METHOD OF MANUFACTURING A LAMINATED PACKAGING MATERIAL AND LAMINATED PACKAGING MATERIAL

Abstract

The present invention relates to a method of manufacturing a laminated packaging material comprising a first, outermost layer of a transparent polymer, to be directed towards the outside of a package made from the laminated packaging material, a substrate layer, and a second, outermost layer of a thermo-sealable polymer, arranged on the other side of the substrate layer opposite to the first outermost layer, and optionally one or more further material layers between the substrate layer and the second, outermost polymer layer, the laminated packaging material exhibiting a visual or tactile pattern, or a combination thereof, in the first outermost transparent polymer layer. The invention also relates to a laminated packaging material produced by the method and to a packaging container for liquid or semi-liquid food, produced from the laminated packaging material.

Claims

1. Method for manufacturing a laminated and decorated packaging material comprising a first, outermost transparent polymer layer, to be directed towards the outside of a package made from the laminated packaging material, a substrate layer, and a second, outermost layer of a thermo-sealable polymer, arranged on the other side of the substrate layer opposite to the first outermost layer, and optionally one or more further material layers between said substrate layer and said second, outermost polymer layer, the laminated packaging material exhibiting a visual or tactile pattern, or a combination thereof, in the first outermost transparent polymer layer, the method comprising steps that include a. laminating the separate material layers in order to form a web of laminated packaging material, i. including laminating said substrate layer and said first outermost layer of transparent polymer to be adjacent and contiguous to each other, and ii. before or after step i., arranging said substrate layer and said second outermost layer of a thermo-sealable polymer to be laminated to each other, b. forwarding a web of the thus laminated packaging material through a nip between two against each other rotatable rollers, said nip consisting of a first roller acting as an anvil roller and a second imprint roller, which has a mantel surface provided with protrusions, plateaus or peaks, within selected areas, the protrusions, plateaus or peaks together forming a pattern corresponding to said visual or tactile pattern on the packaging material, and c. imprinting the pattern of the mantel surface of the second imprint roller into the outermost transparent polymer layer and said laminated packaging material, as it is passing as a web or sheet through the nip, by applying pressure to the roller nip.

2. Method according to claim 1, wherein said substrate layer and said second outermost layer of a thermo-sealable polymer are laminated to each other by extrusion coating of the thermo-sealable polymer onto the substrate layer.

3. Method for manufacturing a laminated and decorated packaging material as defined in claim 1, which packaging material comprises a first, outermost transparent polymer layer, to be directed towards the outside of a package made from the laminated packaging material, a substrate layer, and a second, outermost layer of a thermo-sealable polymer, arranged on the other side of the substrate layer opposite to the first outermost layer, and optionally one or more further material layers between said substrate layer and said second, outermost polymer layer, the method comprising steps that include b. forwarding a web of the laminated packaging material through a nip between two against each other rotatable rollers, said nip consisting of a first roller acting as an anvil roller and a second imprint roller, which has a mantel surface provided with protrusions, plateaus or peaks, within selected areas, the protrusions, plateaus or peaks together forming a pattern corresponding to said visual or tactile pattern on the packaging material, and c. imprinting the pattern of the mantel surface of the second imprint roller into the outermost transparent polymer layer and said laminated packaging material, as it is passing as a web or sheet through the nip, by applying pressure to the roller nip, the thus laminated and decorated packaging material exhibiting a visual or tactile pattern, or a combination thereof, in the first outermost transparent polymer layer.

4. Method according to claim 1, wherein step a. is, or has been, carried out at a first location and steps b. and c. are carried out at a second location and the laminated packaging material is wound up on a reel for intermediate storage or transport, in a step d, between steps a. and b, or before step b., respectively.

5. Method according to claim 1, wherein the thickness of the first, outermost, transparent polymer layer is from 8 to 30.

6. Method according to claim 1, further comprising a step of printing a dcor pattern onto the substrate layer, the dcor pattern to be located at the inside of, and adjacent to, the outermost transparent polymer layer before the step of laminating the separate material layers together, for the decor to be visible from the outside of the package manufactured from the laminated packaging material.

7. Method according to claim 6, wherein the imprinted visual and/or tactile pattern is applied in register alignment with the previously applied printed decor pattern in order to provide an added dimension to the total dcor design, by visual and/or tactile effects in the laminated packaging material.

8. Method according to claim 7, wherein the imprinted visual and/or tactile pattern is applied in register alignment with the previously applied printed decor pattern at an accuracy of the same order as the alignment within the printed decor pattern, between the different colours printed, at a controlling accuracy of from 1 mm to 0.1 mm.

9. Method according to claim 1, wherein the substrate layer is a bulk layer of a cellulose-based, fibrous paper, paperboard or carton.

10. Method according to claim 1, wherein the substrate layer is a pre-manufactured film laminated to a bulk layer comprising cellulose fibres, polymer or other light weight material.

11. Method according to claim 1, wherein the pre-manufactured film is a metallised, pre-manufactured film.

12. Method according to claim 1, wherein the laminated packaging material comprises a barrier layer between the substrate layer and the second outermost thermo-sealable polymer layer, preferably an aluminium foil layer.

13. Method according to claim 9, wherein the barrier is an aluminium foil layer and the thickness of the aluminium foil is from 5 to 10.

14. Method according to claim 9, wherein the depth of the imprint may reach beyond the depth of the outermost transparent layer(s) and into the substrate or bulk layer but stops before reaching the barrier layer located on the inside of the bulk layer and substrate layer.

15. Method according to claim 1, wherein the ratio between the depth of the imprint and the total thickness of the outer imprinted layer(s) and the bulk layer is lower than 0.30.

16. Method according to claim 1, wherein the bulk layer is a paperboard having a density higher than 300 kg/m.sup.3 (ISO 534).

17. Method according to claim 1, wherein the bulk layer is a paperboard having a thickness from 150 to 660 m.

18. Method according to claim 1, wherein the bulk layer (11) is a paperboard having a bending stiffness from 30 to 480 mN.

19. Method according to claim 7, wherein an added dimension to the total design of the dcor is provided by one or a combination of two or more effects, selected from a glossy effect, a matte effect, a light-diffractive effect, a holographic effect or a tactile surface-texture effect, created by an imprinted pattern in the outermost transparent polymer layer and the packaging laminate, which is interacting with the printed dcor on the substrate layer.

20. Method according to claim 1, wherein the outermost transparent polymer is a thermo-sealable polymer, contributing to effective sealing of packages made from the laminated packaging material, such as a polyolefin, such as in the majority low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) or a blend thereof.

21. Method according to claim 1, wherein the laminated packaging material comprises a bulk layer comprising cellulose fibres, polymer or other light weight material, and wherein said bulk layer in a separate method step is provided with weakening crease lines in order to facilitate folding of the laminated packaging material in the manufacturing of packaging containers from the packaging material, and wherein the visual and/or tactile imprinted pattern is applied in register alignment with said weakening crease lines, as well as with any printed decor pattern printed onto the substrate layer.

22. Method according to claim 1, wherein step c. is carried out at a temperature lower than a melting point of the polymer of the transparent, outermost layer.

23. Method according to claim 1, wherein step c. is carried out at a temperature lower than the Vicat softening temperature of the polymer of the transparent, outermost layer.

24. Method according to claim 1, wherein the imprint roller or the mantel surface of the imprint roller is made of metal, and optionally, the anvil roller, has a hardness from 80 to 98 Shore A.

25. Laminated packaging material, exhibiting a visual or tactile pattern, or a combination thereof, in a first outermost layer of a transparent polymer, directed towards the outside of a package made from the laminated packaging material, and further comprising a substrate layer, and a second, outermost layer of a thermo-sealable polymer, arranged on the other side of the substrate layer opposite to the first outermost layer, manufactured according to the method of claim 1.

26. Packaging container manufactured from the laminated packaging material as claimed in claim 25.

Description

DESCRIPTION OF THE DRAWINGS

[0055] Further advantages and favourable characterizing features will be apparent from the following detailed description, with reference to the appended figures, in which:

[0056] FIGS. 1a, 1b and 1c are cross-sectional views of laminated packaging materials according to aspects described herein,

[0057] FIGS. 2a and 2b are schematic views of manufacturing lines for the conversion into the laminated packaging materials of FIGS. 1a and 1b, respectively,

[0058] FIG. 3 shows the principle of how packaging containers may be manufactured from the laminated packaging material in a continuous forming, filling and sealing process,

[0059] FIG. 4a-4d show examples of packaging containers produced from the laminated packaging material according to embodiments described herein,

[0060] FIG. 5 shows an example of an enhanced decorative appearance of a printed and laminated packaging material, which has been further provided with a surface effect in the outermost transparent polymer layer, being of tactile or visible character, or a combination of both, and

[0061] FIG. 6 shows a sleeve carrying the pattern of protrusions, plateaus or peaks, constituting the mantel surface of the second imprint roller or embossing roller, and how the sleeve is mounted onto a metal core of said second roller. The pattern of the sleeve is to be imprinted onto the outermost polymer surface of the laminated packaging material.

DETAILED DESCRIPTION OF EMBODIMENTS

[0062] An example of a laminated packaging material of a traditional type, but significantly changed and improved in appearance by the method of the present invention, is shown in FIG. 1a. The packaging laminate 10a has a bulk layer, or core layer, of paper or paperboard 11. The bulk layer could alternatively be made of other light-weight materials made of cellulose or other polymers. The bulk layer is laminated to a barrier layer 13, traditionally an aluminium foil, by an intermediate thermoplastic polymer bonding layer 12, normally applied by means of melt extrusion lamination. Alternatively, the bonding layer 12 could be arranged by wet coating and drying or by dry lamination with curable adhesive formulations. On the inside of the barrier layer 13, on the side to be directed towards the inside of a package made from the laminated material, thermoplastic, thermo-sealable and liquid-tight polymers 14 are arrangedeither as a mono-layer or as a coextruded multilayer (14a, 14b, 14c) of up to three layers of different olefin monomer based polymers (not shown). Normally, the layer adjacent the aluminium foil is a functionalized polyolefin for optimal adhesion properties to the aluminium foil, e.g. an ethylene acrylic acid copolymer (EAA) or a maleic anhydride modified polyolefin, such as maleic anhydride modified polyethylene or polypropylene, such as a MAH-PE MAHA-PP tie polymer. The outer side of the paperboard 11 is printed with an ink decor 15, preferably by a flexographic printing ink and printing method. Since it in most cases is desirable and necessary to protect the printed decor from wet conditions and abrasion or wear in handling and distribution of the packages, it is further coated on the outside with a transparent, protective layer of a polymer 16. Most conveniently, and in particular for liquid packaging, it is also desirable to be able to seal the packaging containers by heat welding the innermost layer 14 and the outermost polymer layer 16 to each other in the fold forming process into filled and sealed packages, why the outermost polymer layer also is a thermo-sealable and liquid tight polymer layer similar to the thermoplastic polymers of the inside layers 14(a,b,c). On the surface of the outermost, transparent polymer layer 16, is visible, and optionally also tactile, a pattern 17 of indentations, grooves, ridges and protrusions, as imprinted into the polymer layer 16 and the packaging laminate.

[0063] Another example of a laminated packaging material of a traditional type, but significantly changed and improved in its appearance by the method of the present invention, is shown in FIG. 1b. The packaging laminate 10b has in addition to the layers 11, 12, 13 and 14(a,b,c), as previously described in FIG. 1a, a further layer of a strong and/or decorative polymer film 18, which has optionally been coated by a thin, vapour deposition coated metallisation layer 19. The metallised film may be any conventional, optionally metallised, oriented polymer film, such as a polypropylene or polyethyleneterephthalate film (OPP, BOPP, OPET or BOPET). It is laminated to the paperboard bulk layer 11 in a separate lamination operation, preceding the printing operation in which an ink dcor layer 15 is applied. The lamination of the paperboard to the pre-manufactured film is according to an embodiment performed as a melt extrusion lamination, employing a polyolefin bonding layer 20, such as polyethylene such as low density polyethylene (LDPE) or alternatively an adhesive polymer comprising functional carboxylic groups, such as ethylene (meth-)acrylic acid copolymers (E(M)AA). Alternatively, the bonding layer 20 may be arranged by wet coating and drying or by dry lamination with curable adhesive formulations.

[0064] The outer side of the pre-manufactured, optionally metallised, film is thus printed with an ink decor 15, preferably by a flexographic printing ink and printing method. Since it is in most cases desirable and necessary to protect the printed decor from wet conditions and abrasion or wear in handling and distribution of the packages, it is further coated on the outside with a transparent layer of a polymer 16. Most conveniently, and in particular for liquid packaging, it is also desirable to be able to seal the packaging containers by heat welding the innermost layer 14 and the outermost polymer layer 16 to each other in the fold forming process into filled and sealed packages, why the outermost polymer layer is also a thermo-sealable and liquid tight polymer layer similar to the thermoplastic polymers of the inside layers 14 (a,b,c). On the surface of the outermost, transparent polymer layer 16, is visible, and optionally also tactile, a pattern 17 of indentations, grooves, ridges and protrusions, as imprinted into the polymer layer 16 and the packaging laminate.

[0065] According to the invention, and as has already been mentioned, the polymer for the bonding layer 12 can be chosen more or less freely and is thus not limited to any particular type of polymer. An example of a usable polymer for the bonding layer 12 are various extrusion lamination grades of low-density polyethylene (LDPE). Other examples of usable polymers for the bonding layer 12 are linear polymers, which have the advantage of helping to improve the mechanical properties of the finished packaging laminate. Examples of linear polymers that can be used in the method according to the invention are high-density polyethylene (HDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), very low-density polyethylenes (VLDPE), ultra low-density polyethylenes (ULDPE) produced with conventional catalysts or so-called single-site catalysts, or constrained-geometry catalysts, including so-called metallocene catalysts. In some embodiments, a multilayer combination or a blend of two or more of the above mentioned polymers may be effective for bonding the layers 11 and 13 to each other.

[0066] Examples of adhesives useful in the layers 14a (which is adjacent to the barrier layer and 20, are for example ethylene-acrylic acid copolymer (EAA) and ethylene-methacrylic acid copolymer (EMAA). Such adhesive polymers are commercially available under the trade name Primacor from Dow Chemical Company, and another such adhesive can be obtained from DuPont under the trade name Nucrel. A further example is obtainable from ExxonMobil Chemicals under the trade name Escor.

[0067] Other examples of adhesive polymers having free, active carboxylic acid groups, suitable for some aspects of the present invention, are maleic-anhydride functionalised polyolefins, in particular maleic-anhydride functionalised polyethylenes, which provide alternative polyolefin-based polymers having free carboxylic acid functionality.

[0068] Alternative materials that have gas barrier properties and are usable as layer 13 in the packaging material and method according to an embodiment may be of both organic and also inorganic nature. Examples of organic materials are copolymers of ethylene and vinyl alcohol (EVOH) and various types of polyamides (PA). Examples of inorganic materials can be an aluminium foil or a polymer film which, on one or both of its sides, has a coating of metal, e.g. vapour-deposited or vacuum-metallized aluminium or a vapour-deposited coating of an oxide, e.g. aluminium oxide, or silicon oxide (SiOx). An aluminium foil is preferably used which, in addition to having excellent barrier properties against gases, also allows the packaging laminate to be sealed by so-called induction sealing, which is a rapid, simple and effective heat-sealing technique.

[0069] Examples of usable polymers for the liquid-tight, heat-sealable outer layers 14 and 16 according to an embodiment of the material and method are polyolefins, such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE) and polypropylene (PP), copolymers based on olefin monomers, and blends of two or more such polymers.

[0070] In FIG. 1c, a principal and enlarged view of the surface pattern 17, in the surface of the outermost transparent polymer layer 16, is shown. As the drawing illustrates, the surface pattern comprises imprints or indentations or grooves of varying depth in the material surface, but their depth never reaches all the way through the bulk layer 11, i.e. does not risk affecting the surface structure or surface smoothness of the other side of the bulk layer 11 or the inside layers 12, 13 and 14, or in any way come close to affect the barrier layer 13 in any way. As shown, some indentations are only affecting the polymer layers 16, or 16, 20, 19, 18, denoted with X in FIG. 1c, while other indentations reach down to the bulk layer surface or even down into the middle part of the bulk layer. The first imprint indentations mainly create visible or light diffractive effects. The latter create tactile effects in the packaging laminate surface. It also becomes dear from FIG. 1c, that the polymer layers X, do not break or crack by the imprint operation, but simply follow the imprint indentations and still protect the bulk layer 11 towards stains and wet conditions on the outside of the a package to be made from the laminated material.

[0071] According to the invention, the packaging laminate 10a in FIG. 1a can be produced in the manner shown schematically in FIG. 2. A web 200a of paper or paperboard is unwound from a storage reel 200 and printed with an ink dcor to form a printed dcor ink layer, in a printing station, preferably by flexographic printing technology using a minimum of 4 colours CMYK. After the printing operation, the printed paperboard 200b is normally wound up onto a reel for intermediate storage (not shown) before being brought to the lamination operations. For the lamination to the printed paperboard 200b, a corresponding web 203 of a material with barrier properties against gases, in particular oxygen, such as aluminium foil, is unwound from a storage reel 202. The two webs 200b and 203 are brought together with each other and are guided together through a nip between two adjacent rotatable cylinders 204 and 205, while at the same time a laminating material 206 is applied between the webs in order to laminate them to each other and thereby form a durable laminated web 208. The laminating material 206 is applied by melt extrusion with the aid of an extruder 207 arranged above the nip.

[0072] The laminated web 20$ is then conveyed via guide rollers 209 and 210 towards and through a nip between two further adjacent rotatable cylinders 211 and 212, while at the same time one surface of the web 208 is provided with a second outermost liquid-tight and thermo-sealable coating 213 of extrusion-coated polymer. This outermost polymer layer will later form the inside of a packaging container produced from the laminated material. In a subsequent nip between another two adjacent rotatable cylinders 217 and 218, the other surface of the web 208 is provided with a first outermost transparent coating 214 of extruded polymer. These two extrusion-coating steps can be carried out in reverse order and also, wholly or partly, before the lamination step in the nip between the cylinders 204 and 205.

[0073] In the example shown, the outermost liquid-tight coating 213 is applied to one surface of the web by extrusion with the aid of an extruder 215, and the outermost transparent polymer coating 214 is applied to the other surface of the web 208 by extrusion with the aid of a corresponding extruder 216 arranged near the web 208.

[0074] At a final operation 230, the web of the thus laminated packaging material is forwarded through a nip between two against each other rotatable rollers 231 and 232, said nip consisting of a first roller 232 acting as an anvil roller and of a second imprint roller 231, which has a mantel surface provided with grooves or recesses within selected areas, and protrusions, plateaus or peaks within other selected areas, which protrusions, plateaus or peaks together form a pattern corresponding to said visual or tactile pattern in the outermost transparent polymer layer on the packaging material. The pattern of the mantel surface of the second roller is imprinted into the outermost transparent polymer layer as said laminated packaging material is passing as a web or sheet through the nip, when applying pressure to the roller nip 230.

[0075] Following further mechanical or other machining operations, such as cutting, slitting and the like, on the thus coated web, the laminated and enhanced packaging material is finally wound up on a storage reel 219 for onward transport and further handling in which it is formed into dimensionally stable packaging containers for oxygen-sensitive liquid food, e.g. milk, juice, wine and cooking oil, as will be described herein below.

[0076] FIG. 2b shows schematically the main differing part from the manufacturing method shown in FIG. 2a, according to which an alternative laminated packaging material may be manufactured. The alternative laminated packaging material, comprises a decorative pre-manufactured film for enhanced visible appearance on the outer side of the packaging material, i.e. the side intended to form the outside of a package, as illustrated in FIG. 1b.

[0077] In a very first step, a web 200a of paper or paperboard is, unwound from a storage reel 200 and a further material web 220a, being a pre-manufactured polymer film, is unwound from another storage reel 220. The two material webs 200a and 220a are brought together with each other and are guided together through a nip between two adjacent rotatable cylinders 223 and 224, while at the same time a laminating material 221 is applied between the webs in order to laminate them to each other and thereby form a laminated web 225. The laminating material 221 is applied by melt extrusion with the aid of an extruder 222 arranged above the nip, and may be for example a polyolefin material such as polyethylene or a functionalised olefin copolymer such as ethylene acrylic acid copolymer. In case of the latter choice of polymer bonding material, the layer thickness of the bonding layer may be made significantly thinner. The laminated web 225 is further led to a printing station 201, where it is printed with an ink dcor to form a printed dcor ink layer, preferably by flexographic printing technology using a minimum of 4 colours CMYK. After the printing operation, the printed paperboard 226 is wound up on a reel for intermediate storage (not shown) before being brought to the lamination operations. The subsequent lamination operations, after the printing operation, are essentially the same and are continued as in FIG. 2a after the dotted line at the direction of the web towards the lamination nip 204-205. Also in this case, the two steps of extrusion-coating of the two layers 213 and 214 can be carried out in reverse order and also, wholly or partly, before the lamination step in the nip between the cylinders 204 and 205.

[0078] At a final operation 230, the web of the thus laminated packaging material is forwarded through a nip between two against each other rotatable rollers 231 and 232, said nip consisting of a first roller 232 acting as an anvil roller and of a second roller 231, which has a mantel surface provided with grooves or recesses within selected areas, and protrusions, plateaus or peaks within other selected areas, which protrusions, plateaus or peaks together form a pattern corresponding to said visual or tactile pattern in the outermost transparent polymer layer on the packaging material. The pattern of the mantel surface of the second roller is imprinted into the outermost transparent polymer layer as said laminated packaging material is passing as a web or sheet through the nip, when applying pressure to the roller nip 230. As seen in FIGS. 2a and 2b, the imprinting roller or embossing roller 231 is acting on the side of the laminated packaging material which is intended to form the outside of a package manufactured from the material, and may be acting from above or beneath depending on the circumstances in the set-up of the lamination line.

[0079] Following further mechanical or other machining operations, such as cutting, slitting and the like (not shown), on the thus coated web, the laminated and enhanced packaging material is finally wound up on a storage reel 219 for onward transport and further handling in which it is formed into dimensionally stable packaging containers for oxygen-sensitive liquid food, e.g. milk, juice, wine and cooking oil, as will be described herein below.

[0080] From a web of the packaging laminate 10 in FIG. 1 for example, it is possible, as has already been mentioned, to produce dimensionally stable packaging containers of a disposable type for oxygen-sensitive liquid foods, such as milk, juice, wine and cooking oil, by folding and heat-sealing in a manner known per se. Such packaging containers are nowadays produced with the aid of modern packaging machines of the type in which finished packages are shaped, filled and sealed.

[0081] One way in which packaging containers made of the packaging laminate 10 in FIG. 1 can be shaped, filled and sealed is illustrated in FIG. 3. The so-called single-use packages are produced from the web by means of the latter first of all being sterilised and then shaped into a tube 31, in which the longitudinal edges 32, 32a of the web are joined to each other in an overlap seam 33 by melting together the mutually facing surfaces of the plastic layers 14 and 15. The tube is filled 34 with the intended liquid or semi-liquid food product and is divided into contiguous pillow-shaped packaging units 36 by repeated pressing-together and heat-sealing of the tube transversely with respect to the longitudinal direction 35 of the tube, below the product level in the tube. The packaging units 36 are separated from each other and finally given the desired geometric shape, usually by fold forming along prepared crease lines into a cuboid or parallelepipedal shape by means of at least one further folding and heat-sealing step.

[0082] A well-known example of a single-use package of this type is the commercial package sold under the name Tetra Brik Aseptic, which is shown in FIG. 4a. The packaging container is particularly suitable for beverages, sauces, soups or the like. Typically, such a package has a volume of about 100 to 1000 ml. It may be of any configuration, but is preferably parallelepipedal, having longitudinal and transversal seals 51a and 52a, respectively, and optionally an opening device 53. In another embodiment, not shown, the packaging container may be shaped as a wedge. In order to obtain such a wedge-shape, only the bottom part of the package is fold formed such that the transversal heat seal of the bottom is hidden under the triangular corner flaps, which are folded and sealed against the bottom of the package. The top section transversal seal is left unfolded. In this way the half-folded packaging container is still is easy to handle and dimensionally stable when put on a shelf in the food store or on a table or the like. Such packaging containers 40a can also be provided with a suitable opening arrangement 43, for example a screw cap which, when opened, penetrates and removes the packaging material and permits emptying of the packaged product. For this purpose, the laminated packaging laminate can have perforations in the paperboard layer that has been laminated in between the polymers and barrier layers of the laminate. Alternatively, a hole is punched in the laminated packaging material immediately before the filling process, after which the hole is provided with a tape or pull-tab, on both sides of the packaging material. After the packaging container has been filled and sealed, an opening arrangement in the form of a hinge of screw cap can be applied on top of the covered hole. Alternatively, an opening arrangement is applied which is cast onto a punched hole directly during the filling process. It is not necessary to provide the packaging container with an opening device, it can also be torn open by means of a tear-perforation, or by cutting.

[0083] Alternatively, packaging containers can be produced as above but retain, as their final shape, the pillow shape that is obtained directly after the packaging units have been separated from each other and are therefore not further shaped by folding. Such a package is generally produced using a thinner paperboard material and therefore entails great demands on adhesion and integrity of the packaging material with regard to the lamination layers and also to the mechanical strength characteristics, in particular the elastic characteristics, of the polymer layers. An example of one such package is shown in FIG. 4b. Normally, it is not dimensionally stable enough to form a cuboid or wedge-shaped packaging container, and is not fold formed after transversal sealing 52. It will thus remain a pillow-shaped pouch-like container and be distributed and sold in this shape.

[0084] Packaging containers for oxygen-sensitive liquid food, for example juice, can also be produced from sheet-like blanks or prefabricated blanks of the packaging laminate 10a or 10b in FIG. 1a or 1b. From a tubular blank of the packaging laminate 10a that is folded flat, packages are produced by first of all building the blank up to form an open tubular container capsule, of which one open end is closed off by means of folding and heat-sealing of integral end panels. The thus closed container capsule is filled with the intended food product, e.g. juice, through its open end, which is thereafter closed off by means of further folding and heat-sealing of corresponding integral end panels. An example of a packaging container produced from sheet-like and tubular blanks is shown in FIG. 4c and is a so-called gable-top package 40c. There are also packages of this type which have a moulded top and/or screw cap opening device made of plastic.

[0085] A further example of a a bottle-type package is shown in FIG. 4d, which is formed from a packaging material blank into a folded sleeve 44, which is further joined to a moulded top and opening arrangement 45. This type of bottle-like package may be aseptic or non-aseptic. A commercial example of such an aseptic bottle is sold under the name Tetra Evero Aseptic.

[0086] FIG. 5 shows an example of an enhanced decorative appearance of a sheet of printed and laminated packaging material, which has been further provided with a surface effect in the outermost transparent polymer layer, being of tactile or visible character, or a combination of both. The area 56 being printed with a colour print onto the paperboard of a logotype and a word, text or name, has been further enhanced by increased gloss or shine in the outermost, upper polymer layer, such that the logo and name are clearly and brightly enhanced. Also features of other parts 57 of the decorative colour print has been enhanced by surface effects in the outer polymer layer, such as by tactile surface texture, increased gloss or matte effects or by a shiny hologram-like feature. The enhancing surface effects may be tailor-made and adapted to, and aligned with, the colour print of each and every print design and to each and every size and shape of package, by a flexible and economical method as outlined below.

[0087] In FIG. 6, it is shown how a sleeve 61 carrying the pattern of protrusions, plateaus or peaks 62, constitutes the mantel surface of an imprint roller or embossing roller 60; 231, when the sleeve is mounted onto a metal core 63 of such a roller. The pattern is to be imprinted onto the outermost, transparent polymer surface of the laminated packaging material, under the influence of pressure and in some cases heating of the polymer layer to be imprinted and/or of the mantel surface. The mantel surface of the imprint roller may be made of a hard metal material such as of steel, or other chrome or nickel alloys, which is engraved to exhibit the desired protrusions, peaks and plateaus. The counter roller, or anvil roller, most advantageously has a more elastic mantel or mantel surface, for the purpose of creating the imprint pattern at a controlled and pre-determined depth of the polymer layer of the laminated packaging material.

[0088] Thus, the hard metal mantel surface of the imprint roller is brought to act on the laminated packaging material by the help of an anvil roller made of a relatively hard but elastic polymer or rubber material, in order to obtain the adequate and optimal pressure and imprint conditions. This concerns in particular laminated packaging materials having a bulk layer between thin outermost layers of polymer, more particularly carton-based laminated packaging materials. It is believed that the bulk layer of thicker paper-, or paperboard-based material, contributes to the imprint process such that a clear and imprint may be made in the outermost thermoplastic polymer layer, at a relatively high speed and at a low temperature of the polymer, such as even at room temperature.

[0089] By using a system of exchangeable imprint roller sleeves, the process of imprinting after lamination may be kept at only low investment needed in imprinting equipment, and the switching between patterned decors from one package decor to another will not require long stops in the manufacturing line and process. Since relatively high line speeds, such as above 100 m/min, such as at least 200 m/min, and higher, are possible, the system is quite efficient and economical, as a whole.

[0090] By way of conclusion it should be observed that the present invention which has been described above with particular reference to the accompanying drawings, is not restricted to these embodiments described and shown exclusively by way of example, and that modifications and alterations obvious to a person skilled in the art are possible without departing from the inventive concept as disclosed in the appended claims.

INDUSTRIAL APPLICABILITY

[0091] By the method of the present invention, laminated packaging materials with enhanced decorative effects may be produced and tailor-made to their subsequent use, for various package shapes and sizes, as well as to additional patterns of printed decor and creasing lines, in order to produce packaging containers having new or differentiated appearance to consumers and retailers, at comparatively low cost.