Packaging Process and Containers Formed thereby

The present invention relates to the packaging of articles and more particularly to improvements in processes for the packaging of a number of articles within one container.

It is generally known to collate articles and to manipulate them into a desirable format for packaging such that the collated articles can be supplied in a retail pack for purchase in predetermined numbers. In the case of infusion packages, such as, for example, tea bags and the like, it is desirable to collate a predetermined number of the infusion packages into a stack such that the stack either alone or in combination with further stacks, can be packaged in the desired quantities ready for sale.

Various methods and machines for counting and stacking infusion packages at high production speeds are generally known. However the stacks of infusion packages themselves tend to be unstable and, especially in the case of round shaped tea bags, are prone to toppling over upon application of a shear force such as would be applied to the stack by, for example, a moving web such as a conveyor belt. Furthermore the stacks must be manipulated to allow them to be enclosed in a container. Known methods require each individual stack to be supported on multiple sides by holders during movement to the packing location and also during manipulation to package the same, for example within a guide or chute so that the same can be inserted into the required packaging without substantial misalignment of the stack.

The necessity to constrain each stack on all sides and move each stack individually presents a particular problem since it is inherently slower than a conveyor-type motion and causes bottlenecks in the packaging process. This problem is

compounded since it is necessary to provide infusion packages in specific numbers to meet consumer requirements, such as in packs of 20, 40 or 80, and so a process for manipulating stacks of, say, 40 infusion packages will become inefficient when applied to stacks of 20 or 80 infusion packages at a time.

The infusion packages are typically either provided in containers formed of cardboard in which case the stacks are retained relatively rigidly within the container or in flexible containers, often referred to as soft packs or bags. These packs are more problematic in that the containers are more flexible and require the stacks of articles to provide sufficient rigidity to allow the packs to stand upright and to be stacked for transport and display. However the lateral instability of the stacks can result in these bag packs becoming deformed and unsuitable for display. One proposed solution for increasing the uniformity and hence the rigidity of the stack of infusion packages is to vibrate the articles in the stacks prior to insertion into the bag pack.

However this technique requires additional manipulation of the stack during the packing process and, in light of the process efficiency problems described above, adds to the bottlenecks which already occur.

In addition, the soft packs are required to be distributed in bulk quantities . Thus the soft packs themselves must be stacked, resulting in a compressive force on the lower rows of packs which is capable of bursting or otherwise degrading the packs due to the weight of the stack. It is generally known to provide supporting members to bear at least some of the compressive force during transit. However it is far more preferable for the individual packages themselves to be capable of withstanding a vertical compression force without degradation to the package.

To this end, there is a necessity to evacuate a significant proportion of the air from a soft pack so that the stack of infusion packages bears any such force, rather than the trapped air within the pack.

The need to perform such additional process steps, whilst maintaining a required production rate poses a particular problem. It is therefore an object of the present invention to provide a method, apparatus and filled container in a form which increases the rate at which stacks of articles are packed whilst ensuring that the integrity of the packs is maintained.

According to a first aspect of the present invention there is provided a method of packing articles into a container to form a retail pack, said method including the steps of: arranging predetermined numbers of articles into one or more stacks; constraining the articles in said stacks by enclosing one or more stacks within wrappers to form sachets; collating said one or more sachets into a predefined array to provide a predefined number of articles for the retail pack; and, wherein the array of sachets is moved into at least one open ended container formed of flexible sheet material which is then sealed to retain the sachets therein.

The articles may take any shape or size and be made of any material so long as the articles are capable of being stacked. Preferably the articles are laminar in shape and in one embodiment the articles are flaccid such that a stack of articles is prone to toppling over upon application of a force perpendicular to the direction of the stack. According to a preferred embodiment, the articles comprise a particulate, fibrous or else fluid material trapped within an enclosure and may take the form of infusion packages.

Preferably the one or more constrained stacks of articles within a first wrapper of the array has an axis substantially parallel to one or more stacks within a second wrapper. In one embodiment, each stack within the array is disposed in a substantially horizontal plane such that the stacks extend substantially vertically. The wrapper may be sealed and may form a sachet containing one or more stacks.

Enclosing each stack within a wrapper is particularly advantageous in that it allows the stacks to be manipulated without disruption to the stack. As such, a number of stacks can be collated and manipulated at once without the need to support each sachet during manipulation. Typically each sachet includes one stack, and in one embodiment said stack includes one article in each layer or, alternatively, may include a plurality of articles in each layer. In this arrangement the articles in each layer can be joined together for subsequent separation for use of the articles.

According to a preferred embodiment, the constrained stacks are collated into holders, each holder capable of holding one or more stacks and being movable such that the stacks can be provided in an orientation suitable for manipulation. Typically the holders are movable along a conveyor and may take the form of baskets, the movement of which is controlled by a processor. In one embodiment the sachets are accelerated towards the corresponding holder.

Preferably the manipulation of the array acts on all of the sachets within the array at once such that the relative orientation between the sachets within the array is maintained. In one embodiment the constrained sachets are collated to form one or more layers or rows and each row is manipulated at a time.

Typically a row is arranged to be picked and placed within one or more correspondingly arranged containers and the number of sachets in the array may be divisible by the number of containers arranged to receive the same. Preferably the containers are shaped to contain either one or multiple numbers of sachets and are arranged in a side-by-side orientation to receive the array. The sachets may be stacked within each container.

The manipulation of an array containing a predetermined number of sachets is beneficial since various capacities of container can be filled at a substantially constant production rate.

In one embodiment the stacks are manipulated from above and preferably each stack is manipulated by manipulation of the sachet. Typically each sachet is contacted by one or more suckers and moved into position for insertion into a container such that the sachets can be lowered into the container. Preferably the storage area defined within the container, once sealed, has at least one dimension similar to the height of the sachet or array of sachets therein such that the one or more sachets are closely constrained by the container.

In one embodiment the sachets are inserted into the container in such a manner as to allow air within the container to escape and preferably the sachets are inserted at an angle at least during the initial stages of insertion and then placed into the container such that they lie substantially parallel with the container base.

In one embodiment a force may be applied in order to press the sachets into the container. Additionally, or else alternatively, an air evacuation step may be performed after insertion of the sachets by sucking air out of the container.

The combination of holding the individual sachets from above and placing them into containers is beneficial since it avoids the need for any supporting arms to extend along the sides or else underneath the sachets during manipulation of the sachets into the container and thus allows the container to be tightly fitting around the sachets. In addition, picking and placing the sachets into the container allows for greater accuracy of positioning the sachets within the container and thus avoids the possibility of the sides of the container becoming deformed upon insertion of the sachets .

Preferably the container is made of a deformable material and may be preformed to have a substantially flat base. In one embodiment the container takes the form of a bag with four sides, each separated by approximately 90 degrees and a base. In one embodiment the walls and base are formed by a portion of material cut from a continuous web of material.

Typically the container is sealed by pressing the opposing sides of the container into contact at allocation above the sachets from the pack base to define the storage area in which the sachets are located and adhering the contact portions together, possibly by the application of heat. Preferably the container is sealed a distance above the top of the sachets and then the portion of the container between the seal and the top of the sachets is rolled and/or folded against the top of the sachet array.

Preferably retaining means such as a label is applied at this stage to retain the rolled or folded portion in position and thus form the container in its retail pack form. Preferably in this form the retail pack is substantially cuboid, or a cube. In this form the container is particularly adapted to be loaded onto transport

means such as pallets or into outer cardboard boxes to allow a plurality of the containers to be transported in a relatively- secure and rigid form to the retail premises at which the containers can be removed from the outer packaging and then be stacked for display as retail packs .

According to a second aspect of the present invention there is provided apparatus for packing stacked articles into a container to form a retail pack, said apparatus including wrapping means for enclosing one or more stacks of the articles within a wrapper to form a sachet and collating means for arranging predetermined numbers of sachets into an array, wherein said array is arranged to be manipulated by a movement means to insert the array of sachets into one or more containers .

The apparatus may further include sealing means for sealing the container after insertion of a predetermined number of sachets . Typically the wrapping means and the collating means are separated by one or more conveyors and the system may be provided with a plurality of wrapping and collating means connected by a network of conveyors which are joined at one or more junctions such that the sachets of articles from any one wrapping means can be conveyed to any collating means as required.

In one embodiment the movement means contacts the array from above and includes suction means to allow the movement means to impart motion upon the array.

Preferably a packing means is provided for inserting the filled containers into cardboard boxes or onto pallets for subsequent transport.

In a yet further aspect of the ^■ invention there is provided a container formed from a flexible sheet material and including therein a plurality of infusion packages, said packages provided in a series of stacks, said container including a plurality of sachets, each having a longitudinal axis, and said axes arranged in parallel in the container and wherein each of said stacks is wrapped in a sheet material to form a sachet by which the stacking of the articles is maintained.

In one embodiment the sheet material is provided in the form of a bag with an open end through which the sachets are inserted into the bag and removed therefrom for subsequent opening and selective removal of the infusion packages for use.

Typically the container is sealed after the location of the required number of sachets therein, said sealing occurring at a location above the sachets from the base of the container by bringing opposing walls of the container into engagement.

In one embodiment, once sealed, the portion of the container between the seal and the top of the sachets is rolled or folded down onto the top of the sachets and retention means are provided to retain the container in that form for retail display.

In one embodiment the retention means are an adhesive label.

Specific embodiments of the invention will be further described below in relation to the following figures, in which:

Figure I a shows a perspective view of an arrangement of stacked infusion packages for packaging;

Figure Ib shows a perspective view of a sachet in greater detail;

Figure I c shows a perspective view of a series of sachets on a conveying line

Figures 2a and b show a plan view of a first portion of a process according to the present invention;

Figure 3 shows a plan view of a packaging process according to the present invention;

Figure 4 shows various arrangements of collated infusion packages for packaging according to the present invention;

Figure 5 shows a plan view of a container sealing process according to the present invention; and,

Figure 6 shows a plan view of an apparatus for collating the filled containers according to the present invention.

Turning firstly to figure I a, there is shown two different sachet arrangements 10, 16 in which there is provided a stack of tea bags and in each stack there are provided a series of layers of tea bags . The first arrangement 10 shows a single stack 12, shown schematically, of tea bags, whereas the second arrangement 16 shows two stacks 12 of tea bags arranged in a side-by-side orientation. Although not shown, the tea bags with each stack 12 of arrangement 16 can be joined to the tea bags in the adjacent stack by frangible means such that the two stacks 12 are held in alignment and can subsequently be separated for use in brewing tea.

In each arrangement 10, 16 the tea bags are contained within a sealed foil wrapper to form a sachet 14. One process for wrapping the stacks 12 is described within the Applicant's UK

Patent number 2228912, the details of which are incorporated herein by reference.

The tea bags are firstly cut from a continuous web and urged into stacks of a predetermined number which are passed to a wrapping apparatus. The wrapping process allows stacks of tea bags to be closely surrounded by a continuous foil over wrap 17 which is heat sealed along the edges 18, 20 and 22 as shown in Figure Ib and then cut to form discreet sachets which can then be easily handled without disrupting the stack or stacks 12 which are maintained by the over wrap in the stacked condition and avoids the need for specific and tightly toleranced holders to be provided as each sachet forms a discrete package which can then be handled as required.

The sachets then pass through an inspection apparatus with sensors connected to a processor and a display to check that the sachet is not defective and to provide an indication thereof on the display portion. From there the sachets are passed onto a conveyor 24 as a sequence of sachets 14 as shown in Figure I c in the direction of arrow A.

An example of the apparatus, method and containers formed and used in accordance with the invention is now described with reference to Figures 2A-6. It should be appreciated that the Figures 2a, b, 3, 5 and 6 show parts of the same conveying and packaging system and that the system is joined together in practice such that the sachets which leave the apparatus shown in Figure 2a enter the apparatus shown in Figure 3 as do the bagging containers from Figure 2b. The open bags with sachets from Figure 3 enter the apparatus shown in Figure 5 and the closed containers from Figure 5 enter the apparatus shown in Figure 5 such that a continuous apparatus layout is described in section in these figures .

As shown in figure 2a where the sachet transporting apparatus is shown, the sachets 14 on conveyor 24 have been wrapped and are moving in direction A. The movement of the sachets 14 is constrained by side walls or guide rails . The conveyor may have a belt or else a series of rollers driven by a motor.

Part way along conveyor 24 is a junction 26 where the conveyor splits into two separate channels 28,30. The continual flow of sachets 16 may be directed alternately to each channel by the selective movement of a flow splitter at junction 26. A predetermined number of sachets 16 is directed to the first channel 28, followed by a predetermined number of sachets to the second channel 30 such that each channel receives discrete groups 32 of sachets, one of which is shown in this example . Each channel 28, 30 then leads to a separate collator as shown in figure 3.

The splitting of the conveyor into two streams allows the speed of collation and packing the sachets to be matched with the speed at which the tea bags can be stacked and wrapped. In particular the combination of machines stacking and then flow wrapping the dual stacks of tea bags can produce in the region of 50 sachets per minute, each containing 40 tea bags. A preferred embodiment makes use of multiple wrapping stations upstream of conveyor 24, each station feeding a channel and each of the channels converging upstream of conveyor 24 to provide a single stream of sachets 16 on conveyor 24. The benefit of converging a number of channels into a single channel 24 and then splitting the single channel into channels 28,30, or further channels to supply two or more collating stations is that redundancy can be reduced. Since all stations flow into and from a single channel, sachets can be directed to a particular station as required and so maintenance can be undertaken on

any one station at a time without resulting in the stoppage of the entire process.

It will be appreciated that, whilst the following description proceeds in relation to the group of sachets 32 on conveyor 30, the following system is repeated for the conveyor 28.

Turning now to figure 3, the groups 32 of foil sachets are carried on the conveyor 30 to a collator 34, prior to which the sachets pass a sensor unit 36. The sachets break a beam as they pass the sensor such that the number of sachets entering the collator can be determined. The collator includes an acceleration means 42 which includes high speed rollers and/or a belt to accelerate each sachet in turn towards a basket 38. The baskets 38 are arranged on a separate conveyor 40 which in this case runs perpendicular to the conveyor 30 and each basket 38 has an aperture, such as for example an open side or top portion, shaped for reception of one or more sachets 16 from the accelerator 42.

The sensor unit 36 detects the need for a basket 38 to be automatically provided to receive a predetermined number of sachets 16. The groups 32 of sachets enter the collator 34 in a longitudinal orientation and are collated into the baskets, which are then carried away from the collator in a lateral orientation in the direction of arrow B . It will be appreciated that this collation technique can be applied to achieve sets or arrays of any desired number of sachets dependant on the size and shape of the basket and the collator settings. For example each basket may receive a single sachet, or else a number of sachets as necessary. Relative movement between the accelerator 42 and the baskets 38 allows sachets to be accurately inserted into a desired position within each basket 38 such that the desired

number of rows and columns of sachets can be collated in each basket.

The filled baskets 38 move laterally along conveyor 40 and gather at a packing station 44. A further conveyor 46 extends between one or more bag forming machines 48 as shown in Figure 2b and the packing station 44 and the conveyor 46 is substantially parallel to conveyor 40. Each machine 48 is provided with a continuous web of flexible material which is cut into sections and then folded a number of times to form a five- sided container with an open top, in the form of an open bag 50 which are delivered by conveyor 46 to packing station 44 as shown in Figure 3.

In on embodiment, the material on the web is preformed into a tubular shape such that only a base portion of each cut section is required to be folded to form the open container. The container 50 has a generally flat base and right-angled sides such that, once formed, the container retains its shape during transit to the packing station 44.

As described above, a number of filled baskets 38 and open containers 50 arrive at the packing station 44 at once. The packing station includes a robot arm or arms mounted above the conveyors 40 and 46 and supported on rails 52 extending therebetween. The robot arm includes a number of suckers which can move in unison in a vertical direction and arranged above the baskets . Each sucker has an opening connected by an airway to a motor, so that the suckers can lift a number of sachets out of the baskets and move them to a position above the open top of one or more containers 50. The suckers are then moved in a generally downward direction to place the sachets into the corresponding containers as required and the suction is then removed. In addition to vertical and horizontal

motion, the suckers can also undergo a rotational motion. Thus, during insertion of the sachets 14 into the containers 50, the sachets 14 can be tilted at an angle so as to allow air within the container to escape and the sachets are then pressed into the base of the bag.

Dependent on the number of rows of sachets 14 to be inserted into each container, the robot may then pick and place a further layer of sachets into the same container, or else a new set of containers may be introduced by conveyor 46 for filling.

Figure 4 shows various arrangements of multiple sachets for packing into containers in this manner with the number of sachets, and orientation of the same with respect to the base of the bag depending on the particular number of teabags required. It will therefore be appreciated that the bag containers may be provided in varying formats to accommodate, for example, 40, 80, 160 or 240 configurations of sachets as shown in Figure 4. Indeed in the case, in the examples given, of the containers for 40 teabags or 160 teabags, there are two different sachet configurations which can be selectively placed into the bag container. Due to the provision of prearranged sachets as described above, the robot can fill varying numbers of containers 50 at once without significant detriment to the rate of operation.

Once filled, the containers 50 pass along conveyor 46 in the direction of arrow C as shown in Figure 5 towards the bag container sealing apparatus 54. The sealing apparatus includes a number of stations 56 for closing the filled container as it passes along conveyor 46. Prior to sealing the containers, promotional material may be inserted into the containers.

In order to close the open container the same enters the sealing apparatus 54 in the condition as shown in step D where the bag is shown in section with the sachets 14 in position and the top 51 open. It will also be appreciated how the side walls 53,55 of the bag container are higher from the base 57 of the bag than the top face 59 of the sachets in the bag container. At step E, the side walls 53,55 of the container are pressed together at a position above the sachets 14 and heat sealed 61 towards upper edges of the container to form a flap portion 58 extending generally above the sachets inside. The heat sealing 61 is performed sufficiently far from the foil sachets to avoid any detrimental effect to the sachets themselves and the inside of the container is treated such that the heat seal formed can be reliably broken by pulling apart the sides of the bag by hand without deforming the remainder of the container.

Following the sealing step, the excess material above the sealing line is cut away and the remainder of the flap 58 is rolled down to the top face 59 of the sachets by tucking the free end of the flap 58 under itself a number of times and then folding the rolled portion against the top of the sachets 14 as shown at step F. An adhesive tab 63 is then applied to the rolled portion 58 holding it in place such that the tab can be pulled away when access to the sachets is required, and subsequently resealed after opening.

Once sealed, the closed containers 50 pass onto a separate conveyor system 60 in direction G which allows the containers to be weighed prior to passing to a further packing station 62 as shown in Figure 6. Two or more conveyor systems carrying sealed containers may merge and pass through a sensor arrangement (not shown) for detecting the presence of a container prior to arriving at packing station 62.

Once sealed, the containers 50 leave the sealing apparatus 54 travelling in a sideways direction, which is substantially parallel with the orientation of the folded over section. Prior to arriving at packing station 62 it is preferable that the orientation of the containers 50 relative to the conveyor 60 is altered by 90 degrees such that the folded section is arranged laterally to the direction of movement. Thus predetermined numbers of containers arrive at the packing station 62 in a front-to-back, rather than side-by- side, orientation for insertion into cardboard boxes or cartons for transport to the retail site. In this way the containers can be collated in predetermined groups for packing.

Cartons are preformed with an open end and passed towards packing station 62 along runway 64. A robot picks and places a predetermined number of containers into each carton either by way of suckers, one layer at a time, or else using a jaw mechanism as a grab.

Whilst it is preferred to pick and place containers into the cartons one row at a time, it is also envisaged that containers may be dropped into cartons from above by way of a trap door mechanism, or else pushed into an open container from the side.

The present invention therefore provides apparatus, a method and a finished container which allows the advantages of a bag or soft pack container to be achieved. The integrity of the container is maintained during the packaging process and the subsequent retail display of the containers by ensuring that the infusion packages as they are wrapped in the sachets are retained in the stacks . This ensures that the containers are easy to handle and attractive when on display for purchase. The method as herein described also ensures that the containers can be packaged effectively without the conventional tight tolerance requirements and at the required throughput rates.