WO1992004187A1 - Cover for food product package and method for producing said cover - Google Patents
Cover for food product package and method for producing said cover Download PDFInfo
- Publication number
- WO1992004187A1 WO1992004187A1 PCT/FI1991/000277 FI9100277W WO9204187A1 WO 1992004187 A1 WO1992004187 A1 WO 1992004187A1 FI 9100277 W FI9100277 W FI 9100277W WO 9204187 A1 WO9204187 A1 WO 9204187A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- polymer
- cover
- paper
- layer
- heat
- Prior art date
Links
- 235000013305 food Nutrition 0.000 title claims abstract description 28
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 8
- 229920000642 polymer Polymers 0.000 claims abstract description 66
- 239000000463 material Substances 0.000 claims abstract description 18
- 229920000573 polyethylene Polymers 0.000 claims description 11
- 238000007789 sealing Methods 0.000 claims description 7
- 229920001577 copolymer Polymers 0.000 claims description 6
- 239000002861 polymer material Substances 0.000 claims description 6
- 239000004952 Polyamide Substances 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- 229920002647 polyamide Polymers 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 4
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 3
- BFMKFCLXZSUVPI-UHFFFAOYSA-N ethyl but-3-enoate Chemical compound CCOC(=O)CC=C BFMKFCLXZSUVPI-UHFFFAOYSA-N 0.000 claims description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 2
- 239000002253 acid Substances 0.000 claims description 2
- IKZZIQXKLWDPCD-UHFFFAOYSA-N but-1-en-2-ol Chemical compound CCC(O)=C IKZZIQXKLWDPCD-UHFFFAOYSA-N 0.000 claims description 2
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims 1
- 230000008018 melting Effects 0.000 claims 1
- 238000004806 packaging method and process Methods 0.000 abstract description 5
- 239000007788 liquid Substances 0.000 abstract description 3
- 235000011389 fruit/vegetable juice Nutrition 0.000 abstract description 2
- 235000013336 milk Nutrition 0.000 abstract description 2
- 239000008267 milk Substances 0.000 abstract description 2
- 210000004080 milk Anatomy 0.000 abstract description 2
- 235000013618 yogurt Nutrition 0.000 abstract description 2
- 239000000123 paper Substances 0.000 description 30
- 239000005030 aluminium foil Substances 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 230000004888 barrier function Effects 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 235000011850 desserts Nutrition 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- XSMJZKTTXZAXHD-UHFFFAOYSA-N ethene;2-methylprop-2-enoic acid Chemical compound C=C.CC(=C)C(O)=O XSMJZKTTXZAXHD-UHFFFAOYSA-N 0.000 description 1
- 239000003925 fat Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 239000004922 lacquer Substances 0.000 description 1
- -1 or alternatively Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 235000021262 sour milk Nutrition 0.000 description 1
- 239000011782 vitamin Substances 0.000 description 1
- 229940088594 vitamin Drugs 0.000 description 1
- 229930003231 vitamin Natural products 0.000 description 1
- 235000013343 vitamin Nutrition 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/10—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of paper or cardboard
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B1/00—Layered products having a non-planar shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
- B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
- B32B37/15—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
- B32B37/153—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state at least one layer is extruded and immediately laminated while in semi-molten state
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/30—Properties of the layers or laminate having particular thermal properties
- B32B2307/31—Heat sealable
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/724—Permeability to gases, adsorption
- B32B2307/7242—Non-permeable
- B32B2307/7244—Oxygen barrier
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2439/00—Containers; Receptacles
- B32B2439/70—Food packaging
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2553/00—Packaging equipment or accessories not otherwise provided for
Definitions
- the present invention relates to a paper cover, which is oxygen-impermeable, heat-sealable cnto a container with and peelably openable along a heat-sealed seam, for a food product package; said cover being at its inside surface facing the container coated with polymer coat layers, of which the innermost layer forms a hermetically sealed and readily heat-sealable seam between said container and the cover.
- a heat-sealable cover of a package is used in unit packaging of food products, in particular those of the liquid-containing kind such as yoghurt, sourmilk, milk, juices, desserts and the like.
- the cover must provide sufficient hermeticity and hygiene.
- the commonest cover material has been aluminium foil whose heat-sealing onto the rims of the container has been implemented by means of lacquer.
- aluminium foil covers With the increasing demands for environmental compati ⁇ bility set on packaging, aluminium foil covers have become handicapped by the fact that they are nondegrad- able in waste processing. The aluminium foil cover is readily torn, yet not easy to open peelably along its seam line. Furthermore, aluminium covers are produced in an energy-consuming process which is deleterious to the environment and leads to high production costs.
- food product package covers made of paper coated by plastic layers in order to attain impermea ⁇ bility and heat-sealability, but the shelf life of products packaged using these covers has not matched that available with the use of an aluminium foil cover.
- the paper cover according to the invention for a food product package is characterized by having its inside coat layers formed by a polymer bonding layer, a polymer layer of oxygen-impermeable material, another polymer bonding layer and a heat-sealable polymer layer.
- the essential characteristic of the paper cover according to the invention for a food product package is its capability of preventing the penetration of oxygen from ambient atmosphere through the cover into the container.
- oxygen causes a gradual degradation of product quality by oxidizing i.a. fats, flavour substances and vitamins contained in the product.
- An additional benefit of the polymer layer combination used to prevent oxygen from entering the package is its capability of preventing aroma substances from escaping the package.
- the cover is readily and nontearingly openable (peelable) along the heat-sealed seam. Thence, the paper cover according to the invention for a food product package renders the product such a shelf life and ease- of-use that facilitates the use of a paper cover that can replace aluminium foil covers in the packaging of easily decaying or degrading food products.
- a polymer suitable for use as an oxygen barrier in the paper cover according to the invention for a food product package is ethylvinyl alcohol polymer (EVOH) .
- Exemplifying the bonding materials, which are compatible with said polymer can be mentioned, e.g., appropriately modified polyethene that can be laminated in either one or in both bonding layers with the EVOH layer. Thickness of the EVOH layer can be varied in the range 2...15 g/m 2 , preferably 4...10 g/m 2 .
- polyethene terephtalate (PET) whereby grafted polyethene can be employed as a compatible bonding material
- PET polyethene terephtalate
- PA polyamide
- Thickness of the PET layer can be in the range 5...30 g/m 2 , preferably 10...20 g/m 2 .
- Thickness of the PA layer can be in the range 3...20 g/m 2 , preferably 5...10 g/m 2 .
- Thickness of each bonding material layer can be in the range 2...15 g/m 2 , preferably 4...10 g/m 2 .
- the outermost heat-sealable polymer layer of the polymer multilayer system of the cover contains a polymer, such as methacrylic acid and ethylvinyl acetate modified polyethene acting as the adhering component, and a polymer such as a copolymer of ethene methacrylic acid acting as the releasing component.
- Thickness of the heat- sealable polymer layer can be in the range 5...40 g/m 2 , preferably 10...30 g/m 2 .
- Paper material of the cover can be, e.g., sulfate pulp based, bleached, filler-containing and coated paper grade with a basis weight in the range 30...200 g/m 2 , preferably 50...120 g/m 2 .
- the cover paper can be either coated or left uncoated on its other side, which is not coated by said polymer layers, and thus forms the outer side of the package.
- the invention also concerns a method for producing the paper cover described above for a food product package.
- the paper base material is simultaneously coated with several polymer coat layers of which the uppermost is of a heat-sealable polymer or blended polymer material and is characterized in that the coat layers, which comprise a polymer bonding layer, an oxyge -barrier forming pol mer layer, a second polymer bonding layer and a heat-sealable polymer layer, are applied in molten state against each other and at the same time against a moving paper web, and in that the paper coated thereby is used for fabricating said cover by pressing the paper against the rim of a ready-filled food product container and then adhering the cover by heat-sealing.
- Figure 1 shows a food product package sealed by a paper cover according to the invention
- Figure 2 shows a cross-sectioned detail of the seam between said package and the sealing paper cover
- Figure 3 shows the cross-sectioned detail of said cover in a greater scale
- Figure 4 shows schematically the manufacturing process of the paper cover material.
- Fig. 1 Shown in Fig. 1 is a disposable unit package 1 of a liquid-containing food product such as yoghur .
- the package 1 comprises a container 2 and an easily detachable (peelable) paper cover 3 according to the present invention, said cover being heat-sealed onto the rim of said container.
- the container 2 can be of any plastic conventionally used in food packaging such as polypropene or polystyrene, or alternatively, cardboard coated with LD polyethene.
- the material of the container is irrelevant to the invention; for practical reasons, however, its degree of impermeability can be assumed to be at least as high as that of the cover.
- the paper cover 3 which is attached by heat-sealing to the package comprises a paper web layer 4 acting as a carrier for a polymer multilayer system 5 facing the inside of the package, said multilayer system being comprised of four superimposed polymer layers of which the innermost forms a heat- sealable seam 6 between the rim of the container 2 and said cover 3.
- the polymer coat 5 renders the cover an easy detachment and good hermeticity, which prevents the packaged product 7 from decaying.
- Fig. 3 illustrates the polymer layers forming the inside coat 5 of the cover paper 4.
- the polymer bonding layer 8 Closest to the paper 4 is the polymer bonding layer 8, next is a layer of oxygen- barrier forming polymer layer 9, next to it is another polymer bonding layer 10, and finally outermost from the paper, the polymer layer 11 which provides the heat- sealable seam 6.
- the latter is advantageously composed of a blended polymer material containing an adhering component that facilitates heat-sealing and a releasing component that facilitates the detachment of the cover along the heat-sealed seam without tearing the cover.
- an essential impetus is given by the oxygen-barrier forming polymer layer 9 that gives the cover the impermeability required for a satisfactory shelf life of the packaged product.
- the polymer material of the layer 9 can be, e.g., ethylvinyl alcohol copolymer, whereby modified polyethene can be selected as the material of the polymer bonding layers 8, 10.
- modified polyethene can be selected as the material of the polymer bonding layers 8, 10.
- the heat-sealable polymer layer 11 can consist of methacrylic acid and ethylvinyl acetate modified polyethene as an adhering compound and a copolymer of ethenemethacrylic acid as a releasing compound.
- the fabrication of the paper cover according to the invention takes place as a continuous process by routing a continuous paper web 4 to the nip formed between rolls 14, 15, whereby the film webs of the polymer layers 8...11 to be superimposed on the cover base material are simultaneously routed from nozzles 16 to the same nip.
- the nozzles 16 communicate with containers 17...19, from which the polymer bonding material (container 17) , oxygen-barrier forming polymer (container 18) .nd heat-sealab_e polymer (container 19) are fed in molten state to said nozzles.
- the molten polymer layers 8...11 are first aimed against each other, after which they are applied in a single run to the paper 4 in the nip formed between said rolls 14, 15.
- a coated paper web is obtained suitable for the stamping of the covers according to the invention either prior to the fill/heat- sealing stage of the package, or alternatively, in conjunction with this stage.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Laminated Bodies (AREA)
- Packages (AREA)
- Wrappers (AREA)
Abstract
The invention concerns a paper cover (3) for a food product and a method for producing said cover. The cover is intended for the packaging of food products, in particular those of the liquid-containing kind such as yoghurt, milk, juices, and the like. The cover is coated on its inner surface with polymer coat layers (5). The invention is characterized in that the inside coat layers on the base material (4) of said paper cover are comprised of a polymer bonding layer (8), an oxygen-barrier forming polymer layer (9), another polymer bonding layer (10) and a heat-sealable polymer layer (11).
Description
COVER FOR FOOD PRODUCT PACKAGE AND METHOD FOR PRODUCING SAID COVER
The present invention relates to a paper cover, which is oxygen-impermeable, heat-sealable cnto a container with and peelably openable along a heat-sealed seam, for a food product package; said cover being at its inside surface facing the container coated with polymer coat layers, of which the innermost layer forms a hermetically sealed and readily heat-sealable seam between said container and the cover.
A heat-sealable cover of a package is used in unit packaging of food products, in particular those of the liquid-containing kind such as yoghurt, sourmilk, milk, juices, desserts and the like. Here, the cover must provide sufficient hermeticity and hygiene. The commonest cover material has been aluminium foil whose heat-sealing onto the rims of the container has been implemented by means of lacquer.
With the increasing demands for environmental compati¬ bility set on packaging, aluminium foil covers have become handicapped by the fact that they are nondegrad- able in waste processing. The aluminium foil cover is readily torn, yet not easy to open peelably along its seam line. Furthermore, aluminium covers are produced in an energy-consuming process which is deleterious to the environment and leads to high production costs. Known in the art are food product package covers made of paper coated by plastic layers in order to attain impermea¬ bility and heat-sealability, but the shelf life of products packaged using these covers has not matched that available with the use of an aluminium foil cover.
It is an object of the present invention to provide a paper cover for a food product container, said paper
cover being manufacturable by a simple process and offering a degree of hermeticity sufficient for assuring a long shelf life even for sensitive and easily decaying ood products. The paper cover according to the invention for a food product package is characterized by having its inside coat layers formed by a polymer bonding layer, a polymer layer of oxygen-impermeable material, another polymer bonding layer and a heat-sealable polymer layer.
The essential characteristic of the paper cover according to the invention for a food product package is its capability of preventing the penetration of oxygen from ambient atmosphere through the cover into the container. In general, oxygen causes a gradual degradation of product quality by oxidizing i.a. fats, flavour substances and vitamins contained in the product. An additional benefit of the polymer layer combination used to prevent oxygen from entering the package is its capability of preventing aroma substances from escaping the package. By virtue of the heat-sealable polymer layer, the cover is readily and nontearingly openable (peelable) along the heat-sealed seam. Thence, the paper cover according to the invention for a food product package renders the product such a shelf life and ease- of-use that facilitates the use of a paper cover that can replace aluminium foil covers in the packaging of easily decaying or degrading food products.
A polymer suitable for use as an oxygen barrier in the paper cover according to the invention for a food product package is ethylvinyl alcohol polymer (EVOH) .
Exemplifying the bonding materials, which are compatible with said polymer, can be mentioned, e.g., appropriately modified polyethene that can be laminated in either one or in both bonding layers with the EVOH layer. Thickness of the EVOH layer can be varied in the range 2...15 g/m2, preferably 4...10 g/m2.
As alternative polymers suitable for use as an oxygen barrier can be noted polyethene terephtalate (PET) , whereby grafted polyethene can be employed as a compatible bonding material, and polyamide (PA) , whereby a copolymer of ethene and unsaturated carboxylic acid can be employed, as a compatible bonding material. Thickness of the PET layer can be in the range 5...30 g/m2, preferably 10...20 g/m2. Thickness of the PA layer can be in the range 3...20 g/m2, preferably 5...10 g/m2.
Thickness of each bonding material layer can be in the range 2...15 g/m2, preferably 4...10 g/m2.
The outermost heat-sealable polymer layer of the polymer multilayer system of the cover contains a polymer, such as methacrylic acid and ethylvinyl acetate modified polyethene acting as the adhering component, and a polymer such as a copolymer of ethene methacrylic acid acting as the releasing component. Thickness of the heat- sealable polymer layer can be in the range 5...40 g/m2, preferably 10...30 g/m2.
Paper material of the cover can be, e.g., sulfate pulp based, bleached, filler-containing and coated paper grade with a basis weight in the range 30...200 g/m2, preferably 50...120 g/m2.
The cover paper can be either coated or left uncoated on its other side, which is not coated by said polymer layers, and thus forms the outer side of the package.
The invention also concerns a method for producing the paper cover described above for a food product package. In the method the paper base material is simultaneously coated with several polymer coat layers of which the uppermost is of a heat-sealable polymer or blended polymer material and is characterized in that the coat
layers, which comprise a polymer bonding layer, an oxyge -barrier forming pol mer layer, a second polymer bonding layer and a heat-sealable polymer layer, are applied in molten state against each other and at the same time against a moving paper web, and in that the paper coated thereby is used for fabricating said cover by pressing the paper against the rim of a ready-filled food product container and then adhering the cover by heat-sealing.
The invention is next examined in greater detail with the help of an exemplifying embodiment illustrated in the attached drawings, in which
Figure 1 shows a food product package sealed by a paper cover according to the invention,
Figure 2 shows a cross-sectioned detail of the seam between said package and the sealing paper cover,
Figure 3 shows the cross-sectioned detail of said cover in a greater scale, and
Figure 4 shows schematically the manufacturing process of the paper cover material.
Shown in Fig. 1 is a disposable unit package 1 of a liquid-containing food product such as yoghur . The package 1 comprises a container 2 and an easily detachable (peelable) paper cover 3 according to the present invention, said cover being heat-sealed onto the rim of said container.
The container 2 can be of any plastic conventionally used in food packaging such as polypropene or polystyrene, or alternatively, cardboard coated with LD polyethene. The material of the container is irrelevant to the invention;
for practical reasons, however, its degree of impermeability can be assumed to be at least as high as that of the cover.
According to Fig. 2, the paper cover 3 which is attached by heat-sealing to the package comprises a paper web layer 4 acting as a carrier for a polymer multilayer system 5 facing the inside of the package, said multilayer system being comprised of four superimposed polymer layers of which the innermost forms a heat- sealable seam 6 between the rim of the container 2 and said cover 3. In addition to its heat-sealability, the polymer coat 5 renders the cover an easy detachment and good hermeticity, which prevents the packaged product 7 from decaying.
Fig. 3 illustrates the polymer layers forming the inside coat 5 of the cover paper 4. Closest to the paper 4 is the polymer bonding layer 8, next is a layer of oxygen- barrier forming polymer layer 9, next to it is another polymer bonding layer 10, and finally outermost from the paper, the polymer layer 11 which provides the heat- sealable seam 6. The latter is advantageously composed of a blended polymer material containing an adhering component that facilitates heat-sealing and a releasing component that facilitates the detachment of the cover along the heat-sealed seam without tearing the cover.
For the purpose of the invention, an essential impetus is given by the oxygen-barrier forming polymer layer 9 that gives the cover the impermeability required for a satisfactory shelf life of the packaged product. The polymer material of the layer 9 can be, e.g., ethylvinyl alcohol copolymer, whereby modified polyethene can be selected as the material of the polymer bonding layers 8, 10. However, other material combinations than those mentioned above are also possible.
The heat-sealable polymer layer 11 can consist of methacrylic acid and ethylvinyl acetate modified polyethene as an adhering compound and a copolymer of ethenemethacrylic acid as a releasing compound.
According to Fig. 4, the fabrication of the paper cover according to the invention takes place as a continuous process by routing a continuous paper web 4 to the nip formed between rolls 14, 15, whereby the film webs of the polymer layers 8...11 to be superimposed on the cover base material are simultaneously routed from nozzles 16 to the same nip. The nozzles 16 communicate with containers 17...19, from which the polymer bonding material (container 17) , oxygen-barrier forming polymer (container 18) .nd heat-sealab_e polymer (container 19) are fed in molten state to said nozzles. As is evident from Fig. 4, the molten polymer layers 8...11 are first aimed against each other, after which they are applied in a single run to the paper 4 in the nip formed between said rolls 14, 15. As a result a coated paper web is obtained suitable for the stamping of the covers according to the invention either prior to the fill/heat- sealing stage of the package, or alternatively, in conjunction with this stage.
For those versed in the art it is evident that the invention is not limited by the exemplifying embodiment described above, but instead, its applicability can be varied within the scope of the enclosed claims.
Claims
1. A paper cover (3) for a food product container, said paper cover (3) being heat-sealable onto said container (2) with and peelable along a heat-sealed seam (6) , said cover being coated at its inside surface facing said container with polymer material coat layers (8...11) of which the top layer (11) facing the inside of the container forms said hermetically sealed and readily peelable heat-sealed seam (6), c h a r a c t e r i z e d in that the inside coat layers on the base material of said paper cover (4) are formed by a polymer bonding layer (8) , a polymer layer of oxygen-impermeable material (9) , another polymer bonding layer (10) and a heat- sealable polymer layer (11) .
2. A paper cover for a food product package as defined in claim 1, c h a r a c t e r i z e d in that the polymer layer facing the base paper web (4) is of the same polymer material as the heat-sealable polymer layer (11) •
3. A paper cover for a food product package as defined in claim 1, c h a r a c t e r i z e d in that the inside polymer coat layers of the cover (3) are applied in the order as defined in claim 1.
4. A paper cover for a food product package as defined in claim 1, c h a r a c t e r i z e d in that the oxygen-barrier forming polymer layer (9) is of ethylvinyl alcohol polymer (EVOH) .
5. A paper cover for a food^product package as defined in claim 1, c h a r a c t e r i z e d in that the bonding component of the polymer coat is modified polyethene.
6. A paper cover for a food product package as defined in claim 1, c h a r a c t e r i z e d in that the oxygen-barrier forming polymer layer (9) is of polyethene terephtalate (PET) and at least one of the polymer bonding layers (8, 10) is of grafted polyethene.
7. A paper cover for a food product package as defined in claim 1, c h a r a c t e r i z e d in that the oxygen-barrier forming polymer layer (9) is of polyamide (PA) and at least one of the polymer bonding layers (8, 10) is of a copolymer of ethene and unsaturated carboxylic acid.
8. A paper cover for a food product package as defined in claim 1, c h a r a c t e r i z e d in that the heat- sealable polymer layer (11) contains, e.g., methacrylic acid and ethylvinyl acetate modified polyethene as an adhering compound and a copolymer of ethenemethacrylic acid as a releasing compound.
9. A paper cover for a ood product package as defined i-i any foregoing claim, c h a r a c t e r i z e d in that the outside (12) of the cover (3) is a conventional paper surface suitable for printing.
10. A method for producing the cover (3) for a food product package as defined in any foregoing claim, in which method several polymer coat layers (8...11) are applied simultaneously onto the base material of the paper cover, whereby the top layer (11) is of a heat- sealable and peelable polymer or blended polymer material, c h a r a c t e r i z e d in that the coat layers comprised of a polymer bonding layer (8) , an oxygen-barrier forming polymer layer (9) , another polymer bonding layer (10) and a heat-sealable polymer layer (11) are applied in molten state against each other and at the same time against a moving paper web (4) , and in that the paper coated thereby is used for fabricating said cover (3) by bringing the paper against the rim of a ready- filled food product container (2) and then adhering the cover by heat-sealing.
11. A method as defined in claim 10, c h a r a c ¬ t e r i z e d in that the polymer bonding layers (8, 10) are of a single polymer routed from a common melting container (17) .
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI904486 | 1990-09-11 | ||
FI904486A FI904486A (en) | 1990-09-11 | 1990-09-11 | LIVSMEDELSFOERPACKNING FOERSEDD MED ETT LOCK SAMT FOERFARANDE FOER FRAMSTAELLNING AV LOCKET FOER FOERPACKNINGEN. |
FI914268 | 1991-09-10 | ||
FI914268A FI97285B (en) | 1990-09-11 | 1991-09-10 | Food packaging lid and method of making it |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1992004187A1 true WO1992004187A1 (en) | 1992-03-19 |
Family
ID=26158810
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FI1991/000277 WO1992004187A1 (en) | 1990-09-11 | 1991-09-11 | Cover for food product package and method for producing said cover |
Country Status (3)
Country | Link |
---|---|
AU (1) | AU8419591A (en) |
FI (1) | FI97285B (en) |
WO (1) | WO1992004187A1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0630745A1 (en) * | 1993-06-21 | 1994-12-28 | Enso-Gutzeit Oy | Multi-layer product |
WO1995010413A1 (en) * | 1993-10-11 | 1995-04-20 | Yhtyneet Paperitehtaat Oy | Lid for a food can |
EP0687557A3 (en) * | 1994-06-16 | 1996-03-20 | Enso Gutzeit Oy | A cover for a product package and a method for producing the same |
ES2097076A1 (en) * | 1992-09-14 | 1997-03-16 | Takeda Chemical Industries Ltd | Thermosellable cover film. (Machine-translation by Google Translate, not legally binding) |
WO1998030390A1 (en) * | 1997-01-10 | 1998-07-16 | Elopak Systems Ag | A packaging laminate |
WO2003033258A1 (en) * | 2001-10-15 | 2003-04-24 | Stora Enso Oyj | Package lid, method for manufacturing the same and package sealed with the lid |
WO2006007239A2 (en) | 2004-06-17 | 2006-01-19 | Stora Enso North America Corporation | Multi-layer, high barrier packaging materials |
DE102019129712A1 (en) * | 2019-11-05 | 2021-05-06 | Wihuri Packaging Oy | Process for the production of multilayer packaging films, such packaging films and product packaging comprising them |
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DE3012342A1 (en) * | 1980-03-29 | 1982-03-25 | Scheuch Folien- und Papierverarbeitung GmbH & Co KG, 6109 Mühltal | MULTILAYER FILM FOR THE LOCKING OF VESSELS |
US4513036A (en) * | 1983-10-17 | 1985-04-23 | Champion International Corporation | Barrier laminates for containment of essential oils and flavors and cartons made therefrom |
EP0293098A2 (en) * | 1987-05-29 | 1988-11-30 | International Paper Company | Improved non-foil composite structures for packaging juice |
EP0333443A2 (en) * | 1988-03-15 | 1989-09-20 | W.R. Grace & Co.-Conn. | Barrier stretch film |
-
1991
- 1991-09-10 FI FI914268A patent/FI97285B/en not_active IP Right Cessation
- 1991-09-11 WO PCT/FI1991/000277 patent/WO1992004187A1/en unknown
- 1991-09-11 AU AU84195/91A patent/AU8419591A/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
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DE3012342A1 (en) * | 1980-03-29 | 1982-03-25 | Scheuch Folien- und Papierverarbeitung GmbH & Co KG, 6109 Mühltal | MULTILAYER FILM FOR THE LOCKING OF VESSELS |
US4513036A (en) * | 1983-10-17 | 1985-04-23 | Champion International Corporation | Barrier laminates for containment of essential oils and flavors and cartons made therefrom |
EP0293098A2 (en) * | 1987-05-29 | 1988-11-30 | International Paper Company | Improved non-foil composite structures for packaging juice |
EP0333443A2 (en) * | 1988-03-15 | 1989-09-20 | W.R. Grace & Co.-Conn. | Barrier stretch film |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2097076A1 (en) * | 1992-09-14 | 1997-03-16 | Takeda Chemical Industries Ltd | Thermosellable cover film. (Machine-translation by Google Translate, not legally binding) |
US5738933A (en) * | 1993-06-21 | 1998-04-14 | Enso-Gutzeit Oy | Mutli-layer product |
EP0630745A1 (en) * | 1993-06-21 | 1994-12-28 | Enso-Gutzeit Oy | Multi-layer product |
WO1995010413A1 (en) * | 1993-10-11 | 1995-04-20 | Yhtyneet Paperitehtaat Oy | Lid for a food can |
EP0687557A3 (en) * | 1994-06-16 | 1996-03-20 | Enso Gutzeit Oy | A cover for a product package and a method for producing the same |
US5840385A (en) * | 1994-06-16 | 1998-11-24 | Enso-Gutzeit Oy | Cover for product package and method for producing same |
WO1998030390A1 (en) * | 1997-01-10 | 1998-07-16 | Elopak Systems Ag | A packaging laminate |
AU2002333924B2 (en) * | 2001-10-15 | 2007-08-09 | Stora Enso Oyj | Package lid, method for manufacturing the same and package sealed with the lid |
WO2003033258A1 (en) * | 2001-10-15 | 2003-04-24 | Stora Enso Oyj | Package lid, method for manufacturing the same and package sealed with the lid |
NO337556B1 (en) * | 2001-10-15 | 2016-05-09 | Stora Enso Oyj | Packaging lid, process for making it, method for making sealed packaging, as well as sealed packaging. |
CN1308137C (en) * | 2001-10-15 | 2007-04-04 | 斯塔诺阿埃索澳吉有限公司 | Package lid, method for manufacturing the same and package sealed with the lid |
WO2006007239A2 (en) | 2004-06-17 | 2006-01-19 | Stora Enso North America Corporation | Multi-layer, high barrier packaging materials |
EP1758738A4 (en) * | 2004-06-17 | 2008-11-12 | Stora Enso North America Corp | Multi-layer, high barrier packaging materials |
EP1758738A2 (en) * | 2004-06-17 | 2007-03-07 | Stora Enso North America Corporation | Multi-layer, high barrier packaging materials |
DE102019129712A1 (en) * | 2019-11-05 | 2021-05-06 | Wihuri Packaging Oy | Process for the production of multilayer packaging films, such packaging films and product packaging comprising them |
EP3819123A1 (en) | 2019-11-05 | 2021-05-12 | Wihuri Packaging OY | Method for producing multilayer packaging films, packaging films of this type and product packages comprising the same |
Also Published As
Publication number | Publication date |
---|---|
FI97285B (en) | 1996-08-15 |
FI914268A (en) | 1992-03-12 |
FI914268A0 (en) | 1991-09-10 |
AU8419591A (en) | 1992-03-30 |
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