CH683836A5 - Bag packing. - Google Patents

Description

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CH 683 836 A5

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description

The present invention relates to a bag package for fillings which can be heated by microwave treatment, comprising a jacket part or jacket part and bottom part, made of flexible plastic film, the front and back of the jacket part or the jacket part and the bottom part being connected to one another by sealing seams.

From DE-OS 1 786 019 bags and in particular stand-up bags made of thermoplastic or composite material are known, consisting of two side walls with a folded bottom or two separate side walls and a third pre-folded bottom film, the volume restricting adhesive welds or pressure sensitive adhesives being attached, which are attached release a strong increase in pressure so that voltage peaks are dampened by increasing the volume at these points.

The object of the present invention is to provide a bag packaging which can be sterilized, for example, and whose contents can later be reheated by microwave treatment, the volume expansion which occurs when the contents are heated, in particular by steam formation, and an excessive build-up of pressure by means of an automatic pressure relief at a predetermined point to the ambient atmosphere, down to the ambient pressure, is prevented and finally an easy opening of the bag packaging for removal of the filling material is made possible.

The previously proposed solution for pressure relief could not solve the task at hand. The object was achieved according to the invention in that the jacket part is formed from a plastic film which contains a tear layer (peel layer) on the inside and the bag packaging has a removal opening in the region of the upper end of the jacket part which is opened by an easily tearable bag head seam is closed, and the bag has an automatic overpressure relief in the area of the upper end.

The tear-off layer described can also be referred to as a peel layer or peel layer.

In a first expedient embodiment of the bag packaging, the automatic overpressure relief represents a tear-open aid on the bag head seam.

In a second expedient embodiment of the bag packaging, the automatic overpressure relief is arranged within the area of the bag interior in the form of an opening which can be torn open.

The opening which can be tied open is preferably arranged within the area of the bag interior and in the immediate vicinity of the head bag seam.

The present invention relates to pouch packaging, the pouches being able to be constructed, for example, from a substantially centrally folded plastic film connected laterally via seams.

Other exemplary embodiments are

Connection of two plastic films via two side and one bottom seam or the connection of two bag walls and one, if necessary e.g. V or W-shaped folded bottom, made of plastic foils with marginal seams.

Other embodiments are e.g. Bags, constructed from two bag walls and side inserts connected between the bag walls, connected at the edges, and optionally an inserted bottom. Both the inserts and the bottom can be made from a flat or e.g. V-shaped or W-shaped plastic film.

Bags made of a plastic film are preferred, which are folded in the middle and provided in the middle with an inward V-shaped fold. The V-shaped fold then represents the bottom. The inward-facing V-shaped fold usually protrudes 1/20 to 1/3, preferably 1/10 to 1/5, into the bag.

Instead of the V-shaped fold, e.g. a W-shaped fold can also be used analogously.

Marginal seams expediently connect the front and back of the jacket part and the legs of an inward V-shaped bottom fold, also marginally, separably with each other. This ensures that e.g. when filling such a bag or when building pressure in such a sealed bag, only the central part of the V-shaped fold can open. A stand-up pouch is formed.

The present invention preferably relates to stand-up pouches or stand-up pouch packaging. Non-stable pouch packs can also be given stand properties by means of a suitable device, such as a holder, a foot part and the like.

Plastic films are used for the jacket part and the bottom part, plastic films with a tear layer (peel layer) coming to the inside of the bag being used for the jacket part and possibly the bottom part.

Suitable plastic films can have one or more layers and, in the latter case, can be laminates or film composites. The plastic films expediently contain a barrier layer against gases and vapors.

The plastic films can, for example, consist of olefin-based, ester-based, polyamide-based, vinyl halide-based plastics or mixtures thereof, or contain these plastics.

Examples of olefin-based thermoplastics are polyolefins, e.g. such as polyethylene, such as high density polyethylene (HDPE, density greater than 0.944 g / cm3), medium density polyethylene (MDPE, density 0.926-0.940 g / cm3), linear medium density polyethylene (LMDPE, density 0.926-0.940 gl cm3), polyethylene low density (LDPE, density 0.910-0.925 g / cm3) and linear low density polyethylene (LLDPE, density 0.916-0.925 g / cm3), polypropylene, poly-1-butene, poly-3-methylbutene, poly-4-methylpentene and Copolymers or coextrudates thereof, such as of polyethylene with vinyl acetate, acrylic acid, methacrylic acid, acrylic esters,

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Tetrafluoroethylene or polypropylene, as well as statistical copolymers, block copolymers or olefin-polymer-elastomer mixtures.

Ester-based thermoplastics are, for example, polyalkylene terephthalates or polyalkylene isophthalates with alkylene groups or radicals with 2 to 10 carbon atoms or alkylene groups with 2 to 10 C atoms which are interrupted by at least one -0-, e.g. Polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate (polytytamethylene terephthalate), polydecamethylene terephthalate, poly-1,4-cyclohexyldimethylol terephthalate or polyethylene-2,6-naphthalene dicarboxylate or polyalkylene terephthalate and polyalkylene isophthalate, where polyalkylene isophthalate, where 1 to 10 mol%, mixed polymers and terpolymers, as well as block polymers and grafted modifications of the above-mentioned substances.

Suitable ester-based thermoplastics are polyalkylene terephthalates with alkylene groups or radicals with 2 to 10 carbon atoms and polyalkylene terephthalates with alkylene groups or radicals with 2 to 10 carbon atoms which are interrupted by one or two -0-.

Preferred thermoplastics based on esters are polyalkylene terephthalates with alkylene groups or radicals with 2 to 4 carbon atoms, and polyethylene terephthalates are very particularly preferred.

The amide-based thermoplastics include, for example, polyamide 6, a homopolymer of e-caprolactam (polycaprolactan); Polyamide 11, a polycondensate of 11-aminoundecanoic acid (poly-11-aminoundecanamide); Polyamide 12, a homopolymer of co-laurolactam (polylaurin lactam); Polyamide 6.6, a homopolycondensate of hexamethylenediamine and adipic acid (polyhexamethylene adipamide); Polyamide 6.10, a homopolycondensate of hexamethylene diamine and sebacic acid (polyhexamethylene sebacamide); Polyamide 6, 12 a homopolycondensate of hexamethylene diamine and dodecanedioic acid (polyhexamethylene dodecanamide) or polyamide 6-3-T, a homopolycondensate of trimethylhexamethylene diamine and terephthalic acid (polytrimethylhexamethylene terephthalamide), as well as mixtures thereof.

A non-exhaustive list of vinyl halide-based plastics includes, for example, the polymers of vinyl chloride and vinyl plastics containing vinyl chloride units in their structure, e.g. Copolymers of vinyl chloride with vinyl esters of alphalic acids, in particular of vinyl acetate; Copolymers of vinyl chloride with esters of acrylic and methacrylic acid and with acrylonitrile; Copolymers of vinyl chloride with diene compounds and unsaturated dicarboxylic acids or their anhydrides, such as copolymers of vinyl chloride with diethyl maleate, diethyl fumarate or maleic anhydride; post-chlorinated polymers and copolymers of vinyl chloride; Copolymers of vinyl chloride and vinylidene chloride with unsaturated aldehydes, ketones and others such as acrolein, cotonaldehyde, vinyl methyl ketone, vinyl methyl ether, vinyl isobuyl ether, etc .; Polymers of vinylidene chloride and copolymers thereof with vinyl chloride and other polymerizable compounds; Polymers of vinyl chloroacetate and dichlorovinyl ether, chlorinated polymers of vinyl acetate, chlorinated polymeric esters of acrylic and alpha-substituted acrylic acids; Polymers of chlorinated styrenes, e.g. Dichlorostyrene, chlorinated rubber, chlorinated polymers of chlorobutadiene and their copolymers with vinyl chloride; Gum hydrochloride and chlorinated gum hydrochloride; and mixtures of polymers with one another or with other polymerizable compounds and also the corresponding bromides and fluorides.

In the case of plastic films, laminates or film composites, a barrier layer against gases and vapors can preferably also be provided. Suitable are e.g. ceramic barrier layers, as well as plastic barrier layers.

Therefore, the present invention also relates to pouch packaging whose plastic film of the jacket part or the jacket part and the bottom part or the bottom part contains a barrier layer against gases and vapors.

Ceramic barrier layers contain, for example, oxides from the series of silicon oxides, aluminum oxides, iron oxides, nickel oxides, chromium oxides or lead oxides or mixtures thereof. The silicon oxides or aluminum oxides are expedient as ceramic barrier layers. The silicon oxides can have the formula SiOx, where x preferably represents a number from 1 to 2, particularly preferably from 1.1 to 1.9 and in particular from 1.2 to 1.7. The aluminum oxides can have the formula AlyOz, where y / z e.g. represents a number from 0.2 to 1.5 and preferably from 0.65 to 0.85.

The ceramic barrier layers are applied, for example, to a substrate, such as e.g. by means of vacuum thin-film technology, expediently on the basis of electron beam evaporation or resistance heating or inductive heating from crucibles. applied to a plastic layer or plastic film, as mentioned above. Electron beam evaporation is preferred. The described methods can be carried out reactively and / or with ion support. The ceramic layer can have a thickness of, for example, 5 to 500 nm.

Plastic barrier layers can, for example, consist of or contain polymers that are particularly gas and water vapor tight. Behave particularly favorably e.g. Layers or foils based on polyvinylidene chlorides, polyolefins, polyvinyl chlorides, acrylonitrile copolymers, polyethylene terephthalates or biaxially stretched polyethylene terephthalates.

Bag packaging according to the present invention, the barrier layer of which is a ceramic layer, is particularly preferred.

The thickness of the single-layer plastic films or of the individual plastic films in film composites or laminates can be, for example, 8 to 2000 µm, preferably 10 to 600 µm and in particular 10 to 80 µm.

Foil composites or laminates can have the layer structures known per se, such as e.g. containing at least two plastic layers or containing at least one cellulose-containing

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Layer such as paper, cardboard, nonwovens and at least one plastic layer.

In all embodiments, at least one printed, counterprinted or colored layer of a material, e.g. a plastic film may be provided.

At least one of the layers can be insulating and made of closed-cell plastic foam, e.g. made of styrofoam or other materials, e.g. Crepe paper or similar consist.

The different layers, e.g. the plastic films or layers or composites with one another and the plastic films or layers containing ceramic barrier layers can be connected to one another with laminating adhesives and / or adhesion promoters.

Suitable adhesion promoters are, for example, vinyl chloride copolymers, vinyl chloride-vinyl acetate copolymers, polymerizable polyesters, vinyl pyridine polymers, vinyl pyridine polymers in combination with epoxy resins, butadiene-acrylonitrile-methacrylic acid copolymers, phenolic resins, rubber derivatives, acrylic resins, acrylic resins with phenols or epoxy resins, or organosilicon compounds, such as organosilanes.

EAA (ethylene acrylic acid) or modified polyolefins, such as e.g. modified polypropylene.

A preferred modified polypropylene is an adduct of maleic anhydride and an ethylene-propylene copolymer. Dispersions of modified polyolefins are very particularly preferred. An example of a modified polypropylene dispersion is Morprime (trademark of Morton Chemical Division of Norton Norwich Products, Inc.).

Other suitable adhesion promoters are adhesives such as nitrile rubber-phenolic resins, epoxies, acrylonitrile-butadiene rubber, urethane-modified acrylics, polyester-co-polyamides, hot-melt polyesters, polyisocyanates crosslinked with hot-melt polyester, polyisobutylene-modified styrene-butadiene-acid, urethane -Mix polymers and ethylene vinyl acetate copolymers.

If, for example, laminating adhesives are used between the plastic layers, the laminating adhesives can be solvent-based or solvent-free and also contain water. Examples are solvent-based or aqueous acrylate adhesives or solvent-free polyurethane adhesives.

Laminating adhesives based on polyurethane are preferred.

The jacket parts underneath and possibly with the bottom part are e.g. Separately connected by sealed seams. The plastic films have a tear-open layer on the surface of the plastic film that lies to the inside of the bag.

The tear-open layer can extend over the entire surface of the plastic film or can be present or applied only partially, in the area of the seals to be made.

The tear layer can be on the plastic film in film form or in layer form, e.g. be arranged on both sides and expediently on the surface of the plastic film coming to lie on the inside of the bag.

Tear-open layers are known per se and can, for example, be made of polyolefins or polyolefin mixtures, optionally with a filler, or contain such substances. Suitable polyolefins are, for example, LLDPE, LDPE, MDPE, HDPE, polypropylene, cast polypropylene (cPP), modified polypropylene or polypropylene copolymers, such as ethylene-propylene copolymers or polyethylene terephthalate, etc.

Other examples of tear layers are those containing or consisting of an ionomer resin, in particular with about 10% acid content and a high degree of ionic crosslinking; Ethylene-acrylic acid copolymers; Ethylene A / ethyl acetate copolymers; acid modified EVA copolymers or EVA.

Still other examples of tear layers are blends of polypropylene and high pressure polyethylene, blends of polypropylene and polyolefin rubbers.

Modified polyesters or glycol-modified polyesters or copolyesters of aromatic polycarboxyl compounds, ethylene glycol and an additional glycol are particularly preferred. The aromatic polycarboxyl compounds are e.g. aromatic dicarboxylic acids such as terephthalic acid. The additional glycols can have 3 to 20 carbon atoms and are e.g. Propanediols, butanediol, pentanediol, hexanediol or 1,4-cyclohexanedimethanol.

Preferred is, for example, a tear-off layer containing 40 to 97% by weight of at least one copolyester and 3 to 60% by weight of at least one thermoplastic polymer based on acetal, acrylic, amide, carbonate, ester, olefin, Styrene or vinyl base. The copolyester is expediently sealable.

Suitable copolyesters for such tear-open layers are copolyesters of an aromatic or aliphatic polycarboxyl compound, ethylene glycol and / or another glycol or polyglycol. The aromatic polycarboxyl compounds are expediently aromatic dicarboxylic acids. The aliphatic polycarboxyl compounds are expediently aliphatic dicarboxylic acids.

In addition to the polycarboxylic acid mainly present in the copolyester, advantageously an aromatic bicarboxylic acid and preferably terephthalic acid, the copolyester can contain other polycarboxylic acids for modification. The proportion of the other polycarboxylic acid for modifying the copolyester can be, for example, up to 30 mol%. Several aliphatic, alicyclic or aromatic dicarboxylic acids with 4 to 36 carbon atoms, such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, isophthalic acid, 2,6-naphthalene-dicarboxylic acid, ice or trans-1,4-cyclohexanedica-rboxylic acid, 1,2- or 1,3-cyclohexanedicarboxylic acid, monochloterephthalic acid, such as 2-chloroterephthalic acid, dichloroterephthalic acid, such as 2,5-dichloterephthalic acid, methyl terephthalic acid, dimethyl terephthalic acid, tetrahydrophthalic acid, 4,4-diphenyldi-carboxylic acid, trans -4,4-stilbenedicaroboxylic acid,

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Adipic acid, pimelic acid, azelaic acid, suberic acid, sebacic acid, or dodecanedicarboxylic acid can be used. The copolyesters can be prepared either from the acid compound or from an ester or another reactive derivative.

The copolyester contains 5 to 97 mol% ethylene glycol residues and 3 to 95 mol% residues of at least one additional glycol as the glycol or diol portion. Additional glycols are, for example, aliphatic and cycloaliphatic glycols with 3 to 20 carbon atoms, such as the aliphatic glycols 1,2- or 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol , 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol or the cycloaliphatic glycols 1,3- or 1,4-cyclohexanedimethanol, 2,2-dimethyl-1,3-propanediol, 2.2 , 4,4-tetramethyl-1,3-cyclobutanediol and also diethylene glycol or other suitable diols, as well as oligomers of said diols.

The preferred copolyester for the present tear layers contains an aromatic polycarboxyl compound and in particular terephthalic acid or derivatives thereof and the additional glycol is in particular 1,4-cyclohexanedimethanol. Very preferred copolyesters are glycol-modified polyesters, which are known to experts in the field, for example, as PETG.

Particularly suitable copolyesters are, for example, the commercially available products “Koda-bond 5116” from Eastman Kodak Co. or “SELAR PT 8307” from Du Pont.

Examples of thermoplastic polymers which are contained in the tear layer with the copolyester (s) can be based on acetal, acrylic, amide, carbonate, ester, olefin, styrene or vinyl.

Preferred thermoplastic polymers which are contained in the tear layer with the copolyester (s) are the polyolefins and in particular polyethylene or polypropylene, furthermore acid- or alcohol-modified copolymers, such as ethylene acrylic acid (EAA) or ethylene-vinyl alcohol copolymers, non-sealable polyesters, in particular non-sealable polyethylene terephthalates, polyamides, rubber elastomers, for example based on ethylene-propylene-diene elastomers and polycarbonates, in particular based on bisphenol A and phosgene. Polyethylene and in particular LDPE are very particularly preferably used as thermoplastic polymers which are contained in the tear layer with the copolyester (s).

A tear-open layer containing 75 to 90% by weight of at least one copolyester and 10 to 25% by weight of at least one thermoplastic polymer is preferred.

The tear layers can also contain, for example, 3 to 20% by weight of a filler.

Such fillers are known per se and organic fillers and / or mineral fillers with small particle size, such as chalk, talc, quartz, wollastonite, feldspar, calcined kaolinite clay and the like can be mentioned by way of example. Other fillers are e.g. Titanium dioxide or other coloring pigments.

The tear-open layer, like the plastic films, can contain materials which are known per se and which improve properties, such as reinforcing agents, plasticizers, lubricants, antioxidants, light stabilizers, stabilizers and other polymer modifiers.

If necessary, the plastic film containing a tear layer on one side, a sealing layer on the other side, a colored, printed or counterprinted plastic film or a cellulose-containing layer such as paper, cardboard, non-woven fabric, or the plastic film can have a tear layer on both sides.

Preferred plastic films for the jacket part and the bottom part can, for example, be constructed from the outside in from a polyester layer, such as a polyester film, a barrier layer, such as a ceramic layer, a further polyester layer, such as a polyester film, and a tear-off layer, for example as described above.

Plastic foils for the shell part and base part are particularly preferred, comprising a polyethylene terephthalate film, an SiOx layer from the outside inwards, where x is a number from 1.2-1.7, a further polyethylene terephthalate film and a tear-off layer , e.g. Polypropylene, cast polypropylene (cPP), polypropylene copolymer, or sealable polyethylene terephthalate.

The thickness of the individual layers of this latter plastic film can be, for example, 10 .mu.m to 50 .mu.m for the polyethylene terephthalate layers, 10 nm to 100 nm for the ceramic layer and 5 .mu.m to 80 .mu.m for the tear-open layer.

In practice, plastic films are, for example, containing a polyethylene terephthalate film with a thickness of 10-15 µm, an SiOx layer, where x is a number from 1.2-1.7 and the layer thickness is 10 nm to 100 nm, a further polyethylene terephthalate film with a layer thickness of 10 to 15 μm and a tear-open layer in the form of a 40 to 60 μm thick PP or cPP film are preferred. The SiOx layer is expediently applied to the further polyethylene terephthalate layer.

The bag packages according to the present invention are joined, for example, by sealing, welding, ultrasonic sealing or welding or gluing in the form of seams on the jacket parts and, if appropriate, the base part. Sealing and in particular thermal contact sealing is preferred. The strength of the sealing seams is influenced by the sealing geometry, the sealing temperature, the sealing pressure and the sealing time. If the seams are carried out using ultrasound, the necessary energy parameters must be observed accordingly.

The bag packages according to the present invention have e.g. separable sealed bottom and side seams.

The sealing seams are preferably set in such a way that a stand-up pouch results. For this purpose, e.g. From a front and a back, which are obtained by folding a plastic film or by joining two plastic films, the side seams and, if necessary, the bottom

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sealed seams. In the area of the bag foot part, sealing seams running diagonally from the outside downwards can be placed. This increases the inherent stability and stability of a bag. Furthermore, the side sealing seams are relieved during the transition from the 2-layer to the 4-layer bag part (in the area of the V-shaped bottom part). This latter embodiment is preferred for stand-up pouches.

The top seam and the automatic overpressure relief are at least partially sealed easily tearable and then form at least one easily tearable bag head seam, respectively. automatic overpressure relief.

For example in the packaging of moisture-containing products, e.g. from the food sector, the bag packaging can be filled, closed and, if necessary, sterilized under counter pressure. Before the contents are consumed or consumed, the bag packaging can preferably be reheated by microwave treatment in the bag packaging. When a certain internal pressure is reached, e.g. due to the development of steam, pressure is relieved by opening the automatic overpressure relief in the area of the bag head. The automatic overpressure relief can also be carried out by means of a tear-open aid, for example by a sealing seam between the jacket parts in the form of a tear-off tip directed towards the inside of the bag.

After relieving the pressure and heating the contents of the bag as required, the bag head seam can be separated along the easily tearable sealing seam. This opens the bag so that the contents can be easily removed. The easy opening of the bag head seam can also be facilitated by a tear-open aid on the bag head seam.

1 and 1a and 2 illustrate two different embodiments of the bag packaging according to the invention by way of example.

Fig. 1 shows the perspective view of a pre-folded plastic film (1). For the design of a floor part e.g. a V-shaped fold (2) is provided. For example, a W-shaped fold can be used instead of a V-shaped one. The recesses (3) are made in the area of the V-shaped fold, here, for example, in a rectangular shape. When connecting the side seams, e.g. by sealing, touching and sealing the front and back in the area of the hatched areas (4) and (4a) directly. As a result, when the volume of the bag increases, the seam in the area of the V-shaped fold cannot widen, which contributes to the structural stability of the bag and to the formation of a stand-up pouch.

Tear tabs (5) are provided as examples on the front (1b) and the back (1a). The presence and design of these tear tabs are subject to change and are based on purpose and need. Instead of a pull tab, a carrying handle can also be provided, which can optionally also serve as a pull tab at the same time. The tear tab can also have at least one recess for hanging the bag packaging.

FIG. 1 a shows a side view of a plastic film and tear strip joined to a bag according to FIG. 1.

The upper limit of the V-shaped fold (2) is indicated by a broken line, the recesses (3) and the surfaces (4) on which in the area of the V-shaped fold the front and back directly e.g. sealed, are indicated by hatching.

The front and back of the plastic film (1) are connected to one another in a separable manner via the side seams (12). The bevel seams (13) increase the stability of the bag and relieve the side seams (12), particularly in the area of the recesses (3). The bevel seams (13) relieve the side sealing seams in the area of the transition from the 2-layer to the 4-layer (area of the V-shaped bottom) of the bag part. Instead of the recesses 3, overlaps or tabs can also be provided.

In the region of the upper end of the bag, a top seam (14) extending over the entire width of the bag and, in particular, a sealed seam are expediently provided. The head seam (14) preferably has a tear-open aid (15), for example designed as a tear-open tip. The tear-open aid should be designed in such a way that its effect does not develop due to an increase in pressure in the bag, i.e. if the pressure in the closed bag rises, there should be no independent relief of excess pressure through a partial opening of the head seam (14), in particular in the area of the tear-open aid (15). It is therefore advisable to provide, for example, a marking tip with the tip pointing upwards. The pressure is usually built up by heating the contents, e.g. by microwave treatment in a closed bag, e.g. Steam developed. The side seams (12) are preferably slightly above the transverse head seam (14). This reduces the risk of the head seam tearing into the side seam.

The automatic overpressure relief (6) can be, for example, at least one recess (8) in at least one of the jacket surfaces, the recess (8) being completely sealed by a seal (7) which tightly connects the front and rear sides (16) of the jacket part, is surrounded. A recess (8) in the same geometric shape is preferably opposite each other in the front and rear of the jacket part. The recess (8) is drawn as an example circular. Other geometric shapes, such as oval, polygonal, such as triangular, quadrangular, etc., can also be used. The automatic overpressure relief (6) is arranged in the region of the upper end of the bag and in particular close under the head bag seam. It is essential that the automatic overpressure relief (6) is arranged above the maximum fill level of the filling material in the bag, so that the filling material cannot escape through the recess (8).

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As an example, a marking tip (15) is shown in FIG. 1a. This configuration makes it possible to move the automatic overpressure relief far into the area of the upper end and thus to increase the maximum fill level.

As a rule, after the pressure has been released, the head seam (14) between the tear strip and the back of the bag can e.g. by hand, fully opened and the contents of the bag removed.

FIG. 2 shows the side view of a bag package made of a plastic film (21) folded in the bottom area. A V-shaped fold (22) forms the bottom of the bag.

The front and the back of the bag are connected via the side seams (32).

The V-shaped fold (22) in turn shows recesses (23) which make it possible that the side seams of the front and back, in the area of the V-shaped fold, touch and are connected to one another. Furthermore, bevel seams (33) are drawn in, which, as mentioned above, serve to improve the stability of a stand-up pouch and to relieve the side seams. The top seam (34) seals the back with the front of the bag due to its sealing connection.

An automatic overpressure relief (35) is shown as an example in the form of a tear-open tip. The tip expediently points towards the inside of the bag to ensure that the pressure can be relieved at the intended location, the tear-open tip. When the pressure in the bag increases and the resulting volume expansion, the bag head seam at the tear-open point opens to the extent that pressure equalization can take place. It is then possible to open the bag over the entire bag head seam, for example by hand, and to remove the contents.

Further modifications of the examples described above or other combinations of individual described features with one another are possible.

The parts of the bag, such as the front and back and optionally the bottom part, can be firmly connected via the tear-off layer attached to at least one side of the plastic film, or, even without a tear-off layer, by adhesive bonding.

The bag packaging according to the invention expediently has two connections of different strengths, in particular sealing seams. In the area of the base parts and the side seams, a separable connection and in particular a separable seal is preferably used, the head bag seam and the seam of the automatic overpressure relief are advantageously designed to be easy to tear open.

Typical tear forces of the separable connection are greater than 30 N / 15 mm resp. the destruction of the bag next to the separable seams. Typical tear forces of the easily tearable head seam are 5 to 20 N / 15 mm.

The tear forces from the seams can be in the case of sealed seams via the geometry of the sealing tool, the sealing pressure, the sealing temperature and / or the

Sealing time or correspondingly influenced by the amount of energy during ultrasonic welding or sealing.

The sealed seams are expediently carried out with a tool with rounded edges. The sealing seams produced with such a tool have higher strengths than those which were produced with a sharp-edged tool. The latter can have a notch effect. However, this fact can be used to design the seal seams on the tear strip.

The sealing pressure depends on the material and the thickness of the plastic film and is typically 1 to 10 kg / cm2 sealing area.

The sealing temperature also depends on the material and thickness and can range from 140 ° C to 240 ° C.

The sealing is preferably controlled via the temperature and / or time.

Temperatures of 190 ° C. to 220 ° C. are preferably used for separable connections. For connections that are difficult to tear open, e.g. Temperatures from 180 ° C to 200 ° C applied. For easily tearable connections, temperatures e.g. from 170 ° C to 190 ° C.

In practice, the sealing time can be 0.3 to 3 sea. be; a sealing time of 0.6 to 1 sea is preferred. for permanent connections, from 0.4 to 0.8 sea. for connections that are difficult to tear open and from 0.5 to 0.6 lake. for easily tearable connections.

The present invention also relates to the use of the pouch packaging according to the invention and, in particular, stand-up pouch packaging for packaging filling goods which are heated in particular by microwave treatment. Food and food preparations are primarily considered as filling goods. Such foods can be in liquid, pasty, solid form or a mixture of these forms. Food preparations can also be in liquid, pasty, gelatinous, solid or semi-solid form or represent mixtures of such forms. Furthermore, the food and food preparations can be filled into the pouch packaging according to the invention in raw, semi-cooking or cooking form. The pouch packaging can be made, for example, aseptic or low-aseptic. For example, this can be done by sterilization, such as radiation or preferably heat sterilization. Other methods, such as chemical methods using preservatives, are also possible. In practice, the contents are filled into the open-ended bag packaging, the opening is sealed, for example by sealing, and the filled and closed bag packaging under counter-pressure to the sterilization conditions, e.g. Warm to 121 ° C for 30 minutes, subjected. A bag packaging treated in this way can then be stored for longer periods. The filled and closed pouch packaging can be subjected to a microwave treatment to prepare the contents and in particular to reheat it.

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CH 683 836 A5

be set. With increasing heat development and heating of the contents of the bag, the volume increases e.g. through steam development. When a certain internal pressure is reached, e.g. can be between 4 and 10 Pa, the pressure equalization takes place via the automatic pressure relief. After completion of the reheating procedure, all or part of the bag head seam can easily be e.g. opened by hand.

Claims (8)

Claims 1. Bag packaging for fillable goods which can be heated by microwave treatment, comprising a jacket part or jacket part and bottom part, made of flexible plastic film, the front and back of the jacket part or the jacket part and the bottom part being connected to one another by sealing seams, characterized in that the jacket part a plastic film is formed which contains a tear-off layer on the inside and the bag packaging in the area of the upper end of the jacket part has a removal opening which is closed by an easily tearable bag head seam, and the bag in the area of the upper end has an automatic overpressure relief. 2. Bag packaging according to claim 1, characterized in that the automatic overpressure relief represents a tear-open aid on the bag head seam. 3. Bag packaging according to claim 1, characterized in that the automatic overpressure relief is arranged within the area of the bag interior in the form of a tear-open opening. 4. Bag packaging according to claim 3, characterized in that the automatic overpressure relief is arranged within the area of the bag interior and in the immediate vicinity of the head bag seam. 5. Bag packaging according to claim 1, characterized in that the plastic film of the jacket part or the jacket and bottom part has a barrier layer against gases and vapors. 6. Bag packaging according to claim 5, characterized in that the barrier layer is a ceramic layer. 7. Bag packaging according to claim 1, characterized in that the flexible plastic film from the outside inwards a polyethylene terephthalate film with a thickness of 10 to 15 µm, a SiOx layer, where x is a number from 1.2 to 1.7 and the layer thickness is 10 to 100 nm, a further polyethylene terephthalate film with a layer thickness of 10 to 15 µm and a tear layer in the form of a 40 to 60 µm thick PP film or a tear layer in the form of a 40 to 60 thick thick PP film . 8. Use of the bag packaging according to claim 1 for packaging filling goods which are reheated by microwave treatment. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 8th