GB2078168A - Aluminium-based Laminate for Packaging of Foodstuffs to be Pasteurised - Google Patents
Aluminium-based Laminate for Packaging of Foodstuffs to be Pasteurised Download PDFInfo
- Publication number
- GB2078168A GB2078168A GB8020536A GB8020536A GB2078168A GB 2078168 A GB2078168 A GB 2078168A GB 8020536 A GB8020536 A GB 8020536A GB 8020536 A GB8020536 A GB 8020536A GB 2078168 A GB2078168 A GB 2078168A
- Authority
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- United Kingdom
- Prior art keywords
- layer
- laminate film
- film according
- ethylene
- solvent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004411 aluminium Substances 0.000 title abstract description 3
- 229910052782 aluminium Inorganic materials 0.000 title abstract description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title abstract description 3
- 238000004806 packaging method and process Methods 0.000 title description 5
- 239000010410 layer Substances 0.000 claims abstract description 98
- 239000005030 aluminium foil Substances 0.000 claims abstract description 29
- 239000000758 substrate Substances 0.000 claims abstract description 23
- 229920000554 ionomer Polymers 0.000 claims abstract description 16
- 238000007789 sealing Methods 0.000 claims abstract description 15
- 150000003839 salts Chemical class 0.000 claims abstract description 12
- 239000012790 adhesive layer Substances 0.000 claims abstract description 11
- 150000007524 organic acids Chemical class 0.000 claims abstract description 6
- 229920001577 copolymer Polymers 0.000 claims abstract description 4
- 239000005001 laminate film Substances 0.000 claims description 27
- 239000003292 glue Substances 0.000 claims description 18
- -1 polyethylene Polymers 0.000 claims description 17
- 239000002904 solvent Substances 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 15
- 229920000728 polyester Polymers 0.000 claims description 14
- 229920000573 polyethylene Polymers 0.000 claims description 12
- 238000009928 pasteurization Methods 0.000 claims description 11
- 229920001179 medium density polyethylene Polymers 0.000 claims description 10
- 239000004701 medium-density polyethylene Substances 0.000 claims description 10
- 229920002635 polyurethane Polymers 0.000 claims description 10
- 239000004814 polyurethane Substances 0.000 claims description 10
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 9
- 239000004698 Polyethylene Substances 0.000 claims description 9
- 229920001155 polypropylene Polymers 0.000 claims description 9
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 8
- 239000005977 Ethylene Substances 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 7
- 239000004743 Polypropylene Substances 0.000 claims description 6
- 229920001684 low density polyethylene Polymers 0.000 claims description 6
- 239000004702 low-density polyethylene Substances 0.000 claims description 6
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 5
- 238000001125 extrusion Methods 0.000 claims description 5
- 229920006242 ethylene acrylic acid copolymer Polymers 0.000 claims description 4
- 239000005038 ethylene vinyl acetate Substances 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 3
- 239000004677 Nylon Substances 0.000 claims description 3
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical group CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 claims description 3
- 230000001070 adhesive effect Effects 0.000 claims description 3
- 229910052783 alkali metal Inorganic materials 0.000 claims description 3
- 150000001340 alkali metals Chemical class 0.000 claims description 3
- 238000003851 corona treatment Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 229920001778 nylon Polymers 0.000 claims description 3
- 229910052708 sodium Inorganic materials 0.000 claims description 3
- 239000011734 sodium Substances 0.000 claims description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 2
- 239000012736 aqueous medium Substances 0.000 claims description 2
- 238000001704 evaporation Methods 0.000 claims description 2
- 239000012530 fluid Substances 0.000 claims description 2
- 239000011140 metalized polyester Substances 0.000 claims description 2
- 238000006386 neutralization reaction Methods 0.000 claims description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims 2
- 239000005026 oriented polypropylene Substances 0.000 claims 2
- 229910052725 zinc Inorganic materials 0.000 claims 2
- 239000011701 zinc Substances 0.000 claims 2
- 230000015572 biosynthetic process Effects 0.000 claims 1
- 229910052751 metal Chemical class 0.000 abstract description 2
- 239000002184 metal Chemical class 0.000 abstract description 2
- 229920003941 DuPont™ Surlyn® 1652 Polymers 0.000 description 2
- 229920003182 Surlyn® Polymers 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 229920005749 polyurethane resin Polymers 0.000 description 2
- 238000004381 surface treatment Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 235000015241 bacon Nutrition 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 235000013361 beverage Nutrition 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229920006280 packaging film Polymers 0.000 description 1
- 239000012785 packaging film Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000013047 polymeric layer Substances 0.000 description 1
- 235000020991 processed meat Nutrition 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 150000003751 zinc Chemical class 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
- B32B15/00—Layered products comprising a layer of metal
- B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B15/08—Layered products comprising a layer of metal comprising metal 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
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
- A23L3/10—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating materials in packages which are not progressively transported through the apparatus
-
- 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
- B32B15/00—Layered products comprising a layer of metal
- B32B15/20—Layered products comprising a layer of metal comprising aluminium or copper
-
- 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
- B32B38/00—Ancillary operations in connection with laminating processes
- B32B38/0008—Electrical discharge treatment, e.g. corona, plasma treatment; wave energy or particle radiation
-
- 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
- B32B2310/00—Treatment by energy or chemical effects
- B32B2310/14—Corona, ionisation, electrical discharge, plasma treatment
-
- 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
- B32B2311/00—Metals, their alloys or their compounds
- B32B2311/20—Zinc
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Nutrition Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Thermal Sciences (AREA)
- Laminated Bodies (AREA)
- Wrappers (AREA)
Abstract
An aluminium-based laminate includes (a) a substrate layer, (b) a primer layer (c) a bonding layer attached to the substrate layer with the assistance of the primer layer, (d) an aluminium foil layer secured to the bonding layer, (e) a substantially solvent-free adhesive layer applied to the aluminium foil layer, and (f) a sealing layer maintained on the aluminium foil layer by means of the substantially solvent-free adhesive layer. The substantially solvent-free adhesive layer is preferably an ionomer in the form of a copolymer of an alpha -mono-olefin, an unsaturated organic acid, and a metal salt of the unsaturated organic acid.
Description
SPECIFICATION
Aluminium-based Laminate for Packaging of Foodstuffs to be Pasteurised
This invention relates to a laminate containing an aluminium foil layer and polymeric layers for the packaging of foodstuffs to be pasteurised.
Laminate films for packaging foodstuffs containing an aluminium foil layer and polymeric layers are known. The aluminium foil layer acts as a barrier to the passage of oxygen and water-vapour through the packaging film. It is used particularly when the food is to be packaged in a sealed bag of the film and then heated in a steam oven or in water, especially for pasteurisation purposes. The laminate film contains polymeric layers which protect the aluminium foil layer from physical damage and strengthen the whole film. Also, one or both polymeric layers forming the surfaces of the film are used as a sealing layer. That is, when the film is made up into a bag, the surface layers facing each other are joined together, e.g. by heat-sealing, to form longitudinal and/or transverse bonds and thereby close the bag.
In laminate films of the above kind the aluminium foil has to be glued to the flanking polymeric layers with an adhesive. Of course, the bond strength of the adhesion has to be high, to withstand the handling of the packages. Also the bond has to withstand the pasteurisation temperature which is often as high as 11 5 C. We aim to provide a bond strength of at least 500 grams per inch (200 grams per cm.) before and after pasteurisation. All bond strengths referred to herein are determined on an "lnstron" (Registered Trade Mark in the U.K. and many other countries) dynamometer at 23"C and a cross-head speed of 300 mm./minute.
To prepare laminate films of the above kind, we have used the following process. A substrate film of polyester is corona-treated to make it more receptive to the glue layer to be applied next. The corona-treated polyester passes to a glue station where a glue of polyurethane resin is applied. The glue is a mixture of 100 parts of polyurethane resin, i.e. prepolymer, 2.5 parts of a curing catalyst and 50 parts of ethyl acetate as solvent. All parts and percentages throughout this specification are by weight. The glue-coated substrate is passed to a series of ovens in which the solvent is evaporated.
The substrate is then passed over a hot roll and its glued surface is brought into contact with the aluminium foil. The layers are pressed together with a rubber roll. Then the aluminium foil layer of this polyester/polyurethane/aluminium foil laminate is coated with the same glue, the laminate is again passed into a series of ovens and the solvent of the glue is evaporated. The polyester/polyurethane/aluminium foil/polyurethane laminate is passed over a hot roll and its glued surface is contacted with a film of corona-treated medium density polyethylene. This is pressed onto the laminate with a rubber roll. The product is a 5-layer laminate of polyester/polyurethane/aluminium foil/polyurethane/medium density polyethylene.
The above laminate has a bond strength which is normally adequate. A typical value is 700 grams per inch (280 grams per cm.). However we have encountered the problem that 3 to 4%, a significant proportion, of bags made from these laminates have had to be rejected. This is on account of delamination and the opening of seals. Moreover the process of making the laminate is rather lengthy, because of the time needed to evaporate the solvent from the glue.
We have now invented a different laminate film from the 5-layer product described above. Tests on a film laminate of the present invention have shown a bond strength of at least 700 grams per inch (280 grams per cm) before pasteurisation. Surprisingly the bond strength increases as a result of pasteurisation to at least 800 grams per inch (320 grams per cm.) after pasteurisation. Moreover, the laminate can be prepared more easily, only one pass through an oven to evaporate solvent being required instead of two passes in the process referred to above.
The invention is based on the principle that the aluminium foil is bonded to a layer of a polymer of ethylene and/or propylene, as sealing layer, by a layer of an ionomer which is substantially free of solvent. It is contemplated that an ethylene-acrylic acid copolymer or ethylene-vinyl acetate copolymer can be used instead of an ionomer. In this way, the use of solvent-based glue can be avoided in the bonding of the sealing layer to the aluminium foil. The aluminium foil layer can be backed by any polymeric layer(s) appropriate to the use of the laminate film for packaging purposes.
According to an aspect of the invention there is provided a laminate film comprising the following layers in the order stated:
1. A first layer of a polymeric material, preferably a polyester, metallized polyester, bioriented nylon, metallized bioriented nylon, bioriented polypropylene or metallized bioriented polypropylene layer. This is called the "substrate layer".
2. A layer of a primer, which can be a solvent-based glue, e.g. a polyurethane glue.
3. A layer of a low or medium density polyethylene. It is substantially free of solvent. It can be applied by melt-extrusion. This is called the "bonding layer".
4. An aluminium foil layer.
5. A layer of (a) an ionomer, (b) an ethylene-acrylic acid copolymer containing from 2 to 10% of acrylic acid units or (c) an ethylene-vinyl acetate copolymer containing from 5 to 40% vinyl acetate units, this layer being substantially free of solvent. It can be applied by melt-extrusion. This is called the "solvent-free adhesive layer".
6. A layer of an ethylene and/or propylene polymer, preferably a medium or high density polyethylene, polypropylene, an ethylene-propylene copolymer containing from 3 to 20% of ethylene units, or a mixture of polyethylene with polypropylene in which the proportion of polyethylene is from 3 to 20%. The preferred material is medium density polyethylene. This is called the "sealing layer".
The terms "low density" and "medium density" when used herein in relation to polyethylenes refer mainly to densities of 0.89 to 0.925 and 0.926 to 0.935 g./cc respectively.
The "ionomer" is a copolymer comprising units of an alpha-mono-olefin, preferably ethylene, an unsaturated organic acid, preferably an a,P-unsaturated carboxylic acid such as methacrylic or acrylic acid, and a salt of such an acid, preferably an alkali metal, e.g. sodium, salt or a zinc salt. It is ordinarily obtained by partial neutralisation of a bipolymer of the alpha-mono-olefin and unsaturated organic acid components. The proportions of the three components of an ionomer are, for example, 80 to 95% alpha-mono-olefin, 2 to 1 0% unsaturated acid and 0.5 to 1 0% metal salt of the unsaturated acid.
Usually the proportion of the salt component will not exceed 5%. One ionomer which we have found particularly useful is "Surlyn 1652". ("Surlyn" is a Registered Trade Mark of E. I. du Pont de Nemours 8 Co. in the U.K. and many other countries). The solvent-free adhesive layer is ordinarily a meltextruded layer.
The preferred thicknesses of the layers are as follows: 1. Substrate layer10 to 30 microns
2. Primer layer
3. Bonding layer 8 to 50 microns
4. Aluminium foil layer 8 to 20 microns
5. Solvent-free adhesive layer 10 to 50 microns
6. Sealing layer 20 to 100 microns
The preferred laminate of the invention is a 6-layer laminate of the following sequence:- Polyester/primer/low density polyethylene/aluminium foil/ionomer/medium density polyethylene.
Laminates of the invention can be made by a process which comprises (a) providing a bonding layer of low or medium density polyethylene between substrate and aluminium foil layers, by meltextruding it, to form a laminate comprising substrate, bonding layer and aluminium foil; and (b) providing a layer of substantially solvent-free adhesive (defined above under layer 5 of the film of the invention) between the aluminium foil layer of the laminate obtained from step (a) and a sealing layer (defined above under layer 6 of the film of the invention) by melt-extrusion.
Normally the substrate will require a surface treatment, especially application of a primer to bond it to the bonding layers. Suitable primers are known for this purpose. A polyurethane glue containing ethyl acetate.solvent is usable. When the substrate layer is of a polyester, it will usually require surface treatment before the primer is applied. This can be carried out by corona treatment in a known manner.
Thus the process will usually contain the preliminary steps of corona treatment of a polyester, followed by application of a layer of solvent-based primer and evaporation of the primer in an oven or series of ovens before the substrate is ready to receive the bonding layer. Only one pass in an oven is required in this procedure, which more than compensates for the use of a bonding layer in addition to the substrate.
The invention includes also bags made from a film of the invention described above, packages of a foodstuff enclosed within a sealed bag of the invention and a process of pasteurising a foodstuff which comprises heating it in such a bag at a temperature of from 70 to 11 50C for a time sufficient to effect pasteurisation (which will ordinarily be from 20 minutes to 2 hours depending on the temperature). Preferably the heater is carried out in a fluid aqueous medium, e.g. steam in a steam oven or hot water.
It is contemplated that the invention will be particularly useful in the pasteurising of foodstuffs (including beverages), especially processed meat, e.g. hams and bacon joints.
The following Example illustrates the invention.
Example
A laminate was made by the method of the invention. That is, a film of polyester (polyethylene terephthalate) was corona treated and primed with a polyurethane glue, the solvent of the glue was evaporated in an oven. Low density polyethylene was melt-extruded at a melt temperature of 3203300C between the polyester layer and an aluminium foil to form the intermediate bonding layer. The resulting 4-layer laminate and a film of medium density polyethylene were brought into proximity and a layer of the ionomer "Surlyn 1 652" was applied between them by melt extrusion at a melt temperature of 310 to 3200 C. In this way a laminate of the following structure was prepared L Thickness
Layers in microns
Polyethylene terephthalate 12.5
Primer 0.7
Low density polyethylene 16.0
Aluminium foil 9.0
"Surlyn 1652" ionomer 25.0
Medium density polyethylene 75.0
The bond strength of the laminate was found to be at least 700 grams per inch (280 grams per cm.). The laminate was made up into a bag and subjected to pasteurisation conditions in a steam oven at 11 50C for 20 minutes. After pasteurisation the bond strength of the laminate had increased to at least 800 grams per inch (320 grams per cm.).
Claims (10)
1. A laminate film comprising the following layers in the order stated: (a) a substrate layer of a polymeric material; (b) a primer layer; (c) a bonding layer of polyethylene having a density in the range of 0.89 to 0.935 g/cc; (d) an aluminium foil layer; (e) a substantially solvent-free adhesive layer of (i) an ionomer, (ii) an ethylene-acrylic acid copolymer containing from 2 to 10% of acrylic acid units, or (iii) an ethylene-vinyl acetate copolymer containing from 5 to 40% vinyl acetate units; and (f) a sealing layer of an ethylene and/or propylene polymer.
2. A laminate film according to claim 1, wherein said substrate layer is formed of a polyester, a metallised polyester, bi-oriented Nyion, metallised bi-oriented Nylon, bi-oriented polypropylene, or metallised bi-oriented polypropylene.
3. A laminate film according to claim 1 or claim 2, wherein said sealing layer is formed of polyethylene having a density of at least 0.926 g/cc, polypropylene, an ethylene-propylene copolymer containing from 3 to 20% of ethylene units, or a mixture of polyethylene with polypropylene in which the proportion of polyethylene is from 3 to 20%.
4. A laminate film according to claim 3, wherein said sealing layer is formed of polyethylene having a density of from 0.926 to 0.935 g/cc.
5. A laminate film according to any one of the preceding claims, wherein said primer layer is of a solvent-based glue.
6. A laminate film according to claim 5 wherein said solvent-based glue is a polyurethane glue.
7. A laminate film according to any one of the preceding claims, wherein said substantially solvent-free adhesive layer is formed of an ionomer comprising units of an ar-mono-olefin, an unsaturated organic acid, and a salt of such unsaturated acid.
8. A laminate film according to claim 7, wherein said ionomer is obtained by partial neutralisation of a bipolymer of the a-mono-olefin and unsaturated organic acid components.
9. A laminate film according to claim 7 or 8, wherein the a-mono-olefin is ethylene, the acid is methacrylic acid or acrylic acid, and the salt is the salt of an alkali metal.
10. A laminate film according to claim 7 or 8 wherein the salt is a salt of sodium or zinc.
10. A laminate film according to claim 9, wherein the alkali metal is sodium or zinc.
11. A laminate film according to any one of claims 7 to 10, wherein said ionomer comprises from 80 to 95% of a-mono-olefin, from 2 to 10% of unsaturated acid, and from 0.5 to 10% of the salt of the unsaturated acid.
12. A laminate film according to claim 11, wherein the proportion of the salt is from 0.5 to 5%.
13. A laminate film according to any one of the preceding claims, wherein said substantially solvent-free adhesive layer has been applied to the substrate layer by melt-extrusion.
1 4. A laminate film according to any one of the preceding claims, wherein the substrate layer has a thickness of from 10 to 30 microns, the bonding layer has a thickness of from 8 to 50 microns, the aluminium foil layer has a thickness of from 8 to 20 microns, the substantially solvent-free adhesive layer has a thickness of from 10 to 50 microns, and the sealing layer has a thickness of from 20 to 100 microns.
1 5. A laminate film according to any one of claims 1 to 14, wherein the substrate layer is of polyester, the bonding layer is of polyethylene having a density in the range from 0.89 to 0.925 g/cc, and the substantially solvent-free adhesive layer is of an ionomer.
1 6. A laminate film according to claim 1 and substantially as hereinbefore described.
17. A bag formed from the laminate film according to any one of the preceding claims, with the sealing layer innermost and sealed to itself during the formation of the bag.
18. A bag according to claim 17, which has been pasteurised by heating at a temperature of from 70 C to 11 50C for a time sufficient to effect pasteurisation.
1 9. A bag according to claim 18, wherein said pasteurising heating has been carried out in a fluid aqueous medium.
20. A bag according to any one of claims 1 7 to 1 9, including pasteurised foodstuffs.
21. A process for making a laminate film, comprising (a) providing a bonding layer of low or medium density polyethylene between a substrate layer and an aluminium foil layer by melt-extruding it to form a first laminate comprising the substrate layer, the bonding layer and the aluminium foil layer; and (b) melt-extruding, between the aluminium foil layer of said first laminate and a sealing layer of an ethylene and/or propylene polymer, a layer of substantially solvent-free adhesive which comprises either an ionomer, or an ethylene-acrylic acid copolymer containing from 2 to 10% of acrylic acid units, or an ethylene-vinyl acetate copolymer containing from 5 to 40% vinyl acetate units.
22. A process according to claim 21, and including the steps of applying a primer to the substrate layer to bond it to the bonding layer.
23. A process according to claim 22, wherein said primer is a polyurethane glue containing ethyl acetate solvent.
24. A process according to claim 23, wherein the substrate layer is of a polyester and is subjected to corona discharge treatment before application of the primer thereto.
25. A process according to claim 24, and including the step of evaporating the solvent of the primer in at least one oven before applying the bonding layer to the substrate.
26. A process for forming a laminate film substantially as hereinbefore described with reference to the example.
27. A process of pasteurising a foodstuff, which comprises placing it in a bag according to claim 17, sealing the bag, and heating the bag and the enclosed foodstuff to a temperature of from 700C to 11 50C and maintaining it at that temperature for a time sufficient to effect pasteurisation of the foodstuff in the bag.
New Claims or Amendments to Claims filed on 30 July 1981.
Superseded Claims 1 0.
New or Amended Claims:
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8020536A GB2078168B (en) | 1980-06-23 | 1980-06-23 | Aluminium-based laminate for packaging of foodstuffs to be pasteurised |
| FR8107921A FR2484913A1 (en) | 1980-06-23 | 1981-04-21 | ALUMINUM-BASED LAMINATED FILM FOR PASTEURIZING FOOD PACKAGING, PROCESS FOR PRODUCING THE SAME, AND PROCESS FOR PASTEURIZING FOOD |
| DE19813115954 DE3115954A1 (en) | 1980-06-23 | 1981-04-22 | MULTILAYER FILM CONTAINING ALUMINUM FILM FOR THE PACKAGING OF FOODSTUFFS TO BE PASTEURIZED |
| SE8102594A SE451311B (en) | 1980-06-23 | 1981-04-23 | PROCEDURE FOR PREPARING AN ALUMINUM-BASED LAMINATE FILM AND PROCEDURE FOR PASTORIZING FOOD IN PAGE PREPARED |
| NL8102058A NL8102058A (en) | 1980-06-23 | 1981-04-27 | ALUMINUM-BASED LAMINATE FOR THE PACKAGING OF FOODSTUFFS TO BE PASTEURIZED. |
| BE0/204691A BE888683A (en) | 1980-06-23 | 1981-05-05 | ALUMINUM-BASED LAMINATE FOR PACKAGING PASTEURIZED FOODS |
| CH2974/81A CH652650A5 (en) | 1980-06-23 | 1981-05-07 | A MULTILAYER FILM CONTAINING ALUMINUM FILM AND THE USE THEREOF FOR PRODUCING BAGS FOR THE PACKAGING OF FOODSTUFFS TO BE PASTEURIZED. |
| DK272981A DK272981A (en) | 1980-06-23 | 1981-06-19 | ALUMINUM-BASED LAMINATE FOR PACKAGING FOODSTUFFS TO BE PASTEURIZED AND PROCEDURE FOR ITS MANUFACTURING |
| IT22468/81A IT1136798B (en) | 1980-06-23 | 1981-06-19 | ALUMINUM-BASED LAMINATE FOR THE PACKAGING OF FOOD PRODUCTS TO BE PASTEURIZED |
| GB08332127A GB2143173B (en) | 1980-06-23 | 1983-12-01 | Aluminium-based laminate and packaging bag for foodstuffs to be pasteurised |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8020536A GB2078168B (en) | 1980-06-23 | 1980-06-23 | Aluminium-based laminate for packaging of foodstuffs to be pasteurised |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2078168A true GB2078168A (en) | 1982-01-06 |
| GB2078168B GB2078168B (en) | 1985-04-03 |
Family
ID=10514257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8020536A Expired GB2078168B (en) | 1980-06-23 | 1980-06-23 | Aluminium-based laminate for packaging of foodstuffs to be pasteurised |
Country Status (9)
| Country | Link |
|---|---|
| BE (1) | BE888683A (en) |
| CH (1) | CH652650A5 (en) |
| DE (1) | DE3115954A1 (en) |
| DK (1) | DK272981A (en) |
| FR (1) | FR2484913A1 (en) |
| GB (1) | GB2078168B (en) |
| IT (1) | IT1136798B (en) |
| NL (1) | NL8102058A (en) |
| SE (1) | SE451311B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998015407A1 (en) * | 1996-10-08 | 1998-04-16 | H.B. Fuller Licensing & Financing, Inc. | Laminating method and hot melt adhesive |
| US7078075B1 (en) | 1995-02-23 | 2006-07-18 | H.B. Fuller Licensing & Financing Inc. | Method for producing a continuous thermoplastic coating and articles constructed therefrom |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3710157A1 (en) * | 1987-03-27 | 1988-10-06 | Schmalbach Lubeca | PACKAGING MATERIAL WITH TEMPERATURE-RESISTANT TAPE, IN PARTICULAR A Tear-off TAP ON A WALL PART OF A CONTAINER, ADHESIVE THEREFOR AND METHOD FOR GLUING THE TAPE |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA988831A (en) * | 1971-10-11 | 1976-05-11 | Kenichi Hattori | Adhesive resins |
| JPS60225B2 (en) * | 1978-03-31 | 1985-01-07 | 東洋インキ製造株式会社 | Method for manufacturing laminate |
-
1980
- 1980-06-23 GB GB8020536A patent/GB2078168B/en not_active Expired
-
1981
- 1981-04-21 FR FR8107921A patent/FR2484913A1/en active Granted
- 1981-04-22 DE DE19813115954 patent/DE3115954A1/en not_active Withdrawn
- 1981-04-23 SE SE8102594A patent/SE451311B/en not_active IP Right Cessation
- 1981-04-27 NL NL8102058A patent/NL8102058A/en not_active Application Discontinuation
- 1981-05-05 BE BE0/204691A patent/BE888683A/en not_active IP Right Cessation
- 1981-05-07 CH CH2974/81A patent/CH652650A5/en not_active IP Right Cessation
- 1981-06-19 DK DK272981A patent/DK272981A/en not_active Application Discontinuation
- 1981-06-19 IT IT22468/81A patent/IT1136798B/en active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7078075B1 (en) | 1995-02-23 | 2006-07-18 | H.B. Fuller Licensing & Financing Inc. | Method for producing a continuous thermoplastic coating and articles constructed therefrom |
| US7699826B2 (en) | 1995-02-23 | 2010-04-20 | H. B. Fuller Company | Article having a continuous thermoplastic coating |
| US7563479B2 (en) | 1996-08-29 | 2009-07-21 | H.B. Fuller Licensing & Financing, Inc | Method for producing a continuous thermoplastic coating and articles constructed therefrom |
| WO1998015407A1 (en) * | 1996-10-08 | 1998-04-16 | H.B. Fuller Licensing & Financing, Inc. | Laminating method and hot melt adhesive |
Also Published As
| Publication number | Publication date |
|---|---|
| CH652650A5 (en) | 1985-11-29 |
| IT1136798B (en) | 1986-09-03 |
| IT8122468A0 (en) | 1981-06-19 |
| BE888683A (en) | 1981-08-28 |
| NL8102058A (en) | 1982-01-18 |
| SE8102594L (en) | 1981-12-24 |
| GB2078168B (en) | 1985-04-03 |
| DK272981A (en) | 1981-12-24 |
| SE451311B (en) | 1987-09-28 |
| FR2484913B1 (en) | 1985-05-24 |
| DE3115954A1 (en) | 1982-01-28 |
| FR2484913A1 (en) | 1981-12-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |