NL1016978C2 - Device and method for packaging and preparing food and method for manufacturing such a device. - Google Patents

Abstract

Device (1) for the packaging and preparation of food, (20), provided with a dish-shaped container (4), which is provided at the topside with a take out opening, closed by at least two layers of film (8,10) which are placed above each other, whereby at least the bottom film is provided with perforations (18), whereby means are provided to allow for the escape of vapour during use between the bottom film and a film placed above it.

Description

Title: Device and method for packaging and preparing food and method for manufacturing such a device.

The invention relates to a device for packaging and preparing food. Such a device is known from EP 0971849.

This known device, in particular suitable for use in a microwave oven, comprises a plastic container, closed at the top by a foil layer which is sealed on the container. A valve is attached in the foil that functions as a valve. When heating food present in the container, vapor pressure will arise in the container, as a result of which the pressure within the container becomes superatmospheric. As a result, the temperature in the container will simply rise to above 100 ° C, as a result of which food can be prepared particularly quickly, while maintaining the desired food properties. The valve is thereby adjusted such that vapor can escape through the valve at a desired pressure, so that excessive pressures and temperatures are prevented.

This known device has the advantage that food can be packaged and transported therein easily, wherein the food remains fresh, is protected against external influences and moreover is prevented that moisture can leak out of the container. In addition, the food herein can be prepared quickly, while preserving, for example, flavor, texture, vitamins and the like, while preventing excessive pressures. However, a disadvantage of this device is that a relatively expensive valve must be used.

Moreover, the fitting of such a valve (one single or more valves per device) is complex and cumbersome, in particular as this must be done with particular care. After all, in the case of inaccurate mounting, vapor will be able to leak away along the valve and / or the valve will be able to peel off from the film, as a result of which the device as such can no longer function properly. , with all the associated dangers.

Another drawback of this known device is that the valve can become clogged with food, as a result of which it cannot let any vapor escape, at least to a limited extent. A further drawback is that the device will have to be opened fairly quickly after heating by the user, since otherwise the device will be compressed by pressure differences. When opening, there is a danger that the user will come into contact with hot vapor that is still present.

It has already been proposed to provide such a device wherein an opening is provided on the foil layer instead of a flap, closed off by a sticker.

This sticker must be removed by the user prior to heating. A disadvantage of this is that there is no rapid pressure build-up in the device and the user must first manipulate the device for use.

The object of the invention is to provide a device of the type described in the preamble, wherein the drawbacks of the known devices are avoided, while maintaining the advantages thereof. To that end, a device according to the invention is characterized by the features of claim 1.

A device according to the invention offers the advantage that the film layers can be easily applied, wherein during use a desired excess pressure can be created in the package and can be maintained as a result of the means for escaping said vapor. Vapor can only escape when a certain, increased vapor pressure is obtained. Since no valves are necessary, the aforementioned disadvantages are avoided. When assembling the device, the film layers can be supplied together and be fixed on the container, for example as preformed laminate, but can also be separately from each other. 3 are supplied. The film layers can easily be supplied from a roll and be cut to size, so that different sizes of containers can also be used easily. Moreover, as a result, a suitable combination of foil layers and containers can always be selected, for example depending on the food to be packaged and prepared. In this context, preparation should be understood as at least including preparation for consumption, including heating.

In an advantageous embodiment, a device according to the invention is characterized by the features of claim 3.

By designing at least one foil layer, in particular the upper foil layer, gas-tight and liquid-tight, the advantage is achieved that pressure can be built up relatively quickly between the lower and said gas-tight and liquid-tight foil layer, which moreover also rapidly builds up pressure the container is obtained to the desired level.

In an alternative embodiment, a plurality of perforated film layers are provided, wherein in the direction remote from the lower layer, the or each upper film layer has perforations with a total passage area smaller than that of the lower film layer.

In a particularly advantageous embodiment, a device 20 according to the invention is characterized by the features of claim 5.

In such a device, vapor taken up between the two film layers can escape because the second film layer at least partially comes off when the pressure between the film layers exceeds a certain increased preselected pressure. Such a device can be manufactured in a particularly simple manner, while automatic operation is directly obtained, permissible excess pressures being easily adjusted by selecting the said connections.

In an alternative embodiment, the or each second foil layer is designed such that it tears when a certain pressure is exceeded for releasing the excess pressure.

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Use of a closed, gas and liquid-tight foil layer above the perforated lower foil layer offers the advantage in a device according to the invention that in the closed state it is prevented that moisture can leak away through the perforations to the environment, while moreover an airtight seal can be obtained . This means that, for example, a modified atmosphere can also be created within the container before or during packaging, for example for the preservation of packaged food. Only when the film layers at least partially come apart from each other will such a gas be able to escape.

It is preferable that the perforations in the lower film layer are relatively small, for example round with a cross-section between 50 and 5000, preferably between 100 and 750 μπι or otherwise formed openings with a comparable surface area. In particular, the dimension is between 200 and 500 µm. A favorable flow-through resistance for vapor is hereby obtained, while such a perforation can be arranged relatively accurately.

In a device according to the invention, the lower film layer is preferably composed of a thermally stable laminate, in particular a laminate of polyester and polypropylene. The or each film layer located on the lower film 20 is herein preferably a heat-sealable, pealable plastic film, in particular polyester. However, other choices from film materials consisting of one or more layers can also be selected, depending on the application, which choice will be immediately clear to a person skilled in the art.

The invention further relates to a method for manufacturing a device for packaging and preparing food, characterized by the features of claim 10.

Such a method offers the advantage that in a particularly quick and simple manner a package can be manufactured in which food can be packaged, transported and prepared. With such a method, different superimposed films can be supplied, for example as a laminate, prior to being connected to the container, while the film layers can moreover be supplied separately from one another. The film layers can for instance be supplied from a roll and be cut to size immediately before or during placement. A particularly great freedom of design is hereby obtained, whereby packages of different sizes can be easily manufactured.

The invention further relates to a method for preparing food, characterized by the features of claim 13.

With such a method the advantage is achieved that packaged food can be placed directly in an oven, in particular a microwave oven or steam oven, in which the food can be heated and prepared quickly, without the quality thereof being adversely affected. On the contrary, in a method according to the present invention, the qualities of the food are preserved in a particularly favorable manner. In particular, the packaged food is prevented from, for example, drying out or losing texture, color, aromas or the like, at least being undesirably influenced. In addition, vitamins are retained in this way.

The invention further relates to an assembly of at least two foil layers for closing food containers, characterized by the features according to claim 14.

Such an assembly is particularly suitable for use with a device or method according to the invention.

Further advantageous embodiments of a device or method according to the invention are given in the further subclaims.

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V. 6

To clarify the invention, exemplary embodiments of a device and method according to the invention will be further elucidated with reference to the drawing. In the drawing: Fig. 1 schematically shows, in exploded perspective view, a packaging device according to the invention;

Figure 2 is a sectional side view of a package according to Figure 1, in the closed state;

3A - C in three consecutive steps heating food in a package according to the invention;

Figure 4 shows diagrammatically in sectional side view a package according to the invention, in an alternative embodiment.

Figure 5 shows diagrammatically a detail of an edge of a container with foil layers; and Figure 6 shows a corner of a packaging device according to the invention in an alternative embodiment.

Figure 1 shows a packaging device 1 according to the invention, schematically in exploded perspective view. This packaging device 1 comprises a box-shaped container 2, for example manufactured from a heat-sealable plastic, known from practice and suitable for use in a microwave or steam oven. This box-shaped container 2 is provided on the top with a take-out opening 4, surrounded by an outwardly extending, flat edge 6. Furthermore, this packaging device 1 comprises a first, lower foil layer 8 and a second, upper foil layer 10. are understood to be closest to the take-out opening 4, upper foil layer as the or each foil layer on the side of the lower foil layer 8 remote from the take-out opening 4. In the embodiment shown, two foil layers 8, 10 are provided, with a surface size approximately corresponding with the top side of the container 2 defined by the longitudinal edge 6. The film layers 8, 101, 10, 7 are made of a material that can be fixed by heat sealing on the longitudinal edge 6. The lower foil layer is preferably made of a thermally stable heat-sealable laminate, the upper foil layer 10 of a heat-sealable plastic, preferably a heat-sealable 5 and pealable plastic. Figure 5 shows film layers 8, 10 above the longitudinal edge 6. The lower film layer 8 then consists of, for example, a laminate made of a first layer 14 of polypropylene with a thickness of, for example, between 60 and 120 µm, in particular 90 µm and a second layer 12 of polyester applied thereto with, for example, a thickness between 10 and 15 µm, in particular 12 µm. The upper foil layer 10 is then, for example, made of polyester with a thickness of approximately 25 µm, preferably 20 µm heat-sealable and pealable. The materials and dimensions mentioned here are only shown by way of example and should in no way be construed as limiting.

As can be seen from figure 1, a perforation pattern 16 is provided in the lower foil layer 8, in the embodiment shown a series of perforations 18 with a substantially circular cross-section. These perforations have, for example, a diameter between 50 µm and 5000 µm, in particular between 200 and 500 µm, so that water droplets can pass through at least vapor 20 if there is sufficient pressure within the container 2, as will be explained in more detail below.

During use, as appears, for example, from Figure 2, a quantity of food 20 is placed in the box-shaped container 4, whereafter the first, lower foil layer 8 is fixed on the longitudinal edge 6 all around by means of first sealing means 22. The first sealing means 22 are here schematically represented by a hatching. It will be clear that any desired, suitable sealing method can be applied for fixing the first, lower film layer 8 on the longitudinal edge 6, at least on the container 4. In the embodiment shown in Figure 2, the lower 1 8 film layer 8 the second film layer 10 secured with the aid of second sealing means 24, in the embodiment shown directly above the first sealing means 22 and the longitudinal edge 6. The first sealing means 22 and second sealing means 24 are thereby chosen such that the lower foil layer 8 is relatively fixed to the longitudinal edge 6. This connection, formed by the first sealing means 22, is stronger than the connection between the lower foil layer 8 and the second foil layer 10, formed by the second sealing means 24. This object will be further discussed. It will be clear that in the drawing the thicknesses of the foil layers 8, 10, the first and second sealing means 22, 24 and the box-shaped container 4 are not shown in proportion.

When food 20 is packaged in the packaging device 1 in the manner shown in Figure 2, the device can be transported and stored, while the packaging 1 with the food 20 in the closed state can be placed in a microwave (microwave) or steam oven or the like . When the relevant oven is subsequently switched on, the food can be prepared with a method according to the invention, further elucidated with reference to Figs. 3A-C. In this context, preparation should be understood as at least comprising preparation for consumption, including heating.

Figure 3A schematically shows the package 1 according to the invention, in a relatively cold state. A relatively low temperature To (for example room temperature or lower) and a relatively low pressure Po, for example comparable to the atmospheric pressure Pa outside the container 4, prevails in the inner space of the box-shaped container 4.

Optionally, a shielding gas can be included in the inner space of the container 4 for obtaining a modified atmosphere. As a result, in some cases the food is even better protected.

After the oven has been switched on, the food 20 is heated, whereby moisture is present in the food 20 and any added moisture is added. - r 9 is heated and will evaporate. As a result, the pressure within the container 4 will rise to a relatively high pressure Pi, whereby the temperature will also rise to a relatively high temperature Ti. As a result of the pressure increase, vapor will be forced through openings 18, as represented by arrows 25. This vapor will flow between the lower film 8 and the upper film 10, against flow prevented by the second sealing means 24. The pressure will be between the lower foil layer 8 and the upper foil layer 10 therefore rise to a relatively high pressure P2, whereby the temperature will also rise slightly to a temperature T2. When the pressure P2 exceeds an upper limit, at least a part of the second sealing means 24 will be broken, as shown in Fig. 3C, as a result of which vapor can flow away between the lower foil layer 8 and the upper foil layer 10, into the environment, whereby pressure equalization will occur to about atmospheric pressure Pa. The space within the container 4 below the lower film layer 8 will thereby expand, while the pressure will equalize to a pressure P3, which is maximum, while the temperature will be set to a relatively high temperature T3. The temperature T3 will, for example, be above 100 ° C, given the relatively high vapor pressure P3. This means that the food 20 will be heated relatively quickly, the quality of the food being preserved, in particular not undesirably drying out and / or changing in texture, color or taste, while moreover, for example, vitamins are preserved in a particularly suitable manner. Because the second sealing means are automatically broken at least partially when the pressure P2 increases between the film layers 8, 10, a desired pressure is automatically set, depending on, for example, the degree of heating, the amount of vapor occurring, the inner volume of the container 4 below the lower foil 8 and the total passage area of the passage openings 18 in the lower foil layer 8.

Figure 4 shows an alternative embodiment of a device 30 according to the invention, wherein the lower foil layer 8 and the upper foil layer 10 with the aid of first sealing means 22 and second sealing means 24, respectively, both directly on the longitudinal edge 6. are fixed. The advantage is hereby achieved that a particularly good connection is obtained between the second foil layer 10 and the further container 4, 5, also when the upper layer of the lower foil layer 8 is not, at least poorly heat-sealable, or a desired relatively weak connection is not suitable. .

In a further alternative embodiment, as shown in Fig. 6, the upper foil layer 10 and the lower foil layer 8 are directly attached to each other, the lower foil layer 8 being secured directly to the longitudinal edge 6. A weakening line 26 is provided in the upper foil layer 10, which line is initially closed. When this package 4 with food 20 is placed in an oven and is heated, vapor will flow between the first and second foil layer 8, 10 in the manner shown in Fig. 3 A and B, increasing the volume between them and building up a pressure P2.

If the limit pressure P2 is exceeded, the tear line 26 will tear open, allowing vapor to escape to the environment. In this embodiment, the lower foil layer 8 and the upper foil layer 10 can remain connected to each other and, when the packaging device 1 is opened, can be taken together and discarded.

In the embodiment shown a substantially rectangular container 4 is used. However, it may be preferable to use a container with, for example, a round or oval shape, as a result of which a more uniform heating can be obtained, while moreover a more even distribution of heating and vapor pressure can occur.

This description is based on a box-shaped container as it is known from practice. Such a box-shaped container is for instance manufactured from plastic or plastic laminated cardboard, manufactured by, for example, deep-drawing or thin-drawing, vacuum forming, fluorescent; .

11 injection molding or similar techniques. In the exemplary embodiments shown, a box-shaped container is used, made from a material that can be sealed by per se known sealing methods, in particular heat-sealing methods. Such materials usable for this purpose are sufficiently known from practice.

The invention is in no way limited to the exemplary embodiments shown in the description and the drawing. Many variations thereof are possible within the scope of the invention as set forth in the claims. For example, perforations 16, 18 can be provided in a different way, for example in a regular or irregular matrix of openings 18. The number and size of the perforations can easily be selected, depending on the products to be heated, surfaces, contents of the container and such. Such a choice will be immediately clear to the skilled person. It is also possible to use more than two film layers, for example two perforated film layers on top of each other, optionally covered by a closed film layer, wherein the perforations of the intermediate film layer preferably have a joint passage area that is smaller than that of the perforations of the lower film layer, at least a flow resistance that is higher than that of the lower film layer. As a result, pressure can be built up in stages. Furthermore, a container can be used which is divided into different compartments, wherein at least the lower film layer is also fixed on a partition wall of the different compartments. In particular, the perforations in the lower film layer can differ per compartment, for obtaining different pressures and / or temperatures in those compartments. Any suitable material can be used within a packaging device according to the invention. Instead of using heat sealing technology, one or more of the film layers can also be fixed on the container in a different manner, for example using a suitable gluing technique, welding technique or the like. The upper film layer can also be designed in such a way that it tears when a desired maximum pressure is exceeded, to allow vapor to escape.

These and many comparable variations are understood to fall within the scope of the invention as set forth in the claims.

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Claims (16)

1. Device for packaging and preparing food, provided with a box-shaped container which is provided at the top with a removal opening, closed by at least two superimposed layers of foil, wherein at least the lower foil is provided with perforations, means are provided for vapor escaping during use between the lower film layer and an upper film layer. Device as claimed in claim 1, wherein the at least two layers of foil are sealed on a longitudinal edge of the container. Device as claimed in claim 1 or 2, wherein at least one foil layer 10 is gas and liquid-tight. Device as claimed in any of the foregoing claims, wherein at least one foil layer located above the lower foil layer comprises perforations with a total passage that is smaller than the total passage of the perforations in the lower foil layer. Device as claimed in any of the foregoing claims, wherein the lower foil layer is connected to the container and the or a second foil layer is connected to the lower foil layer, preferably along the longitudinal edge thereof, wherein the connection between the lower foil layer and the container is stronger then the connection between the lower foil layer and the second foil layer for the formation of the means for escaping said vapor, all this such that during pressure build-up in the container, gas passes through the perforations in the lower foil layer between the lower foil layer and the the second foil layer can flow and the connection between the second foil layer and the lower foil layer will at least partially break, while the connection between the container and the lower foil layer is maintained. Device as claimed in any of the claims 1-5, wherein the lower foil layer is connected to the container and the or a second foil layer is connected to the lower foil layer, preferably along the longitudinal edge thereof, wherein the connection between the lower foil layer and the container The connection between the lower foil layer and the second foil layer and the foil layers are chosen such that, when pressure builds up in the container, gas can flow through the perforations in the lower foil layer between the lower foil layer and the second foil layer and the connection between the second foil layer and the bottom film layer will break at least partially and / or create an opening in the second film layer for the formation of the means for escaping said vapor for reducing the pressure between the film layers, the connection between the container and the lower film layer is retained. 7. Device as claimed in any of the foregoing claims, wherein the perforations in the lower foil layer have a cross-section between 50 µm and 5000 µm, preferably between 100 and 750 µm, in particular between 200 and 500 µm. 8. Device as claimed in any of the foregoing claims, wherein the lower foil layer is composed of a thermally stable laminate, in particular a laminate of polyester and polypropylene. Device as claimed in any of the foregoing claims, wherein the or each foil located on the lower foil is a heat-sealable, preferably a heat-sealable and peelable plastic foil, in particular a polyester. 10. Method for manufacturing a device for packaging and preparing food, wherein a container is filled with a portion of food, after which the container is sealed substantially gas and liquid tight by at least two superimposed foil layers which are on the container, wherein a foil layer is used as the lower foil layer with perforations through which during use gas, at least vapor, can flow out of the container between the foil layers, such that pressure build-up occurs between the foil layers. 11. Method as claimed in claim 10, wherein a gas and liquid-tight film layer is used as the or a second film layer situated on the lower film layer. 12. Method as claimed in claim 10 or 11, wherein the foil layers are fixed on the container and / or each other, in particular sealed, the lower foil layer being connected to the container in such a way that this connection is stronger than the connection between the or each above 10 foil layer and the lower foil layer and / or the container, all such that the second foil layer during use as a result of pressure build-up between the foil layers at least partially comes loose without the lower foil layer becoming detached from the container. 13. Method for preparing food, wherein the food is brought into a container, which container is closed with at least one lower, perforated film and a second film arranged over it, after which the container is placed in a closed state in an oven, in particular a microwave oven or a steam oven, after which the food is heated, such that vapor is developed in the container, which vapor flows at least partially between the perforated foil and the second foil and between them leads to increased pressure, wherein the second foil at least partially comes loose and / or tears, to release the built-up pressure while the lower foil remains firmly connected to the container and the pressure in the container is kept at least slightly above atmospheric. 14. Assembly of at least two foil layers for sealing food containers, wherein a first foil layer is provided with perforations and a second foil layer is gas and liquid-tight or is provided with perforations with such a total passage surface that the flow resistance iv: over that is greater than the flow resistance of the joint perforations in the lower film layer. An assembly of at least two foil layers according to claim 14, wherein at least the first foil layer is heat-sealable. An assembly of at least two film layers according to claims 14 or 15, wherein the first and second film layer are heat-sealable. 'i; _ .....