Dishware Unit and Method for Sealing Partially Prepared Meals

Abstract

The invention relates to a dishware unit for packaging, transporting, and/or serving meals and to a method for sealing at least partially prepared meals, comprising a body which is covered with a film. An adhesive is introduced between the film and the body in an adhesive region in order to seal the dishware unit. The film and the dishware unit have such a degree of surface tension that the adhesive at least largely adheres to the film when the film is removed, wherein the surface tension in the adhesive region in the film is greater than the surface tension in the adhesive region in the body.

Claims

1. A tray unit, particularly a dish, for the packaging, transport, and/or consumption of foods, with a film covering a body, wherein an adhesive for sealing the tray unit is present between the film and the body in an adhesive region, characterized in that the film and the tray unit have a surface tension such that the adhesive adheres at least predominantly on the film upon removing the film, wherein the surface tension in the adhesive region (8) in the film (15) is greater than the surface tension in the adhesive region (8) in the body (2).

2. The tray unit according to claim 1, wherein the body has at least one base section and at least one edge section and wherein the adhesive region is configured in the edge section.

3. The tray unit according to claim 1, wherein the edge section is raised at least in the adhesive region with respect to the base section.

4. The tray unit according to claim 1, wherein there is configured in the body an application surface for the adhesive, which is provided by the adhesive region.

5. The tray unit according to claim 1, wherein the body (the tray unit) is essentially made of at least a ceramic-type material and wherein the body is particularly made at least partially of magnesium oxide.

6. The tray unit according to claim 1, wherein the film is made of a plastic material and has a thickness of between 50 m and 150 m.

7. The tray unit according to claim 1, wherein the film is made at least partially of a material such as polyethylene terephthalate.

8. The tray unit according to claim 1, wherein the lower side of the film is attached to the body and wherein the surface tension in the lower side of the film is modified by means of a surface treatment.

9. The tray unit according to claim 8, wherein at least a part of the lower side of the film is surface treated by means of a corona treatment.

10. The tray unit according to claim 8, wherein the type, the intensity, and the duration of the surface treatment depend on the surface tension to be set.

11. (canceled)

12. The tray unit according to claim 1, wherein at least one food is arranged in the body and covered by the film and wherein an intermediate space presents a partial vacuum.

13. The tray unit according to claim 12, wherein a gas mixture which is made up of more than 50% CO.sub.2, more than 10% N.sub.2, and less than 10% O.sub.2 is present in the intermediate space.

14. The tray unit according to claim 13, wherein the composition of the gas mixture is adapted to the food arranged in the body.

15. The tray unit according to claim 13, wherein the percentage of O.sub.2 in the gas mixture is greater than 2% or between 3% and 10%.

16. The tray unit according to claim 1, wherein the protruding film is cut contactless outside the body.

17. The tray unit according to claim 1, wherein the adhesive is applied by means of an adhesive application machine comprising nozzles and/or stationary elements such as, for example, scrapers, and/or rotary elements such as, for example, rollers.

18. The tray unit according to claim 1, wherein the adhesive is a hot-melt adhesive.

19. The tray unit according to claim 18, wherein the adhesive is a polyolefin-based adhering hot-melt adhesive and at 160 C. has a viscosity greater than 1500 millipascal-seconds.

20. A method for sealing at least partially prepared foods, in which the foods are positioned in a tray unit and covered with a film, characterized in that an adhesive (21) is applied in an adhesive region of the tray unit and a film is adhered thereto and in that a surface tension of the film and/or of the tray unit is influenced such that the adhesive remains adhere at least predominantly on the film when tearing the film off, wherein the surface tension in the adhesive region in the film is greater than the surface tension in the adhesive region in the body.

21. The method according to claim 20, wherein the lower side of the film being glued to the tray unit is at least partially surface treated to increase the surface tension of the film.

22. The method according to claim 20, wherein the adhesive is applied in the adhesive region of the tray unit by means of rolling, wiping, scraping, and/or spraying.

23. The method according to claim 20, wherein the partial vacuum is generated in an intermediate space between the tray unit and the film, and/or wherein at least a partial gas exchange is carried out in the intermediate space.

24. The method according to claim 23, wherein at least one inert gas is added.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 shows a plan view of a tray unit and a perspective depiction of two tray units in a cooking appliance;

[0030] FIG. 2 shows a highly schematic cross-section through a tray unit;

[0031] FIG. 3 shows a plan view of another tray unit;

[0032] FIG. 4 shows a schematic section through the tray units according to FIG. 3;

[0033] FIG. 5 shows a schematic depiction of a tray unit in an adhesive application machine;

[0034] FIG. 6 shows a highly schematic depiction of a tray unit with foods positioned thereon while covering with a film;

[0035] FIG. 7 shows a highly schematic depiction of a tray unit with foods arranged thereon, sealed with a film;

[0036] FIG. 8 shows a highly schematic depiction of a sealing device for packaging a tray unit with foods arranged thereon in a first position; and

[0037] FIG. 9 shows the sealing device according to FIG. 8 in a second position.

DETAILED DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 shows a highly schematic plan view of a tray unit 1 which is configured as a rectangular dish and comprises a body 2. The body has a base section 3 and an edge section 4 which, in this case, comprises a total of four edge segments in the longitudinal and transverse borders. The edge section 4 laterally demarcates the base section 3. The base section provides a space sufficient for several foods 30 which can be a component of a part of a meal, for example. It is possible for part of a complete meal to be placed in the tray unit 1. Of these foods, at least some can be partially prepared, i.e. at least partially precooked. All the components of a dish may have the same aggregate state, however, the components in different dishes may also have different aggregate states. In that sense, for example, a first tray unit may also contain deep-frozen foods and another tray unit may only contain foods with refrigerated components.

[0039] In the specific embodiment, the tray unit 1 has a tray width 5 of about 17 cm and a tray length 6 of about 33 cm. However, other dimensions are also possible. Particularly, the outer dimensions of the tray unit 1 are adapted to the inner dimensions of a cooking level 102 of a cooking space 101 of a cooking appliance 100. In a particularly preferred manner, two tray units 1 can be located at the same time at the cooking level 102 of the cooking appliance 100. Two or preferably four tray units 1 can therefore be housed at the same time (at two cooking levels). Preferably, the width 105 of the cooking space is about more than twice the width 5 of the tray unit and/or the length 106 of the cooking space is about more than twice the length 6 of a tray unit. The tray units should fill a cooking level 102 of the cooking space 101 as completely as possible, but also still leave a smaller intermediate space with respect to one another and with respect to the cooking space walls. This therefore makes it easier for operator to easily remove the individual tray units. It is particularly advantageous when the intermediate space between and around the tray units is 10% to 40%, and particularly 20% to 40%, of the surface of the cooking level.

[0040] The cooking appliance 100 has at least one high-frequency heat source 103 the irradiated frequency of which can be modified in a controlled manner during operation. Preferably, at least two antennas (not depicted) irradiate high-frequency energy and the irradiated frequencies of the high-frequency heat sources 103 and the phases thereof can be modified depending on the measured scattering parameters. Specific regions and/or components or foods 30 in the tray units 1 can therefore be cooked or regenerated in a targeted manner, whereas other foods 30 remain almost or completely free from the influence of the high-frequency heat source 103 due to their composition and/or consistency. By means of housing two or more tray units at the same time, two or more foods arranged on the tray units can be accordingly regenerated and/or fully cooked at the same time. This therefore reduces the number of cooking appliances that are required at the same time when the final preparation of a food for a group of people should be performed at the same time.

[0041] It is possible for the cooking appliance 100, in addition to the high-frequency heat source 103, to further have additional heat sources, such as those used in conventional cooking appliances.

[0042] FIG. 2 shows a highly schematic cross-section of a tray unit 1. The body 2 of the tray unit 1 has a base section 3 and an edge section 4 in which, in this case, the edge section 4 comprises an oblique region and a horizontal region attached thereto which is oriented essentially parallel to the base section 3. The oblique region has an angle 7 which is, for example, between 10 and 45. Alternatively, the edge section can also be rounded or angled. It is possible for a decorative edge having, for example, a circumferential pattern, to also be configured in the edge section 4.

[0043] FIGS. 3 and 4 show a plan view and a cross-section of a specific embodiment of a tray unit 1. The tray unit 1 is essentially configured as a rectangle and has rounded corners. In this case, the body 2 of the tray unit 1 comprises a large base section 3 occupying an essential part (>50% or >75%) of the surface of the body 2. An edge section 4, which is used for gripping the tray unit 1 and also for holding the film 15, surrounds the base section 3. In this case, there is configured in an independent manner in the embodiment yet another second base section 23 in the body 2 which is used, for example, for housing an independent container 24. A sauce can be housed in the container 24, for example, or other components can be positioned therein.

[0044] In this case, the outer edge 9 forms the gripping edge for gripping the tray unit.

[0045] The adhesive region 8 is provided on an application surface 18 which, in this case, is formed by means of a raised area 19 in the edge section 4. The raised area 19 with the adhesive region 8 is configured such that it is circumferential to and surrounds the base section 3 in its entirety. A reliable sealing of the foods 30 in the tray unit 1 can thereby be assured.

[0046] FIG. 5 shows a highly schematic depiction of an adhesive application machine 20 through which the tray units 1 pass in the through-feed method and are provided with an adhesive coating. To apply the adhesive, nozzles 26 and/or scrapers 27, but preferably a rotary roller 28 can be used, where an adhesive or a sealing material 21 is supplied thereto by means of a storage container 31 with an adhesive store 33. The roller has a relief structure to enable picking up the adhesive better. The transport rollers 32 transporting the tray unit in relation to the roller 28 may have a silicone coating or the like, from which the adhesive that may be located thereon can easily be removed.

[0047] FIGS. 6 and 7 show different tray units 1 when the film 15 is adhered on the adhesive region 8 of the tray units 1, in which FIG. 6 depicts the state before sealing the film 15 and FIG. 7 shows the state after generating the partial vacuum and sealing the film 15.

[0048] The tray unit 1 depicted in FIG. 6, in which different foods 30 are arranged, is in principle already covered with a film 15. In this case, the film 15 is shown before generating the partial vacuum. The size of the film is adapted to the dimensions of the tray unit 1. The film is made of PET and may particularly have a thickness of 75, 85, or 100 m.

[0049] The partial vacuum is generated in the intermediate space 16 between the film and the body 2 to achieve a longer shelf life by means of less oxygen in the sealed inner space. Furthermore, protection against the sliding of the individual foods 30 in the dish 1 is achieved. Preferably, at least 20% of the volume of air is removed from the intermediate space 16, which is obtained by directly covering the foods 30 with the film 15. Preferably, the vacuum is not generated in at least 5% or at least 10% of the volume of the intermediate space, such that an amount of residual air or particularly a gas mixture remains in the intermediate space 16. By generating the partial vacuum, the pressure the film exerts on the foods 30 is reduced. With an excessive vacuum, the pressure exerted by the film may lead to excessive deformation of the individual foods 30, so the foods or the meal arranged therein may lose quality in terms of their appearance and/or taste. By means of sealing (adhesion), the components or foods 30 are housed in a more protected manner without using a film 15, given that the volume of oxygen is limited in the intermediate space 16. Furthermore, the foods 30 are supported. Overturning and sliding during transport or insertion in the cooking appliance 100 are thereby prevented. Furthermore, an additional protection is achieved because before or after generating the partial vacuum, the air is replaced with a particular gas mixture containing a much smaller amount of oxygen. In this case, it is still important for the packaging machine, before performing sealing and supplying the protective gas, to contain therein a clean atmosphere, given that the exchange of the atmosphere that is predominant up until that time in the packaging machine must be performed.

[0050] FIG. 7 shows a tray unit 1 with a film 15, in which the partial vacuum was generated in the intermediate space 16 and air or gas was therefore partially removed from the intermediate space 16. In this case, the sealing material or the adhesive 21 is also illustrated on the surface of the edge section 4 in the adhesive region 8.

[0051] Preferably, the gas mixture at least in the intermediate space 16 is modified. This can be performed, for example, by means of supplying inert gas components. The exchange of the gas or gas mixture present in the region of the foods is preferably performed before generating the partial vacuum. To that end, a considerable carbon dioxide component is preferably supplied. Preferably, a gas mixture of this type is supplied, such that with a partial vacuum between about 60% and 85% carbon dioxide, and between 10% and 30% nitrogen, and between 3% and about 10% oxygen are ultimately located in the intermediate space 16. In a specific configuration, a composition of about 75% carbon dioxide and about 20% nitrogen and about 5% oxygen has been proven to be advantageous. In all the configurations, the percentage of oxygen is preferably at least 2%, and particularly between 3% and 8%, or 10%. Too small of an oxygen percentage can lead to unsightly discolorations of the foods (beef), so a visually unappealing impression is generated. The quality of the foods can also be affected.

[0052] FIG. 7 shows a blade 29 with which the film section protruding out from the edge of the body 2 can be removed without the blade 29 touching the body 2 of the tray unit 1.

[0053] In all cases, the film 15 is first removed before completely cooking or tempering the (partially prepared) foods 30 in the cooking appliance 100.

[0054] FIGS. 8 and 9 show a sealing device or sealing machine 200 for sealing a tray unit 1 or the foods 30 arranged thereon. In this regard, the tray unit is suitably positioned in a housing space 206 of the sealing machine 200 or, for example, moves automatically entering the housing space 206. As described above, in the base section 3 of the body 2 of the tray unit 1 there are positioned components or foods 30 to be covered by means of the film 15. The individual foods 30 can together form a part of a meal. Furthermore, the partial vacuum shall be generated in the intermediate space 16 between the film 15 and the foods 30 or the base section 3. To that end, a suction device 202 is used.

[0055] The film 15 is supplied by means of a film supplying unit 201 and it is then sized or was already suitably sized beforehand. By means of a blowing device that is not depicted, air or another gas mixture is blown between the tray unit 1 and the film 15, and the film 15 is then lowered onto the tray unit 1 with the foods positioned thereon. After that, the sealing tool 204 of the sealing machine 200 moves downwards and presses the film 15, in this case in the embodiment, onto the adhesive region 8 of the edge section 4. Pressing the film onto the sealing material or the adhesive in the adhesive region 8 can also be performed by means of air pressure or gas pressure.

[0056] Previously, the film 15 was heated by means of a tempering device that is not individually depicted, such that it can be more readily expanded.

[0057] FIG. 9 shows the sealing machine 200 in a second position in which the sealing tool 204 has almost reached the edge section 4 or the adhesive region 8 of the tray unit 1. The film 15 is thereby placed at least in sections on the adhesive region 8 and on the top parts of the foods 30 and covers same. After the sealing tool 204 has reached the adhesive region 8 and pressed on the film 15, the gas mixture is suctioned out of the housing space 206, and thereby also out of the intermediate space 16 between the film 15 and the tray unit 1, by means of the suction device 202. In this regard, pressure control is performed by means of a pressure gauge 203 which, by means of the supply conduit of the suction device 202, records a measurement for a space inside the intermediate space 16. However, in this regard, the pressure sensor is not located in the intermediate space 16 between the film and the body of the tray unit 1. A partial vacuum is generated, whereby the degree of vacuum also depends on the foods to be packaged or their components. The parameters to be set in the packaging machine (among others, the sealing time, the sealing temperature, the amount of pressure in mbar) are different for each dish. The fragility of the respective food products requires an adapted partial vacuum, for example.

[0058] After sealing, the tray units 1 with the components found therein are stored, refrigerated, or even deep-frozen according to requirements. It is important for deep-freezing not to be performed until after sealing to prevent condensation on the film 15. The tray unit 1 can then be arranged inside an outer packaging in which more units can also be housed.

[0059] For example, for the exchange of the gas mixture in the intermediate space 16, the inner space of the sealing machine 200 can first be filled with the desired gas mixture, such that the intermediate space 16 is also filled with the desired gas mixture. The partial vacuum can then be generated, such that the volume of the intermediate space 16 is provided with the desired gas mixture.

[0060] Generally, a tray unit 1 which is preferably made of magnesium oxide porcelain is provided. The tray unit is particularly made as a dish and preferably has a total length of about 330 mm (+/15 mm) and a total width of 170 mm (+/15 mm). The tray unit 1 is particularly suitable for the insertion and transport of the dish packaged with the film in standardized Gastronorm food containers. In preferred configurations, at least one additional container can be positioned in the tray unit. For example, a small dispenser or the like, which is suitable for being filled with a sauce or small side dish components and the like, can be provided. The exact positioning of the container is predefined by means of an independent base section of corresponding size. An independent base section of this type also furthermore provides a defined distance of a container of this type with respect to the edge section 4, which is advantageous for the sealing process.

[0061] Preferably, an adhering hot-melt adhesive which provides an adhesive region 8 particularly on a raised area 19 or in the edge section 4 is used. The adhesive region 8 is configured circumferential and continuously and is designed particularly with rounded corners, such that the adhesive as a sealing material may be applied uniformly and with sealing capacity.

[0062] The adhesive to be used preferably has a high stability and particularly a viscosity of at least 1500 millipascal-seconds with an application temperature of about 180. Otherwise, the adhesive is suitable for contact with food products.

[0063] It is possible for a decorative border to be provided in the edge section. However, the dish can also be configured without a decorative border.

[0064] Preferably, a PET film, which is also particularly suitable for contact with food products, is provided for sealing the foods and/or at least partially prepared meal components. The later preparation of the foods in a cooking appliance entails the removal of the film 15 before preparation. It is thereby assured that upon the removal of the film 15 a large part or especially largest part or complete removal of the adhering hot-melt adhesive can be warranted. Surface residues of the adhesive remaining, for example, on the edge of the dish would constitute a drawback and would be unfavorable during use.

[0065] To ensure that the adhesive also peels off as completely as possible when the film is peeled off the tray unit, the film has a correspondingly adapted surface tension of at least 38 mN/m, and particularly 42 or 43 or 44 mN/m.

[0066] Particularly, it is highly advantageous if the surface tension of the film used is greater than the surface tension of the dish. For these purposes, at least the lower side of the PET film used is treated, at least in sections, by means of a surface treatment. Particularly, a corona treatment is performed. In this regard, the side facing the food product is subjected to the surface treatment. The dose to be added in the corona treatment is the specific electric energy input in the continuous band of film. Basically, the adhesive behaves in such a way that it always tends towards the higher surface tension. Basically, the sizing of the corona treatment must be adjusted at most to the level required for optimally generating a subsequent adhesion of the food product thus covered on the lower side of the PET film as much as possible.

[0067] The adhesive is applied on the tray unit 1 with an adhesive application machine, in which the adhesive application machine can have stationary elements as well as rotary elements, as well as nozzles. In a preferred configuration, a rotary element is considered including a shearing effect to prevent crumb formation. The application of the adhering hot-melt adhesive is preferably performed with a clearly specified amount and temperature.

[0068] Preferably, the tool does not touch the tray unit 1 when pressing the film in the sealing process. For example, the pressure can be generated by means of gas pressure, whereby a gas mixture is blown on the film. This prevents the dish from being damaged.

[0069] Generally, the invention provides an advantageous tray unit with foods which are arranged in the body and covered by means of a film and an advantageous sealing method.

List of Reference Numbers

[0070] 1 device in the cooking area [0071] 2 tray unit, dish [0072] 2 body [0073] 3 base unit [0074] 4 edge section [0075] 5 width [0076] 6 length [0077] 7 angle [0078] 8 adhesive region [0079] 9 gripping edge, edge [0080] 10 decorative edge [0081] 11 decorative line [0082] 12 decorative width [0083] 14 lower edge section [0084] 15 film [0085] 16 intermediate space [0086] 17 lower side [0087] 18 application surface [0088] 19 raised area [0089] 20 adhesive application machine [0090] 21 sealing material [0091] 22 auxiliary edge [0092] 23 base section [0093] 24 container [0094] 25 lower cup [0095] 26 nozzle [0096] 27 scraper [0097] 28 roller [0098] 29 blade [0099] 30 food, component [0100] 31 container [0101] 32 transport roller [0102] 33 adhesive store [0103] 100 cooking appliance [0104] 101 cooking space [0105] 102 cooking level [0106] 103 high-frequency heat source [0107] 105 width of the cooking space [0108] 106 length of cooking space [0109] 200 sealing machine [0110] 201 film supplying element [0111] 202 suction device [0112] 203 pressure gauge [0113] 204 sealing tool [0114] 206 housing space