GB2374583A

GB2374583A - Thermochromic indicator for food containers

Info

Publication number: GB2374583A
Application number: GB0109875A
Authority: GB
Inventors: Arnold Edward Rees
Original assignee: Jackel International Ltd
Current assignee: Jackel International Ltd
Priority date: 2001-04-21
Filing date: 2001-04-21
Publication date: 2002-10-23
Also published as: GB0109875D0; WO2002086433A1

Abstract

A food storage container comprising a bag (10) formed of clear plastics film material having indicators (12, 13) printed thereon in the form of a series of frames (20, 21, 22; 23, 24, 25). In one of the frames (21, 24) of the indicators (12, 13) there is printed a " ! " in thermochromic ink and in another of the frames (22, 25) there is printed an "X" in non-thermochromic ink. The "X" is covered by a layer of thermochromic ink. If the temperature of food contained in the bag 10 exceeds a predetermined temperature, ie 05{C for one indicator (12) and 37{C for the other indicator (13), the " ! " and the covering layer of thermochromic ink disappear leaving blank the frame (21, 24) formerly containing the " ! " and showing the "X" in the formerly obscured frame (22, 25).

Description

A FOOD STORAGE CONTAINER This invention relates to a food storage container for storing food in solid or liquid form.

In WO 98/49995 there is disclosed a liquid container incorporating a temperature sensor for indicating when temperature of a wall thereof reaches a predetermined value.

The container has particular but not exclusive application to babies'feeding bottles and provides an indication as to whether the contents of a feeding bottle are too hot to be fed safely to a baby.

In US-A-4,156, 365 there is disclosed a temperature indicator which is carried on a food holding vessel, the indicator comprising a thermochromic layer which is arranged to change colour twice in a selected temperature range. The arrangement is such that there is a first colour change at a lower temperature in the range as the temperature of food in the vessel rises above that lower temperature and there is a further colour change at a higher temperature in the range as the temperature of the food rises above that higher temperature. The purpose of the invention is to indicate whether the temperature of the food is within the range, when it will be safe to consume the food.

It has been discovered that, if baby food is stored in cold storage at a temperature in excess of 5 C, the temperature may provide an environment which could cause incubation of bacteria in the food which, if subsequently heated and

consumed, could result in the baby contracting gastroenteritis.

According to the present invention, there is provided a food storage container carrying an indicator which indicates visually when cold storage of the container has exceeded a predetermined temperature.

Following is a description, by way of example only and with reference to the accompanying drawing, of one method of carrying the invention into effect.

The drawing is an elevation of a food storage container comprising a bag 10 which is formed of a sheet of clear plastics film material which is printed with a scale 11 for indicating volume of contents contained in the bag 10 and which is also printed with indicators 12 and 13. The sheet is folded to provide two layers of film material, one superimposed on another, and to provide a bottom fold 14 of the bag 10. The two layers of film material are welded one to another to provide side seams 15,16 of the bag 10. The sheet may also be provided with a pair of tabs, one of which is shown at 17, and lines of perforations 18 extending across a base of the respective tabs 17. The tabs 17 assist in opening of the bag 10 to provide an opening at 19.

The indicators 12,13 each comprise a series of printed rectangular frames 20,21 and 22 and 23,24 and 25. The frames 20 and 23 have printed therein different symbols 26 and 27 which represent respectively"correct temperature storage"and"correct temperature for consumption". The

frames 21 and 24 each have the symbols ". J" printed therein in thermochromic ink. The frames 22 and 25 each have printed thereon an"X"symbol and the frames 22 and 25 are blocked by a layer of thermochromic ink which is opaque but which clears at a predetermined temperature. With regard to rectangular frames 21 and 22, the change occurs at temperatures in excess of 5 C and with regard to rectangular frames 24 and 25, the change occurs at temperatures in excess of 37 C.

Prior to use, the bag 10 is opened by pulling apart the tabs 17 and then tearing off the tabs 17 along the lines of perforations 18. The bag 10 is then inserted into a bottle having a clear cylindrical wall and an upper circumferential margin of the bag 10 is folded outwardly over a rim of a neck of the bottle.

Contents are then inserted into the bag 10 and a top containing a teat is then located on the neck so as to trap the upper circumferential margin of the bag 10 between the top and the neck of the bottle. The bottle containing the bag 10 and contents is then placed in cold storage.

Assuming that the temperature of the cold storage environment does not rise above 50C the indicator 12 will show the information indicated in the accompanying drawing. However, if the temperature of the cold storage environment rises above 5 C, the thermochromic ink of the indicator 12 will show a change in that the". J" in frame 21 and the opaque covering of the frame 22 will disappear resulting in the frame 21 becoming blank and an"X"appearing in the frame 22. This is a message that the contents contained in the bag 10 have

not been stored at the correct temperature and should not be consumed.

The other indicator 13 will function in a similar manner if the bottle is removed from cold storage and placed in water which is then heated such that the temperature of the contents of the bag 10 rises beyond 37 C, such temperature being in excess of that which is safe for consumption by a baby.

The thermochromic ink referred to above may comprise a thermochromic leuco dye as supplied by Matsui Shikiso Chemical Co. Ltd of Yamashina-ku, Kyoto-shi, Japan or thermochromic chiral nematic or cholesteric esters as supplied by Merck & Co. Inc. of Rahway, New Jersey, USA.

It will be appreciated that the bag 10 may be manufactured by a method different from that described above. For example, the bag 10 may be formed from a tube of clear plastics film material which is sealed at the bottom.

It will also be appreciated that the images which indicate temperature may differ from those shown on the bag 10 shown in the accompanying drawing.

Claims

CLAIMS 1. A food storage container carrying an indicator which indicates visually when cold storage of the container has exceeded a predetermined temperature.
2. A container as claimed in Claim 1 wherein the indictor includes a portion printed in thermochromic ink.
3. A container as claimed in Claim 2 wherein the indicator includes a frame containing a symbol and the symbol is overprinted with the thermochromic ink.
4. A container as claimed in Claim 3 wherein the indicator includes a plurality of frames at least two of which contain respectively the symbol and another symbol, the other symbol being printed in thermochromic ink and the said overprinting and the said other symbol being such as to change at the same temperature.
5. A container as claimed in Claim 4 wherein there is provided a second indicator corresponding to the said indicator but which changes at a different temperature compared with the said indicator.
6. A food storage container substantially as hereinbefore described and as illustrated in the accompanying drawing.