CA1209389A

CA1209389A - Packaging elements and methods

Info

Publication number: CA1209389A
Application number: CA000439579A
Authority: CA
Inventors: Raphael A. Engle; David Martin; Russell A. Cassey
Original assignee: TRI-ENGLE SYSTEMS Ltd
Current assignee: TRI-ENGLE SYSTEMS Ltd
Priority date: 1982-10-22
Filing date: 1983-10-24
Publication date: 1986-08-12
Also published as: IE55101B1; EP0108537A1; ES285005Y; AU2044283A; DE3375296D1; EP0108537B1; ES285005U; AU573543B2; IE832483L

Abstract

A packaging element formable into a container having at least a base and sides perpendicular to the base which comprises at least one layer of stiff material lined on at least one side with a thin flexible material such as plastics. The thin flexible layer of material extends about the outer periphery of the stiff material and parts thereof are used as flaps to secure a container formed from the packaging element in an erected condition. Several embodiments of the packaging element are disclosed including elements formable into open containers and containers which include lids.

Description

This invention relates to packaging elements and methods for forming same.

Conventional packaging elements (containers) are generall~ not fluid impervious, and where there are requirements for liquid and/or gas-tight packaging these have been met in the main by the provision of plastics liners within the containers. If the liners do not totally en~lose the contents often the contents are contaminated by contact with the container body.
This is particularlyso when the elements are used for packing frozen foods~ In recent years attempts have been made to produce a packaging element in which a plastics or plasticised liner is formed integrally with the container body.
US Patent No: 4,056,221 discloses a packaging element formable into a container which has an integrally formed plastics liner having also an external plastics layer. The liner and external plastics layer totally enclose the stif~ening cardboard material and a fluid-tight but open container is formable from the packaging element. As with conventional plain cardboard containers the pre-formed cardboard portion of the element is cut from a single large blank of cardboard with subsequent wastage of materials.

It is an object of the present invention to provide a packaging element and/or container and/or a ~Z~93~9 method of forming a container.
According to the present invention there is provided a packaging element for erection i.nto a container comprising at least one layer of sti~f material lined on at least one side with a thin flexible material including a border which surrounds the stiff material, said stiff material comprising a central base element having end flaps, side elements flanking the base element, the side elements having end gussets aligned with the end flaps of the base element, lid elements flanking the side elements, the lid elements having end gussets aligned with the end fl~ps of the base element, the ~ase element and end flaps therefor being of a substantially rectangular configuration and the end gussets being of a substantially triangular configuration leaving an adjacent triangular portion of flexible plastics material where the stiff material is absent, parallel folding seams between all of the elements and the end flaps and gussets, the arrangement and construction being such that the end flaps and gussets can be folded upright relative to the base side and lid elements about common folding seams, and the side elements can be folded relative to the base element so that they are upright relative to the base element with the triangular portions of the thin flexible material adjacent the base element being accomodated between the end plates and adjacent the base element being accommodated be-tween the end plates and ad~acent gussets of the side elements whereupon contacting portions of thin flexible material can be united to retain the container so formed in an upright position for filling and subsequently opposed portions of the thin flexible materiaL at an opening of the container can be united so that the interiors of the container are airtight, vtd/ ~ - 2 -lzas3ss the united portions of the thin flexible material being sub-sequently usable as straps sea].able against the adjacent sur-faces of the thin flexible material.
According to another aspect there is provided a packaging element for erection into a container comprising at least one layer of stiff material line on at least one side with a thin flexible material including a border which surrounds the stiff material, the stiff material comprising a central base element having end flaps, side elements flanking the base element, the side elements having end gussets aligned with the end flaps of the base element, the base element and the end flaps therefor being of a substantially rectangular configuration and the said end gussets being of a substantiall.y triangular configuration leaving an adjacent triangular portion of thin flexible material where the stiff material is absent, the arrangement and construction being such that the end flaps and side elements can be folded upright relative to the base about common folding seams withthe triangular portions of the flexible material being accomodated between the gussets and the end flaps secured in the upright position by use of portions of the border of the thin flexible material as flaps which can be fixed against adjacent portions of the thin flexible material.
According yet to another aspect of the present inven-tion there is provided a packaging element for erection into a container comprising at least one layer of stiff material lined on at least one side with a thin flexible material in-cluding a border which surrounds the stiff material, the stiff material comprising a central base element having a transverse folding seam, side flaps flanking the base element and in a position which is parallel to the transverse folding seam, and end ,,~. .

- 2a -. vtd/ C~L~

lZQ~3~39 flaps ~oined to the ends of the side flaps extending in the direction of the transverse seam, the arrangement being such that there exists a void area defined by the base element and the end flaps and the adjacent edge of the flexible mater-ial where the stiff material is absent, the packaging element being foldable about folding seams between the side flaps and the base, so that with the side flaps and the gussets under-lying the base, 45 degree seams can be formed to join the void area of the thin flexible material and the flexible material covering the end flaps, and the element can be erected into a container by separating the side walls and end flaps while the base temporarily folds about the transverse seam until the sides are parallel.
Accordin~ to a further aspect of the present invention there is provided a method of manufacturing a packaging element as aforesaid comprising the steps of positioning the stiff material between two layers of flexible plastics material and heating the plastics material such that the plastics material adheres to the stiff material, and, where plastics material to plastics material contact is made, the adjacent layers of plastics material are adhered to one another.
Aspects of the present invention will now be described by way of example only with reference . vtd/ ~ - 2b -~20~3139 to the accompanying drawings în which:

Figure l: is a diagrammatic perspective view of a packaging element in manufacture and in accordance with one aspect of the present invention, and Figure 2: is a diagrammatic side view of an apparatus for manufacturing a packaging element in accordance with the present invention, and Figure 3: is a plan view of a packaging element in accordance with a further possible embodiment of the present invention, and Figures 4,5,6, and 7: are diagrammatic perspective views indicating the manner in which the packaging element of Figure 3 can be erected into a container, and Figure 8: is a plan view of a packaging element in accordance with a further possible embodiment of the present invention, and Figures 9,10 and ll: are diagrammatic perspective views showing the manner in which the packaging element of Figure 9 may be erected into a container, and ` ~ ~
~2a~931 39 Figure 12: is a plan vie~ of a packaging element in accordance with yet a further form of the present invention, and Figure 13: is a plan view of the packaging element of Figure 12 with flaps thereof upright, and Figure 14: is a perspective view of the packaging element of Figure 13, and Figure 15: is a top perspective view of the container of Figures 12,13 and 14 with a lid formed from an element in accordance with the embodiment of Figures 22 and 23 of the drawingsf and Figure 16: is a plan view of a packaging element in accordance with yet a further possible embodiment of the present invention, and Figure 17: is a cross-sectional drawing taken at XVII:XVII of Figure 16, and Figure 18: is a plan view of a packaging element in accordance with Figure 17 with the side sections folded under and with folds formed therein, and ~09,389 Figures 19 and 20: are explanatory cross-sectional drawings respectively of the element of Figure 10 flat and then folded about a seam of the base part thereof, and Figure 21: is a diagrammatic view of an erected package formed from the elements of Figures 16 through to 20, and Figure 22: is a diagrammatic perspective view of a packaging element in accordance with yet a further possible embodiment of the present invention, and Figure 23: is a diagrammatic perspective view of the packaging element of Figure 13 having the ends folded over and folds formed therein, and Figure 24: is a plan view of a packaging element in accordance with a still further possible embodiment of the present invention, and Figure 25: is a diagrammatic partial perspective view of the packaging ele~ent of Figure 24 shown in a folded condition, and i2093~9 Figures 26, 27 and 28- respectively are diagrammatic cross-sectional and perspective views of the packaging element of Figures 24 and 25 folded and then formed into a container.
With respect to Figure 1 of the drawings a pack-aging element generally indicated b~ arrow 1 and according to the example illustrated comprises a first layer 2 of plastics ma-terial, a second layer 3 of stiff material such as cardboard, and a third layer of plastics material 4. The plastics layers

2 and 4 are adhered to the stiff material 3 and to each other where there is not contact with the cardboard 3. The first and third la~ers 2 and 41 in plastics, can be co-extruded film comprising a s~n~irh of EVA film and LDPE film. The EVA has a low melting point and is in contact with and adheres to the cardboard 3 and the other plastics layer.
The second layer 3 of stiff material comprises a centre section 5 and two side sections 6, and the side sec-tions 6 are spaced from and positioned at equal distances from the ends of the centre section 5.
After manufacture the packaging element can be formed into a container with a base 5, sides 6, and ends formed from extending parts 5A of the sections 5 (a bend in the cardboard being made along the broken lines 7) and the corners can be gussetted and sealed-or otherwlse joined.

~S vtd/ ~

` ~LZ~93i~9 As an alternative to the use of co-extruded film,the plastics layers 2 and 4 can be single sheets of plastics, adhered to the stiff material by a suitable adhesive. The stiff material forming the centre and side sections may optionally be a unitary member (not shown) with sides 6 foldable about seams.

Figure 2 of the drawings illustrates an apparatus for making the packaging elements of Figuxe 1. The apparatus illustrated comprises a conveyor 8 positioned upstream from a pair of rollers 9 and 10, fed with plastics film 11 from a supply source indicated by arrow 12. The centre spacings of the rollers 9 and 10 can be adjustable to suit the thickness of the packaging element. Stiffening material 13 is placed on the conveyor 8 r which stops, receives the stiffening material 13 and then feeds the same between the rollers 9 and 10. The rollers 9 and 10 can be heated by a fluid such as oil such that the plastics adheres to the stiffeniny material and the adhesive process is further assisted as it passes through pinch rollers 14 (which can be covered with a soft material such as rubber or felt material) downstream of the rollers 9 and 10 which applies pressure to the top and bottom suraces of the packaging element as it passes between them.~_~ rotating hot or cold knife 15 canbe positioned downstream of the - l2as3ss of the rollers 14, such being designed to perforate or cut (see broken line of figure 1) the plastics material to make one element easily separable from the element following. Box-making collection and forming plant at 16 complete the process for formin~ the packaging elements into a container.

, Where a co-extruded film as aforesaid is used the ~ .inner layer(which may be EVA plastics)softened during the manufacturing process and becomes, in effect, an adhesive. The conveyor 8 and the pinch rollers 14 are optional.

Figures 3 to 7 of the drawings illustrate one possible embodiment of a packaging element in accordance with the present invention, the element generally indicated by arrow 17 being formable into a container (generally indicated by arrow 18 and illustrated by Fig~re 7), said container having a base 19 and sides 20 and a lid section generally indicated hy arrow 21. The packaging element comprises a first layer of plastics 22, a second layer of stiff material 23 and a third layer of plastics material 24, said first and third layers 22, 24 being adhered to the stiff material 23 and to one another where they overlap. A border 25, where there is surface contact between the plastics layers is provided about the periphery of the element 17. The stiff material 23 comprises a substantially rectangular base 26 with ~Z09389 flaps 27 foldable with respect to the base 26 and flaps 28 foldable with respect to the flaps 27 such ~olding being made about seams 29. Each of the flaps 27 and 28 are provided with gussets 30 and 31 and the base 26 i~ provided with end sections 32, the gussets 30 and 31 and end sections 32 foldable with respect to the flaps 27 and 28 and the base 26 respectively. The gussets 30 are of a triangular shape defined by seams 33, a long side 34, and short side 35. The gussets 31 are similarily shaped.

At one end of the packaging element 17 an additional strip 36 of stiff material is provided such being foldable about seams 37. In addition to the border 25 plastics to plastics contact between the first and third layers is provided at triangular areas 38 void o~ the stiff material.

The packaging element 17 of Figure 3 an be er cted ~o6~r~t~6 ~ ~.iinto the container 18 of Figure 7 in ~r~r~si~
steps as is illustrated by Figures 4, 5 and 6.
The first step (see Figure 4) is to fold the end sections 32 and the gussets 30 and 31 into an upright position with respect to the base 26 and flaps 27 and 28. The next step in the erection of container 18 is illustrated by Figure 5 which shows the opposed flaps 27 and 28 being folded about seam 29 which is common with the base 26 such that gussets 30 overlap the outside end sections 32 of the element, and void area~ 38A are accommodated between the gussets 20 and the end sections 32.

` 12~93~39 This later step is further progressed until the flaps 27 are perpendicular with the base 26 (see Figure 6) and at that point edges 39 of the i~R.~o~--~P ~ dLr 25 overlap and can be adhered together by blocking, heat sealing or the like. When the sides of the element are upright (or as part of a process for achieving this step) an inverted "T" shaped seal T is made binding together all adjacent overlying plastics layers. A container ready to receive lQ articles is thus formed, and overlapping and adjacent edges 39 have been utilised to secure the container in its erected position. The container 19 can be filled and the ends of the top edges extended in the direction of the arrows 40.

Figure 7 illustrates the manner in which the lid 21 (formed from flaps 28 and gussets 31) can be sealed by the matching of the strip 36 to border portion 25a as the flaps 28 and gussets 31 lay flat (a natural consequence of movement of the lid section in direction of arrow 40), and finally the sealed container can be closed by folding down the flap formed by the joined border portion 25a and the strips 36, folding the triangular lid ends 41 formed from gussets 31 downwards in the direction of arrow 42, and fixing the lid ends to the base and/or the ends of the container. To make it easier to form the step of Figure 6, that is, the sealing and/or blocking when the cont~;ner is ready to receive goods (see Figure 6) the gusset tips 43 may be trimmed off at ~2a9389 line 31a when the stiff element is fabricated, and prior to the application of the plastics layers 22 and 24.

The packaging element 17 could have its base 26, and flaps 27 and 28 formed from separate pieces of material in a similar manner to the element of figure 1. By so doing material savings can be made when the stiff material is pre-cut~

Figures 8 through to 11 of the drawings illustrate one further embodiment of a packaging element in accordance with the present invention, which is somewhat similar to that illustrated by Figures

3 through to 7 of the drawings. For that reason ` 6 t~ L ~
~ cquivilont-components are denoted by the same numerals used with respect to the Figures 3 to 7 embodiment. The main difference between the previously described embodiment i5 that the gussets 31 of the Figures 3 to 7 embodiment do not exist and in fact triangular gussets 44 are provided which are fixed about seam 29 of gussets 30 as shown. The strip 36 from the previous embodiment is omitted.

The steps in the erection of the element of Figure 8 into a container are identical to those described in relation to Figures 4 and 5 of the Figures 3 to 7 embodiment. However at the L6~Jr ~q~ivil~r.L stage to Figure 6 the overlapping edges 39 are sealed or blocked on both outer and inner edges of the container. To close off the lid the gussets 44 are drawn to the flat position as the ends of the lid section are pulled in the direction of arrow 40 and opposed border sections 25B are matched and sealed in the equivilent to the Figure 7 stage previously referred to. The end parts formed from gussets 44 can then be folded down and fixed as previously described.

With respect to figures 12 through to 15 of the drawings and in accordance with a further possible embodiment of the present in~ention there is provided a packaging element generally indicated by arrow 45 comprising a first layer of plastics material 46, a second layer of stiff material 47 and a third layer of plastics material 48 wherein the plastics layers 46 and 48 are adhered to the stiff material 47 and the element 45 can be formed into a container having at least a base 49 and sides 50.
The first and second layers 46, 48 are wider and longer than the stiff material 47 so that there is a border 51 about the periphery of the stiff material 47 where the plastics is adhered together so that the stiff material is completely enclosed within the plastics material.

lZ09389 As previously described the first and second layers of plastics can be co-extruded film with a layer which makes immediate contact with the stiff material being EVA with a low melting point.

In the particular embodiment illustrated by Figures 12 through to 15, and by way of example, the stiff material can be a cardboard blank which comprises a base 49 with flaps foldable with respect to the base 49 forming sides 50 where at least two opposite flaps 50a have gussets 52 on the ends thereof foldable with respect to the flaps, the arrangement being such that a container can be formed from the blank when the flaps 50 are folded upxight and the gussets 52 overlie adjacent flaps 50A and the border section 51A at the ends of the flaps can be folded over and sealed against the adjacent surfaces to secure the flaps 50 in an upright position with respect to the base 49.

In the particular example illustrated the border 51~ at the sides can be less than say one centimetre whilst the border 51~ at the ends is larger, say five centimetres so that it is foldable with respect to the edges 55 of the adjacent flaps 50.

12~3~9 ~hilst the ~ase 49 and the flaps 50 are shown as being integrally formed, these may be formed from separate pieces of material (not shown) from the base 49.

With respect to Figure 12 of the drawings the element illustrated can be folded to form the container illustrated by Figures 13, 14 and 15.
By way of example the opposite flaps 50A and 50B
can be folded into an upright position to be perpendicular with respect to the plane of the base 49 and the gussets 52 lapped o~er the adjacent surfaces of the flaps 50B and finally border sections 51~ are folded downwardly as indicated by the arrows of Figure 15 and sealed against the plastics layers of the outer surface of the flaps 50~ thus, a container which is completely ~luid-tight(except or its opening) can be formed.

It will be appreciated by those skilled in the art that the gussets 52 may be attached to any of the flaps of the blank, not just to the side flaps in the rectangular container illustrated and furthermore that when the blank is erected to form the container it is optional to have the gussets on the inside of the flaps 50 and the border section 51~ sealed also against the inside of the flaps.

It is to be appreciated that the element 45 of ~2~389 ~igures 12 to 15 could include further flaps (not shown) formable into integrall~ fixed lids for a container. Such further flaps could be attached to the flaps 50A or 50B.
In a further modification to the embodiment of Figure 12 the gussets 52 may be eliminated, such that the basic element is substantiall~ the same as that illustrated and described in relation to Figure 1. Again, the flaps 50A and gussets 52 could be made from separate pieces of stiff material.
Having erected the container of Figures 12, 13 and 14 a lid formed from an element similarily constructed tsee Figures 22 and 23) can be placed on the container after it has bee~ filled with articles and then the lid can be taped to the container using a tape 56 which is capable of providing a moisture and air-tight seal. The element of Figures 12, 13 and 14 and/or the lid of Figure 15 can be provided with a cut-out portion 57 cut from the stiff material 47 forming the base of the lid and where the plastics layers are trans-parent a window is formed so that the contents of the container can be viewed. Alternatively, the lid may be a plastics lid and may be fabricated or moulded from a separate sheet of stiff material.
When the packaging element is erected as described the plastics area X between gussets 52 and the flaps 50B is easily accommodated behind the gussets.

.,, ;, , ,. ~ - ~

12~9389 Further possible emhodiments of the present invention are illustrated by Figures 16 through to 21 and 24 through to 28 of the drawings and in accordance therewith and the present invention a packaging element can comprise a first layer of plastics material 60, a second layer of stiff material generally indicated hy arrow 61 and a third layer of plastics material 62. The plastics layers 60 and 62 are adhered to the stiff material 61 and the stiff material is shaped such that a container at least having a base and sides can be formed from the packaging element.

~Referring speci~ically to the packaging element illustrated by Figures 16 through to 21 of the drawings the stiff material 61 can comprise a base 63, end parts 64 and side parts 65 substantially in a rectangular configuration.
A unitary element is formed when the plastics layers 60 and 62 are adhered to the stiff material 61 and where the stiff material is absent such as at the sections 66 - the plastics layer 60 is adhered to the plastics ~ 62 such being indicated by the shading in the drawing.

The stiff material 61 comprising a base, end and side parts can be formed from one sheet of cardboard with seams as shown or alternatively and as illustrated the stiff material is provided with separate pieces comprising conjoined side and end 3u parts 64 and 65 and a separate base part 63 with 12~93~39 a consequential seam formed between the separate pieces. When the plastics is adhered to the stiff material there is provided a sealed border around the periphery of the elements such that the stiff material is completely enclosed within the plastics material. Figure 17 of the drawings is an enlarged cross-section at XVII:XVII of Figure 16 with both the plastics layers being shown in exaggerated size for clarity.

The element of Figure 16 can begin to be formed into a container having a base and sides when the ends and side parts 64 and 65 are folded under the base part 63, and fold lines are formed by the cre~tion of 45 degree seams 67 or blocking at 67~ where the adjacent plastics layers 60 and 62 are joined together. From the condition illustrated by Figures 18,19 and 20 the container can be formed b~ opening out the side and end parts and folding the base about a seam 68 to form a container having a base and sides as illustrated by Figure 21.
.

When the element is formed into a container the meeting of the edges 69 of the end parts 64 can be secured together by a tape and/or the adjacent layers of the plastics material can be adhered together by the formation of seals.

~2~93~9 In a further alternative to the example illustrated by Figures 16 through to 21 the stiff material forming the base part 63 can be eliminated such that in the end, the container is formed having a stif material forming sides and ends only. In such a case and/or as an alternative to securing the container at its erected position with the tape and/or sealing as described the edges 73 of the plas~ics material (see Figure 18) can be sealed together after the seams 67 are formed or blocking is carried out (the sealing for the edges 72 being preceded by folding down as illustrated by Figure 20 or by blanking)as has been explained in relation to Figure 18.

Figures 22 and 23 of the drawings illustrate by way of example a method by which the lid for the container of Figures 16 through to 21 or another container can be manufactured. The lid can comprise a ba~e part 73 of stiff material and side parts 74 and end parts 75 of stiff material sandwiched between the two layers of plastics 76,77 leaving void sections at the corners 78 of the edges 79 where the plastics is adhered to the plastics. The side and/or end parts 74t75 can be formed as part of the base 73 having sear~s between the base and sides or -~2~389 ends or alternatively as illustrated the base sides and ends can all be formed from pieces of stiff material. From the element illustrated by Figure 22 the end part 75 can be folded over as shown by Figure 23 and a fold seal 80 made at 45 degrees joining adjacent layers of plastics material. ~fter that step the lid can be erected by folding outwardly and upwardly the sides and the end parts with taping at the corners being optional. In a modification to the example illustrated tnot shown) stiff material can be left out of the base 73 the plastics layers being joined together to form said base part.

With respect to Figure 24 through to 28 of the drawings these illustrate a further possible em~odiment of a packaging element in accordance with the present invention such comprising as before a first layer of plastics 60, a second layer of stiffmaterial generally indicated by arrow 61 and a third layer of plastics material 62 wherein the plastics layers are adhered to the stiff material and the stif material is provided in a form which includes the base and sides for a container.

In the example illustrated the stiff material provides a base 81, sides and ends 82,83 respectively, and optionally a lid section 84. The base 81 and the sides and ends 82,83 and the lid sections 84 can lZ~9389 be separate although it would be appreciated by those skilled in the art that the sections can be formed from the one section having seams (not shown) dividing them. As with the previous example the folds are formed by the provision of seams 85 at approximately 45 degrees or by blanking and the seams 85 or the blanking (not shown) can be formed or carried out when the element of Figure 24 is folded into the configuration illustrated by Figure 25.

After the seaming (or blanking) operations have been completed the packaging element is erected by manipulation of the element as illustrated by Figures 26 of the drawings and to facilitate such manipulation the base part 81 can be provided with an elongate seam or join 86.

With respect to Figure 26 Gf the drawings the blank is manip~lated as shown folded flat and ends 88 are sealed together to form the container of Figures 28 by opening the ends of the container flaps in the direction of the arrows of Figure 27 a container as shown in Figure 28 can be formed which can be sealed along the edyes 89 thus sealing the interiors of the container. Triangular overhanging parts 90 can then be folded over and sealed (or otherwise fixed) to the sides of the container.

Depending on the use to which the container is to be put to there are se~eral alternative modifications ~2~g389 or completion steps which can ~e carried out.

For example if the stiff lid is not required, the stiff material 84 can be left out of the lid of the container.

Whilst it has been known in the art to package food in cardboard containers lined with plastics (to prevent the cardboard from contaminating the foo~) and to make the containers lined with plastics these are not completely hygienic. Such containers lined with plastics have edges at which the cardboard is exposed. In contrast, the present invention provides a container which has no exposed areas of cardboard. Additionally, and in accordance with aspects of the present invention a cardboard container can be formed with no flaps or joining strips in the cardboard material.

Containers in accordance with aspects of the present invention are substantially tamper-proof particularly if a tape such as EVA tape which is sealable against the outer edges of the container and/or lid is used. A glue tape may also be used.

Because plastics is a fluid impervious material containers of the present invention are liquid imper~ious and can be made gas impervious by using a gas impervious material and one of the layers of a co-extrusion laminate. Examples of suitable gas impervious mterials are nylon, aluminium or PVDC.

0~389 Whilst the containers described can be conveniently made using co-extruded plastics it would be appreciated from the aforegoing that a more suitable general description would be that the container walls are multi-laminates and optionally co-eY~trusions can be used.

It is to be appreciated from the aforegoing that a container can be formed having a hygienic non-fibrous surface of for example plastics material in a simple yet effective manner which will allo~ for example meat to be packed in an atmosphere free of cardboard fibres as the containerscan be formed a substantial distance or indeed in a different factory to the place where they are filled. At the filling station all cardboard is contained within the first and third layers and therefor the risk of cardboard fibres being present in the atmosphere or otherwise coming into contact with meat products is substantially reduced.

Further advantages of the containers of the present invention are that the blanks can be pre-printed and a lighter weight, less rigid cardboard can be used and even re-cycled cardboard could be used.

At leas~ f~r some embodime~ts~of the present invention fold lines are eliminated and these 12~9389 ,~ S~
are thought to be the ea~e of problems at xemoval and tha~ing when containers are used to store food under refridgeration.

Whilst containers/cartons of the present invention are ideally suited for storage and cartage of foods (frozen, chilled or otherwise) it is to be appreciated that the containers may be used for any purpose whatsoever.

Several examples of the present invention have been described herein where the stiff material is provided with separate pieces or as a unitary member. Although this system has advantages it should be appreciated that the stiff material can be optionally provided in separate pieces, or as a unitary member with the various portions of stiff material foldable-about a seam formed therein.

It is to be appreciated that the flexible layers 2Q of material although most likely to be from plastics may be from other materials, such as sheet foil or the like.

Aspects of the present invention have been described by way of example only and it will be appreciated that modifications and additions thereto may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

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

1. A packaging element for erection into a container comprising at least one layer of stiff material lined on at least one side with a thin flexible material including a border which surrounds the stiff material, said stiff material comprising a central base element having end flaps, side elements flanking the base element, said side elements having end gussets aligned with the end flaps of the base element, lid elements flanking the side elements, said lid elements having end gussets aligned with the end flaps of the base element, the said base element and end flaps therefor being of a substantially rectangular configuration and the said end gussets being of a substantially triangular configuration leaving an adjacent triangular portion of flexible plastics material where the stiff material is absent, parallel folding seams between all of the elements and the end flaps and gussets, the arrangement and construction being such that the end flaps and gussets can be folded upright relative to the base side and lid elements about common folding seams, and the side elements can be folded relative to the base element so that they are upright relative to said base element with the triangular portions of the thin flexible material adja-cent the base element being accomodated between the end plates and adjacent the base element being accommodated between the end plates and adjacent gussets of the side elements whereupon contacting portions of thin flexible material can be united to retain the container so formed in an upright po-sition for filling and subsequently opposed portions of the thin flexible material at an opening of the container can be united so that the interiors of the container are airtight, the united portions of the thin flexible material being subsequently usable as straps sealable against the adjacent surfaces of the thin flexible material.

2. A packaging element as claimed in Claim 1 wherein a further strip of stiff material is applied to the outer edge of one of the lid elements, a folding seam between the strip of stiff material and lid element, said strip acting to stiffen one opposed portion of the opening of the container.

3. A packaging element as claimed in Claim 1 including a second layer of thin flexible material applied over the stiff material so that the stiff material is sandwiched be-tween two layers of thin flexible material, said layers of thin flexible material being adhered to the stiff material and to one another where they overlap such that there is surface to surface contact therebetween at least about the periphery of the stiff material and the stiff material is hermetically and hygenically sealed within the flexible material.

4. A packaging element for erection into a container comprising at least one layer of stiff material lined on at least one side with a thin flexible material including a border which surrounds the stiff material, said stiff material comprising a central base element having end flaps, side elements flanking the base element, said side elements having end gussets aligned with the end flaps of the base element, the said base element and the end flaps therefor being of a substantially rectangular configuration and the said end gussets being of a substantially triangular con-figuration leaving an adjacent triangular portion of thin flexible material where the stiff material is absent, the arrangement and construction being such that the end flaps and side elements can be folded upright relative to the base about common folding seams with the triangular portions of the flexible material being accomodated between the gussets and the end flaps secured in said upright position by use of portions of said border of the thin flexible material as flaps which can be fixed against adjacent portions of said thin flexible material.

5. A packaging element as claimed in Claim 4 including a second layer of thin flexible material applied over the stiff material so that the stiff material is sandwiched between two layers of thin flexible material, said layers of thin flexible material being adhered to the stiff material and to one another where the overlap such that there is surface to surface contact therebetween at least about the periphery of the stiff material and the stiff material is hermetically and hygienically sealed within the flexible material.

6. A packaging element for erection into a container comprising at least one layer of stiff material lined on at least one side with a thin flexible material including a bor-der which surrounds the stiff material, said stiff material comprising a central base element having a transverse folding seam, side flaps flanking the base element and in a position which is parallel to the transverse folding seam, and end flaps joined to the ends of the side flaps extending in the dir-ection of the transverse seam, the arrangement being such that there exists a void area defined by the base element and the end flaps and the adjacent edge of the flexible mater-ial where the stiff material is absent, said packaging element being foldable about folding seams between the side flaps and the base, so that with the side flaps and the gussets underlying the base, 45 degree seams can be formed to join the void area of the thin flexible material and the flexible material covering the end flaps, and the element can be erected into a container by separating the side walls and end flaps while the base temporarily folds about the transverse seam until the sides are parallel.

7. A packaging element as claimed in Claim 6 wherein free border edges of the thin flexible material provide straps to secure the container in an upright condition.

8. A packaging container as claimed in Claim 6 wherein the stiff material includes two lid elements flanking the side elements.

9. A packaging element as claimed in Claim 6 including a second layer of thin flexible material applied over the stiff material so that the stiff material is sandwiched be-tween two layers of thin flexible material, said layers of thin flexible material being adhered to the stiff material and to one another where they overlap such that there is surface to surface contact therebetween at least about the periphery of the stiff material and the stiff material is hermetically and hygienically sealed within the flexible material.

10. A method of manufacturing a packaging element as de-fined in Claim 1 comprising the steps of positioning said stiff material between two layers of flexible plastics material and heating the plastics material such that the plastics material adheres to the stiff material, and, where the plastics material to plastics material contact is made, the adjacent layers of plastics material are adhered to one another.

11. A method as claimed in Claim 10 wherein the plastics material comprises layers of co-extruded plastics material.

12. A method as claimed in Claim 10 including the further step of creating folds in the element by seaming or blocking adjacent layers of surface material of the element to create erectable sides for a carton to be formed from the element, folding the blank, and erecting the blank to form a package having at least a base and sides.

13. A method as claimed in Claim 11 including the further step of creating folds in the element by seaming or blocking adjacent layers of surface material of the element to create erectable sides for a carton to be formed from the element, folding the blank, and erecting the blank to form a package having at least a base and sides.

14. A method as claimed in Claim 12 or 13 including the further step of sealing the upper edges of the sides of the container formed from the blank to form a completely fluid-tight package.