CA2270748C - Insulated transit bag - Google Patents

Abstract

The insulated transit bag is made from bubble-wrap material, bonded to aluminum foil. The material is doubled-over, folded, and heat welded to form sealed seams. The bag is used for transporting heat-sensitive medicines etc.

Description

1 Title: INSULATED TRANSIT BAG

2

3

4 This invention relates to transit bags or pouches for containing special contents, and particularly temperature-6 sensitive medicines, for transport of the contents by mail, 7 or by courier.

BACKGROUND TO THE INVENTION

12 Many medicines lose their efficacy if kept for more than a 13 few hours at the wrong temperature. Insulin, for example, 14 deteriorates if allowed to rise above about 15 degC for more than an hour or two. As a result, insulin cannot be sent 16 through the post. Generally, insulin cannot even be sent by 17 overnight-courier.

19 Special medical courier services are available, but they are inordinately expensive for everyday items. Persons who have 21 need of temperature-sensitive medications, therefore, when 22 travelling, have to have the medications made up by a local 23 pharmacist. Such persons would much prefer their 24 prescriptions to be made up by their home pharmacist, if only there were an inexpensive means for transporting the 26 prescriptions.

28 The invention is aimed at providing a transit bag that can 29 contain a prescription quantity of insulin, and which is sufficiently thermally insulated to enable the insulin to be 31 maintained at a temperature of less than 15 degC, during 32 transit, for a period of about two days. The invention is 33 aimed at providing a bag which is also light in weight, and 34 inexpensive to manufacture.
36 As will be apparent from the descriptions herein, the bag 37 can be designed for the transport of items other than 38 insulin prescriptions.

1 The material from which the bag of the invention is made is 2 bubble-wrap sheet. The invention also uses a composite or 3 lamination of a plastic bubblewrap sheet and aluminum foil.
4 The aluminum foil is bonded or welded to the bubbles of the plastic bubblewrap sheet.

7 The sheets are arranged to form bags, which are arranged one a inside the other, with the aluminum of the outer composite 9 sheet facing outside. The composite sheets are welded or otherwise secured together at the edges to form a pouch, and 11 an open mouth is left for inserting the temperature-12 sensitive contents. The mouth can be welded closed, or 13 otherwise closed, after the contents are inserted.

The bubblewrap material provides excellent thermal 16 insulation, in that air is trapped inside the bubbles.
17 Preferably also, the spaces between the bubbles are also 18 confined, and the air is trapped in those spaces too.
19 (Still air is, of course, one of the best insulators known.) The aluminum foil provides protection against radiant heat 21 transfer. The aluminum foil also provides structural 22 robustness to the outside of the bag, as a protection 23 against the inevitable minor knocks that occur during 24 transport and handling. It may be noted that although the aluminum is thin, it is structurally well-supported, because 26 the bubblewrap material provides many surfaces that extend 27 at right-angles to the plane of the foil.

29 As will be explained, the bag can be designed to be inflated, after the contents are inserted, which provides 31 good structural rigidity, good shock-absorption, and 32 improved thermal insulation. Even so, the bag is light in 33 weight (which of course is important in a transportation 34 bag) and inexpensive to manufacture and use.
36 Preferably, the inner bag has an inside layer which is of 37 relatively strong material, which may be plastic, or 38 aluminum foil, and provides a robust surface against which 39 the contents can bear directly. The inside of the bag, though mechanically robust, generally does not need to be 41 liquid-tight, because liquid medicines, and other liquids 1 being transported, would in any case be placed in a liquid-2 tight sachet or other suitable container prior to being 3 placed in the bag. On the other hand, by configuring the 4 bubble material in different ways, as will be explained, the inside of the bag can be liquid-tight if desired.

7 The bag is not (quite) light-tight. However, the bag 8 provides excellent protection against, for example, U/V and 9 other radiation to which some items can be sensitive.
Writable CDs, for example, which can be sensitive to U/V
11 light, can usefully be transported in the designs of transit 12 bag as described herein.

14 In fact, the use of the bag, with its metal shielding, might make it difficult for authorities to detect some illegal 16 substances. Where that is a possibility, bags containing 17 approved contents might be provided with pre-cleared-customs 18 identification. The bag as described herein is suitable for 19 this function, in that it is easy for the designer to ensure that any tampering with the sealed bag, either though the 21 metal itself, or through the sealed edges, would inevitably 22 be apparent.

24 Bubble-wrap plastic film material is of course commonly available. Bubble wrap material laminated with aluminum 26 foil also is available; under the brand name Ayr-Foil, for 27 example.

29 Bubblewrap material has been conventionally used for making transit bags. For example, Jiffy Bags (TM) have stiff paper 31 covers adhered to a bubble layer, and are used as postage 32 envelopes. The bags are crimped at the edges, in order to 33 form the mechanical structure of the bag. Such bags are 34 however just one single layer of bubble-wrap, inside the paper cover; they have not been designed to be thermally 36 insulative.

38 Bubble-wrap material is popular for many uses. It can be 39 formed into a closable bag. It is not too bulky. It is inexpensive. But it is recognised that just one bag (i.e 41 just one thickness) would not do, thermally. The main 1 property which has made bubble wrap popular has been its 2 shock absorbing properties, which make it highly suitable as 3 a packaging material.

Bubble wrap on its own does not lend itself to the function 6 of providing thermal insulation. The spaces between the 7 bubbles offer very little insulation. Even if two layers of 8 bubblewrap are provided, further steps are still needed to 9 ensure the non-bubble areas of adjacent layers are spaced io apart from each other. If the non-bubble areas touch, there 11 is very little insulation. It is recognised that if the 12 layers were just laid flat over each other, several layers 13 would be needed to ensure freedom from any areas where the 14 non-bubble areas might touch. Bubble wrap material is quite thick, so several layers quickly becomes cumbersome (in 1.6 volume, if not in weight).

18 So, even providing two bubblewrap bags, one inside the 19 other, and placing the article inside the inner bag, cannot be expected to provide a thermal insulation performance that 21 will ensure the contents can remain at say 15 degC for two 22 days, during transit 24 It is recognised in the invention that what is needed is to provide two sealed bags, and also to seal the space between 26 the two bags, and also to provide an outer cover, preferably 27 of aluminum foil. Preferably the space between the two bags 28 is inflated, i.e pressurised, prior to sealing.

With that construction, the excellent thermal insulation 31 properties of bubble wrap material can now be exploited.

33 The invention is aimed at providing a good compromise 34 between volumetric bulk and insulative effectiveness. The design of transit bag as described herein can be expected to 36 keep medicines etc at several degrees below room 37 temperature, during transit by couriers (or even by mail), 38 even in summer, for at least two days, and usually for as 39 many as four days. Just one layer of bubble wrap would not work; several layers wrapped and overlapped might do, but 41 that would be too bulky.

1 Preferably, the sealed space between the two bags should be 2 inflated prior to sealing. Inflating the space means the 3 outer bag is stretched taut, which can increase the 4 resistance to mechanical indentation. Inflation is a useful

5 measure not only from the mechanical protection standpoint,

6 to prevent the contents of the bag from being damaged, but

7 also from a thermal performance standpoint, to prevent the

8 bubbles of the bubblewrap material from being collapsed or

9 damaged, and to prevent the two bags from touching (at least, over much of their areas), which would probably 11 increase heat transfer between the bags.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

17 By way of further explanation of the invention, exemplary 18 embodiments of the invention will now be described with 19 reference to the accompanying drawings, in which:
21 Fig 1 is a pictorial view of a thermal bag that embodies the 22 invention, the bag being shown open and ready to 23 receive contents;
24 Fig 2a is a diagram of the configuration of a sheet that is a composite of the bubble-wrap material and aluminum 26 foil, from which the bag of Fig 1 is made;
27 Fig 2b is a diagram of the configuration of an alternative 28 composite;
29 Fig 2c is a diagram of the configuration of an alternative composite;
31 Fig 3 is a pictorial view of some components of the bag, 32 shown at a stage during manufacture;
33 Fig 4 is a cross-section on line 4-4 of Fig 1;
34 Fig 5 is a cross-section on line 5-5 of Fig 1, and shows the bag at a subsequent stage of manufacture;
36 Fig 6 is a pictorial view similar to Fig 3, of some 37 components of a second bag that embodies the 38 invention;
39 Fig 7a is a cross-sectional view, showing the mouth of the second bag;
41 Fig 7b is the same view as Fig 7a, and shows the bag in a 1 fully closed condition;
2 Fig 8 is the same view as Fig 5 of a third bag that embodies 3 the invention;
4 Fig 9 is the same view as Fig 1 of a fourth bag that embodies the invention;
6 Figs lOa,lOb,lOc are cross-sectional views showing the mouth 7 area of a further transit bag.

9 The apparatuses shown in the accompanying drawings and described below are examples which embody the invention. It 11 should be noted that the scope of the invention is defined 12 by the accompanying claims, and not necessarily by specific 13 features of exemplary embodiments.

The bag 20 shown in Fig 1 is suitable for the containment, 16 during transportation, of thermally-sensitive items, such as 17 medicines and perishable materials.

19 The material from which the bag is made is shown in more detail in Figs 2a,2b,2c. The material itself is 21 conventional, and is based on the common polyethylene 22 bubble-wrap material. In Fig 2a, a layer 60 of aluminum 23 foil, which is typically about 0.002 inches thick, is 24 provided with a film 62 of polyethylene, which is about 0.003 inches thick. The plastic film 62 is in intimate 26 bonded adherence to the aluminum foil layer 60.

28 The combined plastic-aluminum sheet 63 is welded to a bubble 29 sheet 64 of plastic film, by passing the bubble sheet and the plastic-aluminum sheet between rollers, under such 31 conditions of heat and pressure as will cause welding. The 32 bubbles 65 are formed in that the roller against which the 33 bubble sheet 64 contacts is provided with many recesses, 34 each with a vacuum supply, into which the film of the bubble sheet is drawn. Composite sheet 67 is the result of welding 36 the plastic-aluminum sheet 63 to the bubble sheet 64.

38 The bubbles 65 have a diameter of about 0.4 inches, and are 39 arranged in regularly-pitched rows.
41 In Fig 2b, a composite sheet like the sheet 67 of Fig 2a is 1 provided with a backing sheet 68 of plastic film. The 2 backing sheet 68 is welded to the tops of the bubbles 65, 3 again by passing the composite sheet 67 and the backing 4 sheet 68 between rollers under conditions of heat and pressure. Now, the backing sheet 68 is compressed between 6 the roller and the tops of the bubbles 65, whereby some 7 skill is needed to ensure that the backing sheet 68 adheres 8 properly to the tops of the bubbles, but such skill is 9 within the competency of a skilled manufacturer.
11 The final composite sheet 69 in Fig 2b can be used in a bag 12 that embodies the invention, as can the composite sheet 67 13 of Fig 2a.

Fig 2c shows another variation. Here, a backing sheet 68 16 and a bubble sheet 64 are pressed together by passing the 17 two films between rollers, under conditions of heat and 18 pressure, as described. Then, the plastic-aluminum sheet 63 19 is pressed onto the tops of the bubbles, again as described.
The resulting composite sheet 70 can also be used in a bag 21 that embodies the invention.

23 Other variations to the manner of arranging the sheets are 24 also possible. For example, two of the composite sheets as shown in Fig 2a can be pressed together, bubble-to-bubble, 26 to form a single bonded sheet.

28 As shown in Fig 3, the bag 20 is made from an outer 29 composite sheet 27 and an inner composite sheet 28. Whether the composite sheet is the sheet 67 of Fig 2a, the sheet 69 31 of Fig 2b, or the sheet 70 of Fig 2c, or some other 32 variation, generally the designer will prefer to use the 33 same type of sheet throughout. In making the bag, the outer 34 composite sheet 27 and the inner composite sheet 28 are assembled with the respective plastic base layer 23 sides of 36 the sheets together, i.e with the aluminum foil 25 sides of 37 the sheets outermost.

39 A crease 29 is made in the outer and inner composite sheets 27,28. The crease 29 is folded over, until all four 41 thicknesses of the sheets overlie each other.

1 The composite sheets are welded together along the left and 2 right side margins 30,32, as shown in Fig 4, thus forming 3 the sheets into a rectangular pouch or bag, which is closed 4 on three edges, and has an open mouth 34 on the fourth edge.
The top thickness 35 of the bag comprises half of the inner 6 composite sheet 28 and half of the outer composite sheet 27, 7 and the bottom thickness 36 of the bag comprises the other 8 halves of the composite sheets. The aluminum foil of the 9 outer composite sheet faces outwards, and the aluminum foil io on the inner composite sheet faces inwards and lines the 11 inside of the bag.

13 It may be noted from the drawings that the aluminum foil 25 14 of the inner composite sheet 28 does not extend to the edges is of the bubbles 24 of the inner sheet. The aluminum foil of 16 the inner sheet is short, and leaves bubble-exposed margins 17 37 to left and right of the inner composite sheet. In 18 respect of the outer composite sheet 27, there are no 19 bubble-exposed margins, but rather the aluminum foil 25 of 20 the outer sheet covers the whole area of the bubbles of the 21 outer sheet, and is co-extensive with the base layer 23 of 22 the outer composite sheet.

24 Because the aluminum foil 25 of the top and bottom halves of 25 the inner sheet 28 does not extend to the edge of the inner 26 sheet, when the left and right margins 30,32 of the top and 27 bottom thicknesses 35,36 of the bag are squeezed together, 28 it is the respective plastic base layers 23 of the inner and 29 outer composite sheets 27,28 that come together in direct 30 contact (Fig 4). Thus, at the margins 30,32, the aluminum 31 is not present between the sheets, whereby the plastic of 32 the inner and outer sheets of the top and bottom thickness 33 of the bag can all be welded together.

35 The side margins of the bag are sealed and secured as 36 described above. The mouth of the bag 20 is also sealed and 37 secured, in a manner as will now be described.

39 In the bag depicted in Fig 1, the inner composite sheet 28 40 has been cut shorter (lengthwise) than the outer composite 41 sheet 27, and, as shown in Fig 5, the end-edges of the inner 1 sheet are secured to the outer sheet by means of adhesive 2 tape 43. (The tape 43 is not shown in Fig 1.) To seal the 3 bag after the contents have been inserted, the top and 4 bottom portions of the outer layer can be pressed and welded together. As shown in Fig 5, the adhesive tape 43 is 6 provided to guide the items to be placed in the bag into the 7 correct place: if the tape were omitted, a careless person 8 might insert the item between the inner and outer composite 9 sheets, rather than between the two halves of the inner lo composite sheet.

12 Figs 6,7a show an alternative arrangement of the sheets at 13 the mouth of the bag. As shown in Fig 6, the aluminum foil 14 is absent from the ends of the inner composite sheet, thus 1s exposing the bubbles at end-margins 38,39, just as the 16 bubbles at the side margins are exposed. As shown in 17 Fig 7a, the inner and outer sheets 28,27 of the top 18 thickness 35 are squeezed and pre-welded together, at 40, 19 during manufacture of the bag, as are the inner and outer 20 sheets 28,27 of the bottom thickness 36, at 41. Again, it 21 may be noted that the aluminum foil 25 stops short, and 22 leaves end margins 38,39 of exposed bubbles of the inner 23 sheet 28.

25 After the contents have been inserted into the bag, the bag 26 is sealed. This is done by pressing the pre-welded portions 27 40,41 between heated bars 42, which welds the then-touching 28 plastic together. As shown in Fig 7b, after that, the mouth 29 of the bag lies sealed in much the same manner as the side 30 margins of the bag.

32 In the alternative shown in Fig 8, a piece of adhesive tape 33 45 is provided for sealing the mouth of the bag shut after 34 the contents have been inserted. The tape 45 is provided 35 with a peel-off backing strip 46, which is removed just 36 before the tape 45 is folded over and pressed against the 37 aluminum foil 25 in the area 47 of the bottom 36 of the bag.
38 It may be noted that flat aluminum foil is well suited to 39 being adhered to by the tape.
41 Also, in Fig 8, it may be noted that the bag is made from a 1 single composite sheet 48, which is doubled and folded over, 2 as shown, to form the inner and outer sheets 28,27 of the 3 top and bottom thicknesses 35,36 of the bag. In this case, 4 the aluminum foil 25 is discontinuous, in that the foil does 5 not extend over the bottom lip 49 of the mouth of the bag.

7 It will be noted that, in the bags as illustrated, the e aluminum foil forming the inside lining of the bag is 9 physically isolated from the aluminum foil forming the io outside of the bag. Not only that, but the inside foil is 11 everywhere kept away from the areas where the sheets are 12 squeezed together, and in fact the inner foil is everywhere 13 separated from the outer foil by two full thicknesses of the 14 un-compressed plastic bubblewrap material.
16 Removing the inside aluminum foil from the margins is 17 advantageous for two reasons: first, it means the plastic 18 components of the sheets are in direct touching contact at 19 the margins, whereby the plastic components can be welded together at the margins; and second, it allows the inside 21 and outside aluminum foils to be kept everywhere well spaced 22 apart. If the inside and outside foils were allowed to 23 touch, the resulting capacity to conduct heat would destroy 24 much of the insulative nature of the bag. Indeed, if the inside and outside foils were allowed even to be close 26 together (if, for example, the inside and outside foils were 27 separated only by squeezed bubbles), it can be expected that 28 the insulative properties would decline considerably. As 29 shown in the drawings, the inner and outer foils are kept spaced apart everywhere by two thicknesses of un-crushed 31 bubbles.

33 Fig 9 shows a means for enabling the space between the inner 34 and outer composite sheets to be inflated. The inflating means 50 is made up from two sheets of plain plastic film, 36 which are bonded together over most of their area, except 37 for an intermediate narrow strip 52. The inflating means 50 38 is trapped between the inner and outer composite layers 39 28,27, as shown in Fig 9. The un-bonded strip 52 serves as a tube, through which air can be injected into the space 54 41 between the inner and outer sheets, after the items have 1 been placed in the bag. The inflating means 50 can be 2 withdrawn, prior to sealing the mouth of the bag, or the 3 inflating means can be tucked over, and left in place.

Inflating the space 54 between the base layers of the inner 6 and outer sheets provides a degree of extra packing in the 7 bag, without extra weight or cost. The extra air also 8 provides better insulation. Plastic being slightly 9 permeable to air, only a very low inflation pressure can be io sustained over time -- but the bag is intended for short-11 term packaging.

13 When the bag is used by a pharmacist, the pharmacist can 14 affix an information label to the outside surface of the bag: it may be noted that the outside of the bag comprises 16 aluminum foil, not plastic bubbles, and so it is easy to fix 17 adhesive labels thereto. It is the intention that the bag 18 as described herein will be placed in a further envelope, 19 for example in a conventional (cardboard) courier-envelope.
Alternatively, the bag as described can be utilised itself 21 as the complete envelope.

23 The bag as described herein, especially when welded closed, 24 provides a tamper-proof enclosure, in the sense that if the contents are tampered with, that fact is obvious to the 26 recipient. Also, a slip of temperature-sensitive material 27 can be inserted into the bag, which would indicate to the 28 recipient if the temperature inside the bag had risen above 29 (or fallen below) that required to ensure efficacy of the contents.

32 Figs 10a,10b,lOc show another manner of sealing a transit-33 bag 75.

The inner-bag 76 comprises a top sheet 78 and a bottom sheet 36 79. A press-lock fastener 80 is secured inside the mouth 82 37 of the inner bag 76. The press-lock fastener comprises a 38 key-strip 83 and a lock strip 84, which are secured (welded 39 or glued) one inside the top sheet 78 and the other inside the bottom sheet 79.

1 the press-lock fastener, i.e the strips that comprise it, 2 are commonly available as a proprietary item.

4 The top sheet 86 and the bottom sheet 87 of the outer bag 85 s are cut with extensions 89, which protrude a little way 6 beyond the end of the inner-bag 76.

8 Fig l0a shows the components during a preliminary stage of 9 manufacture, the bags being placed one inside the other.
Fig lOb shows the components when the top sheet 86 of the 11 outer bag and the top sheet 78 of the inner bag have been 12 compressed and sealed together; and when the bottom sheet 87 13 of the outer bag and the bottom sheet 79 of the inner bag 14 have been compressed and sealed together. The key strip 83 and the lock strip 84 lie in the compressed areas, as shown.

17 Fig lOc shows the components when the bag has been sealed, 18 ready for transit. The extensions 89 of the outer bag have 19 been compressed and sealed together.
21 After transit, the recipient opens the bag 75 by cutting the 22 material of the bag (with scissors) along the line indicated 23 at 90. Now, the inner bag 76 remains sealed with the press-24 lock fastener 80. The recipient can pry the press-lock fastener apart, in order to get at the contents in the inner 26 bag. However, the recipient can then relock the inner bag, 27 by remaking the press-lock fastener.

29 The thermal barrier provided by the press-lock fastener is considerably less insulative than the thermal barrier 31 provided by the welded-together extensions 89. However, the 32 recipient now has the delivered articles in his possession, 33 and he can keep the articles refrigerated, for such periods 34 as may be required. The press-locked transit bag 75 serves as an excellent means for carrying the articles about, and 36 keeping them handy, and maintains adequate short-period 37 insulation.

39 As mentioned above, the inner layer, i.e the piece of material that lines the inner bag, preferably is of aluminum 41 foil. Aluminum foil is preferred because of its mechanical 1 robustness, whereby the possibility of the layer being 2 damaged by the insertion of the article, even by a careless 3 person, is minimal. By contrast, if no inner layer were 4 provided at all, i.e if the inside of the inner bag were constituted by the bubbles themselves, that would hardly be 6 satisfactory from the robustness standpoint, because the 7 bubbles might be snagged by the article as the article was 8 being inserted into the inner bag.

However, aluminum foil is expensive, and the special shaping 11 of the foil, to ensure that the foil is not present in the 12 marginal edges of the inner bag, only adds to the expense.
13 The designer might therefore wish to compromise on the 14 robustness, and go with plastic film as the inner layer.
Apart from plastic being cheaper, now it is not so important 16 to keep a plastic film out of the marginal areas, as it was 17 with the metal foil. Also, a bag with a plastic inner layer 18 can be expected to be a little more insulative, with cold 19 articles, than a bag with a metal inner layer. If the bag is used for the transit of articles that have to be kept at 21 a warm temperature, on the other hand, a metal inner liner 22 can improve insulativeness, by preventing the escape of heat 23 from the article by radiation. For warm articles, strictly 24 from the isnsulation standpoint, the inner layer mgith be of metal and the outer liner of plastic: however, the outer 26 layer must be of metal, even when the articles need to be 27 kept warm than kept cold, for robustness reasons. Besides, 28 the application of the transit bag as described herein is 29 mainly to the fields of articles that are to be kept at temperatures below ambient, rather than above ambient.

32 The inflation of the space or cavity between the inner bag 33 and the outer bag is preerred because of the extra 34 insulatoive qualities of the still air thus introduced, and vbecause of the extra mechanical robustness. Inflation 36 holds the bags apart, and the less the inner bag touches the 37 outer bag, the less the heat transmission therebetween.
38 From the robustnmess standpoint, the protection given by 39 inflation does not benefiot only the article, but benefits the bubblkes themselves. Without inflation, it would be 41 much more possible for the bubbles to be compressed, and 1 perhaps even to be damaged, by rough handling. The bubbles 2 are at their most insulative when they are intact, and not 3 touching anything.

The designs of transit-bag as described herein are aimed at 6 making it possible to transport such things as temperature-7 sensitive medicines by ordinary courier services, more or 8 less anywhere in the world. It is recognised that bubble-9 wrap material, though very common, is generally not used for thermal insulation. The bubbles themselves are good 11 insulators, but the areas between the bubbles are not. So, 12 for a thermal application, the areas between the bubbles 13 have to be prevented from transmitting heat. Generally, the 14 designer would infer that a good many layers of bubble-wrap material would be required for good insulation performance.
16 The designs as described herein show how the (inexpensive) 17 bubble-wrap material can be used for thermal insulation 18 purposes. Its natural limitations in that direction are 19 ameliorated by the arrangement of the material in the manner as described.

Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An insulated transit-bag for containing a temperature-sensitive article for transport, wherein: the transit-bag includes an inner-bag and an outer-bag, made from bubble-wrap;

the inner-bag is physically attached inside the outer-bag in such manner as to create a between-bags-cavity, the outside of which is defined by the inside of the outer-bag and the inside of which is defined by the outside of the inner-bag;

the inner-bag and the outer-bag have respective mouths; the transit-bag is so structured that the mouth of the inner-bag lies open, and accessible for the placement of the article inside the inner-bag;

the transit-bag includes an operable bag-sealing-means, which is effective, upon being operated after the article is placed in the inner-bag:

(a) to leave the inner-bag as a substantially airtight enclosure with the article sealed inside;

(b) to leave the outer-bag as a substantially airtight enclosure with the inner-bag sealed inside;

(c) to leave the between-bags-cavity as a substantially airtight enclosure;

the outer-bag has an outward-facing-surface, and the transit-bag includes an outer-layer of a relatively strong film material, and the outer-layer is secured to the outward-facing-surface of the bubble-wrap from which the outer-bag is made;

the outer-layer is of such extent as to substantially completely cover the outward-facing-surface of the outer-bag.

2. An insulated transit bag as claimed in claim 1, wherein:

the bubble-wrap is a plastic sheet material comprising a base-film of thin plastic film and a bubble-film of thin plastic film;

the bubble-wrap includes bubble-areas and between-bubbles-areas;
in the between-bubbles-areas of the bubble-wrap, non-bubble areas of the bubble-film lie in adhering face-to-face contact with corresponding non-bubble areas of the base-film;

in the bubble-areas of the bubble-wrap, bubble-roofs of the bubble-film lie spaced from, and separated from, corresponding bubble-floors of the base-film;

the bubble-film includes bubble-side-walls, which extend between the non-bubble-areas of the bubble-film and the bubble-roofs of the bubble-film, and which define bubbles of trapped air between the base-film and the bubble-film;

the bubble-film lies to a bubble-side of the bubble-wrap, and the base-film lies to a base-side of the bubble-wrap.

3. An insulated transit bag as claimed in claim 2, wherein the outer-layer outside the outer-bag is aluminum foil.

4. An insulated transit bag as claimed in claim 2, wherein the bubble-wrap from which the outer-bag is made lies bubble-side inwards, base-film outwards, and the outer-layer is secured directly to the base-side of the bubble-wrap from which the outer-bag is made.

5. An insulated transit bag as claimed in claim 4, wherein the bubble-wrap from which the inner-bag is made lies base-side inwards.

6. An insulated transit bag as claimed in claim 2, wherein:

the transit-bag includes an inner-layer of relatively strong material, and the inner-layer comprises an inwardfacing-surface of the inner-bag;
the inner-layer is of such extent as to cover the inwardfacing-surface of the inner-bag over at least a major portion thereof.

7. An insulated transit bag as claimed in claim 6, wherein the inner-layer is of relatively thick plastic film.

8. An insulated transit bag as claimed in claim 6, wherein the inner-layer is of aluminum foil, and the inner-layer is limited in its extent, in that the inner-layer stops short of the marginal edges of the inner-bag.

9. An insulated transit bag as claimed in claim 2, wherein:
the mouths of the bags are defined by inner-bag-lips and outer-bag-lips respectively;

the outer-bag-lips surround and encircle, and are sealingly secured to, the inner-bag-lips;

whereby the between-bags-cavity is sealed, and whereby the mouth of the inner-bag is open;

and the operable bag-sealing-means is effective, when operated, to seal the mouth of the inner-bag.

10. An insulated transit bag as claimed in claim 2, wherein:

the inner-bag comprises an inner-bag-top-sheet and an innerbag-bottom-sheet, made from bubble-wrap;

the outer-bag comprises an outer-bag-top-sheet and an outerbag-bottom-sheet, made from bubble-wrap;

the said four sheets are positioned flat against each other, and on top of each other, in direct touching contact, thereby forming a stack of four sheets;

along the marginal side edges of the stack of four sheets, the sheets are collapsed and flattened, and sealingly secured, the inner sheets to each other and to the outer sheets above and below.

11. An insulated transit bag as claimed in claim 2, wherein:

the transit bag includes a first operable means for closing the mouth of the outer bag, and a second operable means for closing the mouth of the inner bag;

the two means are separate in the sense that the means for closing the mouth of the outer bag can be detached and removed from the transit bag, leaving the means for closing the inner bag still intact and operable.

12. An insulated transit bag as claimed in claim 11, wherein the means for closing the inner bag comprises a press-lock strip fastener.

13. An insulated transit bag as claimed in claim 2, wherein the transit bag includes an operable inflation-means, for inflating the between-the-bags cavity with pressurised air, and for sealing the cavity closed, with pressurised air trapped inside.

14. An insulated transit bag as claimed in claim 13, wherein:

the inflation-means comprises a tube of plastic material; the tube connects the between-the-bags cavity with the outside;

the inflation-means, when operated, is effective to pass outside air into the cavity.

15. An insulated transit bag as claimed in claim 14, wherein the tube is so arranged in relation to the bag-sealing-means that operation of the bag-sealing-means to seal the mouth of

16. An insulated transit bag as claimed in claim 15, wherein the tube comprises two strips of plastic film, laid flat upon each other, which are adhered to each other over marginal edges thereof, but are not adhered over a central strip thereof.