one area (P1, P2, P3, P4), said at least one area (P1, P2, P3, P4) being configured to provide a crease line (BC, LCC, DC, LCB), said crease line (BC, LCC, DC, LCB) contributing to folding said packaging material (100) into a bottom corner (PC1, PC2, PC3, PC4) of a package (10) to be formed,

characterized in that said at least one region (P1-P4) comprises an intersection Point (PIX) of a plurality of ridges (PBC, PLCB), each of said plurality of ridges (PBC, PLCB) having a triangular cross-section, whereas said plurality of ridges (PLCC, PDC, PBC ') of said first set of crease lines (134) are terminated such that they end at a distance (D) from said intersection Point (PIX), each of said plurality of ridges (PLCC, PDC, PBC') having a triangular cross-section and having a virtual extension passing through said intersection Point (PIX).

13. The board (220) of claim 12, wherein the total height of the ridges (PBC, PLCB) at the intersection Point (PIX) is substantially the same as the height (PBC, PLCB, PLCC, PDC, PBC') of a single ridge away from the intersection Point (PIX).

14. The panel according to claim 13, wherein the total height of the ridges (PBC, PLCB) at the intersection points is between 1mm and 2mm, preferably between 1mm and 1.5 mm.

15. The plate of any one of claims 12 to 14, wherein the triangular ridge (PBC, PLCB, PLCC; PDC, PBC') is asymmetric in cross-section.

Technical Field

The present invention relates to a method for producing a packaging material, in particular a method for producing a packaging material suitable for forming individual packages capable of storing liquid food products.

Background

Packages for storing liquid food products exist on the market and filling machines enable such food product packages to be produced at very high speeds. According to one accepted principle, a continuous series of packages is manufactured by sealing longitudinal ends of a continuous web of packaging material to each other to form the web into a tube. When the tube is continuously filled with liquid contents to be stored by the package, a transverse seal is made below the liquid level within the tube. In a single sealing action, two seals are created at substantially the same time: the upper end seal of the leading package and the lower end seal of the immediately following package. After the sealing action is completed, the knife is activated to cut the tube transversely in the area between the upper and lower end seals, thereby separating the leading (now sealed) package from the upstream tube. Alternatively, a similar package may be made from pre-cut blanks or sheets of laminated packaging material, which are folded and sealed longitudinally into tubular capsules (capsules) and then fold formed at a first end and filled and sealed at the other end in a stepwise filling operation.

Crease lines are arranged on the packaging material. These crease lines enable the packaging material to be folded at specific locations defined by the exact arrangement of the crease lines, which are usually provided first on the core material layer of the packaging material before the packaging material is further laminated to form the inner and outer layers of the core material layer. For this purpose, a pressing tool, for example a pressing roller, is usually used, wherein the operating surface of the pressing tool has a plurality of ridges. When these ridges are pressed into the layer of core material, crease lines are formed.

The crease line is thus a linear deformation of the core material layer, which enables the package to be folded at a specific location of the crease line. In particular for three-dimensional cubic packages formed by folding the packaging material along predetermined crease lines, certain areas are associated with increased difficulty of forming. The difficulty of forming is also increasing due to the increased machine speed, both during laminate production and in the filling machine speed, which also requires higher folding and heat sealing speeds.

The same applicant describes in WO2015/193358 an improved crease line and a method for producing the same. Also, one area of increased difficulty in folding and forming is the bottom end of the package, particularly the corners of the bottom end. The shaping of the corners is indeed described in the above prior art reference, which describes how improved corner folding is achieved if the crease lines meet at the corners.

Although the above disclosure provides a good (elegant) improvement over earlier attempts to provide precisely shaped bottom corners, there is a continuing effort to further improve the shaping and forming of packages into desired shapes.

Accordingly, there is a need for an improved packaging material.

Disclosure of Invention

It is an object of the present invention to at least partially overcome one or more of the above identified limitations of the prior art. In particular, it is an object to provide a packaging material which enables a well-defined folding and shaping of the bottom corners.

To achieve these objects, a packaging material is provided. The packaging material comprises a core material layer and at least one polymer layer laminated thereto, wherein the core material layer is provided with at least one area configured to facilitate folding of the packaging material into a bottom end corner of a package to be formed. The packaging material comprises a first set of crease lines designed to form a bottom end of the package and a second set of crease lines designed to form a body of the package. The at least one region includes an intersection of a plurality of crease lines, each of the plurality of crease lines having a triangular cross-section, and a plurality of crease lines of the first set of crease lines are terminated such that they terminate at a distance from the intersection, each of the plurality of crease lines having a triangular cross-section and having a virtual extension through the intersection.

The distribution of the crease lines in the respective areas and the combination of the triangular cross-section of the crease lines provide a very well-defined corner fold. The reasons for this are two: first, the triangular cross-section of the crease line ensures a narrow and well-defined single axis of rotation during folding, so that the actual folding will take place exactly where the apex of the ridge is pressed into the packaging material to form the crease line. Secondly, folding of the corners is generally achieved by enabling the folding guides of the filling machine to move along a predetermined movement curve; these motion profiles are determined by the configuration of the cam curve. This means that the folding guides do not have a perfectly linear movement but follow a curved path during the longitudinal movement of the packages. Since the folding of the packaging flap will be guided by the current position of the folding guide, the exact corner position may drift during the folding sequence. In view of this configuration of the filling machine, the inventors realized that terminating some crease lines slightly before the intersection point is reached, while allowing other crease lines to actually intersect at the intersection point, will enable the exact angular position to float during folding until the final folding is completed. In this last step, a perfect alignment of the dog-ears is achieved.

The imaginary extension of the terminating crease line of the termination of the first set of crease lines may coincide or substantially coincide with one of the intersecting crease lines of the second set of crease lines. Thus, the corner regions will define the rectangular shape of the package.

In one embodiment, the imaginary extension of the longitudinal terminal crease of the first set of crease lines may deviate from the intersecting longitudinal crease line of the second set of crease lines by 0.3mm to 0.5 mm. In another embodiment, the imaginary extension of the transverse terminal crease line of the first set of crease lines may deviate from the intersecting transverse crease line of the first set of crease lines by 0.3mm to 0.5 mm. The termination crease line of at least one region may comprise one transverse crease line, one longitudinal crease line and one diagonal crease line. Thereby enabling improved folding of the bottom flap.

The intersecting crease lines may be arranged perpendicular to each other, which enables a rectangular bottom end of the resulting package.

The distance may be in the range of 1 to 10mm, for example in the range of 1.5 to 5mm, preferably in the range of 1.5 to 3 mm. This has proven to provide very beneficial results in terms of corner forming of the package.

The packaging material may comprise two regions configured to form two rear bottom corners of the package, wherein each region comprises an intersection of a plurality of crease lines, each crease line having a triangular cross-section. A plurality of crease lines of the first set of crease lines are terminated such that they terminate at a distance from the intersection point, each of the plurality of crease lines having a triangular cross-section and having an imaginary extension through the intersection point. Due to twoThe rear bottom corner is shaped by folding the area shaped according to the first aspect described herein, so it makes it possible to improve the shaping of the entire bottom, in particular for TetraAnd (7) aseptic packaging.

The regions may be configured to form rear bottom corners disposed on opposite sides of the longitudinal seal region.

The packaging material may comprise four regions configured to form four bottom corners of the package, wherein each region comprises an intersection of a plurality of crease lines, each crease line having a triangular cross-section. A plurality of crease lines of the first set of crease lines are terminated such that they terminate at a distance from the intersection point, each of the plurality of crease lines having a triangular cross-section and having an imaginary extension through the intersection point. Such a configuration, wherein all four corners are shaped by folding the area constructed according to the first aspect described herein, has been demonstrated for TetraAseptic type packaging is particularly advantageous.

The triangular crease line may be asymmetric in cross-section. This asymmetric configuration provides several advantages. For example, it will create a distinct shear fracture initiation zone in the packaging material at a location corresponding to the location of the side wall of the embossed portion of the ridge of the pressboard used to provide the crease line. By providing the ridge with an asymmetric embossed portion, there will be a particularly well-defined area where significant shear fracture initiation occurs, resulting in a very well-defined fracture upon folding. By operating the pressing tool, the applied force will induce a downward stress on the surface of the packaging material facing the pressing plate. If a symmetrical embossing section is used, a similar effect will be seen, i.e. a concentrated and defined fracture-inducing region will become apparent. However, the symmetric embossing in the packaging material will become more severe and the method is crucial for control within a narrow operating window to avoid simply cutting through the material by the symmetric triangular ridges of the pressing device. Thus, the asymmetric crease ridges provide a more well-defined crease and enable a more robust creasing operation.

According to a second aspect, a package is provided which is produced by sealing and shaping a packaging material. The package includes at least one bottom corner. The at least one bottom corner is formed by folding the packaging material in the relevant area. The at least one bottom corner is defined by the intersection of a plurality of crease lines, each of the plurality of crease lines having a triangular cross section, and a plurality of crease lines terminated such that they terminate at a distance from the intersection, each of the plurality of crease lines having a triangular cross section and having a virtual extension through the intersection.

According to a third aspect, a method for producing a packaging material is provided. The method comprises the following steps: providing a layer of core material having at least one area configured to facilitate folding of the packaging material into bottom end corners of a package to be formed, and providing a first set of crease lines designed to form a bottom end of the package and a second set of crease lines designed to form a body of the package, such that the at least one area comprises an intersection of a plurality of crease lines, each of the plurality of crease lines having a triangular cross-section, and a plurality of crease lines of the first set of crease lines being terminated such that they terminate at a distance from the intersection, each of the plurality of crease lines having a triangular cross-section and having a virtual extension through the intersection.

According to a fourth aspect, a board for a pressing tool for providing crease lines in a core material layer of a packaging material is provided. The panel includes at least one area configured to provide a crease line that facilitates folding of the packaging material into a bottom corner of a package to be formed. Said at least one region comprises an intersection of a plurality of ridges, each of said plurality of ridges having a triangular cross-section, while said plurality of ridges of said first set of crease lines are terminated such that they terminate at a distance from said intersection, each of said plurality of ridges having a triangular cross-section and having an imaginary extension through said intersection.

The total height of the ridges at the intersection points may be approximately the same as the height of a single ridge away from the intersection point. Thus, the depth of the resulting crease line will be constant in the corner area, whereby the folding action will be easier to control.

The total height of the ridge at the intersection point may be between 1mm and 2mm, preferably between 1mm and 1.5 mm. This has proven to be a beneficial height in order to provide crease lines of the required dimensions.

The triangular ridge may be asymmetric in cross-section.

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

Drawings

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which

Fig. 1 is an isometric view of portions of a filling machine, which is configured to provide a series of successive liquid food packages from a tube of packaging material,

figure 2 is an isometric view of a package made of packaging material,

figure 3 is a top view of a web of packaging material for forming packages according to the prior art,

figure 4a is a top view of a web of packaging material for forming a package according to an embodiment,

fig. 4b is an enlarged view of a portion of the packaging material shown in fig. 4 a.

Figure 4c is a top view of a web of packaging material for forming a package according to one embodiment,

figure 5 is a cross-sectional view of a pressing tool for providing crease lines in a layer of core material,

figure 6a is a cross-sectional view of a plate of a press tool such as the one shown in figure 5,

figure 6b is a top view of the plate shown in figure 6a,

fig. 7 is an enlarged cross-sectional view of a creasing tool pressing and imprinting crease lines into a web of packaging material, as shown in figs 4a-4c,

fig. 8 is a cross-sectional view of a packaging material according to an embodiment, which is provided with crease lines having a triangular profile,

figure 9 is a system for producing a packaging material according to one embodiment,

fig. 10 is a schematic view of a method of producing a packaging material according to an embodiment.

Figure 11 shows a package corner from the prior art with a defective corner fold configuration.

Detailed Description

The packaging material with the core material layer may be used in many different applications to provide cost-effective, environmentally friendly and technically superior packaging for a large number of products. In liquid product packaging, for example in liquid food packaging, paperboard (carton) -based packaging materials are often used to form dimensionally stable packages, which are therefore also supported so as to be free-standing after opening.

The paperboard-based packaging material to be produced by the method described herein is configured to be suitable for liquid packaging and, according to an embodiment, has certain characteristics suitable for the purpose. The packaging material therefore has a layer of cardboard core material which meets the requirements for providing rigidity and dimensional stability to the packages produced from the packaging material. Thus, the cardboard commonly used is a fibrous paperboard, i.e. a paperboard having a main body of a web-like structure of cellulose fibers, which has suitable density, stiffness and resistance to possible exposure to moisture.

On the other hand, non-fibrous cellulose-based paperboard, including corrugated board or honeycomb or cellular (cellular) paperboard, is so-called structural paperboard and is unlikely to be suitable for the purposes of the present invention. Alternatively, such structural paperboard is typically folded and provided with lines of weakness to be folded by a different mechanism than the present invention. They are constructed according to the i-beam principle, in which a structural intermediate layer (e.g. corrugated, honeycomb, porous foam) is sandwich laminated between thin flanges of paper plies. Due to the non-uniform nature of the structural interlayer, the outer flange is attached to such a structural interlayer only at defined areas or points, rather than over its entire surface.

In particular, the core material layer of fibre type or paperboard or cardboard suitable for the packaging material and method of the invention is a fibre structure consisting of homogeneous fibre layers, which is also advantageously configured as an i-beam or sandwich structure, but with the respective intermediate layers and flanges being connected to each other over their entire surfaces facing each other. Typical fibers that can be used in the fibrous body are cellulosic fibers from chemical pulp, CTMP, TMP, kraft pulp, and the like.

According to one embodiment, the fiber bulk layer, paperboard or cardboard suitable for the purposes of the invention has a weight of more than 300kg/m according to methods ISO 2493-1 and SCAN-P29: 95³A density of, for example, more than 700kg/m³And 6.0 to 24.0Nm⁶/kg³Bending stiffness index (equivalent to 0.5 to 2.0 Nm)⁷/kg³). The flexural rigidity index is calculated as the geometric mean of the machine and transverse directions.

Referring now to fig. 1, the components of a filling machine 1 are shown. The filling machine 1 operates continuously at high speed according to the following principle: the web of packaging material 100 is moved forward and the tube 2 is formed by joining the longitudinal edges 101, 102 of the packaging material 100 to each other in the overlap joint 3.

The tube 2 is filled with the desired liquid food product by a filling duct 4 and is divided into individual packages 10 at predetermined distances from each other below the liquid level of the filled contents in the tube 2 by repeated transverse seals 5 of the tube 2.

The package 10 is separated by a cut in the transverse seal and the desired geometric configuration is obtained by fold formation along prepared crease lines in the material.

Alternatively, a similar package may be made from pre-cut blanks or sheets of laminated packaging material, which are folded and sealed longitudinally into tubular capsules (capsules) and then fold formed at a first end and filled and sealed at the other end in a stepwise filling operation.

The package 10 resulting from the packaging process of fig. 1 is shown in more detail in fig. 2. As shown here, the package 10 is formed by longitudinally sealing the packaging material 100 by longitudinally overlapping sealing areas LSA and transversely sealing by upper and lower transverse sealing areas TSA, TSA. The package 10 has a body MB closed by a top end TP and a bottom end BP. Package 10 is also provided with a plurality of corners PC1-PC 4. In the example shown, there are four corners PC1-PC4 due to the rectangular shape of the bottom end TP. However, it should be appreciated that the package 10 may have other numbers of corners depending on the size of the package 10.

To further understand the various embodiments described herein, fig. 3 schematically illustrates a prior art example of a packaging material 100 designed for producing a package 10 as shown in fig. 2. The packaging material 100 shown is for example configured to be fed into a filling machine 1 of the type shown in fig. 1.

The packaging material 100 may for example be provided as a continuous web, which is rolled up to cooperate effectively with the filling machine 1 of fig. 1. For other applications, packaging material 100 may be provided as a separate blank, or in any other configuration suitable for final forming into individual packages 10 by folding along crease lines 130.

The width of the packaging material 100 corresponds to the size required to form one single package 10. The web of packaging material 100 comprises a plurality of zones arranged in series; following the first region 110 for forming the first or leading package 10 is a second region 120 intended to form a second package 10 or a subsequent package 10. As will be readily appreciated, following the second region 120 is a third region, a fourth region, etc. (not shown).

Each region 110, 120 is provided with a respective crease line 130, shown in solid lines in fig. 3. The crease lines 130 of the first region 110 are designed to define the shape of a first package 10, while the crease lines 130 of the second region 120 are designed to define the shape of an adjacent second package 10.

Although only shown for the first region 110, the crease lines 130 of one region 110, 120 comprise a first set of crease lines 132 designed to form the bottom end of the package 10, a second set of crease lines 134 designed to form the body of the package 10, and a third set of crease lines 136 designed to form the closed upper end of the package 10.

It should be noted that only a few crease lines in fig. 3 carry the reference numeral 130. In practice, all solid lines shown within the boundaries of the longitudinal edges 101, 102 represent crease lines. Two further dashed lines 140 extend perpendicular to the machine direction MD; these indicate the cut lines, i.e. the positions where the cutting knife separates the sealed package 10 from the upstream tube.

In this regard, it should be noted that the crease lines 130 may be arranged in various configurations to provide a folding direction for a particular type of package 10. The crease lines 130 are arranged not only in the so-called machine direction MD, i.e. the longitudinal direction (also typically the longitudinal or vertical direction of the standing formed packages) of the packaging material 100. Also the crease lines 130 are arranged in other directions, i.e. in a direction not parallel to the machine direction MD, e.g. perpendicular to the machine direction MD. For other systems and applications also within the contemplation of the present description, the longitudinal crease lines and the transverse crease lines of the packaging material are in opposite directions, i.e. the machine direction corresponds to the transverse direction and not to the longitudinal direction (i.e. the vertical direction when viewing the upright package). This is particularly common when producing packages from a single blank of packaging material, and these embodiments are also within the contemplation of the present application.

As can be seen from fig. 3, four regions C1-C4 are provided. These regions C1-C4 are arranged at various positions intended to form the bottom corners PC1-PC4 of the package 10 to be formed. As can be seen in FIG. 3, each of the regions C1-C4 forms an intersection between at least one fold line 130a of the first set of fold lines 132 and a longitudinal fold line 130b of the second set of fold lines 134.

As mentioned in the background section, it is desirable to further improve the accuracy of the package dimensions, especially in the region of the bottom corners. The inventors have surprisingly realised that this can be achieved by redesigning the crease line arrangement.

In fig. 4a an embodiment of a packaging material 100 is shown, which packaging material 100 has proven successful in solving the above-mentioned problems. Except for the details of regions C1-C4, packaging material 100 is the same as packaging material 100 shown in FIG. 3. One of these areas, C1, is shown enlarged in fig. 4 b.

As can be seen in fig. 4a, each region C1-C4 includes the intersection IX (see fig. 4b) of the plurality of crease lines of the first set of crease lines 132 (i.e., the crease lines intended to form the bottoms BP of the crease lines of the package 10). A transverse crease line BC extends across each region C1-C4 and extends in a direction perpendicular to the machine direction MD. The transverse crease lines BC can be considered as separating the first set of crease lines 132 from the second set of crease lines 134. It is not important whether the transverse crease line BC is considered to belong to the first portion of the crease line 132, the second portion of the crease line 134, or both.

Intersection point IX is formed by the intersection of transverse crease lines BC with longitudinal crease lines LCB of the second set of crease lines 134, forming an L-shape. The longitudinal crease lines LCB of the second set of crease lines 134 terminate at an intersection point IX. As can be seen from fig. 4b, the transverse crease line BC also ends at the intersection point IX and continues across the intersection point IX, so that the transverse crease line BC in fact comprises a plurality of sections BC, BC', all aligned and distributed in the transverse direction, so that each region C1 will have only one section of the transverse crease line BC intersecting the respective longitudinal crease line LCB of the second set of crease lines 134. The section of the crease line BC that does not intersect the longitudinal crease line LCB will be labeled BC' from here on.

In addition to intersection point IX, each region C1-C4 also includes diagonal crease lines DC and longitudinal crease lines LCC of the first set of crease lines 132. Neither of these two crease lines DC, LCC nor the other section BC' of the transverse crease line BC extends into the intersection point IX, but ends before reaching the intersection point IX; as shown in fig. 4 b. In fig. 4b, the distance between the intersection point IX and the end of the crease line LCC, DC (and the terminating section BC' of the transverse line segment BC) is indicated by reference D. For typical packaging of liquid food the distance D may be in the range of 1 to 10mm, for example in the range of 1.5 to 5mm, preferably in the range of 1.5 to 3 mm.

The inventors have surprisingly realized that an improved shaping of corners PC1-PC4 of package 10 can be achieved when crease lines BC, LCB, LCC and DC have a triangular, preferably asymmetric cross section and crease lines LCC, DC, BC' are terminated such that they end at a distance D from intersection point IX, as shown in fig. 4 b.

In fig. 4b, the asymmetric configuration of crease lines BC, LCB, LCC and DC is shown. Each crease line BC, LCB, LCC and DC is represented by three lines, namely one solid line and an associated dashed line on each side of the solid line. The solid lines represent where the apex 225 (see fig. 6a) has been pressed into the packaging material 100, while the lateral distance between the solid lines and the nearest neighboring dashed lines represents where the steep side 222a (see again fig. 6a) of the ridge 222 has been pressed into the packaging material 100. The lateral distance between the solid line and the less adjacent dashed line thus represents the position where the less steep side 222b (fig. 6a) of the ridge 222 has been pressed into the packaging material.

Preferably, the orientation of the asymmetric crease lines BC, LCB, LCC and DC is as follows: LCB and BC are both aligned such that their respective steep sides face the side of intersection IX where diagonal crease line DC is disposed. This diagonal crease line DC is in turn positioned so that the steep flank is longitudinally downward, i.e. towards the longitudinal crease line LCC. The longitudinal crease line LCC is positioned in the same direction as the longitudinal crease line LCB, i.e. the steep sides of the crease line LCC are directed towards the diagonal crease line DC.

In the example shown, the resulting bottom end BP of the package 10 will be rectangular, meaning that there will be four corners PC1-PC4 formed by four respective regions C1-C4. Each region C1-C4 comprises a point of intersection IX of a plurality of crease lines LCB, BC, while the other crease lines LCC; DC, BC' are terminated such that they terminate at a distance D from the intersection point IX. Thus, the crease line LCC; all regions C1-C4 are constructed in a similar manner to the extent that DC, BC' ends before reaching intersection IX.

It should be noted, however, that for certain embodiments, it is not necessary to have this configuration on all of the regions C1-C4. Alternatively, only one or more of the corner regions C1-C4 may be configured as described above with reference to FIG. 4 b. For example, tests have been conducted which suggest that the improvement in corner shaping is significant if only two rear corners PC1, PC4 are formed by folding only the corner regions C1, C4 designed with the terminating crease lines BC, DC, LCC. For such embodiments, the two front corners PC2, PC3 may be formed by folding regions C2-C3, which regions C2-C3 may be constructed according to prior art designs. For the scope of the present description, there is an advantage of bottom corner folding if at least one of the regions C1-C4 is constructed in the manner described with reference to FIG. 4 b.

A package with a typical rear bottom corner defect is shown in fig. 12. These corners are not shaped as the vertices of a cuboid but are concave and convex, resulting in a poor appearance of the package. The stability of the stand-up package may be compromised due to bottom corner depressions and bends (buckly). This drawback is reduced or even completely avoided by the corner fold configuration of the present invention.

In fig. 4a, the packaging material 100 is provided with crease lines 130 to form a rectangular shaped package 10, e.g. shaped as TetraAnd (6) packaging. In fig. 4c, another example of a packaging material 100 is shown, for which the third set of crease lines 136 is configured to provide a slanted top, e.g. corresponding to TetraAnd (5) sterile edge packaging. Also for this package, the bottom corner regions C1-C4 may be constructed in accordance with the description of FIGS. 4 a-b. However, for TetraSterile edge packaging, it may be advantageous to provide only the rear bottom corner regions C1, C4 according to the above description, while providing a conventional crease pattern for the front corner regions C2, C3.

Turning now to fig. 5, an example of a system 200 for providing crease lines 130, BC, LCB, LCC, DC to a core material layer 140 of a packaging material 100 to be formed later is shown. Preferably, the system 200 includes a crease line pressing tool 210 in the form of a pressing tool roll and an anvil 212 in the form of an anvil roll. At least one of the rollers 210, 212 is driven such that the core material layer 140 may be fed into the nip 216 and through the nip 216 formed between the rollers 210, 212. As shown in fig. 5, for this embodiment, the core material layer 140 may preferably be provided as a roll, thereby enabling continuous operation of the system 200.

The press tool 210 is provided with a plate 220, the plate 220 covering at least a part of the outer circumference of the press tool roll 210. The plate 220 may, for example, be a metal body that may be bent to accommodate the cylindrical shape of the roller 210, or the plate 220 may be formed from a plurality of bent sections that together form the outer shell of the roller 210.

The plate 220 includes at least one ridge 222 (see, e.g., fig. 6a) extending in a normal direction (i.e., radially outward toward the anvil roll 212).

The anvil 212 forms a roller having an outer layer 213 of reversibly deformable elastomeric material, such as a material composition comprising rubber or a polymer having elastic properties. Preferably, the elastic material covers the entire surface of the roller 212 that is in contact with the core material layer 140 to be creased. The resilient material may for example be a rubber-like material having a thickness of about 2-50mm and having a hardness of 70 shore a to 80 shore D, for example 60 shore D or 95 shore a.

Preferably, the diameter of the press tool roll 210 is different from the diameter of the anvil roll 212. As shown in fig. 5, the anvil roll 212 has a smaller diameter than the press tool roll 210, but in some embodiments, the anvil roll 212 may have a larger diameter than the press tool roll 210. By making the diameters of the rolls 210, 212 different, the ridges 222 of the press tool plate 220 will not impact the same location of the anvil roll 212 during operation, thereby ensuring the durability of the anvil roll 212. Thus, it should be understood that in the most preferred embodiment, the diameter of one of the rollers 210, 212 is different than the diameter of the other of the rollers 210, 212, and the circumference of one of the rollers 210, 212 is different than any multiple of the circumference of the other of the rollers 210, 212.

Fig. 6a shows an embodiment of the configuration of a ridge 222 having a base 223, an embossed portion 224 and an apex 225. The illustrated panel 220 includes at least two spaced apart ridges 222, each extending to form a longitudinal structure suitable for providing a crease line 130 to the core material layer 140. Each ridge 222 is triangular in cross-section, whereby the base 223 is formed by the lower part of the ridge 222, i.e. by the part arranged adjacent to the flat surface of the plate 220. The embossed portion 224 (i.e., the portion of the ridge 222 that is in contact with the core material layer 140 during the formation of the fold) extends from the base 223 to the apex 225.

The ridge 222 is shown having steep sides 222a and less steep sides 222 b. The sides 222a, 222b intersect at a vertex 225. This means that the angle α 1 between the steep side 222a and the plane of the plate 220 is larger than the angle α 2 between the less steep side 222b and the same plane of the plate 220, as shown in fig. 6 a. Thus, although less pronounced due to the elasticity of the material, one side of the resulting crease line will be steeper than the other side of the same crease line.

In fig. 6b, a top view of the plate 220 is shown. The panel 220 includes a plurality of ridges 222, each ridge 222 configured to provide a crease line 130 in the core material layer 140. However, some of the ridges PBC, PLCB, PLCC, PDC are configured to provide crease lines BC, LCB, LCC, DC of regions C1-C4, which, as previously described, are intended to assist in forming corners PC1-PC4 of package 10.

These ridges PBC, PLCB, PLCC, PDC have a triangular, preferably asymmetric cross section and they are arranged at the respective regions P1-P4 so that a creasing operation using the sheet 220 will result in the packaging material 100 having the regions C1-C4, as previously described, in particular with reference to fig. 4 b. Thus, the arrangement of the ridges PBC, PLCB, PLCC, PDC in fig. 6b corresponds to the arrangement of crease lines shown in fig. 4 a.

If the ridge is triangular and symmetrical, the angle and size of the steep side 222a will be substantially the same as the angle and size of the less steep side 222 b.

The operation of the indentation system 200 is shown in more detail in fig. 7. Here is schematically shown a cross-sectional view of a process of forming crease lines (e.g. any of crease lines BC, LCB, LCC, DC).

This method of providing the packaging material layer 140 with triangular crease lines BC, LCB, LCC, DC will create a distinct shear fracture initiation area in the core material layer 140 at a location corresponding to the location of the less steep side 222b of the embossed portion 224.

By operating pressing tool 210, the force applied will cause a stress directed from the side of sheet 140 of packing material facing plate 220.

The crease lines BC, LCB, LCC, DC will typically reduce the thickness of the embossed or embossed core material layer 140 by about 5% to about 25%, such as about 10% to about 25%, as compared to non-creased material.

An example of a creased packaging material 100 is shown in fig. 8. For this example, core material layer 140 has been laminated through outer layer 142 and inner layer 144. The outer layer 142 and the inner layer 144 may be provided as a multi-layer structure; as shown in fig. 8, the inner layer 144 is formed by an inner laminate layer 145, an intermediate barrier layer 146 and an innermost layer 147, which innermost layer 147 will be in contact with the filled product contained in the package made of packaging material. The packaging material is preferably embossed by crease lines from the outside of the material, i.e. on the side where the outer layer 142 is arranged.

Any thermoplastic material or polymer may be coated or laminated onto the core layer before or after the creasing operation is performed. Thus, when referring to creasing a packaging material, the term "packaging material" includes creasing only the core layer, then laminating the other layers into the laminated packaging material, as well as creasing already (partially or fully) laminated structures comprising the core layer. This versatility is valid for all embodiments described in this specification.

The outer layer 142 may be formed from an outermost liquid-tight coating of a heat-sealable thermoplastic polymer. The thermoplastic polymer may for example be a polyolefin, such as Polyethylene (PE) or polypropylene (PP), such as Low Density Polyethylene (LDPE), or a blend of LDPE and linear low density polyethylene.

In order to provide the packaging material 100 with barrier properties against primarily gases, in particular oxygen, the packaging material additionally has at least one further material layer 146, which material layer 146 provides such barrier properties and is bonded to the core material layer 140 by means of an inner laminate layer 145, preferably a laminate layer formed from Low Density Polyethylene (LDPE).

Examples of materials for intermediate barrier layer 146 may be: a layer or film comprising a polymer with intrinsic barrier properties, such as a copolymer of ethylene and vinyl alcohol (EVOH) or Polyamide (PA); or a preformed film coated with a liquid film coated or vacuum deposited or vapor deposited layer or coating liquid having the corresponding barrier properties. Common examples of such coated prefabricated films are oriented films of polyester (e.g. polyethylene terephthalate (PET)) or polypropylene (PP) coated with a metallized layer or with a layer coated by plasma enhanced vapour deposition. Usually an aluminium foil is used which, in addition to having excellent barrier properties against gases, in particular oxygen, also has advantageous properties enabling heat sealing of the packaging material 100 by means of induction sealing, which is a fast, simple and effective heat sealing technique.

An example of a system 300 for producing the packaging material 100 is shown in fig. 9. The system 300 includes a supply 310 of core material 140 unwound from a storage reel 312 and a supply 320 of intermediate barrier layer 146 unwound from a corresponding storage reel 322. The two webs 140, 146 are brought together and both are guided through a laminating nip 350 between two adjacent rotatable cylinders 332, 334 while a supply device 340 applies a laminate 342, typically comprising Low Density Polyethylene (LDPE) forming an inner laminate layer 145, between the webs 140, 146 to permanently bond the intermediate barrier layer 146 to the core material layer 140.

Thereafter, a liquid impermeable polymer (e.g., polyethylene, typically including Low Density Polyethylene (LDPE)) coating is provided on both sides of the paper or paperboard web (not shown) to form an outer layer 142 and an inner, innermost layer 147, and the paper or paperboard web is then wound onto a finished packaging spool for further transport and handling.

By using triangular, preferably asymmetric crease lines 130 for the core material layer 140, the thickness of some laminate layers can be reduced without reducing the stability of the packaging material and thus without risking material damage in sensitive areas. In the case of an asymmetric crease line with a triangular cross-section, such that the first side of the crease line has steeper embossing walls than the second side, it has turned out that in the step of laminating the core material layer to the further polymer layer, the core material should preferably be fed to the laminating roller nip such that the crease line first enters the laminating nip with its second side. The use of asymmetric crease lines in combination with a determined feed direction during lamination reduces the risk of defects occurring, so that an increase in the speed and quality of the lamination can be achieved.

Turning now to fig. 10, a method 400 for producing the packaging material 100 is schematically illustrated. The method 400 includes: a first step 402 of providing a layer of core material 140 or a plastic coated or laminated packaging material 100, wherein at least one region C1-C4 is configured to assist in folding packaging material 100 into bottom end corners PC1-PC4 of a package 10 to be formed; and a second step 404 of providing a first set of crease lines 132 and a second set of crease lines 134, the first set of crease lines 132 being designed to form a bottom end TP of the package 10 and the second set of crease lines 134 being designed to form a body of the package 10. Steps 402 and 404 are performed such that said at least one region C1-C4 comprises a point of intersection IX of a plurality of crease lines BC, LCB, each of which has a triangular, preferably asymmetric, cross section, whereas the plurality of crease lines LCC, DC, BC' (each of which has a triangular, preferably asymmetric, cross section and has a virtual extension through the point of intersection IX) of the first set of crease lines 134 is terminated such that it ends at a distance D from said point of intersection IX.

The core material layer is laminated to the further material layer before or after the creasing operation.

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