AU2005317983A1

AU2005317983A1 - Cooking bags

Info

Publication number: AU2005317983A1
Application number: AU2005317983A
Authority: AU
Inventors: Robin W. Chudley
Original assignee: FFP Packaging Solutions Ltd
Current assignee: FFP Packaging Solutions Ltd
Priority date: 2004-12-22
Filing date: 2005-11-09
Publication date: 2006-06-29
Also published as: ZA200704922B; JP2008525276A; KR20070104345A; GB0428229D0; GB0522886D0; GB2421488A; CN101087724A; EP1831086A1; CA2591135A1; WO2006067363A1

Description

WO 2006/067363 PCT/GB2005/004321 1 Cooking Bags The present invention relates to sealed bags in which food stuffs can be cooked. In recent times, there has been a general move towards providing pre-packaged food stuffs in packaging which can be put straight into a cooking appliance such as an oven, the food contained within the packaging then being cooked whilst still contained within the packaging. This has the advantage that the packaging can contain and, if appropriate control the cooking environment to a degree, for example by controlling the pressure within the packaging, so improve the cooking operation. Different food types may also be cooked in the same oven without being exposed to each other, which the case of particularly aromatic foods, can result in a detrimental effect on the taste of the food. Furthermore, the cooking by-productions such as juices and the like are retained within the packaging and can easily be disposed of following removal of the packaging from the oven, thereby providing a much cleaner cooking experience. These systems have the drawback, however, that once cooking is finished, the packaging must be removed from the cooking appliance and then opened to enable the contents to be removed for consumption. The packaging is normally very hot when it is so removed from the appliance and there is hence a high risk of the user burning themselves during this operation. According to the present invention there is provided packaging suitable for use in or on a heating appliance, comprising a bag in which, in use, is sealed an article for heating, the bag having an aperture formed therein over which is sealed a film of material which forms a window in the bag, wherein the seal between said film and the material of the bag is sensitive to temperature and/or pressure such that the window at least partially detaches automatically from the bag upon the temperature and/or pressure within the bag reaching a predefined level so as to vent the atmosphere within the bag.

WO 2006/067363 PCT/GB2005/004321 2 A packaging in accordance with the invention has the advantage that the food stuffs can be packed within the bag for compact storage and, upon heating, the increase in pressure will cause the packaging to expand to form a pillow before the window vents the internal atmosphere. The aperture within the bag can then be used to remove the food from the packaging once it is cooked using suitable tongs or the like without the user having to handle the packaging itself, the film then being easily removable by the user fully to expose the aperture. In this way, the problems of the prior art system are overcome whilst the advantages such as containing the cooking by-products are maintained. Preferably, the bag is formed of a material which is stiff enough to maintain the pillowed shape of the bag once the internal pressure is released upon detachment of the window. In this way, the bag can advantageously be used as a container to serve the food through the window. Advantageously, the film window is sealed to the foil with a seal that has a rupture strength lower than that of the bag such that, in use, the bag allows any steam build up to vent without rupturing the bag, thus removing any need for the customer to pierce the bag. Preferably, the strength of the seal is furthermore such that, in use, the window is user detachable at any time. In this way, the film can be removed early on in the cooking process for a drier, more roasted result, whilst the film can be left in place longer for a more steamed, succulent result. Preferably, the bag is formnned of an aluminium foil material, in particular of gauge between substantially 25 and 500 microns, but preferably of gauge between substantially 25 and 100 microns, which has advantageously high temperature resistance suitable for withstanding the high temperatures of grilling and oven cooking. Desirably, the aperture is formed in one side panel of the bag which, in use, may be positioned upward facing in a cooking appliance. The film is preferably WO 2006/067363 PCT/GB2005/004321 3 formed of a polyester or polyester polythene material and may be formnned as a panel which is slightly larger than the aperture in the bag, the overlap with the bag providing the seal between the film and the bag, or, alternatively, may extend across the whole side panel of the bag in which the aperture is formed. In one embodiment, the film may be transparent so as to enable view of the food stuff whilst the packaging is still sealed. Advantageously, the film is furthermore anti-fog coated to ensure that the food stuff can be seen at all times, particularly when, in use, the bag is taken out of a chiller and on to a hot grill. Some food products may require breathable properties for which a suitable film solution can be produced. The gas transmission rates can then be adjusted, preferably via micro-perforations in the film, to match the respiration rate of the food stuff to be stored therein so as to maximise the shelf life of the product. The packaging may have food stuffs pre-packaged therein, but, in one embodiment is provided with a user sealable opening by means of which user prepared products can be inserted into the bag and the bag then sealed for cooking the produce in the manner described above. The opening, for example, may be provided with an adhesive strip of a strength which has a greater resistance to pressure than the seal between the window and the bag. In particular, the adhesive may be provided on a lip which is folded over a number of times before adhering to the bag so as to ensure a good seal. Advantageously, the sealable opening is created with adhesive on the outside of the bag only such that no adhesive can, in use, migrate into the food stuff within the bag when very high temperatures are reached. Preferably, however, the opening is sealable, either mechanically or by hand, without adhesive. In particular, the lip of the opening is desirably folded over a number of times before being crushed together so as to ensure a good seal. Alternatively, though, where the bag is formed of a weldable material, the opening is WO 2006/067363 PCT/GB2005/004321 4 sealable with a pennrmanent weld seal once the bag has been filled with a food product. In particular, ultrasonic welding is desirably used to create the weld seal. The packaging is suitable for a wide range of cooking appliances but is particularly advantageous for use on a barbeque or the like, the bag with a pre-prepared food product, in possibly a raw, partially or fully cooked state, being placed directly onto the barbeque with the window facing upwards so as to prevent escape of cooking by-products or the like from the bag. Upon the bag expanding into a pillow shape, the material of the bag is preferably stiff enough to support itself in its expanded position once the film has released to vent the bag and hence relieve the internal pressure.

Claims

1. A packaging suitable for use in or on a heating appliance, comprising a bag in which, in use, is sealed an article for heating, the bag having an aperture formed therein over which is sealed a film of material which forms a window in the bag, wherein the seal between said film and the material of the bag is sensitive to temperature and/or pressure such that the window at least partially detaches automatically from the bag upon the temperature and/or pressure within the bag reaching a predefined level so as to vent the atmosphere within the bag.

2. A packaging according to claim 1, wherein the bag is formed of a material that is stiff enough to support its own weight and to maintain an inflated shape once, in use, the window detaches from the bag.

3. A packaging according to any of the previous claims, wherein the bag is formed of an aluminium foil material.

4. A packaging according to claim 3, wherein the aluminium foil material is of gauge between substantially 25 and 500 microns.

5. A packaging according to any of the previous claims, wherein the aperture is formed in one side panel of the bag.

6. A packaging according to any of the previous claims, wherein the film is polyester or polyester polythene.

7. A packaging according to any of the previous claims, wherein the film is larger than the aperture but has a border running proximately thereto.

8. A packaging according to claim 7, wherein the film extends across the whole side panel of the bag in which the aperture is formed.

9. A packaging according to any of the previous claims, wherein the film is transparent

10. A packaging according to any of the previous claims, wherein the film has a gas transmission rate that, in use, matches the respiration rate of the food product.

11. A packaging according to any of the previous claims, wherein the bag has a user-sealable opening by means of which a user prepared article for heating can be inserted into the bag. WO 2006/067363 PCT/GB2005/004321 6

12. A packaging according to claim 11, wherein the opening is provided with an adhesive strip of a strength which has greater resistance to pressure than the seal between window and bag.

13. A packaging according to claims 12, wherein the adhesive strip is provided on a lip which, in use, is folded over a number of times before adhering to the bag.

14. A packaging according to any of claims 1-10, wherein the bag has an article for heating pre-packaged therein.

15. A packaging according to any of the previous claims, wherein the packaging is for use in or on a cooking appliance and, in use, the article for heating is a food product.