RU2586143C2 - Non-foil packing laminate, method for production thereof and packing container made therefrom - Google Patents

Abstract

FIELD: packaging industry.

SUBSTANCE: invention relates to non-foil packing laminate for packaging liquid food product. Invention also relates to a method of producing a packaging laminate, to a packing container made from packing laminate and method of induction welding packing laminate in packing containers. Laminate comprises a layer of paper or other cellulose-containing material, outermost liquid-impermeable heat-sealed layers of polyolefin-containing polymers and deposited from vapour phase on inner side of layer of paper or other cellulose-containing material, metal coating sensitive to induction heating.

EFFECT: invention provides reduction of costs when producing packaging material.

23 cl, 15 dwg, 1 tbl

Description

FIELD OF THE INVENTION

The present invention relates to a non-doped packaging laminate for induction welding in packaging for a liquid food product or beverage. The invention also relates to a method for manufacturing a packaging laminate and to a packaging container made of a packaging laminate using an induction welding method for a non-foiled packaging laminate.

BACKGROUND OF THE INVENTION

Disposable packaging containers for a liquid food product are often obtained from a packaging laminate based on cardboard or thin cardboard. One such commonly found packaging container is sold under the brand name Tetra Brik Aseptic and is mainly used for sterile packaging of liquid foods such as milk, fruit juices, etc., sold for long-term storage under environmental conditions. The packaging material in said known packaging container is typically a laminate comprising a bulky core layer of paper or cardboard and outer liquid-impermeable layers of thermoplastics. In order to make the packaging container gas-tight, in particular oxygen-gas-tight, for example, for the purpose of sterile packaging and packaging of milk or fruit juice, the laminate in said packaging containers usually contains at least one additional layer, more often than usual, aluminum foil.

On the inside of the laminate, i.e. the side intended to face the fillable liquid food content of the container obtained from the laminate has the innermost layer deposited on aluminum foil, the innermost layer may consist of one or more partial layers containing weldable adhesive polymers and / or polyolefins. Also on the outside of the paper or paperboard is the outermost heat sealable polymer layer.

Aluminum foil, in addition, makes the packaging material heat-sealable by induction heat sealing, which is a fast and efficient welding technology for producing mechanically strong, liquid and gas impermeable welded joints or seams in the process of obtaining containers.

Packaging containers are typically produced using modern high-speed packaging machines of the type that forms, fills and seals packages from web or from preformed blanks of packaging material. Packaging containers can thus be obtained by forming a laminated packaging material into a tube, when both longitudinal edges of the web are joined together by overlapping by welding together the innermost and outermost thermosetting thermoplastic polymer layers. The tube is filled with the intended liquid food product and then divided into separate packages by repeated transverse welds of the tube with a certain interval from each other below the level of contents in the tube. The packages are separated from the tube by cutting along the transverse welds and give the desired geometric configuration, usually parallelepiped, when folded along the fold lines obtained in the packaging material.

The main advantage of the concept of this continuous method of forming a tube, filling and sealing is that the web can be sterilized continuously even before forming the tube, thus providing the possibility of a sterile packaging method, i.e. a method in which the liquid content is filled, as well as in the packaging material, the bacteria content is reduced, and the filled packaging container is obtained in clean conditions, so that the filled packaging can be stored for a long time even at ambient temperature without the risk of microorganisms growing in the filled product. Another important advantage of the Tetra Brik type continuous packaging method is, as stated above, the possibility of continuous high-speed packaging, which has a significant impact on cost-effectiveness.

The layer of aluminum foil in the packaging material provides excellent gas barrier properties compared to most polymer gas barrier materials. The traditional packaging material containing aluminum foil for sterile packaging of a liquid food product is the most cost-effective packaging material with its level of performance available on the market today. In order to compete, any other material must be more cost-effective in terms of starting materials, have comparable food preservation properties, and have a relatively low complexity of converting to the final packaging laminate.

Now there is a growth trend towards the development of such packaging materials that do not have aluminum foil in the laminated structure, towards the search for an improvement in the surrounding profile of the resulting material. In this case, of course, it is desirable to reduce the cost of obtaining packaging material and maintain the necessary properties for sterile long-term storage of packaging containers obtained from the packaging laminate.

At the same time, it would be ideal if the packaging material were directly suitable for use in the already established base of filling and packaging machines currently operating in dairy plants and filling stations around the world. The absence of aluminum foil in the packaging laminate, however, presents a technical problem that can be solved from the point of view of welding the outermost thermoplastic layers, since there is no longer material in the laminate that is susceptible to inducing current from the generation of heat from the magnetic field in the method carried out with aluminum foil. Instead, alternative technologies, such as heat generation using ultrasonic vibration methods or previous traditional convection and hot air welding, were considered and developed. The implementation of such alternative welding technologies leads to the fact that it is necessary to completely rebuild the sealing part of the packaging machines already installed in dairy plants and filling areas.

Obviously, packaging laminates having two or more barrier layers, of which one is a metallized layer, may present possible alternatives to foil-containing laminates, however, with the above complexity, that modern induction welding equipment cannot be used.

However, it has now become clear that contrary to all previous opinions, it is possible to really generate enough heat to melt the adjacent thermoplastic layer using a metallized layer using induction welding technology, provided that some less revolutionary changes will be made on existing machines. The metallized layers, first tested mainly, were deposited on a substrate of oriented PET film.

However, in connection with the continuous work on the modification of induction welding technology for metallized layers, it was noted that different substrates differ in their suitability for metallization and subsequent induction welding. In order to work well, apparently, the metallized layer must have a certain combination of thickness or optical density with the quality of the layer. By quality, it is mainly understood that the layer must be homogeneous and have substantially the same thickness over the entire width and length of the laminated packaging material.

PET film substrates are usually quite expensive to provide a packaging laminate of the type described above. Indeed, the only thing they make a significant contribution to the packaging laminate is that they act as a carrier of the metallized layer. Although it is believed that induction welding technology is likely and possible to apply to other less expensive polymer substrates, it is clear that the welding method probably needs to be calibrated and controlled more in order to work efficiently and reliably. It is also seen that the choice of substrate can affect the quality and durability of the metallized layer during the welding process.

Accordingly, there is still a need for cost-effective and robust, i.e. reliable, even with moderate variations in the conditions of receipt and processing, packaging material that does not contain aluminum foil for sterile packaging of a liquid food product, for example, milk and other drinks, where this material provides sufficient barrier properties in packaging containers for long-term sterile storage in the environment environment, and where this non-foiled packaging material is welded using induction welding on an established base of filling and welding equipment.

SUMMARY OF THE INVENTION

Therefore, the aim of the present invention is to overcome or mitigate the above problems in obtaining non-folded induction-welded paper or paper-cardboard packaging laminate.

Another objective of the present invention is to provide a non-folded paper or paper-cardboard packaging laminate suitable for long-term sterile packaging of a liquid or wet food product that can be welded into packaging containers with good impermeability to liquid and gas by induction welding.

Another objective of the present invention is to provide a cost-effective non-folded paper or paperboard packaging laminate suitable for long-term sterile packaging of a liquid or wet food product, which can be welded into packaging containers with good impermeability to liquid and gas by induction welding, while packaging containers have good barrier properties not only to gas and water vapor, but also to volatile and odorous substances. These objectives are thus achieved in accordance with a non-doped packaging laminate for induction welding into packages for a liquid food product or beverage, the packaging laminate comprising at least one first layer of paper or other cellulosic material, the first paper layer being located on the inside of the packaging laminate and pre-coated to obtain and carry a metal layer deposited from the vapor phase susceptible to induction heating, so that ind heat seal-skilled in the thermoplastic polymer material, wherein the packaging laminate further comprises a vapor deposited metal layer deposited on the inner side of said pre-coated with a first layer of paper or cellulose-containing material, and further comprises an oriented film, laminated with a metal vapor deposited layer; and further comprises a innermost layer of liquid impermeable heat sealable thermoplastic polymeric material deposited on the inside of the oriented film; and / or said oriented film comprises a liquid-tight heat sealable layer representing the innermost layer of the film, where said oriented film is stretched in at least one direction with a stretch ratio of 2 or more and has a core layer of material having a higher melting point than the material the innermost layer (s).

In one aspect, an oriented film is applied to the vapor deposited metal layer by an intermediate bonding layer, and / or said oriented film comprises an adhesive layer on its outer side laminated with a vapor deposited metal layer.

In one aspect of the invention, there is provided a method for producing a non-folded packaging laminate comprising the steps of providing a first layer of paper or other cellulose-containing material, precoating a first layer of paper or other cellulose-containing material to produce and carry an induction heating susceptible vapor deposited coating layer resistant to induction welding on the inside of a layer of paper or other cellulosic material, applying susceptible to and heating the metal layer onto the inner side of the paper layer thus coated, providing an oriented film (20) stretched in at least one direction with a drawing ratio of 2 or more, and providing a core layer of a material having a higher melting point than the material of the innermost a layer of non-foamed packaging laminate, lamination of an oriented film with a metal-coated paper layer, providing one or more layer (s) of liquid-tight thermal a variable thermoplastic polymer material deposited on the inside of the oriented film and / or providing a liquid impermeable heat seal layer as part of an oriented film representing the innermost film layer, where either a liquid impermeable heat seal thermoplastic polymer material or a liquid impermeable heat seal film is the innermost layer of non-foamed packaging laminate.

In one aspect, the objectives of the present invention are realized by a packaging container obtained from the packaging laminate described above.

In one aspect, the objectives of the present invention are realized by a method of welding an unfoldable packaging laminate comprising the steps of providing an unfoldable packaging laminate, as described above, in the form of a continuous web, forming the packaging laminate in the form of a web in a continuous tubular form and applying a longitudinal weld in the longitudinal direction, filling the packaging laminate tube with a liquid food product, forming welding zones using induction heating at certain intervals in the butt echnom direction and cutting the filled tube through the center of each transverse weld zone, to form a resulting separate containers.

Brief Description of the Drawings

In the following, preferred embodiments of the invention will be described with reference to the drawings, in which:

on figa, 1a, 1b, 1b2, 1b3, 1b4, 1c and 1c2 schematically shows a cross section of the first, second, third and fourth variants of the packaging laminate according to the present invention;

figure 2 schematically shows a method of applying from a liquid polymer composition to a layer of paper substrate;

figure 3 shows a diagram of the installation of vapor deposition of the preferred metal layer on the substrate;

on figa and 4b schematically shows an example of a method for producing the packaging laminates shown in figure 1;

5b and 5b show examples of packaging containers obtained from a packaging laminate according to the present invention; and

figure 6 shows the principle of how such packaging containers are obtained from the packaging laminate in a continuous manner, and the method of filling and welding.

DETAILED DESCRIPTION OF THE INVENTION

According to one aspect of the invention, the main objectives are achieved by a non-folded packaging laminate for induction welding into packaging for a liquid food product and a beverage, the packaging laminate comprising at least one first layer of paper or other cellulosic material, the first paper layer being located on the inside of the packaging laminate and previously is coated with the receipt and bearing susceptible to induction heating of the layer deposited from the vapor of the metal, in order to induce l welding in a thermoplastic polymer material, wherein the packaging laminate further comprises such a vapor deposited layer deposited on the inside of said precoated first layer of paper or other cellulose-containing material, and further comprises an oriented film laminated to a vapor deposited layer; and further comprises a innermost layer of liquid impermeable heat sealable thermoplastic polymeric material deposited on the inside of the oriented film; and / or said oriented film comprises a liquid-tight heat sealable layer, which is the innermost layer of the film, where said oriented film is stretched in at least one direction with a drawing ratio of 2 or more and has a core layer of material having a higher melting point than material of the innermost layer (s).

The oriented film is laminated with a vapor-deposited layer by an intermediate bonding layer, and / or said oriented film contains an adhesive polymer layer on its outer side, laminated with a vapor-deposited layer. According to a well-functioning embodiment of the invention, in order to provide a smooth receiving surface for coating by vapor deposition of the metal and to obtain paper for supporting said metal coating in an acceptable manner during the subsequent welding operation, the first layer of paper or other cellulosic material is coated with a resistant to induction welding with a layer having a higher melting point than the innermost layer of heat-sealing material. Then, on the inner side of the coating layer resistant to induction welding, the specified layer of a coating susceptible to induction heating deposited from metal vapor is additionally applied, which is intended to induce welding in an adjacent thermoplastic polymer layer.

The most cost-effective way of providing such a coating on a paper layer in order to prepare it for coating by vapor deposition of a metal is to coat it using a liquid coating method, often also commonly called film coating from a liquid or from a dispersion, of a liquid composition on a paper layer and its subsequent drying, the liquid composition comprising a polymer binder resistant to induction welding, dispersed or dissolved in an aqueous or solvent

According to some well-functioning examples, an induction-welding-resistant coating layer is formed from a composition mainly containing a polymer selected from the group consisting of polyvinyl alcohol (PVOH), water-dispersible ethylene vinyl alcohol (EVOH), copolymer (ethylene vinyl alcohol) vinyl acetate, polyvinylidene chloride ( PVDC), a water-dispersible polyamide (PA), a water-dispersible polyester, a polysaccharide, polysaccharide derivatives, including starch and starch derivatives, and combinations of two or more of them. It is important that the layer thus coated has a higher melting point than the innermost layer of thermoplastic material or a liquid-tight heat-sealable oriented film layer, which is designed for heat welding of a packaging laminate into filled and sealed packages. The weldable, durable coating layer is a thermomechanically stable layer. Preferably, the outermost and innermost thermoplastic heat sealable material as well as the liquid impermeable heat sealable layer are based on polyolefins, more preferably based on polyethylene, and most preferably based on low density polyethylene, such as, for example, LDPE, LLDPE, m-LLDPE and PEONP and mixtures thereof.

When it is desired to use a polymer that has a more cost-effective and positive external profile, the induction weld resistant coating layer is formed from a composition mainly containing PVOH, water-dispersible EVOH or starch. Water-dispersible EVOH has a higher number of vinyl alcohol units than molten EVOH and is more similar in nature to PVOH than to EVOH. Pure PVOH and starch-containing polymers may be more or less biodegradable, therefore such polymers may be more desirable for some packaging applications.

In addition, some polymer binders suitable for application from a liquid also have gas barrier properties, which makes them even more desirable in a packaging laminate. Accordingly, it may be preferable to form an induction welding-resistant coating layer from a composition mainly containing a polymer selected from the group consisting of polyvinyl alcohol (PVOH), water-dispersible ethylene vinyl alcohol (EVOH), a copolymer (ethylene vinyl alcohol) -vinyl acetate, polyvinylidene chloride ( PVDC), water-dispersible polyamide (PA), starch, starch derivatives and combinations of two or more of them.

Compared to aluminum foil, PVOH as a liquid-coating barrier polymer has many desirable properties with the result that it is the most preferred barrier material in many contexts. Among them, good film-forming properties, compatibility with foodstuffs and economic importance together with its high oxygen gas-barrier properties can be indicated. In particular, PVOH provides a packaging laminate with high odor barrier properties, which is especially important for packaging milk.

Like many other such high melting polymers, such as, for example, starch and starch derivatives, polyvinyl alcohol is suitably applied using a liquid coating method, i.e. in the form of an aqueous or solvent-containing dispersion or solution, which, when applied, is sprayed with a thin uniform layer on a substrate and then dried.

Water systems usually have some environmental benefits. Preferably, the liquid gas barrier composition is water-containing, since such a composition usually also has better environmental performance than solvent-containing systems.

In order to improve the barrier properties to water vapor and oxygen of the PVOH coating, a polymer or compound with functional carboxyl groups can be incorporated into the composition. Suitable polymer with functional carboxyl groups is selected from a copolymer of ethylene and acrylic acid ((EAA) (EAA)) and copolymers of ethylene and methacrylic acid ((EMAA) (EMAA)) or mixtures thereof. One known such preferred mixture of the barrier layer consists of PVOH, EAA and an inorganic laminar compound. The EAA copolymer is then introduced into the barrier layer in an amount of about 1-20% of the mass. in relation to the dry weight of the coating.

It is believed that the improved barrier properties to oxygen and water are the result of the esterification reaction between PVOH and EAA at elevated drying temperatures, as a result of which PVOH is crosslinked by hydrophobic EAA polymer chains, which are therefore integrated into the PVOH structure. Such a mixture, however, is more expensive due to the cost of the additives. In addition, the compositions can be made more durable by drying and curing at elevated temperatures. Crosslinking can also be introduced in the presence of multivalent compounds, for example, metal compounds, such as metal oxides, although such compounds are less preferred in coating compositions for this purpose.

Recently, special types of water-dispersible ethylene vinyl alcohol (EVOH) polymer have been developed that may be possible for an oxygen-barrier liquid coating. Conventional EVOH polymers, however, are typically designed for extrusion and cannot be dispersed / dissolved in an aqueous medium in order to obtain a thin barrier film deposited from a liquid of 5 g / m ² or lower, preferably 3.5 g / m ² or lower. It is believed that EVOH must contain a fairly high amount of vinyl alcohol monomer units in order to be water dispersible or water soluble, and that the properties should be as close as possible to the properties of the PVOH varieties applied from the liquid. The extruded EVOH layer is not an alternative to EVOH applied from a liquid, because by its nature it has properties that are less similar to PVOH than EVOH grades for extrusion application, and because it cannot be applied in a cost-effective amount below 5 g / m ² as a single layer during extrusion application or extrusion lamination, i.e. this requires coextruded adhesive polymer layers, which are usually very expensive polymers. In addition, very thin extruded layers cool too quickly and do not contain sufficient thermal energy to maintain sufficient bonding between the lamination and adjacent layers.

Other examples of polymer binders suitable for application from a liquid are polysaccharides, in particular starch or derivatives of starch, such as, preferably, oxidized starch, cationic starch and hydroxypropyl starch. Examples of such modified starches are hypochlorite, oxidized potato starch (Raisamyl 306 from Raisio), and hydroxypropylated corn starch (Cerestar). However, other forms and derivatives of starch may also be possible liquid coating binders.

Other examples of polymeric binders are coatings containing mixtures of polymers containing carboxylic acid, such as polymers of acrylic acid or methacrylic acid, and polyalcohol polymers, such as PVOH and starch. The crosslinking reaction of these polymer binders is preferred, as described above, for resistance to high humidity.

However, most preferably, the binder polymer is PVOH, since it has all the good properties mentioned above, i.e. in addition to good resistance to induction welding, there are also good film-forming properties, gas-barrier properties, economic efficiency, compatibility with food and barrier properties to smell.

A PVOH-containing gas barrier composition works best when PVOH has a saponification degree of at least 98%, preferably at least 99%, although PVOH with lower saponification degrees also provides good properties.

According to one embodiment, the liquid composition further comprises inorganic particles in order to further improve oxygen gas barrier properties.

The polymer binder material may, for example, be mixed with an inorganic compound that is laminar in shape or flaky. When layered flake-like inorganic particles are placed, the oxygen gas molecule migrates along a longer path along the winding path through the oxygen barrier layer than the usual direct path through the barrier layer.

According to one embodiment, the inorganic laminar compound is the so-called compound of nanoparticles dispersed in a layered state, i.e. lamellae of a layered inorganic compound are separated from each other by a liquid medium. Thus, the layered compound can preferably swell or be split by a polymer dispersion or solution, which in dispersion penetrates the layered structure of the inorganic material. It can also swell in a solvent before being introduced into the polymer solution or polymer dispersion. Thus, the inorganic laminar compound is dispersed in a delaminated state in the liquid gas barrier composition and in the dried barrier layer. The term “clay minerals or clays” includes minerals of the following types: kaolinite, antigorite, smectite, vermiculite, bentonite or mica. In particular, laponite, kaolinite, dicit, nakrit, galloisite, antigorite, chrysolite, pyrophyllite, montmorillonite, hectorite, saponite, saukonite, sodium tetra-silicon mica, sodium thieniolite, ordinary mica, margaritol, vermite, can be mentioned as suitable clay minerals. etc. Preferred nanoparticles are nanoparticles of montmorillonite, most preferably purified montmorillonite or sodium exchange montmorillonite (Na-MMT). The nanoscale inorganic laminar compound or clay mineral preferably has a dimensional ratio of 50-5000 and a particle size of up to about 5 microns in a layered state.

Preferably, the inorganic particles mainly consist of such laminar bentonite particles having an aspect ratio of 50 to 5000.

Suitable barrier layer contains from about 1 to about 40 wt. -%, more preferably, from about 1 to about 30% of the mass. and, most preferably, from about 5 to about 20% of the mass. inorganic laminar compounds in relation to the dry weight of the coating. If the amount is too low, the gas-barrier properties of the deposited and dried barrier layer will not be significantly improved compared to when an inorganic laminar compound is not used. If the amount is too high, the liquid composition becomes more difficult to apply as a coating and more difficult to process in storage containers and channels of the applicator system. Preferably, the barrier layer contains from about 99 to about 60% by weight, more preferably from about 99 to about 70% by weight, and most preferably from about 95 to about 80% by weight. polymer with respect to the dry weight of the coating. An additive, such as a dispersion stabilizer or the like, may be incorporated into the gas barrier composition, preferably in an amount of not more than about 1% by weight. in relation to the dry weight of the coating.

According to another embodiment, the inorganic particles mainly consist of laminar talc particles having a dimensional aspect ratio of 10 to 500. The composition typically contains an amount of 10 to 50% by weight, more preferably 20 to 40% by weight, of talc particles relative to dry weight. Below 20% of the mass. there is no significant increase in gas barrier properties, whereas above 50% of the mass. the applied layer may be more brittle and destructible, since there is less internal cohesion between the particles in the layer. Above 50% of the mass. the polymer binder is too small to surround and disperse the particles and laminate them to each other in the layer.

Alternatively, good oxygen gas barrier properties can be achieved when using colloidal silicon dioxide particles having a particle size of 3-150 nm, preferably 4-100 nm, and even more preferably 5-70 nm, the particles being preferably amorphous and spherical. The use of colloidal silica particles further has the advantage that the liquid barrier composition can be applied at a dry content of 15-40% by weight, preferably 20-35% by weight, and even more preferably 24- 31% of the mass., Therefore, the need for forced drying is reduced.

Other alternative inorganic particles that may be used are particles of kaolin, mica, calcium carbonate, etc.

A preferred polymer binder, also when using inorganic particles to provide oxygen gas barrier properties, is, for example, again PVOH to some extent due to its useful properties mentioned above. In addition, PVOH is preferred in terms of mixing, i.e. it usually readily disperses or delaminates inorganic particles in an aqueous solution of PVOH to form a stable mixture of PVOH and particles, thus providing a good applied film with a homogeneous composition and morphology.

Preferably, according to the present invention, said induction welding resistant layer is applied in a total amount of from 0.5 to 7 g / m ² , preferably from 0.5 to 5 g / m ² , more preferably from 0.5 to 3 g / m ² dry weight. Below 0.5 g / m ² there is too little resistance to induction welding and there is a risk of pinholes depending on the characteristics of the paper or substrate due to the removal of water or solvent to dry the applied barrier layer if the applied layer is too thin. On the other hand, when the amount is above 7 g / m ^{2, the} applied layer does not introduce cost-effectiveness into the packaging laminate due to the high cost of polymers in general and due to the high cost of energy for evaporating the dispersion liquid.

In addition, a recognized level of the oxygen barrier is achieved with a PVOH content of 0.5 g / m ² or higher, and a good balance between barrier properties and cost is achieved in the range of 0.5 to 3.5 g / m ² .

According to one embodiment of the invention, the oxygen gas barrier layer is applied in two successive stages with intermediate drying as two-part layers. When applied in such a way as two-part layers, each layer is suitably applied in amounts of from 0.3 to 3.5 g / m ² , preferably from 0.5 to 2.5 g / m ^2, and ensures a high quality overall layer of less the amount of liquid gas barrier composition. More preferably, two-part layers are applied in an amount of from 0.5 to 2 g / m ² each, preferably from 0.5 to 1.5 g / m ² each.

The vapor deposited metal layer is applied by vapor condensation ((KPF) (PVD)) onto a thin coated paper substrate. The thin metal vapor-deposited coatings of the present invention have a nanometric thickness, i.e. have a thickness that is most suitably calculated in nanometers, for example, from 5 to 500 nm (50-5000 Å), preferably from 5 to 200 nm, more preferably from 5 to 100 nm and, most preferably, from 5 to 50 nm .

Typically, below 5 nm, the resistance properties to induction welding may be too weak to use, and above 200 nm the coating may be less flexible and thus more prone to cracking when applied to an elastic substrate.

Typically, such a vapor deposited coating having resistance to induction welding is made of a metal compound and, preferably, the induction-welded layer of the vapor deposited metal coating is a layer essentially consisting of aluminum. Typically, an aluminum metallized layer essentially has a thin surface portion consisting of aluminum oxide due to the nature of the metallization method used.

A suitable vapor-deposited coating metal layer has an optical density ((OD) (OD)) of from 1 to 5, preferably from 1.5 to 3.5, more preferably from 2 to 3.

The aluminum-containing thin vapor-deposited layer preferably has a thickness of 5 to 100 nm, more preferably 5-50 nm, which corresponds to less than 1% of the metal aluminum material present in the aluminum foil of a conventional thickness, i.e. 6.3 microns.

In order to improve the adhesion of the coating to the substrate, before the coating of vapors, in particular, metallization of the substrate, a surface treatment step for the film substrate can be carried out.

A preferred metal according to the present invention is aluminum, although any other metal capable of being applied in a vacuum as a homogeneous coating can be used according to the present invention. Thus, less preferred and less common metals such as Au, Ag, Cr, Zn, Ti or Cu are also possible. Typically, thin coatings of a metal or a mixture of a metal and a metal oxide provide barrier properties against water vapor and are also used when the desired function is to prevent the migration of water vapor into and through the multilayer film or packaging laminate. Most commonly, however, the metal in the metallized coating is aluminum (Al).

In order to make the vapor deposition method of a metal vapor coating cost-effective, a substrate, i.e. the first innermost layer (11) of paper or other cellulosic material should be as thin as possible so that as many meters as possible can be wound into a roll of coated paper. Preferably, the first paper layer has a surface weight of 20 to 100 g / m ² , preferably 20 to 70 g / m ² , more preferably 30 to 60 g / m ² . When the paper is too thin, it will naturally be more difficult to handle it in subsequent coating and laminating processes. On the other hand, the thinner the paper can be, the more cost effective it can be in a vapor deposition coating method. From the point of view of stiffness, it is obvious that the thicker first paper layer also contributes to higher stiffness and fastening ability of the overall structure of the packaging laminate.

A second layer of paper or paper board for use as a stabilizing layer in a conventional liquid packaging carton typically has a thickness of from about 100 μm to about 600 μm and a surface weight of about 100-500 g / m ² , preferably about 200-400 g / m ² , more preferably 200 to 300 g / m ^2, and may be conventional paper or paperboard of suitable packaging quality.

On the other hand, a thinner packaging laminate having a thinner paper layer can be used for low cost sterile long-term packaging of a liquid food product. Packaging containers made of such packaging laminates are not molded, but more like pillow-shaped elastic bags. A suitable unitary paper layer for such packet packages then typically has a surface weight of from about 30 to about 140 g / m ² , preferably from about 50 to about 120 g / m ² , more preferably from 50 to about 110 g / m ² , most preferably 50 to 70 g / m ² .

In one embodiment, such a low cost packaging laminate may alternatively comprise two or more thin layers of paper, of which the first inner paper layer is coated with vapor deposition of an induction-sensitive material according to the present invention. When there are two paper layers in the structure of the packaging laminate, the second outer paper layer suitably has a surface weight of 20 to 100 g / m ² , preferably 20 to 70 g / m ² , more preferably 20 to 50 g / m ² .

In order to further improve the properties of the non-folded packaging laminate on the metallized layer (a layer deposited from metal vapor), an oriented film is applied. The use of oriented film provides favorable barrier properties. The use of film can reduce the cost of the final packaging and improve or change its properties. The film also acts as a protective layer for the metallized layer during the lamination process, thereby reducing the risk of cracking or pinholes. Suitable films are oriented films elongated in at least one direction with a drawing ratio of 2 or more and having a core layer of a material having a higher melting point than the heat-sealing material of the inner layer of the packaging laminate. Typically, the melting temperature of the core layer is above 130 ° C. The degree of drawing depends on the material used in the film, but the degree of drawing can be up to about 10. In some aspects of the invention, it is preferable to have a drawing degree of 3 or more. Examples of suitable films are uniaxially oriented films having at least a core layer of a polymeric material selected from polypropylene ((OPP) (OPP)), polyethylene terephthalate ((OPETP) (OPET)), polyamide ((OPA) (OPA)), polyethylene naphthalate ((OPEN) (OPEN)), polybutylene terephthalate ((OPBTF) (ORVT)), polytrimethylene terephthalate ((OPTT) (OPTT)); biaxially oriented films, such as biaxially oriented polypropylene ((DOPP) (BOPP)), polyethylene terephthalate ((DOPETF) (BOPET)), polyamide ((DOPA) (BOPA)), polyethylene naphthalate ((DOPEN) (BOPEN)), polybutylene terephthalate ( (DOPBTF) (BOPTT)), polytrimethylene terephthalate ((DOPTT) (BOPTT), or oriented films of two or more of these polymers, i.e. polypropylene, polyethylene terephthalate, polyamide, polyethylene naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, mixed and then used uniaxial molding or biaxially oriented films. Some of the advantageous properties of these films are high tensile strength, which facilitates high-speed processing, good puncturing and cracking during bending over a wide temperature range, potentially good water vapor barrier properties, resistance to oils and fats and moisture resistance, as well as resistance to wrinkling or shrinkage due to changes in environmental conditions.

The oriented film may be a film that contains additional layers when the core layer of the film is represented by the films mentioned above as examples. In some aspects of the invention, the core layer of the film is a polymer selected from uniaxially oriented polypropylene ((OPP) (OPP)), polyethylene terephthalate ((OPETP) (OPET)), polyamide ((OPA) (OPA)), polyethylene naphthalate ((OPEN) ( OPEN)), polybutylene terephthalate ((OPBTF) (ORVT)), polytrimethylene terephthalate ((OPTTF) (OPTT)); biaxially oriented polypropylene ((DOPP) (BOPP)), polyethylene terephthalate ((DOPETF) (BOPET)), polyamide ((DOPA) (BOPA)), polyethylene naphthalate ((DOPEN) (BOPEN)), polybutylene terephthalate ((DOPBTF) (BOPWT) ), polytrimethylene terephthalate ((DOPTTF) (BOPTT).

The film may further comprise one or more of the following: a bonding layer, an adhesive layer and a liquid impermeable heat seal layer. A bonding layer is used to facilitate bonding between preformed webs or films, and typically consists of a thermoplastic polymer. The adhesive layer is used to improve adhesion between the film and other layers and usually consists of an adhesive polymer containing functional groups that promote adhesion. According to the present invention, the adhesive layer is an oriented film layer. The adhesive layer can be applied before drawing, for example, by coextrusion with the core layer, or after drawing, for example, when applying the dispersion. Such an adhesive polymer layer on the outer side of the oriented film provides lamination by applying heat and pressure when connecting the oriented film and the coated paper web in the gap between the rolls of the laminating device without extruding an additional intermediate connecting layer between the two preformed webs.

Typically, the thickness of the oriented film is from 4 to 25 microns. This is usually applicable when the film does not contain a liquid-tight, heat-sealable inner layer, since then the film may be thicker.

In some embodiments of the present invention, an adhesive layer is absent in the film itself, but the film is connected to the metallized layer by a separate connecting layer, which is usually applied by extrusion lamination with an intermediate melt extrusion layer when laminating a preformed film with a pre-coated metallized paper layer.

In some embodiments of the present invention, both the adhesive layer as part of the oriented film and the intermediate bonding layer are present and used to laminate the oriented film with metallized paper.

Alternative examples of material suitable as bonding layers for extrusion lamination of the layers are polymers based on low density polyethylene polymers selected from modified and unmodified LDPE and LLDPE polymers, copolymers or grafted copolymers of ethylene polymers with functional groups containing monomer units such as carboxyl or glycidyl functional groups, for example, monomers of (meth) acrylic acid or monomers of maleic anhydride (MAG), (i.e. the ethylene- (acrylic acid) copolymer (EAC) or the ethylene- (methacrylic acid) copolymer (EMAK), the ethylene- (glycidyl (meth) acrylate (EG (M) A) copolymer) or the grafted copolymer (maleic anhydride) -polyethylene can be used (MAG-p-PE). Another example of such modified polymers or adhesive polymers is the so-called low density polyethylene ionomers. In one embodiment, the modified polyethylene is an ethylene- (acrylic acid) copolymer (EAA) or an ethylene- (methacrylic acid copolymer ) (EMAC).

In some aspects, it may be advantageous to use LDPE and LLDPE as the bonding layer.

Examples of adhesive layers are polyethylene functionalized with carboxyl groups based on LDPE and LLDPE, including copolymers or grafted copolymers with a functional group containing monomer units, such as monomer units, such as carboxyl or glycidyl functional groups, for example, (meth) acrylic acid monomers or maleic anhydride monomers (MAG), (i.e., ethylene- (acrylic acid) copolymer (EAA) or ethylene- (methacrylic acid) copolymer (EMAK), ethylene- (glycidyl (meth) acrylate (EG (M) A) copolymer and and grafted copolymer (maleic anhydride) polyethylene (MAG-p-PE). Another example of such modified polymers or adhesive polymers are so-called ionomers or ionomer polymers. Preferably, the adhesive layer is selected from ethylene- (acrylic acid) (EAA) copolymer copolymer of ethylene- (methacrylic acid) (EMAK), copolymer of ethylene- (glycidyl (meth) acrylate (EG (M) A) and grafted copolymer (maleic anhydride) -polyethylene (MAG-p-PE)), preferably ethylene copolymer - (acrylic acid) (EAA) or ethylene- (metacr) copolymer lovaya acid) (EMAA). The adhesive layer can be introduced into the film by any conventional technology, such as applying a dispersion and then drying it onto the core layer of the film substrate or applying coextrusion of the adhesive layer to the core layer.

One or more liquid impermeable heat seal layers are required as the innermost part of the packaging material for direct contact with the product filling the packaging container obtained from the packaging material. The liquid impermeable heat seal layer contained in the oriented film may be an alternating or complementary layer to provide a separate, innermost liquid impermeable heat seal layer. The term "liquid impermeable heat sealable layer" generally refers to an oriented film layer. The liquid impermeable heat seal layer is selected from the same type of polyolefins as the outermost and most internal liquid impermeable heat seal layers. Suitable thermoplastics for the liquid impermeable heat sealable layer and for the outermost and inner most liquid impermeable heat sealable layers are thermoplastics based on polyolefins, such as, for example, polyethylene and polypropylene, preferably polyethylene, and, more preferably, low density polyethylene, such as for example, LDPE, linear LDPE (LLDPE) or polyethylenes (m-LLDPE) obtained using single-center metallocene catalysts, linear low-density polyethylene density (ULDPE), or mixtures of two or more thereof. Such liquid-impermeable heat sealable layers are conventionally used and may include an adhesive layer to provide improved adhesion to the core layer of the oriented film. The adhesive layer can thus be applied as a coextruded portion of the innermost layer of a liquid impermeable heat sealable thermoplastic polymer material onto the inner side of the oriented film. The innermost layer of liquid impermeable heat sealable thermoplastic material is often also sterile impermeable.

The first paper layer coated with a vapor-deposited metal may be connected to the second paper or paperboard layer by one or more intermediate polymer layer (s), for example, a thermoplastic polymer layer and, more preferably, a polymer layer selected from polyolefins and polyolefin-containing copolymers, often known as modified or adhesive polymers, especially LDPE or polyethylene-containing polymers or copolymers, or adhesive polymers, as described in the above paragraph.

In order to improve the light barrier of the packaging laminate according to the present invention, if necessary, particles or pigments providing light barrier properties can be mixed into one or more layers of the laminate. One example is light-absorbing particles, such as carbon black. The black color of the intermediate layer is then predominantly hidden to the outside by a paper or paperboard layer, and to the inside of the laminate by a metallized, for example, aluminum, layer. Another example is reflective particles such as titanium dioxide. Such particles, in addition, can be introduced for a whiter appearance of the packaging laminate.

For thinner segmented packaging laminates that have a thinner core paper layer, such reflective inorganic white pigments can improve the light barrier properties of the packaging laminate as well as improve the appearance of the packaging material from the outside.

For packaging laminates with higher characteristics, for example, for which long-term sterile storage is required, it is, of course, possible to introduce additional barrier layers. One simple way, for example, to further increase the oxygen barrier properties of the packaging laminate, is to use a thermoplastic bonding layer containing a melt-extruded layer to connect the vapor-deposited coating metal on the inside of the first paper layer with another second layer of paper or paperboard. According to this embodiment, the only thing to change in order to obtain packaging laminates with higher characteristics should include the introduction of additional melt-extruded polymer layer (s) in the processing method at the lamination stage (for example, an additional barrier layer and, possibly, one or two extrudable melt bonding layer). According to another, more preferred embodiment, a thin layer of the polymer barrier layer can be applied by coextrusion together with optional bonding layer (s) and the innermost heat seal layer (s) on the metallized inner side of the first paper layer. Such a coextruded inner barrier layer must be kept thin in order to easily transfer the induced heat from the coating deposited from the metal vapor to the heat-sealing layer.

Alternatively, a layer of liquid film oxygen barrier coating may be applied to the other outer side of the first innermost paper layer. Alternatively or additionally, a liquid film oxygen barrier coating layer may be applied to the inside of any other paper layer in the structure of the packaging laminate.

According to another aspect of the invention, there is provided a packaging container obtained from an unfolded packaging laminate of the invention. The packaging container is suitable for long-term sterile packaging of a liquid or wet food product and has good packaging integrity with durable, reliable welds from induction welding.

According to yet another aspect of the invention, there is provided a method for producing a packaging laminate as defined in an independent claim.

Thus, the method comprises the steps of providing at least a first layer of paper or other cellulose-containing material, pre-coating a layer of paper or other cellulose-containing material to produce and carry a vapor deposited metal susceptible to induction heating resistant to induction welding on the inside a layer of paper or cellulose-containing material, applying said metal layer susceptible to induction heating on the inside of the coated same way paper layer provide an oriented film and oriented film lamination with the metallized paper layer. As described above, the film itself may contain a liquid-impermeable heat sealable layer, which is the innermost layer of the film, and, optionally, an adhesive layer representing the side of the film deposited on a metal layer susceptible to induction heating.

In one embodiment, the method comprises using an intermediate bonding layer between the metal layer susceptible to induction heating and the oriented film.

At any stage of the process, the outermost layer of heat sealable thermoplastic polymer material can be provided and laminated to the outermost opposite side of the packaging laminate. In cases where the structure of the packaging laminate comprises a second paper layer located on the outside of the packaging laminate, the outermost heat sealable polymer layer is then laminated on the outside of the second paper layer.

The metal layer susceptible to induction heating is sufficiently homogeneous and continuous in nature, capable of conducting an electric current as a result of the induced magnetic field and becoming heated, so that the thermoplastic polymer layer is heated and melted to allow heat sealing of the polymer. If the metal layer is not continuous due to uneven application or due to cracks, there is no heating provided in the weld zone.

In the preliminary deposition of the metal-receiving layer, the method further comprises the steps of providing a liquid composition containing a polymer binder dispersed or dissolved in an aqueous or solvent-containing liquid medium and forming a thin, induction-welding-resistant layer containing said polymer binder adjacent to the inside of the first paper layer by applying a liquid composition to the inner side of the specified layer of paper or other cellulosic material further drying with evaporation of the liquid, wherein said polymer binder has a melting point higher than that of the thermoplastic polymer material of the innermost heat-sealing layer.

Preferably, the induction welding resistant polymer contained in the liquid composition is selected from the group consisting of polyvinyl alcohol (PVOH), water dispersible ethylene vinyl alcohol (EVOH), copolymer (ethylene vinyl alcohol) vinyl acetate, polyvinylidene chloride (PVDC), water dispersible (polyamide) starch, starch derivatives and combinations of two or more of them.

According to an embodiment, the induction welding resistant layer (12) is applied in a total amount of from 0.5 to 7 g / m ² , preferably from 0.5 to 5 g / m ² , more preferably 0.5 to 3 g / m ² dry mass.

When applied as two-part layers, each layer can be suitably applied in amounts of from 0.3 to 3.5 g / m ² , preferably from 0.5 to 2.5 g / m ² , which provides a high-quality common layer from a smaller the amount of liquid polymer composition. More preferably, two-part layers may be applied in an amount of from 0.5 to 2 g / m ² each, preferably from 0.5 to 1.5 g / m ² each.

In order to reduce the amount of moisture released from the paper layer in the vacuum chamber during the metallization process, the paper layer coated with vapor deposition of the metal can also be coated on the other side with a liquid polymer composition in an aqueous or solvent-containing dispersion or solution before the metallization step way. It is desirable to avoid moisture in the vacuum metallization chamber, because it can reduce the speed at which the metallization method can be performed.

In addition, the reverse transfer of paper dust can be prevented during subsequent processing of the coated paper webs on the drums with this application to the back side.

For food products requiring better barrier properties against gaseous oxygen, a gas barrier coating layer may be applied to the outside of the first paper layer.

In cases where the structure of the packaging laminate comprises a second paper layer located on the outside of the packaging laminate, a gas barrier coating layer may also be applied to the inside of said second paper layer.

In the case where the packaging laminate structure comprises a second paper layer located on the outside of the packaging laminate, the method of the invention further comprises the step of extruding the vapor deposited thin paper substrate with the inside of the second paper layer by means of an intermediate polymer bonding layer, preferably a thermoplastic polymer connecting layer.

Another aspect of the invention is a method for heat welding an unfoldable packaging laminate, comprising the steps of providing an unfoldable packaging laminate, as previously defined, in the form of a continuous web, forming the packaging laminate in the form of a web in a continuous tubular shape and applying a longitudinal seam in the longitudinal direction, filling the packaging laminate tube with liquid food product, forming heat-welding zones using induction heating at certain intervals in the transverse direction Aviation of the filled tube and cutting through the center of each zone of transverse welding with the formation of individual containers as a result.

For a further description of the invention, it will be considered in view of the drawings.

FIG. 1 a shows in cross section a first embodiment of a packaging laminate 10 a for sterile packaging and long-term storage under ambient conditions obtained according to the present invention. The laminate has a first paper layer 11 having a surface weight of 50 g / m ² .

The paper is obtained with a coating 12 deposited from metal vapor, which can act as a material susceptible to induction heating and transfer heat for efficient heat welding in the innermost oriented film 20.

Thin paper sequentially coated with vapor deposition can be obtained by coating or by impregnation of the paper layer, or by mixing chemicals in a paper pulp at the stage of obtaining a paper web, or any combination of these tools or other means to obtain .

The resulting thin paper web is then metallized by vapor deposition to an optical density (OD) of about 3.

The outer liquid permeable and heat sealable polyolefin layer 15 is applied to the outer side of the core layer 11, where the indicated side is directed to the outer side of the packaging container obtained from the packaging laminate. The polyolefin of the outer layer 15 may be a conventional low density polyethylene (LDPE) of heat seal quality. Oriented film 20 is laminated to the inner side of the vapor-deposited layer 12, which is directed inside the packaging container obtained from the packaging laminate, and the oriented film 20 will be in contact with the packaged product. The core layer of the oriented film is preferably selected from uniaxially oriented films such as polypropylene (OPP), polyethylene terephthalate (OPETF), polyamide (OPA), polyethylene naphthalate (OPENF), polybutylene terephthalate (OPBTF), polythenylene terephthalate (OPTTF); biaxially oriented films, such as biaxially oriented polypropylene (DOPP), polyethylene terephthalate (DOPETF), polyamide (DOPE), polyethylene naphthalate (DOPENF), polybutylene terephthalate (DOPBTF), polythenylene terephthalate (DOPTF), or more than one of the specified polymers from these two films. e. polypropylene, polyethylene terephthalate, polyamide, polyethylene naphthalate, polybutylene terephthalate, polytriethylene terephthalate, polymers mixed or copolymerized and then used to form a uniaxially oriented or biaxially oriented film.

In some embodiments, such as the options shown in figa, fig.1b and figs, oriented film contains one (or more) liquid impermeable heat sealable layer (s), which represents the innermost side of the oriented film and is subsequently located in contact with the packaged product. A liquid impermeable heat seal layer representing the innermost part of the film is a liquid impermeable heat seal thermoplastic polymer material, such as a polymer based on low density polyethylene, such as LDPE and / or LLDPE. In one embodiment, low density polyethylene includes LLDPE obtained by polymerizing an ethylene monomer with C4-C8, more preferably C6-C8, an alpha-olefin alkylene monomer in the presence of a metallocene catalyst, i.e. the so-called metallocene LLDPE (m-LLDPE). Oriented film 20 may further comprise an adhesive layer on an outer side laminated with a layer 12 deposited from metal vapor.

In one embodiment, similar to that described in FIG. 1a and shown in cross section in FIG. 1a2, an oriented film is laminated to the inside of the vapor-deposited layer 12, which is directed toward the inside of the packaging container obtained from the packaging laminate. The innermost liquid impermeable heat sealable thermoplastic polymer material 14, such as low density polyethylene, such as LDPE and / or LLDPE, is placed on the inside of the oriented film 20. In one embodiment, low density polyethylene includes LLDPE obtained by polymerization of an ethylene monomer with C4 -C8, more preferably C6-C8, alpha-olefin alkylene monomer in the presence of a metallocene catalyst, i.e. the so-called metallocene LLDPE (m-LLDPE). The innermost heat-sealing layer 14 may consist of two or more layers-parts of the same or different types of polymers. In one embodiment, shown in FIG. 1a2, the oriented film (20) may or may not contain a liquid impermeable heat seal layer representing a film layer directed toward the inner side on the opposite side of the film as a vapor deposited layer 12. Often preferably have only one liquid impermeable heat sealable layer, in particular for cost reasons. However, there are applications where there are two heat sealable layers, one as a liquid impermeable heat sealable oriented film layer and the other as a liquid impermeable heat sealable thermoplastic polymer material 14.

Throughout the description, it is applicable that when the innermost liquid impermeable heat seal layer 14 is present, a liquid impermeable heat seal layer of the film may or may not be present.

In some embodiments of the invention, for example, shown in the figures, the oriented film 20 is connected to the layer deposited from the vapor of the metal, using an adhesive layer, such as a copolymer of ethylene- (acrylic acid). The adhesive layer is a layer of oriented film. Alternatively or complementaryly, the bonding layer 19 may be applied as an intermediate layer between the oriented film and the metallized paper layer. Suitable connecting layers are based on low density polyethylene polymers and are selected from modified or unmodified LDPE or LLDPE polymers, copolymers and grafted copolymers with monomer units containing a functional group such as carboxyl or glycidyl functional groups, for example, (meth) acrylic monomers can be used acids or monomers of maleic anhydride (MAG) (i.e., ethylene- (acrylic acid) copolymer (EAA) or ethylene- (methacrylic acid) copolymer (EMMAK), ethylene copolymer n- (glycidyl (meth) acrylate (EG (M) A) or maleic anhydride grafted polyethylene (MAG-p-PE). Another example of such modified polymers or adhesive polymers are so-called low density polyethylene ionomers. In one embodiment the modified polyethylene is a copolymer of ethylene (acrylic acid) (EAA) or a copolymer of ethylene (methacrylic acid) (EMAK). The described modified polymers may also be suitable in the optional adhesive layer contained in the film.

In some cases, when a thicker heat-sealing layer is required, it is possible, although not preferable from a cost point of view, to apply an additional liquid-impermeable heat-sealing layer of polyethylene on the inner side of the innermost layer 14.

Fig. 1b shows in cross section a second embodiment of a packaging laminate 10b for sterile packaging and long-term storage under environmental conditions, obtained according to the present invention. The laminate contains a first paper layer 11 having a surface weight of 50 g / m ² , and a thin, resistant to induction welding layer 13 is formed by applying a liquid polymer composition from a liquid and then drying it onto a first paper layer 11. The composition contains an aqueous solution of PVOH, and after drying the applied layer thus contains PVOH. Preferably, the PVOH has a saponification degree of at least 99%.

The deposited thin paper web is then metallized by vapor deposition on its coated side to an optical density (OD) of about 3. The resulting packaging laminate thus contains a thin paper substrate 11 first coated with PVOH and then a thin layer 12 deposited from the vapor phase , aluminum metal with a thickness of about 50 nm. The innermost oriented film 20 is connected to the vapor-deposited layer by means of an adhesive layer and / or a bonding layer (as shown in FIG. 1b3) on the inside of the vapor-deposited layer 12, which should be directed inside the packaging container obtained from packaging laminate, and oriented film 20 will be in contact with the packaged product. The core layer of the oriented film is preferably selected from biaxially oriented polymer layers.

In one embodiment, similar to the embodiment discussed in FIG. 1b, and as shown in cross section in FIGS. 1b2 and 1b4, an oriented film is bonded to the inner side of the vapor deposited layer 12 by an adhesive layer contained in film (fig.1b2), or a connecting layer (fig.1b4). The innermost, liquid-impermeable heat sealable thermoplastic polymer material 14 of low density polyethylene, such as, for example, LDPE and / or LLDPE, is placed on the inside of the oriented film (which may or may not contain a liquid impermeable heat seal). In one embodiment, the low density polyethylene contains LLDPE obtained by polymerizing an ethylene monomer with C4-C8, more preferably C6-C8, an alpha-olefin alkylene monomer in the presence of a metallocene catalyst, i.e. the so-called metallocene LLDPE (m-LLDPE). The innermost heat-sealing layer 14 may consist of two or more parts-layers of the same or different types of polymers. In one embodiment, the innermost liquid impermeable heat seal layer 14 further comprises an adhesive layer in order to improve the bonding between the liquid impermeable heat seal layer 14 and the oriented film 20. In another similar embodiment, the oriented film contains an adhesive layer on its inner side, when to be laminated or extruded onto a liquid tight heat sealable layer 14.

In some cases, when a thicker heat-sealing layer is required, it is of course possible, although not preferable from a cost point of view, to apply an additional liquid-impermeable heat-sealing layer of polyethylene on the inner side of the innermost layer 14.

An outer, liquid tight and heat sealable polyolefin layer 15 is applied to the outside of the core layer, where this side should be directed to the outside of the packaging container obtained from the packaging laminate. The polyolefin of the outer layer 15 may be a conventional low density polyethylene such as LDPE and / or LLDPE of suitable heat seal quality.

Fig. 1c shows in cross section an embodiment of a packaging laminate 10c for sterile packaging and long-term storage under environmental conditions obtained according to the present invention. The laminate contains a first paper layer 11 having a surface weight of 50 g / m ² and a thin, resistant to induction welding layer 13 formed by applying a liquid polymer composition from a liquid and then drying it onto a first paper layer 11. The composition contains an aqueous solution of PVOH and 30% mass particles of bentonite, and after drying, the deposited layer thus contains PVOH and, optionally, layered bentonite particles homogeneously distributed in a laminar manner in the PVOH layer. Preferably, the PVOH has a saponification degree of at least 99%.

The resulting thin paper web is then metallized by vapor deposition to an optical density (OD) of about 3.

The packaging laminate thus comprises a thin paper substrate 11, first coated with PVOH and then coated with a thin layer 12 deposited from the vapor phase, aluminum-metal at a thickness of about 50 nm.

In addition, the packaging laminate comprises a second core layer 16 of paper board having a surface weight of at least 200 g / m ² or, preferably, about 300 g / m ² . The first and second paper layers are suitably connected to each other using the intermediate layer 17. The intermediate layer 17 is usually based on a polyolefin-containing polymer, preferably low density polyethylene (LDPE). The intermediate bonding layer 17 is preferably formed by extrusion lamination of the metallized first paper layer and the second paper layer with each other. The intermediate layer 17 may be one or more layers.

The outer, liquid tight and heat seal layer 15 is defined as in FIGS. 1a and 1b.

In one embodiment, similar to the embodiment described in FIG. 1c, and as shown in cross section in FIG. 1c2, an oriented film is connected to the inside of the layer 12 deposited from the metal vapor by a thin, induction-welding-resistant layer 13 formed by applying liquid of the liquid polymer composition and subsequent drying on a paper layer 11. Between the vapor deposited layer 12 and the oriented film 20, the adhesive layer as a part of the film 20 is laminated with the vapor deposited layer 12. The innermost, liquid impermeable a heat-sealable thermoplastic polymer material 14 is placed on the inner side of the oriented film 20. In this embodiment, low density polyethylene contains LLDPE obtained by polymerization of ethylene monomer with C4-C8, more preferably C6-C8, alpha-olefin alkylene monomer in the presence of a metallocene catalyst, t. e. the so-called metallocene LLDPE (m-LLDPE). The innermost heat-sealing layer 14 may consist of two or more parts-layers of the same or different types of polymers. As described above for FIG. 1 b2, the innermost liquid impermeable heat seal layer 14 may further comprise an adhesive layer, or the oriented film may comprise an adhesive layer on its inner side, where the liquid impermeable heat seal layer 14 is to be laminated.

As other options not considered, similar to the options discussed in FIGS. 1c and 1c2, there may be a connecting layer, as described for FIGS. 1b3 and 1b4, between the vapor-deposited layer 12 and the oriented film 20.

In some cases, when a thicker heat-sealing layer is required, it is of course possible, although not preferable from a cost point of view, to apply an additional liquid-impermeable heat-sealing layer of polyethylene on the inner side of the innermost layer 14.

In order to reduce the amount of moisture released from the paper layer in the vacuum chamber during the metallization process, the first paper layer covered by vapor deposition of the metal can also be coated on the other side with a liquid polymer composition in an aqueous or solvent-containing dispersion or solution before the step metallization method. It is desirable to avoid moisture in the vacuum metallization chamber, because it can reduce the speed at which the metallization method can be performed. In addition, the reverse transfer of paper dust can be prevented during subsequent processing of coated paper webs on drums.

1a and 1b, the first paper layer 11 may be a thin paper layer of about 50 g / m ² or even less. Since the paper layer is very thin, an additional light barrier may be required when pigments are introduced into one or more layers of the laminate. There may be, for example, reflective white pigments, such as, for example, titanium dioxide (TiO ₂ ), and / or light absorbing pigments, such as, for example, carbon black, introduced into a liquid-deposited, induction welding resistant layer 13, such as PVOH. Such pigments are predominantly hidden from the inside by a coating 12 deposited from metal vapor, and at least to some extent by a paper layer 11 from the outside.

Figure 2 graphically schematically shows a method of applying a layer of paper or paper cardboard from a liquid. The paper layer 21a is fed from the storage drum to a liquid spraying station 22a, where the liquid polymer composition is applied in such an amount that the amount of the applied and dried layer is about 1-3 g / m ² when the coated paper passes the drying station 22b. Preferably, the liquid deposition operation is carried out in two stages, i.e. first, 0.5-1.5 g / m ² is applied, dried in an intermediate stage, and then 0.5-1.5 g / m ² is applied a second time, and the total liquid-applied layer is finally dried to obtain a coated paper layer 21b .

FIG. 3 is a diagram of an example of an apparatus for vapor deposition of a metal layer 12 onto a coated thin first paper layer obtained as shown in FIG. 2. The thin paper web 21b of FIG. 2 is subjected to continuous coating on the coating side 30 of the vaporized metallized layer of aluminum, possibly mixed with alumina, and a coating is obtained with a thickness of 5-100 nm, preferably 5-50 nm, so that it is formed metallized paper layer 34a of the invention. Vapors of aluminum come from the source 31 of evaporation of the solid fragment.

FIG. 4 a shows a laminating method 40 a in which induction welding and / or oxygen-barrier coated paper layer 34 a, additionally coated with a thin vapor-deposited coating 21 b, is thermolaminated with an oriented film 50 having an adhesive layer 50 a on the side facing the metallized layer, and the innermost heat sealable layer 14, 43b of LDPE and / or LLDPE is extruded onto the inner side of the oriented film 50 and pressed together in the roll clamp 45b. Then, the laminated paper and film pass through a second extruder 47 and a lamination clip 48, where the outermost heat sealable LDPE layer 46 is applied to the outside of the paper layer. Finally, the finished packaging laminate 49b is wound on a drum (not shown).

FIG. 4b shows an alternative embodiment in which induction welding and / or oxygen-barrier coated paper layer 34a, further coated with a thin vapor-deposited coating 21b, is extruded by a bonding layer 50b with an oriented film 50 at the first lamination point and then coated by extrusion by the outermost polymer layer (s) 46 at the second lamination point and pressed together in the roll clamp 45c. The laminated paper and film then passes through the third extrusion lamination point 48, where the outermost heat sealable layer 14, 43b of LDPE and / or LLDPE is applied to the inside of the film 50. Finally, the finished packaging laminate 49c is wound onto a drum (not shown).

Alternatively, a packaging laminate is possible containing an additional second paper and paperboard layer, and the second paperboard is connected to the first metallized paperboard by extrusion lamination of the metallized first paper layer and the second paper layer using an intermediate layer of a polyolefin-containing polymer, preferably low density polyethylene (LDPE) ), and then the implementation of the stages shown in figa and fig.4b, respectively.

Fig. 5a shows one example of a packaging container 50 obtained from a packaging laminate 10c according to the present invention. The packaging container is especially suitable for drinks, sauces, soups or the like. Typically, such a package has a volume of about 100-1000 ml. It can be of any configuration, but is preferably brick-like, having longitudinal and transverse welds 51 and 52, respectively, and, optionally, an opening device 53. In another embodiment (not shown), the packaging container can be made in the form of a prism. In order to obtain such a “prism shape”, only the lower part of the package is folded, so that the transverse weld of the bottom is hidden under the triangular corner valves, which are folded and welded to the bottom of the package. The upper part of the transverse weld remains uncomplicated. Thus, the semi-folded packaging container is still easy to handle and has stable dimensions when it is placed on a food storage rack or on a table or the like.

Fig. 5b shows an alternative example of a packaging container 50d obtained from a packaging laminate 10b according to the present invention. Since the packaging laminate 10b is thinner having a thinner paper core layer, it is not dimensionally stable even when forming a parallelepiped or prismatic packaging container and does not fold after transverse welding 52b. He thus remains a pillow-shaped bag-like container and is distributed and sold like him.

Figure 6 shows the principle as described in the introductory part of this application, i.e. the web of packaging material is molded into the tube 61 when the longitudinal edges 62, 62 'of the web are connected to each other in a longitudinal joint 63 overlap. The tube is filled with 64 intended liquid food products and is separated into separate packages by repeated transverse welds 65 of the tube at defined intervals from each other below the level of the filled contents in the tube. The packages 66 are separated by cutting in transverse welds, and they are given the desired geometric configurations by folding along the obtained bend lines in the material.

The present invention is not limited to the options shown and described above, but may vary within the scope of the claims.

EXAMPLES

Example 1

Obtaining an aqueous coating composition for resistant to induction welding layer

An aqueous dispersion of layered laminar particles of montmorillonite (Kunipia F from Kunimine Kogyo Co.), having a dimensional ratio of about 50-5000, is mixed with an aqueous solution of about 30% by weight. PVOH (Mowiol 15-99, saponification degree above 99%) at 60-90 ° C for 1-8 hours. The dispersion of the stratified laminar particles of the mineral can be stabilized by the addition of a stabilizer. Alternatively, laminar mineral particles exfoliate directly in the PVOH solution at 60-90 ° C for 1-8 hours.

An aqueous composition of dissolved and dispersed in water PVOH and 30% of the mass. layered bentonite clay is applied by applying it from a liquid in two successive stages with intermediate drying to a thin paper web having a surface weight of 50 g / m ² with a total of 3 g / m ² PVOH. The wet coating is dried with hot air and the water evaporated.

In a subsequent step, the PVOH coated paper is coated with a metal aluminum coating using a vapor deposition method to an optical density of 3 on the PVOH layer.

The PVOH coated paper thus coated is laminated with a thick cardboard of 260 mN (about 270 g / m ² ) by extrusion lamination of a low density polyethylene (LDPE) thermoplastic bonding layer, and thus the laminated paper sandwich is subsequently coated with thermoplastic heat sealable LDPE layers on the outer side.

The inner side is covered by extrusion lamination with a DOPP film using LDPE as the bonding layer on the inner side of the laminated paper sandwich. The innermost layer of liquid impermeable heat sealable LDPE is applied by extrusion to the inner side of the DOPP film.

The laminate product thus formed is used and tested for heat sealing quality in a traditional filling machine of the Tetra Brik Aseptic trademark using induction welding of the resulting packaging containers. For example, it was seen that in order to achieve sufficiently efficient heating with a very thin metallized layer, it was necessary to significantly increase the frequency used in the induction welding method.

The appearance and characteristics of the welds of the thus filled and welded packaging containers were investigated by tearing off the welds again. Appearance was fixed and compared between samples. The width and uniformity along the line of the weld were determined and compared using another test in which all the packaging material is dissolved around the weld, with the exception of heat-sealing thermoplastics. Finally, the packaging integrity of the filled and welded packaging container was tested using a red paint test. All of these tests are well known in dairies and filling areas for Tetra Brik Aseptic packages, for monitoring the quality of welding of daily filled filled packaging containers.

The weight characteristics and quality of samples of welded packaging containers are evaluated based on years of experience in quality control of traditional packaging laminates for Tetra Brik Aseptic packaging containers.

The quality of heat welding and the integrity of the resulting packages is very good and on par with the welding quality of today's Tetra Brik Aseptic aluminum foil packages according to the estimates of the tested plates. In the red paint test, all 300 of the 300 filled and infused packages are liquid tight without leakage points.

Example 2

An aqueous composition of dissolved and dispersed in water PVOH having a degree of saponification above 99%, and 10% of the mass. layered bentonite clay is obtained analogously to example 1 and is applied by the method of applying from a liquid in two successive stages with intermediate drying to a thin paper web having a surface weight of 50 g / m ² with a total of 3 g / m ² PVOH. The wet coating is dried with hot air and the water evaporated.

In a subsequent step, the PVOH coated paper is coated with a metal aluminum coating using a vapor deposition method to an optical density of 3 on the PVOH layer.

The PVOH coated paper thus metallized is laminated with a thin paper of 50 g / m ² by extrusion lamination of a thermoplastic bonding layer of low density polyethylene (LDPE). The inner side is additionally covered by thermal lamination of a DOPP film having an adhesive layer of an EAA on the inner side of a laminated paper sandwich. The inner side of the DOPP film is coextruded with two layers of LDPE. The innermost layer is a liquid impermeable heat sealable LDPE extruded at a temperature of approximately 280 ° C.

The coated and laminated paper sandwich is then coated with thermoplastic heat-sealing layers of LDPE on both sides and tested for the quality of heat sealing in a traditional Tetra Brik Aseptic filling machine using induction welding of the resulting packaging containers.

Alternatively, it is technically possible to metallize a thicker paper layer, for example, about 100 g / m ² and not laminate it with any other paper layer, but save it as a laminate with a single paper layer coated with external heat sealable thermoplastic layers. Currently, however, it will be economically inefficient to apply a vaporized metallized layer onto such a thick paper substrate, therefore, the above laminate sandwich is prepared so as to provide a laminate with an appropriate required thickness and rigidity.

The quality of heat sealing and the integrity of the resulting packaging are equally very good in accordance with the same rating of the same test plates.

Comparative Example 1

A 12 μm oriented PET film (polyethylene terephthalate) film substrate is coated with an aluminum metal coating using a vapor deposition method to an optical density of about 3.

Thus metallized PET film is laminated with thick paperboard of about 260 mN (or about 270 g / m ² ) by extrusion lamination of a thermoplastic bonding layer of low density polyethylene (LDPE) and then coated with thermoplastic heat-sealing layers (LDPE) on both sides and tested on the quality of heat sealing in a traditional filling machine of the Tetra Brik Aseptic trademark using induction welding of the resulting packaging containers.

The quality of heat sealing and the integrity of the resulting packages is acceptable according to the evaluation of the test plate on the properties of tearing the welds and the integrity of the package using the test with red paint in comparison with the above examples. However, the welding results from test to test are not consistent and reliable, as for laminated material with paper substrates.

Reference Example 2

A thin paper web having a surface weight of 50 g / m ² is coextruded with a first layer of LDPE at 1 g / m ² and a second layer of SEAC (ethylene (acrylic acid copolymer)) at 5 g / m ² .

In a subsequent step, the coextruded coated paper is additionally coated with aluminum metal using a vapor deposition method on an SEAC layer.

LDPE / SEAC coated paper thus metallized is laminated with thermoplastic heat-sealing layers on both sides and tested for the quality of heat sealing in a test device that simulates real conditions in a traditional Tetra Brik Aseptic filling machine using induction welding of the resulting packaging containers. In addition, laminated paper is tested in a traditional Tetra Brik Aseptic filling machine using induction welding of the resulting packaging containers.

The weight characteristics and quality of samples of welded packaging material and containers are evaluated based on years of experience in quality control of traditional packaging laminates for Tetra Brik Aseptic packaging containers, and it has been seen that improperly welded packages can be formed in the Tetra Brik Aseptic machine, so any other packaging integrity tests are redundant. In addition, the test results for tearing welded samples on the test device show that the welds are not good enough.

Thus, the heat sealing quality and integrity of the resulting packages are not good and not quite at the level of welding quality of today's Tetra Brik Aseptic aluminum foil packages in accordance with tests of the same test plate.

Example 3

Example 3 is carried out analogously to example 1, except that the layered laminar particles of montmorillonite are not present.

The heat sealing quality and integrity of the resulting packages are very good at the level of welding quality of today's Tetra Brik Aseptic aluminum foil packages in accordance with the tests of the test plate. When tested with red paint, all 300 of the 300 filled and sealed packages are liquid tight without leak points.

Example 4

Thin paper webs of various surface weights are coated by a method of applying from a liquid in two successive stages with intermediate drying with an aqueous composition of dissolved and dispersed in water PVOH having a degree of saponification above 99% and 10% by weight. layered bentonite clay, as shown in table 1. Wet applied coatings are dried with hot air with evaporation of water.

In a subsequent step, PVOH coated paper webs are coated with aluminum metal using a vapor deposition method on a PVOH layer.

The PVOH-coated paper webs thus coated on the inside are coated by extrusion lamination with a DOPETP film using LDPE as the bonding layer on the inside of the laminated paper sandwich. The innermost layer of liquid-impermeable heat sealable LDPE is applied by extrusion to the inner side of the DOPP film. The laminate thus obtained is then coated with thermoplastic heat-sealing layers on the outside of the laminate and tested for heat sealing quality when welding in a test device that simulates real conditions in a traditional Tetra Brik Aseptic filling machine using induction welding of the resulting packaging containers.

From the results obtained, it can be seen that thickened paper to a certain surface mass provides better welding results than thinner paper. You can also see that a higher density (OD) coating deposited from a metal vapor provides a somewhat better welding result than a lower OD coating from a metal vapor. In addition, it can be seen that thicker PVOH layers provide somewhat better welding results than thinner layers. All samples from table 1 provide very good welding quality in tests in the device and should provide equally good test results for integrity of the packaging in tests in the filling machine, similar to that shown in example 1. Although the best welding results are felt with thicker paper substrates with 70 g / m ² , thinner substrates with 50 g / m ² are usually used in tests, since thicker substrates become much more expensive.

Table 1 Sample No. The mass of the surface of the paper, g / m ² PVOH, g / m ² OP one fifty 2x0.7 3 2 fifty 2x1.5 1,5 3 fifty 2x1.5 3 four 70 2x1.5 3 5 70 2x0.7 1,5 6 70 2x0.7 3

Of course, there are also opportunities to further increase the gas-barrier properties by slightly thickening the coating or additional layers of the PVOH composition or by filling the PVOH layer with a higher amount of inorganic particles. For example, when applying a composition of a thicker and denser filled gas barrier layer, improved odor barrier properties are obtained. An excellent example of such a barrier composition comprises PVOH and from 10 to 50% by weight, preferably from 20 to 40% by weight. talc particles. Another example of such a barrier composition contains PVOH and from 10 to 50% of the mass. particles of talc and from 1 to 40% of the mass. nanoparticles, such as those described above, for example, clay.

Claims (23)

1. Non-folded packaging laminate (10) for induction welding in packaging for a liquid food product or beverage, the packaging laminate comprising at least one first layer (11) of paper or other cellulosic material, where the first paper layer (11) is located on the inside packaging laminate and pre-coated to accept and carry an induction-sensitive metal layer (12) deposited from the vapor phase in order to weld the thermoplastic polymer material welding, wherein the packaging laminate further comprises a vapor deposited layer (12) deposited on the inside of said first coated first layer (11) of paper or cellulose-containing material, further comprises an oriented film (20) laminated with a vapor deposited layer (12); and further comprises the innermost layer (14) of a liquid impermeable heat sealable thermoplastic polymeric material deposited on the inside of the oriented film (20); or said oriented film contains a liquid-tight heat-sealing layer representing the innermost layer of the film, where said oriented film (20) is stretched in at least one direction with a drawing ratio of 2 or more and has a core layer of material having a higher melting point than material of the innermost layer (s). 2. The non-folded packaging laminate according to claim 1, wherein said oriented film (20) is laminated with an intermediate bonding layer deposited from a metal vapor layer (12) or said oriented film (20) comprises an adhesive layer on its outer side laminated with deposited from metal vapor layer (12). 3. The non-folded packaging laminate according to claim 2, wherein said adhesive layer comprises an adhesive polymer selected from an ethylene-acrylic acid copolymer (EAA), an ethylene-methacrylic acid copolymer (EMAA), an ethylene glycidyl (meth) acrylate copolymer (EG ( M) A) and maleic anhydride grafted polyethylene (MAH-g-PE). 4. The non-folded packaging laminate according to claim 2, wherein said connecting layer is based on low density polyethylene polymers and is selected from modified or unmodified LDPE and LLDPE polymers, copolymers or grafted copolymers of ethylene polymers with monomer units containing functional groups such as carboxyl or glycidyl functional groups, and from ionomers based on low density polyethylene. 5. The non-folded packaging laminate according to claim 4, wherein said connecting layer is selected from (meth) -acrylic acid monomers or maleic anhydride (MAH) monomers, ethylene-glycidyl (meth) acrylate (EG (M) A) copolymer or polyethylene with inoculation of maleic anhydride (MAH-g-PE). 6. The non-folded packaging laminate according to claim 1, wherein at least the core layer of the oriented film is selected from the group consisting of layers of a uniaxially and biaxially oriented polymer film of polypropylene (OPP, BOPP), polyethylene terephthalate (ORET, BORET), polyamide (OPA , BOPA), polyethylene naphthalate (OPEN, BOPEN), polybutylene terephthalate (ORVT, DORVT), polytrimethylene terephthalate (ORTT, VORTT) or from mixtures or copolymers of these polymers. 7. The non-folded packaging laminate according to claim 6, wherein the at least the core layer of the oriented film is biaxially oriented polypropylene or biaxially oriented polyethylene terephthalate. 8. The non-folded packaging laminate according to claim 1, wherein the thickness of the oriented film is less than 30 microns. 9. Non-folded packaging laminate according to claim 1, characterized in that the first layer (11) of paper or other cellulose-containing material is coated on its inner side with an induction welding-resistant coating layer (13) having a higher melting temperature than the innermost non-folded layer packaging laminate, and the fact that on the inner side of the coating layer resistant to induction welding, an additional layer of a coating sensitive to induction heating (12) deposited from metal vapor is additionally deposited. 10. Non-folded packaging laminate according to claim 9, characterized in that the induction welding resistant coating layer (13) is formed from a composition mainly containing a polymer selected from the group consisting of polyvinyl alcohol (PVOH), water-dispersible ethylene-vinyl alcohol (EVOH), copolymer (ethylene vinyl alcohol) vinyl acetate, polyvinylidene chloride (PVDC), water-dispersible polyamide (PA), polysaccharide, polysaccharide derivatives, starch, starch derivatives and combinations of two or more of them. 11. Non-folded packaging laminate according to claim 9, characterized in that the induction welding resistant coating layer (13) is formed from a composition mainly containing a polymer selected from the group consisting of PVOH, water-dispersible EVOH or starch. 12. Non-folded packaging laminate according to claim 9, characterized in that the induction-heating sensitive layer (12) applied by vapor deposition of the metal is a layer essentially consisting of aluminum. 13. Non-folded packaging laminate according to claim 10, characterized in that the layer (12) deposited by vapor deposition of the metal has an optical density (OD) of from 1 to 5, preferably from 1.5 to 3.5, more preferably from 2 until 3. 14. Non-folded packaging laminate according to claim 9, characterized in that the first, most internally located layer (11) of paper or other cellulosic material has a surface weight of from 20 to 100 g / m ² , preferably from 20 to 70 g / m ² , more preferably 30 to 60 g / m ² . 15. Non-folded packaging laminate according to claim 9, characterized in that it further comprises a second layer of paper or cardboard laminated to the outer side of the first layer of paper, the second paper layer having a surface weight of from 50 to 500 g / m ² , preferably from 200 to 400 g / m ² , most preferably 200 to 300 g / m ² . 16. A method for producing an unfolded packaging laminate (10) according to claim 1, comprising the following steps:
- providing a first layer (21) of paper or other cellulosic material,
- pre-coating a layer of paper or other cellulose-containing material for accepting and bearing an induction heat-sensitive metal coating resistant to induction welding, deposited from metal vapor, on the inside of said layer of paper or other cellulose-containing material,
- applying the specified, susceptible to induction heating of the metal layer (12) on the inner side of the coated paper layer,
- providing an oriented film (20) stretched in at least one direction with a drawing ratio of 2 or more and having a core layer of material having a higher melting point than the material of the innermost layer of the non-folded packaging laminate,
- lamination of oriented film (20) with a paper layer (11) coated with metal (12),
- providing one (or more) layer (s) of liquid impermeable heat sealable thermoplastic polymer material (14) deposited on the inside of the oriented film (20), or providing a liquid impermeable heat seal layer as part of an oriented film (20) representing the innermost a film layer, where either a liquid-impermeable heat-sealable thermoplastic polymer material or a liquid-impermeable heat-sealable film layer is the innermost An early layer of unfolded packaging laminate. 17. A method for producing an unfolded packaging laminate (10) according to clause 16, wherein the oriented film (20) is laminated with a metallized deposited layer (12) with an intermediate connecting layer; or said oriented film (20) contains an adhesive polymer layer on its outer side, which is laminated with a vapor deposited layer (12). 18. The method of obtaining non-foamed packaging laminate (10) according to clause 16, in which
liquid-tight thermosetting thermoplastic polymer material is a low density polyethylene selected from LDPE, LLDPE, m-LLDPE and PEONP and mixtures thereof;
the adhesive layer is selected from a copolymer of ethylene (acrylic acid) (EAA), a copolymer of ethylene (methacrylic acid) (EMAK), a copolymer of ethylene glycidyl (meth) acrylate (EG (M) A) and polyethylene grafted with maleic anhydride (MAG- p-PE); and
the connecting layer is a layer based on low density polyethylene polymers selected from modified or unmodified LDPE or LLDPE polymers, copolymers or grafted copolymers of ethylene polymers with monomer units containing functional groups, such as carboxyl or glycidyl functional groups, and from polyethylene based ionomers low density. 19. A method of producing a non-foiled packaging laminate (10) according to clause 16, wherein at least the core layer of the oriented film is selected from the group consisting of layers of uniaxially and biaxially oriented polymer film of polypropylene (OPP, DOPP), polyethylene terephthalate (OPETP, DOPETP ), polyamide (OPA, DOPA), polyethylene naphthalate (OPENF, DOPENF), polybutylene terephthalate (OPBTF, DOPBTF), polytrimethylene terephthalate (OPTTF, DOPTTF) or from mixtures or copolymers of these polymers. 20. A method for producing an unfolded packaging laminate (10) according to claim 19, wherein the at least the core layer of the oriented film is biaxially oriented polypropylene or biaxially oriented polyethylene terephthalate. 21. A method for producing an unfolded packaging laminate (10) according to claim 16, wherein the thickness of the oriented film is less than 30 microns. 22. A method for producing a non-foamed packaging laminate (10) according to claim 16, wherein said preliminary coating comprises the following steps:
- providing a liquid composition containing a polymeric binder dispersed or dissolved in an aqueous or solvent-containing liquid medium,
- forming a thin, resistant to induction welding layer containing the specified polymer binder adjacent to the inner side of the first paper layer, applying (22a) a liquid composition to the inner side of the specified layer of paper or other cellulose-containing material and subsequent drying (22b) to evaporate the liquid, said polymer binder has a melting point higher than the innermost layer. 23. A packaging container (50a, 50b) obtained from a packaging laminate (10a, 10b) according to any one of claims 1-15.

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