GB2451329A

GB2451329A - Insulating liner

Info

Publication number: GB2451329A
Application number: GB0813170A
Authority: GB
Inventors: Paul Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-07-24
Filing date: 2008-07-18
Publication date: 2009-01-28
Also published as: GB0813170D0

Abstract

This invention relates to a removable thermally insulating liner 40 for a food transport box and a food transport box containing such a liner 40. The liner 40 has a plurality of foam sheet members 43, 45 joined and relatively articulatable so that they can lay flat or be formed to line the food box as shown in Figure 4a. The joins in the liner are mitred for an insulating joint and have castellations 46, 48 which hold the liner in its assembled condition. A lid (35 Fig 4b) can be provided. The invention provides a cleanable thermal liner 40 that can be introduced into an existing food transportation box to keep the delivered food hot or cold and yet can be removed from the box when food is delivered which does chilling or heating. The liner 40 may include a thermometer.

Description

* 2451329 Insulating Liner This invention relates to a removable thermally insulating liner for a food transport box.

Recently there has been an increase in home delivery of foods, for S example from supermarkets and take-away restaurants. The usual procedure for transporting hot or cold foods is to put them in a heated or cooledcompartment in a delivery vehicle. This procedure involves the use of extra energy provided by the delivery vehicle for keeping the food hot or cold. Where "green" delivery vehicles are used, e.g. electrically powered vehicles, then the extra energy requirements from the batteries of such vehicles for heating or cooling the food results in significantly reduced operating ranges for such vehicles.

Take-away food, for example pizzas, have been wrapped in a thermally insulating blanket to keep them warm. However, these blankets do not provide support for the food within the blanket so the food can be crushed and they are difficult to keep clean.

Home delivery personnel tend to treat food packaging or transportation boxes very roughly and so known polystyrene boxes which are used for keeping food hot or cold would not last long at the hands of the delivery personnel. In addition, polystyrene can crack and split and the fissures caused by such cracks or splits will harbour bacteria and the like and are impossible to clean. Since supermarkets have already invested in food delivery boxes there is a need for a -maog[iiygieniçy keepuig food hot or cold without ushg the delivery -vehicle's energy source and yet using the supermarket's existing hardware.

Thus, the inventor has realised that there is a need for a cleanable thermal liner * $ I that can be introduced into an existing food transportation box to keep the delivered food hot or cold and yet can be removed from the box when food is delivered which does not require external influence to keep the food hot or cold.

According, to the invention there is provided a removable thermally insulating liner for a food transport box, the liner having a plurality of foam sheet members, joined and relatively articulatable so that they can lay flat or be formed to line the food box.

Preferably the members have a food grade plastics coating on at least one face. More preferably the coating completely encapsulates the members.

The coating may be PVC, and may include a woven fabric layer. The member(s) may include a foil surface or other radiant heat reflective surface. Preferably, said reflective surface is innermost when the liner is formed to line the box.

Preferably, where joined, the members are joined at respective edges only by the coating of the members. More preferably, the respective edges at the joins are oblique to allow folding of one member relative to the other.

Preferably the liner has a rectangular base member and four side members joined to the base member, one at each of the rectangle's four edges, for folding into an open topped liner.

Preferably, the edges of the side members which come together when formed into said open topped liner are oblique such that they meet to form a mitred joint.

Preferably-said_edges_haveeernplemefltary_forn,ations_wjc interfere.

when brought together so that the edges are held together to assist assembly.

Preferably, an internal radius is formed when the side members come together.

Preferably, the liner further includes a lid which may be formed from the same material as the remaining liner, and may be formed in two relatively articulatable pieces.

Preferably, one or more of the liner members are formed, at least partially, from a resilient closed cell foamed material, having the property that the foam tends to return to its original shape following deflection.

Preferably, said foam, or said closed cell foamed material comprises an expanded polypropylene (EPP).

The invention extends to a method of manufacturing the liner mentioned above by means of: a) introducing plastics into a mould; b) expanding the plastics to substantially fill the mould; and C) moulding a liner according to any one of the paragraphs above.

The invention extends to a mould when used in the method mentioned above.

The invention extends to any novel feature described herein or any novel combination of features described herein whether or not such features are described herein in that combination.

The invention can be performed in numerous ways. Embodiments of the _____ inytion are described below with the aid of the_drawings wherein: -Figure 1 shows a folded liner according to the invention; Figure 2 shows the liner in Figure 1 in a flat configuration; U a Figure 3 shows a pictorial view of the liner shown in Figures 1 and 2, including alternative lids; Figure 4a shows a further liner according to the invention together with a lid; Figure 4b shows a detail of the liner shown in Figure 4a; and Figure 5 shows the liner of Figure 4 laid flat.

Figure 1 shows a liner 10 having a lid 5, the liner and lid are insertable into a standard size box used for home delivery of groceries, for example by supermarkets. The liner 10 is formed from open cell sheet material, for example ethylene vinyl acetate (EVA), low density polythene (ldpe), flexible polyurethane, a polyolefin or polypropylene. In each case the material is foamed to form a closed cell sheet material which has the characteristic that it is semi-rigid, i.e. it is slightly flexible and has a memory such that it will return to its original shape when it is depressed or deformed. Such a material has the advantage that when delicate food is thrown into the delivery crate the liner within acts as a cushion but does not split so it retains its continuous surface and therefore is less likely to harbour bacteria.

The close cell foam is encapsulated in a food grade pvc coating which has a fabric material layer embedded therein to increase tear resistance. In addition, the inner surfaces 12 of the liner have a metalised surface, for example foil, to reflect heat back into the liner or to prevent heating of the liner from -----externaLsources... -The liner includes a thermometer 14 so that delivery personnel can ensure that the food within the liner reaches the customer at the correct temperature. The liner has a base member (16 Figure 2) and four side members 18. The base and sides are joined so that they are foldable into the liner shape.

The joins are formed from hinges, formed from the PVC and fabric material. The foam is shaped so that the sides and base all come together to form angled joints which produce flat mitred joints to prevent air currents into or out of the liner. The folded liner 10 has a lid 5 which includes a mid-hinge 20 formed in the same manner as the joints mentioned above. End tabs 25 are included on the lid to allow access to the box.

Figure 2 shows a folded flat plan view of the liner 10 shown in Figure 1.

In this view it is apparent that the liner can lie in a flat plane and that the base 16 has four side pieces 18 attached thereto. The side pieces are articutatable relative to the base to form the box shape shown in Figure 1. The foam sheets have V' slots 19 which allow folding into the shape shown in Figure 1.

Figure 3 shows a pictorial view of the liner 10 in flat form, together with the lid 5 and an alternative lid 5'.

Lid 5 includes a further V' slot 19, to form a central hinge 20. Lid 5' has no central hinge but the material of the lid 5' is the same as that of the box.

Figure 4a shows a pictorial broken away view of a further liner 40 which is assembled and ready for insertion in a standard delivery crate (not shown). The liner 40 includes a lid 35.

Liner 40 and lid 35 perform the same function as the liner 10 and lid 5 -______ described above. In this embodiment the liner 40 and lid 35 are manufactured from expanded polypropylene (EPP). The liner 40 and lid 35 are moulded to have a plate finish i.e. a substantially flat and smooth surface with no significant fissures or roughness, to avoid harbounng bacteria and the like. This material is also a closed cell foam which is flexible, light weight and has a memory to return to its original shape after absorbing an impact. Since its surface can be moulded smoothly, there is no need to provide a cover over the foam in this embodiment. In addition expanded polypropylene has the property that it maintains its flexibility at low temperatures for example a temperature of _200 to 300 used for storing frozen food.

Liner 40 and lid 35 are intended to nest within a crate so that they each lie below an upper surface of the crate in order to allow for stacking of multiple crates. A recessed handle 36 is provided, and a divider 39 may be employed also, for dividing the space in the liner 40.

Referring to Figure 4b, there is shown an enlarged partial view of the liner 40 and lid 35 in the area 4b shown in Figure 4a. The liner 40 has an upstanding portion 42 which fits snugly in a recess 38 in lid 35 to provide an edge seal 41.

The liner 40 is manufactured by expanding polypropylene beads in a steam heated mould. The mould will have a polished surface to form the plate finish of the liner as mentioned above.

Figure 5 shows liner 40 in a flat condition prior to its folding to a shape shown in Figure 4. As well as mitred edges 44 the corner sections of the liner 40 include castellations 46 which come together when folded with complimentary castellations 48. The castellations 46 and 48 are an interference -----fitsothatthecomersofthelinerstayjQgthjwtIenmated. --------When brought together the sides 43 of the liner 40 and the base 45 are held together by the castellations 46 and 48 and an internal radius R in Figure 4 is formed which inhibits the collection of dirt, bacteria, etc. A radius R of about 50mm has been found to be suitable.

S Since the liner is manufactured in one piece and then folded into shape, along narrow portions of the EPP formed between the sides 43 and the base 45, there is no chance of losing pieces and no need to affix one piece to another.

Use of a closed cell foam which has some inherent resilience means that the foam will return to its original shape when it is deformed. This allows the foam to recover its shape and it remains effective as an insulator and does not permanently compress, tear or split, or otherwise degrade so that the foam is easy to clean and bacteria and the like can be removed readily. The use of light-weight foam also encourages delivery drivers to use liners because the liner does not add significantly to the overall weight of a delivery crate.

In use the liner 10/40 can be inserted into a standard food carrying box used for home delivery of foodstuffs. The liner is necessary only when food is to be kept hot or cold. At other times the liner can be removed and stored flat, for example at the delivery depot. If the liner is used only when necessary then this allows extra capacity in the standard boxes and the liner is less likely to be damaged by heavy items such as tins of food.

Claims

Claims 1. A removable thermally insulating liner for a food transport box, the liner having a plurality of foam sheet members, joined and relatively articulatable so that they can lay flat or be formed to substantially line the food box.

2. A liner as claimed in claim 1, formed from a rectangular base member and four side members joined to the base member, one at each of the rectangle's four edges, for folding into an open topped liner, to line the box.

3. A liner as claimed in claim 2, wherein edges of the liner members where they meet other members are oblique such that the respective edges meet to form a mitred joint or joints.

4. A liner as claimed in claim 3 wherein said oblique meeting edges have complementary formations which interfere when brought together so that the edges are held together to assist assembly.

5. A liner as claimed in claim 3 or 4 wherein, an internal radius is formed when the side members and base are brought together.

6. A liner as claimed in any one of the preceding claims wherein, the members have a food grade plastics coating on at least one face.

7. A liner as claimed in claim 6 wherein, the coating completely encapsulates the members.

8. A liner as claimed in claim 6 or 7 wherein, the coating is PVC formed on a --_9._ A4inerasclairnedJn_any_oneoLtbe_ptc.edingjms 6 to 8 wherein, the members are joined at respective edges only by the coating of the members.

10. A liner as claimed in claim 9 wherein, the respective edges at the joins are oblique to allow folding of one member relative to the other.

11. A liner as claimed in any one of the preceding claims wherein, the members include a radiant heat reflective surface such as a foil surface.

12. A liner as claimed in claim 11 wherein said reflective surface is innermost when the liner is formed to line the box.

13. A liner as claimed in any one of the preceding claims wherein, the liner further includes a lid which is formed from the same material as the remaining liner, and is formed in two relatively articulatable pieces.

14. A liner as claimed in any one of the preceding claims wherein one or more of the liner members are formed, at least partially, from a resdient closed cell foamed material, having the property that the foam tends to return to its original shape following deflection.

15. A liner as claimed in claim 14 wherein said closed cell foamed material comprises an expanded polypropylene (EPP).

16. A method of manufacturing a liner comprising the steps of: a) introducing plastics into a mould; b) expanding the plastics to substantially fill the mould; and c) moulding a liner, according to any one of the preceding claims 17. A mould when used in the method of claim 16.

18. A food transport crate or box, having a removable heat insulating --moulded liner said liner having a plurality of foam sheet membersjed_aod_ ---relatively articulatable so that they can lay flat or can be folded and so formed to line the food box.

19. A liner or food transport box including a liner, substantially as described herein optionally with reference to the drawings.