EP1384685A1 - Thermally insulative containers - Google Patents

Abstract

A compact container with a high degree of thermal insulation for transportingproducts, particularly for primary health care, can be folded to a flat pack for ease ofstorage. The container is formed from a single sheet (14) of flexible sheet material, whichcan be wiped clean, defining wall panels (2-12). Each wall panel has a pocket (18)containing a vacuum insulation panel (40) formed of fumed silicon dioxide with poreshaving dimensions in the nanometer range. Free edges of the sheet (14) have flaps (24, 28)carrying strips of Velcro tape (26, 30) forming releasable joints for holding the container inthe erected condition.

Description

• This invention relates to thermally insulative containers, particularly though notexclusively for transporting pharmaceutical products and other products having applicationto health care, particularly primary health care.
• The common vacuum flask, consisting of two concentric thin glass walls separatedby a very high vacuum region, provides a thermally insulative container with extremelygood thermal insulation. It is however a very fragile construction and is normally used onlyfor holding fluids.
• Various types of thermal containers in the form of boxes or bags are in commonuse, where the wall panels contain a porous plastic foam material, e.g. polyurethane orexpanded polystyrene typically with pore diameters between 10 and 100 microns (µm).These provide a degree of thermal insulation, and are commonly used in consumerapplications. However, to provide a substantial degree of insulation, the foam materialmust be thick, of the order of centimetres or inches, and is therefore too bulky for manymobile applications, particularly for primary health care situations, where for example anurse has personally to transport products.
• A type of material which has recently been developed in the form of wall panels forthermal containers, and which has far superior characteristics to plastics foam, both in termsof thermal insulation and mechanical strength and stability, is known as VIP - vacuuminsulation panels. VIP includes a compound such as fumed silicon dioxide having porediameters less than 1µm in diameter, and preferably in therange 10 to 100 nanometres (nm), enclosed in an air tight envelope, with a moderate vacuum pressure, for example ofless than 10 mbar existing within the envelope. The pore diameters are so small that heatconvection by movement of air is prevented or at least significantly restricted, since airmolecules within the pores are trapped and prevented from significant movement. Such aVIP will be referred to herein as "vacuum insulation panels of the type described".
• There are other known types of vacuum insulation panel formed of open cell foam,where because of the larger pore diameter, high vacuum conditions need to be maintainedwithin an air tight envelope to ensure adequate thermal insulation.
• There is a need for containers for transporting products for health care applications,particularly hand portable containers for primary health care applications, safely, and underthermally insulated conditions, the containers desirably being compact and not bulky, atleast when stored.
Summary of the Invention
• The present invention provides a thermally insulative container, foldable to a flatpack for storage, the container comprising a plurality of wall panels which in the erectedcondition are joined together by joints, each wall panel being formed of a sheet material,and each wall panel including holding means, the holding means of each wall panel holdingat least one vacuum insulation panel of the type described, which covers at least the greaterpart of the wall panel, such that in the erected container, the vacuum insulation panels ofadjacent wall panels are positioned sufficiently closely together to restrict significantthermal leakage there between, and wherein at least some of the joints between adjacentwall panels are releasable to permit the adjacent wall panels to be moved away from eachother to enable the container to be folded up into a flat pack. Vacuum insulation panels of the kind described are compact, with excellent thermalcharacteristics, and are therefore preferred with the invention. However, the inventionextends to other vacuum insulation panels as described above, which may be preferred incertain circumstances.
• In a further aspect therefore, the invention provides a thermally insulative container,foldable to a flat pack for storage, the container comprising a plurality of wall panels whichin the erected condition are joined together by joints, each wall panel being formed of asheet material, and each wall panel including holding means, the holding means of eachwall panel holding at least one insulation panel comprising a cellular material enclosed inan air tight envelope under vacuum conditions, which covers at least the greater part of thewall panel, such that in the erected container, the insulation panels of adjacent wall panelsare positioned sufficiently closely together to restrict significant thermal leakage therebetween, and wherein at least some of the joints between adjacent wall panels are releasableto permit the adjacent wall panels to be moved away from each other to enable thecontainer to be folded up into a flat pack.
• The container in accordance with the invention provides a high degree of thermalinsulation, and is not bulky in construction. It may therefore be used a a hand portablecontainer in health care applications, for example. It can be folded into a flat pack byreleasing joints between the wall panels. As preferred, the sheet material of the wall panelscomprises a single piece of woven or continuous plastics material, which is moistureresistant and can therefore be wiped clean. When laid open flat, the sheet material is in theform of a cross, with the arms of the cross being formed by the wall panels. Where thesheet material is formed as a single piece, the joints between adjacent wall panels areformed by the flexible sheet material. Free edges of the sheet material carry releasable jointmeans, such as Velcro tape, so that the free edges can be interconnected by the releasable joint means to form the erected container. In alternative forms, the sheet material may beformed of more than one piece, the separate pieces being interconnected along joint lines byfurther releasable joint means.
• As preferred, there are four side wall panels, a top wall panel and a base wall panelto provide a rectangular container: However, three or more than four wall panels arepossible, for containers of a polygonal shape
• The insulation panel of each wall panel is preferably held in a pocket formed of apocket sheet of the same material as said flexible sheet material and sealed thereto along itsedges, but leaving one edge free as an opening. A flap may form a cover for the pocketopening. Alternatively, the holding means may be of any desired type: for example, it maycomprise straps for holding the vacuum insulation panel against said sheet material.
Brief Description of the Drawings
• A preferred embodiment of the invention will now be described, with reference tothe accompanying drawings, wherein:
• Figure 1 is a perspective view of the preferred embodiment in a laid-open condition,and showing a vacuum insulation panel as a separate item;
• Figure 2 is a plan view corresponding to Figure 1; and
• Figure 3 is a perspective view of the container in an erected position with the toppanel partially open.
Description of the Preferred Embodiment
• Referring to Figures 1 and 2, a preferred form of a hand portable thermallyinsulative container according to the invention is shown in laid open condition andcomprises abase wall panel 2, atop wall panel 4 andsidewall panels 6, 8, 10, 12. In itslaid open condition, the container is in the form of a cross or crucifix withside wall panels8, 10, 12 forming three arms of the cross, and the longer fourth arm being formed bytopwall panel 4, joined tobase wall panel 2 viaside wall panel 6. The container is formedfrom a single piece ofsheet material 14. The material is a woven plastics material, such asnylon. This material is moisture resistant, and can be wiped clean of fluids and solidproducts for hygiene. Apocket sheet 16 of the same type of material is secured tosinglepiece 14 at each wall panel in order to provide apocket 18. The edges of thepocket sheet16 are secured to thesheet 14 by welding or sewing and an open end of thepocket 18 has acover flap 20 for covering the open pocket. Thepocket 18 covers essentially the wholeextent of the respective panel, apart from a small external margin, as can be seen in Figure2.
• Thespaces 22 between the panels, comprising solely theflexible sheet material 14,form flexible joints between the panels. Side edges ofwall panels 6, 10 andtop wall panel4 haveedge flaps 24, each flap carrying a strip of Velcrotape 26. In addition,top wallpanel 4 has atop flap 28, which also carries a strip of Velcrotape 30. As can be seen inFigure 3, strips of Velcrotape 32 are positioned on the underside ofsheet material 14, asshown in Figures 1 and 2, for connecting with Velcrotape strips 26, 30. Thus, theflaps 24,28 and Velcrostrips 26, 30, 32, provide releasable joints, and a means of assembling thecontainer to the erected condition as shown in Figure 3, and then disassembling thecontainer to the flat position shown in Figures 1 and 2.
• Eachpocket 18 contains avacuum insulation panel 40 of the type described, asindicated in Figure 1, and formed of fumed silicon dioxide. Eachpanel 40 fits closelywithin therespective pocket 18 so as to be held securely therein and is sealed inside bytopcover flap 20, which has Velcro tape on its underside to connect with a further strip ofVelcro tape along the top of the pocket.
• The exterior of the container has carryinghandles 50, a topcover securing clasp 52,pockets for identification information, etc.
• With theinsulation panels 40 fitted within thepockets 18 of each wall panel, thecontainer as shown in Figure 1 may be folded up to a flap-pack condition, merely byfolding the panels one upon the other. Alternatively, it may be preferred to take out one orall of the vacuum insulation panels of the type described before folding the container up toa flat-pack condition.
• In order to erect the container, from the position shown in Figure 1, thesidewallpanels 6, 8, 10, 12 are first folded upwardly aboutjoint lines 22 to stand perpendicular tobase panel 2.Flaps 24 are then folded over the sides of adjacent side panels as shown inFigure 3 so that the respective pieces of Velcro tape interconnect. These flaps of Velcrotape therefore form releasable joints between the respective sidewall panels. In thatcondition, as shown in Figure 3, thetop wall panel 4 may then be folded down on top of theside wall panels and its side flaps andtop flap 24, 28 may be folded over so that the stripsof Velcrotape 26, 30 interconnect with Velcrostrips 32 to form a totally sealed container,with theflaps 24, 28 forming releasable joints between all panels. As can be seen in Figure 3, in the erected condition, the sidewall panels are positioned so that thepockets 18 ofpanels 6 and 10 have their side edges abutting against the pocket edges ofend panels 8, 12.In addition, the lower edges of the pockets ofwall panels 6, 8, 10, 12 abut against the upperpocket surface ofbase panel 2. Whentop panel 4 is folded over the wall panels, the upperpocket edges of the wall panels abut against the lower pocket surface ofpanel 4. Thus,there is formed a container with no significant thermal leakage paths between the panels.Although there is in practice a certain spacing between the edges of the insulating wallpanels in the erected condition as a result of the flexibility necessary for assembling anddisassembling the container, the amount of heat that can be conducted along these spaces isnegligible.

Claims (12)

1. A thermally insulative container, foldable to a flat pack for storage, the containercomprising a plurality of wall panels which in the erected condition are joined together byjoints, each wall panel being formed of a sheet material, and each wall panel includingholding means, the holding means of each wall panel holding at least one insulation panelcomprising a cellular material enclosed in an air tight envelope under vacuum conditions,which covers at least the greater part of the wall panel, such that in the erected container,the insulation panels of adjacent wall panels are positioned sufficiently closely together torestrict significant thermal leakage there between, and wherein at least some of the jointsbetween adjacent wall panels are releasable to permit the adjacent wall panels to be movedaway from each other to enable the container to be folded up into a flat pack.
2. A thermally insulative container, foldable to a flat pack for storage, the containercomprising a plurality of wall panels which in the erected condition are joined together byjoints, each wall panel being formed of a sheet material, and each wall panel includingholding means, the holding means of each wall panel holding at least one vacuuminsulation panel of the type described, which covers at least the greater part of the wallpanel, such that in the erected container, the vacuum insulation panels of the type describedof adjacent wall panels are positioned sufficiently closely together to restrict significantthermal leakage there between, and wherein at least some of the joints between adjacentwall panels are releasable to permit the adjacent wall panels to be moved away from eachother to enable the container to be folded up into a flat pack.
3. A container according to Claim 1 or 2, including a single piece of flexible sheetmaterial forming all said wall panels.
4. A container according to Claim 3, wherein said single piece is in the form of across.
5. A container according to Claim 3 or 4, wherein a plurality of edges of said singlepiece have flaps, adjacent the wall panels, carrying releasable securing means for formingreleasable joints for securing the container in the erected condition.
6. A container according to Claim 5, wherein the releasable securing means comprisesVelcro tape.
7. A container according to any preceding claim, wherein each said holding meanscomprises a pocket formed by a piece of sheet material, attached to the wall panel.
8. A container according to Claim 7, the holding means including a flap forming acover for the pocket opening.
9. A container according to Claim 7 or 8, wherein a respective insulation panel forms aclose fit within each said pocket.
10. A container according to claim 2, wherein each vacuum insulation panel of the typedescribed comprises nanoporous fumed silicon dioxide.
11. A container according to any preceding claim, including one or more exteriorhandles for hand carrying the container.
12. A kit of parts for a thermally insulative container, foldable to a flat pack for storage,the container comprising a plurality of wall panels, each wall panel being formed of a sheetmaterial, means for joining said wall panels together, and each wall panel including holdingmeans, for holding at least one insulation panel of cellular material enclosed in an air tightenvelope under vacuum conditions, such that in the erected container, the insulation panelsof adjacent wall panels are positioned sufficiently closely together to restrict significantthermal leakage there between,
    and wherein at least some of the joining means are releasable to allow adjacent wall panelsto be moved away from each other to enable the container to be folded up into a flat pack,and the kit of parts including a plurality of said insulation panels for fitting in said holdingmeans.

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