WO1992022474A1

WO1992022474A1 - Improvements relating to the packaging of tea

Info

Publication number: WO1992022474A1
Application number: PCT/GB1992/001044
Authority: WO
Inventors: John Tugman; Peter Megson
Original assignee: Premier Brands U.K. Limited
Priority date: 1991-06-11
Filing date: 1992-06-11
Publication date: 1992-12-23
Also published as: ZW9192A1; AU1923792A; GB9112580D0; CN1069001A

Abstract

A flat, flexible package for holding tea comprises an outer sealed paper casing (10) and an inner, hermetically sealed bag (12) for containing the tea. To open the package for filling, the sealed outer casing (10) is opened at one end and a folded portion (36) of the inner bag (12) is unfolded so that its end projects from the outer casing (10). By means of a template (66) a corner of the inner bag (12) is removed to create an opening (74) through which tea is charged into the inner bag (12). As soon as the opening is created, an oxygen scavenging sachet (54, 54) carried by the inner bag (12) starts to remove oxygen from the atmosphere which enters the bag (12) with the tea. When filling has been completed the cut corner of the inner bag (12) is resealed using heat sealing jaws (80, 82), and the inner bag (12) projecting end is refolded with the outer casing (10) and the outer casing end is resealed. The oxygen scavenging sachet continues to work so that tea freshness is maintained.

Description

Improvements Relating to the Packaging of Tea

This invention relates to the packaging of tea- and in particular concerns the packaging of tea at the specific location of tea estates.

Tea estates are the locations where tea is grown and packaged, for transportation to other locations, typically overseas where the packaged tea may be blended with tea from another estate or other estates, and the tea is eventually packaged for domestic consumption. It is convenient to refer to the packages in which the tea is transported from the estates to the said other location or locations as transport packages, in order to distinguish these packages from the packages in which the tea is placed for the domestic market, which conveniently can be referred to as domestic packaging.

At a tea estate, when the tea is initially picked, it is processed by various known processes including comminution and drying and other treatments, until the tea has been properly conditioned for the transport packaging. When that processing has been completed, it is desirable that the tea should be packaged for transport as soon as possible, as it is known that tea exposed to the atmosphere is deleteriously affected by the oxygen in the air, and it is desirable to maintain the freshness of the tea as long as possible during transportation. To this end, we have disclosed in our co- pending Patent Application No 9012289.6 that the tea after the processing at the tea estate preferably is charged into a packaging bag which has its interior conditioned by any of several means or combination of such means in order to maintain the freshness of the tea. The said means essentially are related to the displacement or extraction' of oxygen from inside the package, and to this end the means may comprise an oxygen scavaging device, or flushing the interior of the bag with an inert gas such as nitrogen, or by vacating the interior of the bag to provide vacuum packaging of the tea. The bag into which the tea is packed is relatively large, and preferably will be constructed of or include a material which exhibits high oxygen or atmosphere barrier characteristics, and the bag preferably is hermetically sealed, which measures prevent the ingress of oxygen during transportation.

The present invention is also concerned with the maintenance of the absence of oxygen in such a transport package containing tea, and whilst by far the greatest application for the invention is specifically the transport of tea between tea estates and domestic packaging location, it should be mentioned that as at least one aspect of the invention is concerned with the construction of the transport packaging bag, the invention is not to be considered as completely limited to the packaging of tea except in aspects where other interpretations are impossible.

Various containers for the holding of produce in hermetically sealed condition are known for example in German patent specification DE 3328471 Al which discloses that a box-like container is provided with an outer case and an inner sealable envelope, the package being designed to be reusable, French patent specification 6941996 which discloses that a package of air and permeable material has the contents charged therein followed by sealing of the bag, and the bag also including an oxygen scavenging material whereby the resulting sealed bag and its contents may be subjected to irradiation for the killing of bacteria, US patent specification 4556590 which discloses a material for manufacture of a bag or envelope which can be sealed ' by laminating the material to itself, and US patent 3958749 which discloses a sealed package comprising an outer case and an inner envelope of air in permeable material. The inner envelope is attached to the outer case but contains a tear line so that when the outer case is opened, the inner envelope can be detached from the outer case by a tearing action along the tear line, the inner envelope continuing to be sealed after removal from the outer case.

In each of these prior arrangements, the final sealing of the container or package does not take place until the contents have been charged therein which means that atmosphere can enter the interior of the packages whilst they are for example stored ready for use.

In the instant invention, the problem is approached from a different direction, and provides that the packages are completely sealed prior to filling so that there is no possibility of ingress of contaminating atmosphere during storage.

In a preferred aspect of the invention, the package furthermore includes an oxygen scavenging means embodied therein, which is activated upon contact with atmospheric oxygen and therefore providing the package in an unfilled and sealed condition protects the oxygen scavenging means from becoming active at too early a time.

According to a first aspect of the invention, a transport package for tea comprises an outer casing and an inner bag, the inner bag being sealed, said inner bag being of a material which exhibits oxygen and air barrier characteristics.

The outer casing may be of paper, but may also be sealed, requiring breaking open of the seal to gain access to the inner bag. The inner bag preferably is such as to require to be cut open for the charging of tea into the inner bag, and is preferably of a nature which can be readily re-sealed at said opening after the tea has been so charged into the inner bag, and preferably when the inner bag has been so charged and re-sealed, the outer casing can be re-sealed around the inner bag to create the transport package.

The inner bag preferably is folded when contained in the sealed outer casing and before filling of same, so that when the sealed outer casing is opened, the end of the inner bag can be pulled clear of the adjacent end of the outer casing, so that a corner of the inner bag can be severed to provide the opening for the charging of the tea into the inner bag.

An end of the inner bag may be glued to the inner surface of the outer case at an end thereof which is opened to gain access to the inner bag.

The inner bag may comprise a layer of polyethylene plastic film to which is laminated one or more films of metalised polyester. Indeed the inner bag may be constructed as described in our said co-pending patent application.

Preferably also, the inner bag embodies at least one sachet of an oxygen scavenging substance, which becomes active in absorbing the oxygen from the atmosphere as soon as the inner bag is cut open.

The oxygen scavenging substance may be the substance sold under the name AGELESS by Mitsubishi Gas Chemical Company Inc.

The advantage of embodying the one or more sachets in ^"the inner bag is that the bags prior to filling can be manufactured in factory conditions, not necessarily in the vicinity of the estate, and can then be shipped to the estate, leaving the estate workers only to open the transport package as indicated above, to fill the inner bag, and seal same, and finally re-seal the outer case, making the filled transport package ready for despatch. The oxygen scavenging substance will commence working as soon as it comes into contact with the atmosphere at the initial opening of the inner bag. The tea will therefore be maintained fresh during transportation somewhat automatically, because the estate workers in fact do not need to know that the transport package contains oxygen scavenging substance, only that the inner bag should be sealed as soon as it is filled.

With this arrangement, it is not necessary to flush the interior of the inner bag with an inert gas such as nitrogen, although if such flushing provides any additional advantage, there is no reason why it should not be done. Equally, the interior of the bag can be vacated, but it is felt that such evacuation of the inner bag probably will not be necessary and that the filling of the tea into the inner bag can take place without any flushing or evacuation, making the process particularly simple.

When the transport bags are supplied to the estate, they may also be supplied with a template suitable for use in the cutting of the corner of the inner bag, to ensure that the cut is at a particular location in relation to the inner bag, and the bags may also be supplied with a bar sealing device to enable the inner bag to be re-sealed after it has been filled.

The present invention therefore provides a number of aspects comprising the provision of a sealed inner bag contained in a sealed outer case, the provision of a bag to be filled with tea which is sealed, and which embodies oxygen scavenging sachets which become operative when the bag is opened, and in this connection there ma be a single sachet or more than one, and they may be trapped between layers of the inner bag or may simply be glued or otherwise fixed to the inner surface of the inner bag, and the method of filling the transport packages by cutting open the inner bag, preferably at the corner and using a template, charging the tea into the inner bag, re-sealing same, and then re-sealing the outer casing, the outer casing being specifically constructed for this purpose.

Other aspects of the present invention will become apparent from the following description which is made with reference to the accompanying drawings, which show an embodiment of the invention, and wherein:-

Fig. 1 shows in side elevation a packaging container according to an embodiment of the invention, prior to the final closuring of the top end?

Fig. 2 shows the packaging container of Fig. 1 in perspective elevation;

Fig. 3 shows the inner bag of the container of Fig. 2 after transverse folding of same;

Fig. 4 shows the bag of Fig. 3 after tucking of the corners;

Fig. 5 shows the bag of Fig. 3 in sectional elevation on the line V-V in Fig. 3;

Fig. 6 shows, in a view similar to Fig. 2, the container with the inner bag completely inside the outer case and prior" to closuring of the outer case; Figs. 7 to 10 show the sequence of closuring the outer case;

Fig. 11 illustrates in perspective view how a corner of the inner bag is removed for the filling of same;

Fig. 12 shows how the inner bag is filled;

Fig. 13 shows how the cut corner of the inner bag is re¬ sealed; and

Fig. 14 shows the filled and sealed container.

Referring to the drawings, and firstly to Fig. 1, the container shown comprises an outer case 10 of stout craft paper or the like, and an inner flexible bag 12 of a material which has good oxygen barrier properties. The container shown in the Fig. 1 condition is empty, and is flat, and the lower end is closed by means of a fillet folded arrangement 14 which will be somewhat similar to the closuring arrangement for the top end which will be described in detail hereinafter.

As shown, the inner bag 12 extends beyond the top 14 of the outer case, and along one side it has a folded over portion 16 so that in fact when it is opened out it is wider than the bag 10, but this is necessary due to the fact that the inner bag eventually will be filled with tea and will have to expand to fill the volume of the outer case when the container is filled.

The inner bag 12 is completely hermetically sealed by means of a peripheral seal 18, which typically will be a heat seal and the material of the bag 12 will therefore be of a heat sealable type. As shown, the top end of the outer case is creased as indicated by double dotted line 24 to 30, and the inner bag 12 has corner crease lines 32 and 34. The outer case 10 is similarly creased on the opposite side.

In order to close the end of the container, the inner bag 12 is first of all folded transversely as shown at 36 in Fig. 3, and in the interests of clarity, the outer case has been omitted in this figure. This folding 36 has the effect of reducing the overall length of the inner bag so that it lies more of less flush with the top 14 of the outer case. Next, the corners of the inner bag at the top end are folded about fold lines 32 and 34 until the position shown in Fig. 4 is reached. On one side 38 of the inner bag, is applied spot gluing 40, so that, as will be understood from Fig. 6, the top end of the folded inner bag is spot glued to the inner face of one side of the outer case 10.

From the position shown in Fig. 6, the top end of the container is closed by folding and gluing. The outer case is folded about fold lines 20 and 22 to produce the fillets 42 and 44 which are glued on their inner sides to the underlying layer of the outer case, but not to the folded inner bag portion.

Next, the outer case is folded about fold lines 26 to define trapezoidal portions 46, 48, which overlap and which are glued together where they overlap thereby to form the end closure as shown in Fig. 8. Finally, a paper adhesive label 50 is applied over the trapezoidal portions 46 and 48 and end triangular portions 42 and 44 as shown in Fig. 9 to complete the closuring of the end of the container. For packaging and transportation, the folded end is folded about hinge 24, so that the container reaches the flattened form shown in Fig . 10 .

This container is now ready for transportation for example to a tea estate for the charging of the container with the tea to be packaged.

The container is provided with a further advantageous feature as shown in Figs. 3 and 5 in that the inner bag 12 has embodied therein sachets 52 and 54, preferably four in number, which contain oxygen scavenging material. The sachets are not active as long as the inner bag is flattened and sealed so as to exclude any atmosphere, but as soon as the inner bag is opened, the sachets become operative. These sachets may for example be of a type sold under the trade mark AGELESS by Mitsubishi Gas Chemical Company Inc, and in this particular application the sachets which are used are the AGELESS sachets type.

In the arrangement shown in Fig. 5, the sachets 52 and 54 are shown as being trapped between layers 56 and 58 of one side of the inner bag, the other side being indicated by a single layer 60. It will be noticed that layer 60 lies closely adjacent layer 56 because air is excluded from the inner bag. When the inner bag is opened however, layer 60 may take up the position shown for example in dotted lines in Fig. 5, allowing air to contact the AGELESS sachets 52 and 54 thereby to make them operative so that they will commence extraction of oxygen from the atmosphere which has been introduced. The extraction of oxygen from the air means that the tea will remain in excellent condition during transportation in the transportation package. The removal of oxygen increases the shelf life of the tea, and eliminates or inhibits mould, and counteracts bacterial growth and insect invasion.

The resulting package as shown in Fig. 10, therefore constitutes a novel construction and arrangement and provides an extremely useful means for despatching to tea estates, because at the estate the operator simply opens the package and fills same with tea, preferably in the manner now to be described. The operator does not have to worry about placing AGELESS sachets into the bag, which is a considerable advantage.

As to the steps to be taken when filling the package, to some extent the steps already described are reversed, but in addition the person filling the bag has to use some additional components namely the metal template 62 shown in Fig. 1 which comprises plate 64 on which a corner of the inner bag 12 is placed, a guide plate 66 which overlies and is spaced from the plate 64, and a spacer 68 which keeps the plates 64 and 66 in spaced relationship. When the corner of the bag 12 is positioned under plate 66 by being inserted as indicated by arrow 68 in Fig. 11, a knife 70 guided along the sloping edge of plate 66, is then used to sever the corner 12 as shown at 72 in Fig. 12 so that an opening 74 in the corner of the bag is formed for an insertion pipe 76 by which tea is charged into the bag as indicated by arrow 78. When the inner bag 12 has been filled, and immediately after it has been filled, the opening 74 is sealed by a pair of bar sealers 80 of an appropriate sealing machine, preferably of the type known as Johnson Light Jaw Sealers. A minimum of atmospheric air is therefore allowed to enter the bag 12, and any oxygen therein will immediately be scavenged by the AGELESS sachets as above described.

In order to initially open the bag from the position shown in Fig. 10, the covering strip 50 is gently lifted and opened at one side, and the strip 50 should not be torn from the outer case completely. The end of the outer case can now" be opened to the position shown in Fig. 6, and at this stage the person filling the bag breaks the spot seal between the inner bag and outer case gently by hand, and then the inner bag can be pulled out to the position shown in Fig. 1 so as to extend some 200 mm beyond the end 14 of the outer case to facilitate the filling procedure. The jaw sealer should be ready to be put into operation immediately at this time and the tea should be ready to be charged into the bag 12. The operator now cuts the corner of the inner bag as shown in Figs. 11 and 12, and charges the tea into the inner bag as described. Immediately after filling sealing is effected as indicated in Fig. 13, and then the closuring procedure already described above is repeated except that it may not be necessary to glue the top of the inner bag by spot glue as indicated by reference 40 in Fig. 6 but rather the inner bag can first of all be folded down into the outer case, and then the outer case can be sealed by gluing as indicated in Figs. 7 to 10. The outer strip for label 50 remains connected to the outer bag and finally is glued into position as shown in Fig. 14, and there results a particularly effective transport package for tea.

The inner bag may comprise a suitable oxygen barrier material and may be a laminate. For example the inner bag may comprise a laminate or an inner layer of polyethylene film, to which one or more outer layers of metalised polyester may be applied. Any other suitable construction may be used.

Claims

1. A flexible transport package for tea comprising an outer casing (10) and an inner bag (12) , characterised in that prior to filling with tea, the package is flat and the inner bag (12) is sealed preventing ingress of oxygen and air, and is of a material which exhibits oxygen and air barrier characteristics.

2. A package according to Claim 1, characterised in that the outer casing (10) is of paper, and is also sealed, requiring breaking open of the seal to gain access to the inner bag (12).

3. A packagine according to Claim 1 or 2, characterised in that the inner bag (12) is such as to require to be cut open for the charging of tea into the inner bag (12) .

4. A packaging according to Claim 2, characterised in that the inner bag (12) is of a nature which can be readily re¬ sealed at said opening after the tea has been so charged into the inner bag (12) .

5. A package according to Claim , characterised in that when the inner bag (12) has been so charged and re-sealed, the outer casing (10) can be re-sealed around the inner bag (12) to create a filled transport package.

6. A package according to any preceding claim, characterised in that the inner bag (12) is folded (36) when contained in the sealed outer casing (10) and before filing of same, so that when the sealed outer casing (10) is opened, the end of the inner bag (12) can be pulled clear of the adjacent end (14) of the outer casing (10), so that a corner of the inner bag (10) can be severed to provide the opening (74) for the charging of the tea into the inner bag (12) .

7. A package according to any preceding claim, characterised in that an end of the inner bag (12) is glued to the inner surface of the outer case (10) at an end thereof which is opened to gain access to the inner bag (12) .

8. A package according to any preceding claim, characterised in that the inner bag (12) comprises a layer of polyethylene plastic film to which is laminated one or more films of metalised polyester.

9. A package according to any preceding claim, characterised in that the inner bag (12) embodies oxygen scavenging means (52, 54), which becomes active in absorbing the oxygen from the atmosphere inside the bag (12) as soon as the inner bag (12) is cut open.

10. A package according to Claim 9 characterised in that said oxygen scavenging means (52, 54) comprises at least one sachet of oxygen scavenging substance carried by the wall of the inner bag (12) .

11. A package according to Claim 10, characterised in that the substance sold under the name AGELESS by Mitsubishi Gas Chemical Company Inc.

12. A package according to Claim 9, 10 or 11, characterised in that the oxygen scavenging means is contained between two layers (56, 58) of the wall of the inner bag (12).

13. A package according to any one of the preceding claims, characterised by its combination with a template (66) suitable for use in the cutting of the corner of the inner bag (12) , to ensure that the cut is at a particular location in relation to the inner bag (12) .

14. A package according to Claim 13, characterised by its combination with a bar sealing device (80, 82) to enable the inner bag (12) to be re-sealed after it has been filled.