FIELD OF THE INVENTION

The present invention relates to a coolant pack particularly useful in the cold storage of items such as foodstuffs.

Whilst the following description is in terms of packaging of foodstuffs, it is to be understood that the invention is not so limited and in particular could apply to packing of any article which requires a cool atmosphere. For example, horticultural products.

BACKGROUND OF THE INVENTION

When packaging foodstuffs such as fruit, care must be taken to ensure that the cooling medium is not such as to burn the fruit. In particular, the use of the dry ice may burn or discolour frui though nevertheless keeping it at a temperature to assist its longevity. Normal ice has the same effect.

In one attempt to provide a substitute for these conventional cooling mediums, it is known to use packages of coolants which are either pre-frozen or pre-cooled and are placed arbitrarily i the packaging for the foodstuffs. The use of such coolant packages has been found to be effective. However, some food¬ stuffs are still sensitive to direct contact with very cold surfaces and as such may be marked or discoloured.

The object of the present invention is to provide a means for indirectly cooling articles. Thereby minimising the effect of very cold surfaces upon the product to be packed.

DESCRIPTION OF THE INVENTION

The present invention provides a coolant pack comprising:

(a) a first chamber defined by a plurality of walls of flexible material;

(b) coolant disposed in the first chamber, and

(c) at least one second chamber which is filled with gas and disposed on or about the first chamber.

The use of the second chamber which is gas-filled, interposed between the coolant and the article to be cooled, considerably reduces the likelihood of such coolant marking or discolouring, articles sensitive to extremes in temperature, for example, a foodstuffs. Additionally, this pack permits the use of varying types of coolants which hitherto were found unsuitable because o their effect upon foodstuffs or the like.

The principal involved in this form of pack is the use of the gaseous medium as a heat exchanger which permits gradual cooling of the article in a controlled way. By varying the amount of ga located in the second chamber or the size of the second chamber, it is possible to provide a pack which is suitable for cooling any type of article.

The provision of the gas-filled second chamber is also conducive to save handling of the packed article. Clearly, by appropriate pressurisation of the gas within the second chamber, the second chamber will present a cushion to absorb shocks which may otherwise be transmitted to the article during movement of a container in which the article is packed.

In one preferred form of the invention, the first chamber may be partially or fully filled with coolant. Whether there is a partial or full filled of coolant depends upon the proposed use of the coolant pack. Where only small gaps are presented betwee articles, a partial filled first chamber is more desirous as it

enables ready deformation of the pack to the space in which it i to be located.

The gas with which the second chamber is filled may be any convenient gas such as air or other gas which is preferably iner to both the cooling medium and article to be cooled. Similarly, the gas should be innocuous to humans so that upon leaking it will not present a health hazard to any person packing or unpacking the container.

In a further embodiment of the invention, the flexible material may be moisture impermeable in which case coolant material which is sensitive to the presence of moisture can be utilised. Further maintenance of a moisture level in the packaging may be desirable. For example, in horticultural products, it is desirable to ensure that the horticultural products such as flowers do not dry out.

In another embodiment of the invention, the flexible material ma be moisture permeable and present an additional advantage. Wher it is desirable that any moisture be removed from about the article adjacent to the material, the outer surface of the first chamber is provided with openings and the coolant material selected from superabsorbent coolant materials. The superabsorbent material will absorb any itinerant water or moisture passing onto the outer surface of the first chamber. Further maintenance of a moisture level in the packaging may be desirable. For example, in horticultural products, it is desirable to ensure that the horticultural products such as flowers do not dry out.

In yet a further embodiment of the invention, the second chamber is defined by flexible gas impermeable material and is formed as a plurality of second chambers about the first chamber. By adoption of a regular array of second chambers about the first chamber, it is possible to maximise the cushioning advantage of the coolant pack. Typically, the second chambers are in the for of bubbles disposed on the first chamber. As indicated, each of these bubbles is filled with gas and if one of the bubbles is

ruptured, this will not affect the usefulness of the other bubbles thereby ensuring that the cushioning and cooling effect is substantially maintained.

Further, by providing discreet areas between the second chambers, it is possible to effectively separate the article from the firs chamber and allow air permeating there through to also carry out heat exchange.

In yet a further embodiment, the second chambers may be only disposed in one discreet area or on one side of the first chambe where a direct cooling effect is also desirable on one side of the first chamber whilst an indirect cooling is desirable on the other side.

DESCRIPTION OF THE DRAWINGS

The invention will now be illustrated in more detailed with reference to accompanying drawings in which:

Figure 1 is a perspective view of the pack according to one aspect of the invention.

Figure 2 is a cross-section of the pack of Figure 1.

Figure 3 is an exploded perspective view of Figure 1.

Figure 4 is an exploded view of an alternate form of the invention.

Figure 5 is a cross-sectional view of the alternate form of the invention of Figure 4.

In the drawings, a package A is depicted having an outer layer 1 of flexible plastic material forming a container into which coolant material 3 is placed. Outer surface 1 is sealed about its periphery thereby encapsulating coolant material 3. A

plurality of bubbles 2 are formed on the outer surface 1, each bubble 2 being filled with gaseous material.

The plurality of bubbles 2 provide a cushion for shock resistanc for both the article (not shown) against which it is packed and for the coolant material 3. The extent of this cushioning can b varied according to the pressure of the gaseous material placed into the bubbles 2. These bubbles 2 also ensure that the coolan material 3 is spaced from the article to be cooled. The gaseous material in bubbles 2 provide a convenient heat exchange medium to thereby control the rate at which the cooling of the article take place. Marking or other deleterious effects on the article is reduced or eliminated.

The valleys formed between bubbles 2 may be provided with apertures which extend through outer surface 1. These are provided where moisture circulating or present adjacent the package A needs to be removed. In this alternative, coolant material 3 is a superabsorbent polyomer which is capable of absorbing this moisture. Of course, in some applications, the presence of moisture is to be maintained and therefore it is not necessary to either select a superabsorbent polyomer 3 nor provide holes in the valleys between bubbles 2.

An alternate arrangment is shown in Figures 4 and 5 in which onl one side of the pack is provided with bubbles 2. This is particularly useful as a lining for the container in which case the bubbles 2 are presented towards the article being packed.

The package of the present invention is a significant improvemen over the present packaging which does not allow for control cooling of articles. The system proposed therein is simple and maintains control of cooling. It is also advantageous shock absorbing properties.