WO1996024522A1

WO1996024522A1 - Method for forming, filling and sealing sachets containing tea bags

Info

Publication number: WO1996024522A1
Application number: PCT/GB1996/000171
Authority: WO
Inventors: Steven John Barratt
Original assignee: Premier Brands Uk Ltd.
Priority date: 1995-02-08
Filing date: 1996-01-26
Publication date: 1996-08-15
Also published as: GB9502446D0; AU4493096A

Abstract

The present invention provides that tea bags, especially round tea bags, are packaged in sachets by producing the sachets from a web of heat sealable material which is fed downwards and as it is, it is formed into tubular configuration, with longitudinal seam. Simultaneously, batches of round tea bags are produced and are delivered in batches to the location where the web is being formed into tubular configuration, and then are dropped into the formed web. The web is sealed transversely in synchronism with the feed of the web and the delivery of the batches so that sachets are produced each containing a pre-determined number of tea bags. Also provided is a weigher which weighs each batch of tea bags and causes the dosing of the tea in the tea bag making machine to be adjusted automatically to ensure that each sachet package will contain the correct weight of tea.

Description

METHOD FOR FORMING, FILLING AND SEALING SACHETS CONTAINING TEA BAGS

This invention relates to the packaging of tea and the like bags, referred to hereinafter collectively simply as tea bags in the interest of simplicity.

The invention applies mainly to tea bags, but it will be appreciated that items which are similar to tea bags can be handled in accordance with the invention as set forth herein.

In the high speed production of tea bags, webs of tea bag material i.e. permeable tissue type paper are fed continuously at high speed, and between the webs are placed portions or doses of tea in spaced arrangement in two rows lengthwise of the webs. The webs are sealed together and are cut to form pairs of rectangular tea bags which are stacked in a magazine. These stacks are then pushed transverse to their height into for example cardboard packaging cartons, and the tea bags are sold in this form in vast numbers in countries such as United Kingdom and Australia where large quantities of tea are drunk.

Production speeds of these tea bag machines can reach as high as 2,000 - 4,000 tea bags per minute. The retention of the tea bags in inter-connected pairs (which are subsequently split by the user into single tea bags) enhances the high¬ speed operation of the machine, but more recently there has been a move towards the production of single tea bags in different shapes and in particular single round tea bags have been produced by these machines, by suitable adaptation of the cutters and the stacking and feeding mechanisms. Difficulty has however been encountered in the packaging of the round tea bags in cartons, because the tea bags are produced as singles, and the stacks in the magazine must inevitably be in single bags and opposed to twin bag arrangements. In consequence, when the tea bags eventually reach the packaging carton, they tend to be distributed randomly throughout the carton, and when the carton is opened by the consumer the dispersed and random array of round tea bags is not particularly aesthetically pleasing. Nevertheless, round tea bags have become popular with the consumer.

The present invention is concerned with the production and packaging of singles tea bags, especially but no exclusively round tea bags, wherein a novel form of packaging of the bags is adopted, whereby the disadvantages of the conventional method as discussed above are overcome.

In accordance with the invention in a first aspect thereof, singles tea bags are packaged in sachets formed by wrapping and sealing a web of sheet material by forming a longitudinal seam after the web has been wrapped, and a transverse seam, wherein the web travel as the sealing takes place is in a downwards direction, and predetermined batches of the tea bags are dropped into the forming web.

By this means, the tea bags fall under gravity into the forming web, and therefore there is no requirement to stack the bags as in the conventional packing method. Furthermore, as the tea bags eventually become contained in a sachet or pillow pack arrangement, which normally will be subsequently opened at the end to gain access to the contents, when the sachet is opened, the consumer will see only the edges of the tea bags as opposed to the sides, and the random distribution of the bags in the sachet will not constitute an aesthetic disadvantage.

As the tea bags fall under gravity, they will as can be appreciated, take up a disposition in which the tea bags lie in planes which are upright, due to the weight of the tea in the bag (which does not completely fill the bag cavity) and due to the air resistance to the bags as they fall.

After the batch or batches of tea bags has or have been loaded into the forming web, the web is again sealed in order to complete the sachet containing the bags, and to form the seal for the next sachet to be formed.

The bags may be produced by the conventional high speed tea bag producing machines, but the output from such machine will be marshalled so that the bags are fed to a weighing device which weighs the bags in the said batch or batches . Typically, a batch may comprise forty tea bags. Following the weighing operation, the batches of tea bags may be handled so as to be grouped, for example into a bucket type conveyor in which each bucket contains a single batch of bags. The bucket conveyor can then transport the batches of bags to a feed mechanism for dropping the bags into the forming web.

In order to batch the bags into the buckets of the bucket conveyor, there may be a pair of pneumatically operated bucket feeders each comprising a pair of shells, the shells of each feeder being adapted to be opened and closed so that the batches of bags can be dropped from the respective feeder buckets. One feeder bucket may be located above the other, and the lower feeder bucket may be located above the bucket conveyor.

A weighing device embodying a weighing conveyor may serve to feed the upper bucket feeder with the tea bags.

The movement of the bucket conveyor is synchronised with the operation of the web forming and sealing machine so that typically, two batches of forty tea bags are dropped into each sealed sachet.

The material used for the sachet may comprise a metallic foil material or appropriate plastics material or any combination of these materials, which has a high degree of imperviousness to the surrounding atmosphere so that when the tea bags are packaged in the sachets, they will be isolated from the atmosphere and moisture therein to a great extent enabling the tea in the tea bags to remain fresher longer.

In another aspect of the invention, tea bags are fed to a web forming and sealing machine by batching the tea bags into batches of a pre-determined number, and feeding such batches to a web forming and sealing machine via a bucket conveyor of which each bucket contains one or more batches.

The advantages of the invention are considerable insofar as the speed of producing the final packages is extremely high, as the weighing and batching apparatus can operate at least as fast as the tea bag making machine, and in fact will probably be able to operate much faster so that two or more tea bag making machines will be arranged to supply a single web forming sealing machine. In such case, the bags produced by the tea making machines are fed to a single weigher, which in turn feeds a single bag forming and sealing machine.

The bucket conveyor can be arranged to raise the batches of tea bags to an elevated location for the dropping of same into the web being formed into sachets.

If required, steps can be taken to flush the atmosphere of the inside of the sachet (with the example nitrogen) before it is finally sealed in order to exclude as much oxygen as possible thereby further enhancing the preservation of the freshness of the tea in the tea bags contained in the sachet.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, wherein:-

Fig. 1 shows a package containing tea bags according to one embodiment of the invention;

Fig. 2 shows how tea bags according to Fig. 1 are manufactured;

Fig. 3 shows the machine for manufacturing the tea bag packages as shown in Figs. 1 and 2, Fig. 3 being a side elevation;

Fig. 4 is a plan view of the machine shown in Fig. 3;

Fig. 5 shows a feeding arrangement for the supply of tea bags to the machine shown in Figs. 3 and 4; and

Fig. 6 is various diagrams showing how tea bags produced by a tea bag making machines are fed to the equipment of Figs. 3, 4 and 5.

Referring to the drawings, in Fig. 1 a package 10 is shown which is of the type which will be produced in accordance with the method of the embodiment of the invention. The package 10 is essentially a sachet 12 of a suitable hermetically sealable material such as a metallised foil or foil which is typically plastic coated, or may be laminated with other layers of plastic material. The outer sheet material forming sachet has a longitudinal seal and transverse seals 14 and 16. The tea bags which are contained in the package 10 are indicated by reference 18, and they will be seen to be round tea bags, as this invention has particular application to the packaging of such tea bags.

For the manufacture of the packages 10 on a mass production basis, the method indicated in Fig. 2 of this embodiment of the invention is adopted.

Referring to Fig. 2, a supply sheet 20 of the material to form the sachets 12 is fed downwardly as indicated by arrow 22 from a suitable supply such as a reel of the material. As the material is fed downwardly, it is wrapped so that the free edges overlap for example as indicated by reference numeral 24. Thes overlapping edges in the region 24 extend vercially, and are sealed by means of a pair of vertical sealing bars 26 and 28 which preferably are of a heat sealing variety, although any suitable sealing arrangement can be adopted. With the formation of a longitudinal seal by the bars 26 and 28, a hollow is formed in the interior of the material 20 in that it becomes basically tubular. When it is in this condition, tea bags 18 are charged into the hollow interior of the formed web by being dropped vertically from an overhead feed hopper. In the arrangement shown, the lower end of the material 20 has already been provided with a transverse seal 30 by means of reciprocable transverse sealing bars 32 and 34 which again may be of the heat sealing variety, and which are movable as indicated by arrows 36 and 38 towards and away from each other in order to crimp and seal the material 20 transversely. These sealing bars 32 and 34 may be associated with cutting means for severing a previously formed sachet 12 from the one which is in the process of formation as shown in Fig. 2. It should be mentioned that the bars 26 and 28 are also reciprocable as indicated by arrows 40 and 42. The sachet being formed in Fig. 2 is suitable for holding 80 tea bags, and the first batch 18A of forty tea bags has already been dropped into the interior of the wound material 20, and the second batch 18B is in the process of dropping. When they have dropped into the interior of the wound material 20, it is moved downwardly and the sealing bars 32 and 34 are againg operated to form the transverse seal of the sachet. The cutting means severs the sachet from the remainder of the material 20 and the process is repeted and is continued at high speed.

Figs. 3 and 4 show a layout of equipment suitable for the production of the sachets 12, and referring to these drawings, reference numeral 50 indicates a bucket conveyor which has buckets 52 each of which is adapted to receive a batch, typically forty, tea bags. The bucket conveyor 50 leads to an elevator section 54 in which the buckets travel vertically upwardly, and then they travel in horizontal upper section 56 in the direction 58. As each bucket reaches the end of section 56, it tips its contents into a hopper 60, and these contents fall as shown in Fig. 2 into the web 20 which has been formed into tubular configuration. The small feed conveyors 62 serve to feed the web material 20 in a downwards direction, and the sealing bars 26, 28 and 32, 34 are also shown.

Fig. 5 shows the bucket conveyor 50 and the buckets 52, and the input end of this conveyor is located under a feeder mechanism 70 which comprises a pair of feed buckets 72 and 74 each comprising a pair of bucket halves, and the halves are pivotable between an open position as shown by feeder bucket 72, and a closed position shown by feeder bucket 74. Feeder bucket 72 is located above feeder bucket 74, and bucket 72 is fed by means of a feeder conveyor 76 whose input end is coupled to a weigher 78. The weigher 78 receives tea bags from the tea bag manufacturing machine, and weighs these bags so that it will feed tea bags of the correct weight to the system. If the weigher detects that the tea bags deviate in weight from a preset valve, the tea bag making machine is automatically adjusted to dose more or less tea for the individual bags until each batch weighs the preset amount. Each batch is then fed to the bucket 72 which will be closed until filled with the appropriate number of tea bags. Bucket 72 then opens and drops its contents into bucket 74, and bucket 72 again closes ready to receive the next batch. Bucket 74 opens and drops its batch into the underlying bucket of the bucket conveyor 50 which steps to the left as shown in Fig. 5 to feed the machine as shown in Figs. 3 and 4 as described hereinbefore. The operation of the various sections of the equipment are synchronised so that the batches of tea bags such as 18A and 18B are fed in the correct sequence and at the correct time to enable production to be coninuous.

By way of indication of how the equipment can be fed from tea bag making machines, reference is made to Fig. 6. The tea bag making machines are indicated by the reference numerals TB, and it will be seen that the outputs from these machines are brought together, and the tea bags are collated into a single supply typically supplying the weigher 78 as shown in Fig. 6, parts (a) and (b) .

The invention approaches the packaging of tea bags in a novel and inventive manner and provides hermetically sealed packages which although containing the tea bags in a loose formation, provides that the package can be opened at one of the sealed ends 14 or 16, and the tea bags can readily be removed one by one. The tea bags will in general lie in planes parallel to the plane containing the seals 14 and 16 making removal particularly appropriate. The invention has particularl application to the packaging of round tea bags, but as will be understood from the above, can be applied to tea bags of other shapes and indeed items other than tea bags.

Claims

1. A method of manufacturing shachets containing a plurality of tea bags or the like articles, wherein a web of sheet material is wrapped into tubular form and is provided with a longitudinal seal, and wherein the tea bags or the like articles are placed in the tubularly formed web, and transverse seals are formed to complete the sachet sealing the tea bags or the like articles therein, characterised in that the web of sheet material is formed into tubular form whilst it travels downwards, and the tea bags or the like articles are dropped under gravity in batches into the tubular from web.

2. The method as claimed in Claim 1, characterised in that the batches are dropped from an overhead bucket conveyor having buckets and into individual buckets of which batches of the tea bags or the like articles are dropped.

3. The method of Claim 2, wherein the articles being handled are tea bags, and the method includes producing the tea bags in batches (typically 40 in each) and weighing each batch characterised by the step of automatically correcting the dosage of tea dispensed by the tea bag making machine if the total weight of any batch of tea bags deviates from a precept amount by more than an allowable tolerance.

4. The method according to Claim 3, characterised in that the batches of tea bags are fed from the weighed to a feeder comprising a first feeder hopper into which the batches are dropped one by one and a second feeder hopper into which the batches are dropped one by one from the first feeder hopper, which is in two sections which can be swung apart for this purpose, and from which the batches are dropped one by one into respective buckets of the bucket conveyor which travels substantially horizontally under the second feeder hopper.

5. The method according to any one of the preceding claims, wherein the web is of heat sellable material, and the said longitudinal and transverse sealing is effected using sealing bars.

6. The method according to any preceding claim, characterised in that the articles are round tea bags.

7. Sachets produced according to the method of any of the preceding claims.