GB2449660A

GB2449660A - Fluid filled device for indicating thawing of frozen food products

Info

Publication number: GB2449660A
Application number: GB0710258A
Authority: GB
Inventors: Julian Poyner; Giles Poyner
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-30
Filing date: 2007-05-30
Publication date: 2008-12-03
Also published as: GB0710258D0

Abstract

A device for indicating whether a frozen food product 50 has thawed comprises an enclosure 10 encapsulating a fluid 20, said enclosure comprises means 30 to allow the fluid to escape from the enclosure on thawing to indicate thawing of the frozen food product. In a first embodiment the means comprises a hole, which may be covered with a flap, that allows the fluid to flow out of the enclosure on thawing. In a second embodiment the device comprises a second enclosure (130, Fig 2a) and the means comprises a passageway (150, Fig 2a) between the two enclosures that allows the fluid to flow therebetween on thawing. Thawing of the frozen food product is indicated by the emptying of the fluid from the enclosure. The application also discloses a method for manufacturing the device (Fig 3).

Description

A device and associated manufacturing process for indicating if a

frozen food product has thawed Freezing food is a common method for preserving the quality of the food once it has been cooked. This process normally involves cooking the food, placing it into a suitable container whilst it cools, freezing the food, sealing the container and then presenting the food in a suitable protective and decorative package. These food packages are then stacked in a suitable container and shipped to a warehouse for further distribution or delivered straight to the retailer or food outlet.

During the storage, delivery or shelving of the frozen food product it can start to thaw if not kept in a refrigerated state. The food can then start to grow bacteria that would be harmful to the consumer of the food. This thawing process is unseen by the manufacturer, retailer and more importantly the consumer of the food product.

The prior art for this type of detection is to use a temperature strip that can show the extremes of temperature that the food product has undergone. The issues with these strips are that they are expensive to put on individual frozen food products.

It is an object of the current invention to show two configurations of a device and a method for producing said device which is low cost for indicating that the product has undergone a harmful thawing process.

According to the first aspect of the invention there is a small thin film plastic enclosure (similar to bubble wrap or film) that contains a fluid. The fluid inside the enclosure is frozen.

Preferably, the enclosure is further described by detailing a hole or flap attached to the enclosure that allows a fluid to enter the enclosure and exit the enclosure.

Preferably, the enclosure is manufactured from thin film plastic which is deformable allowing the fluid to escape during a thawing process.

Preferably, the enclosure further comprises, where needed, an adhesive backing for permanently fixing the device to the frozen food product packaging.

According to the second aspect of the invention there is a frozen fluid within the enclosure. The puipose of the frozen fluid inside the enclosure is to indicate if any thawing of the food product has occurred by the fluid exiting through the hole or flap in the enclosure. This leakage of fluid is then used as an indicator of the frozen food product having undergone a thawing process.

Preferably, the fluid is inserted into the enclosure and then immediately frozen solid.

Preferably, the colour, staining potential, freezing and thawing properties of the fluid can vary as required. The colour of the fluid can change so that it can be clearly seen by the colour mismatching against the artwork of the packaging or staining said packaging. The freezing and thawing aspects of the fluid can be varied based on the temperature that the frozen food should thaw against to indicate that the food product should not be consumed.

According to the third aspect of the invention is described an alternative enclosure comprising a double chamber that allows the fluid to flow from one chamber to another chamber.

Preferably, the flow between the chambers is prevented or assisted by a hole, flap or membrane between said chambers.

According to the fourth aspect of the invention there is a manufacturing process for building such device.

Preferably, this comprises a sheet of small enclosures, which are pierced by a syringe style dispenser and the fluid encapsulated within the enclosure. The enclosure is then immediately frozen and is ready as a finished device.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figures Ia depict the device made from a thin film plastic enclosure encapsulating the fluid in a liquid or frozen state with an entrance/exit hole or flap. If required the enclosure can have an adhesive backing allowing it to be permanently fixed to the food packaging; Figure lb depicts the thin film plastic enclosure once the fluid has thawed and exited the enclosure; Figure 2a depicts a double chambered thin film plastic enclosure encapsulating the fluid in one chamber with a hole, flap or membrane between the chambers; Figure 2b depicts the double chambered thin film plastic enclosure once the thawed fluid has passed into the second chamber; and Figure 3 depicts the sheet of enclosures from Figures 1 a being filled with fluid by the syringe and then being immediately frozen.

The Figures are schematic representations useful for understanding the present invention, and are not drawn to scale.

Figure 1 a is a side view of the device with an enclosure 10, containing the fluid 20, which has been inserted through the entrance/exit hole 30 and then frozen.

The enclosure 10 is typically greater than 4mm diameter with better results occurring around the 25mm diameter and takes the form similar to commercially available bubble wrap or film. The volume of the enclosure can change depending on the quantity of fluid 20 that is required to exit the enclosure 10. The enclosure 10 can be made from a thin film of plastic which is able to contain the fluid 20 whilst it is in a frozen state and then deform sufficiently to allow the fluid 20 to escape whilst undergoing the thawing process. It will be appreciated that the enclosure 10 can be made from any suitable material (for example rubber or urethane) that can enclose a frozen fluid 20 with an entrance/exit hole 30 that allows the fluid to escape during a thawing process.

It will be appreciated that the enclosure 10 is for convenience to indicate that a fluid has thawed and escaped through the exit hole 30. It could also be envisaged that the fluid 20 could be frozen, in an ice cube tray, and placed on or near the frozen food product in its raw state thereby negating the need for an enclosure.

It will be appreciated that where advantageous the enclosure 10 can have an adhesive backing 40 to permanently fix it to any part of the product packaging 50. This will help prevent the product from being dislodged from the product packaging during transit and handling.

It will also be appreciated that the enclosure 10 can be assembled to the frozen food product itself, its sealed film lid or the outer packaging.

The purpose of the fluid 20 is to indicate that thawing has occurred on the frozen food product. The exiting of the fluid 20 from the enclosure 10 is a clear visual indication that thawing of the frozen food product has occurred, as shown in Figure lb. The fluid 20 can have valying properties depending on the application. These can be, and not limited to, the temperature it freezes and thaws at, the speed at which it thaws, its colour and ability to stain the packaging, its density and whether it is food safe.

By experimentation it can be found at what temperature and by what rate the frozen food product thaws and how quickly the food product produces harmful bacteria. By measuring these thawing parameters the chemical constitution of the fluid 20 can be matched or tailored to suit. For example if the product develops harmful bacteria after minutes then the fluid 20 can be designed to exit the enclosure 10 before or closely after this time.

The exiting of the fluid 20 through the entrance/exit hole 30 of the enclosure 10 is used as a visual indication that the frozen food product has undergone a thawing process, as shown in Figure lb. Therefore the colour and staining of the fluid 20 can be designed to show most vividly against the packaging it is attached to. The fluid 20 could even change colour upon thawing. If the enclosure 10 is attached to the sealing film of the frozen food package then the ability of the fluid 20 to stain the film is important as most films are made from chemically resistant plastic.

It is also beneficial to insert the fluid 20 into the enclosure 10 using a syringe type of apparatus with a needle and keep the needle inside the enclosure 10 during the freezing process. This helps to maintain a fluid pressure inside the enclosure 10 by stretching the thin film material wall which tries to contract during thawing process and forces the fluid 20 out of the entrance/exit hole 30.

It will be appreciated that the fluid 20 could take the form of a gel or paste that remains in a state where it cannot escape the enclosure until it reaches the desired thawing temperature.

The entrance/exit hole 30 is either created in the enclosure 10 beforehand or made when the syringe needle or other dispensing apparatus pierces the enclosure 10. The purpose of the hole 30 is to allow fluid 20 to enter the enclosure 10 and then allow the fluid 20 to exit the enclosure 10 during the thawing process. The fact that the fluid 20 is frozen prevents the fluid 20 from escaping the enclosure 10 unnecessarily. It will be appreciated that this hole 30 can take any form that will allow fluid 20 to easily enter and exit the enclosure 10. The position of the hole 30 can also appear at any location on the enclosure 10. By experimentation, the best position is towards the lower section of the enclosure 10, as shown in Figures 1 a. For manufacturing ease and where an adhesive strip is not being used, the hole can be placed underneath the bubble near the centre. If advantageous the entrance/exit hole 30 can take the form of a flap. This can be used to delay the fluid 20 exiting the enclosure 10 when in a liquid form for a period of time.

Figure 2a shows a second embodiment of this invention. The enclosure 110 has two chambers 120 and 130. The fluid 140 is contained within chamber 120 in a frozen state and then only transfers through to chamber 130 through a hole, flap or membrane 150 between the chambers. The fluid entrance hole 160 in chamber 120 is sealed once the fluid has entered chamber 120 so that during thawing it can only enter chamber 130. The advantage here is that instead of the fluid leaking over the packaging it is neatly retained within chamber 130.

The fluid 140 has similar properties as described above for fluid 20.

The hole or flap 150 has similar properties as described above for hole or flap 30.

The membrane is semi permeable or fully permeable of any sort that will allow the fluid 140 to pass from chamber 120 to chamber 130. It is preferable for the fluid to flow to chamber 130 and remain within that chamber indicating that a thawing process has occurred, as shown in Figure 2b.

Figure 3 shows a potential manufacturing flow for producing the device. A sheet 210 of enclosures 10 is pierced by a syringe 220 or a number of syringes in a row. If needed, the syringe 220 first sucks a quantity of air from the bubble. The syringe 220 then dispenses the fluid 20 into the enclosure 230. The fluid 20 is dispensed until the enclosure 230 is stretched causing a fluid pressure build up within the enclosure 230.

Once the row of filled enclosures 230 is complete the enclosures 230 undergo an immediate freezing process using an appropriate freezing machine 250 locally and, or across the row. At an appropriate point near the freezing of the edges of the fluid 20 the syringe apparatus 220 can be withdrawn from the frozen enclosure 240. The frozen enclosure 240 is then ready for packaging and shipping to be used on a frozen food product.

Claims

Claims 1. A device that indicates if a frozen food product has thawed

comprising: an enclosure; the enclosure including an entrance / exit hole or flap; the enclosure encapsulating a fluid which is then frozen to retain it within the enclosure; the frozen fluid being encapsulated within the enclosure until a thawing process occurs and then escapes the enclosure through the entrance I exit hole or flap.
2. A device as claimed in claim 1 wherein, the enclosure is made from a suitable material to encapsulate a fluid in a frozen state; a suitable material being commercially available bubblewrap.
3. A device as claimed in claim 2 wherein, the enclosure being made of a suitable material which deforms to allow a fluid to escape under a thawing process.
4. A device as claimed in claim I where the enclosure encapsulates a frozen fluid, gel or paste where a change to the fluid, gel or paste occurs during the thawing process.
5. A fluid as claimed in claim 4 where the fluid, gel or paste exits an enclosure during the thawing process only.
6. A fluid as claimed in any preceding claim, which is in a frozen state without an enclosure but sealed within the packaging whereby it can be seen if the fluid has undergone a thawing process.
7. A fluid as claimed in any preceding claims wherein, the properties of the fluid can be tailored to suit the application. These properties being, and not limited to: its freezing point; its thawing point: the speed at which it thaws; its initial colour and colour after thawing; its staining ability; its density.
8. A fluid as claimed in any preceding claims that is dispensed into the enclosure either under pressure or not and then frozen.
9. A device as claimed in claim 1, wherein the enclosure being made such that it can have a preformed hole for accepting a fluid or being able to be pierced to accept a fluid.
10. A hole as claimed in claim 9, wherein this same hole is able to release fluid under a thawing process.
11. A hole as claimed in any preceding claim where the form of the hole can vary with respect to its diameter or shape (a slit).
12. A hole as claimed in any preceding claim where the position of the hole on the enclosure can vary with respect to the amount of fluid to escape and the ease at which the fluid needs to escape the enclosure.
13. A hole as claimed in any preceding claim where a flap is created near to the hole to prevent the fluid from exiting the enclosure with the flap's form varying as required to suit the application.
14. An alternative second device that indicates if a frozen food product has thawed comprising: an enclosure with two chambers; the first chamber being able to encapsulate a frozen fluid and the second chamber able to accept a thawing fluid through a hole, flap or membrane between the two chambers A hole, flap or membrane between the two chambers which allows fluid to pass from one chamber to the next under a thawing process.
15. A device as claimed in claim 14 where previous claims 2 to 5, 7 to 9, 11 and 13 apply.
16. A device as claimed in claim 14, wherein a membrane separates the two chambers.
17. The membrane as claimed in claim 16, which allows thawed fluid to pass from one chamber to an adjoining chamber during a thawing process but not return.
18. A device for detecting the thawing of a frozen food product that is attached to the outer packaging or the sealed film lid, or placed inside the food container or attached to the food product itself.
19. A food container as claimed in claim 18, wherein a dedicated compartment is formed within the food container to house the device so that it can be clearly seen.
20. Outer packaging as claimed in claim 18, wherein the outer packaging is formed to house a dedicated compartment to clearly show where the device is located.
21. A manufacturing process that is able to take a sheet of enclosures and preferably follow these associated steps: pierce the enclosure with a syringe type of apparatus; if required, suck any air from the enclosure; dispense a fluid into the enclosure and then immediately freeze the enclosures to create finished devices.