WO2003049934A1

WO2003049934A1 - Method and equipment for transportation of packages

Info

Publication number: WO2003049934A1
Application number: PCT/FI2002/000854
Authority: WO
Inventors: Tapio Hintsa
Original assignee: Upm-Kymmene Corporation
Priority date: 2001-12-05
Filing date: 2002-11-04
Publication date: 2003-06-19
Also published as: AU2002337215A1; FI20012405A0; FI20012405A

Abstract

In the method, a casing (OP), after being formed, is transferred to a filling and sealing unit. Before the transfer into the filling and sealing unit, the casings (OP) are stored temporarily on top one another, with their sidewall portions against each other, essentially in a horizontal position, in one or more storage magazines (VV). The casings are transferred to the storage magazine (VV) essentially in a direction parallel to the longitudinal axis of the sidewall portion of the casing (OP), and the casings are transferred from the storage magazine (VV) essentially in a direction parallel to the longitudinal axis of the sidewall portion of the casing (OP) onto the conveyor track (PV) leading to the filling and sealing stages.

Description

Method and equipment for transportation of packages

The invention relates to a method for a packaging machine, in which method the casing is transferred to the next process stage. The invention also relates to a packaging machine, wherein the above-mentioned method is applied.

It is known in the art to form cylindrical containers from liquid packaging board, which containers comprise a cylindrical sidewall portion, normally situated in a vertical position, which is formed by fixing together the opposite vertical margins of a blank provided with a heat seal coating, and of end members closing the blank at the top and at the bottom, the upper member having an opening which can be opened and is closed, for example with a closure cap or a closing flap. Containers of this kind are used for sterile and airtight packaging of various beverages.

The container into which the material to be stored, such as a beverage, is fed at a later stage, is formed automatically in a container-forming unit, wherein the sidewall portion is formed by wrapping. The container is then removed from the container-forming unit and by means of a conveyor track conveyed to a filling unit for filling and closing.

The publication EP-456011 is referred to as regards the state of the art. This publication discloses a packaging machine, in which casings are transferred from the casing formation stage to the next process stage by means of a conveyor on which the casings are placed in a vertical position one after the other. Particularly when the objective is to obtain a high-speed container- forming apparatus, the transfer stage in question is problematic in terms of process technology when carried out in the way described in the publication EP- 456011. Firstly, the casing is removed from the mandrel in a substantially horizontal direction, after which the casing has to be turned into a vertical position and placed on the moving conveyor track in a vertical position. The above-mentioned turning motions for bringing the casing onto the conveyor track are very difficult to carry out if the objective is high-speed and operationally reliable mass production. In addition, the speed of movement of the conveyor must be accurately controlled so as to allow the casings to be placed on it without disturbances and to be transferred in succession on to the next process stage. Consequently, the prior art solution for transferring the casings is both technically complex and in continuous production apt to cause production breakdowns.

In US Patent 4318703, a casing transfer device is presented, wherein a casing is transferred by air impingement from the container-forming units mandrel into a pocket of a turret, which as it turns lifts the casing into an upright position, and from this position it is pushed onto the conveyor leading to the next processing stage. US Patent 4100842 presents a tube into which the casing is ejected from a cup-like space by means of compressed air introduced into the bottom of the space. The casings advance in the tube with their open ends first and land in a stack, with the open ends down.

Finnish patent application 981221 presents a method and packaging machine to be used in such processes where the forming, filling and closing of the container have been linked together to form successive process stages. In the packaging machine the casings are conveyed in succession on a tubular conveyor track leading to the next process stage in the direction of the longitudinal axis of the casing sidewall portion, thus at the final stage bringing the casings in succession onto the conveyor track leading to the next processing stage, where they begin to move in succession in the direction of the conveyor track towards the next processing stage. In order to allow controlled transfer of the casings from the tubular part of the track onto the conveyor track, the transfer time for the casings must be accurately predictable. However, in practice, the casing transfer times are subject to constant slight variations, and moving the casings according to the solution presented in the publication is apt to cause production breakdowns in continuous production.

The purpose of the present invention is to remedy the above-mentioned defects relating to the state of the art and to simultaneously improve the state of the art in processes carried out in connection with packaging machines in which container forming and container filling and closing are to be linked to form successive process stages. To realize these purposes, the method according to the invention is mainly characterised in that, prior to the transfer of the casings to the filling and closing unit, the casings are temporarily stored in a stack with the sidewall portions against one other (horizontally) in one or more storage magazine. In a preferred embodiment, the casings are transferred to the storage magazine by means of a tubular conveyor track in the direction of the longitudinal axis of the casing's sidewall portion. In another preferred embodiment, the casings are removed from the storage magazine and placed in succession on a conveyor track, where they begin to move in succession in the direction of the conveyor track towards the next processing stage.

Other preferred embodiments of the method according to the invention are furthermore presented in the accompanying dependent claims.

Another purpose of this invention is to produce a packaging machine that allows simple and reliable transfer of the casings to the next unit, in particular to the filling and closing unit. Accordingly, the packaging machine is characterised in that the conveyor track has a storage magazine where the casings have been arranged to await transfer to the next process stage.

The conveyor track preceding the storage magazine, which track feeds the casings from the container-forming unit to the storage magazine, is preferably the flow channel for a gaseous medium, in which flow channel both the transfer and the feeding of the casings into the flow channel can be performed by using the force exerted by the pressure and flows of the gaseous medium.

Other preferred embodiments of the packaging machine according to the invention are presented in the accompanying dependent claims.

The invention is illustrated in more detail in the following description referring to the embodiment presented in the accompanying drawings. In the drawings Fig. 1 is a vertical cross-section of the casing formed in the container- forming unit,

Fig. 2 is a view of the container-forming unit seen from above,

Fig. 3 is a side view of the container-forming unit viewed from the side,

Fig. 4 is a side view of the storage magazine according to the invention,

Fig. 5 is a more detailed side view of the point where the flow channel links with the storage magazine,

Fig. 6 is a front view of the storage magazine according to the invention,

Fig. 7 illustrates the operating principle of the container removal station as a sequence of pictures,

Fig. 8 is a side view of a preferred embodiment according to the invention, and

Fig. 9 is a view of the embodiment of Fig. 8 seen from above.

In this context the following terms are used to refer to the different parts of the liquid package:

- Container : a sales package or a casing depending on the context

Sales package, a finished and a closed liquid package filled with the contents

- Casing : an unfilled and unclosed outer shell of a sales package

- Can : a container that typically has a portion, namely a sidewall, wrapped to form a structure that is closed in its cross-section perpendicular to the longitudinal axis, i.e. a sidewall portion, having one or both ends closed with an end member - Container blank: a straight, plane piece, generally made of liquid packaging board, which is joined to form a casing, and which may be separated from a material with a larger surface area, such as a long strip

- Outer surface of a blank or blank material: a surface forming the surface of a finished package that is visible outwards and which is generally provided with printing and a heat seal coating

- Inner surface of a blank or blank material: a surface forming the surface of the finished package that is in contact with the contents of the package and which is generally provided with a heat seal coating - Blank material: raw material of blanks, generally liquid packaging board coated with a heat seal coating

The packaging machine includes a container-forming unit in which is formed the can-shaped vertical part presented in Fig. 1, the horizontal section of which forms a closed shape, that is a sidewall portion O, to which is fixed the end member P closing its open end. The can-shaped container thus formed with one end still open is transferred to the filling unit of the packaging machine, where the finished sales package is formed, which sales package is not described here in more detail.

The container-forming unit presented in Fig. 2 includes a transfer table 1, arranged to rotate horizontally, on the perimeter of which there are forming parts placed at fixed angular intervals from one another, supporting the above- mentioned container at its different forming stages. The forming parts are identical, each consisting of a vertical mandrel 2 around which the sidewall portion for the casing is formed and which hereafter will be referred to as a wrapping mandrel.

In addition to the transfer table 1 , the container-forming unit also comprises a fixed frame on which the table is arranged to rotate and which is referred to in general by the reference number 10. There are as many processing stations on the frame as there are wrapping mandrels 2, in each of which processing stations a single stage of forming the can open at one end is performed. At the stopping points, when the processing stations carry out certain operational stages, the mandrels are at the location of the processing stations, and at the transfer stage the mandrels advance by short rotational movements of the table equal in length to the angular distance between the wrapping mandrels 2 to the next station for the next processing stage.

At the wrapping station A, a blank of fixed height is cut from the lower end of the blank web L transferred to the station by means of transfer devices on the frame, whereafter the blank is pushed onto the wrapping mandrel 2 and wrapped around it to the shape determined by the outer surface of the mandrel. In this way the sidewall portion of the can-like casing is formed, which sidewall portion has a closed shape in horizontal section, a round shape when the mandrels are cylindrical.

At the sidewall sealing station B, the blank's vertical sidewall margins placed on top of one another at the wrapping station are sealed together permanently. This is done with a pressing surface, which presses together the overlapping margins and simultaneously cools the heat seal coating on the blank's inner surface, which has previously been heated to bonding temperature.

At the preheating station C, hot air is blown into the side-sealed part at the top end, causing the heat seal coating at that point on the blank material's inner surface to heat up to a suitable temperature.

At the end member station D, end members corresponding in outline to the sidewall portion's horizontal section are die-cut from the continuous blank web M fed to the station, whereafter one member at a time is forced through an opening, simultaneously bending the outer edges. The member is then pushed down into the sidewall portion's open top end using the upper surface of the wrapping mandrel as a counter-surface, in such a way that the member's folded-up outer edges are pressed against the inner surface of the sidewall portion. At the first heating station E, hot air is blown onto the end member's outer surface directing it towards the edges, causing the member's lower surface to heat up at the edge folded up towards the inside of the top end of the sidewall portion.

At the second heating station F, the same procedure is performed to assure sufficient heating over the whole perimeter of the top end.

At the clenching station G, the upper edge of the sidewall portion, which is above the folded-up edge of the end member, is turned down towards the centre by pressing it from above, so that it covers the end member's folded-up outer edge.

At the first end sealing station H, the end margin of the sidewall portion is pressed against the folded-up edge of the end member so that the heat seal coatings, which were heated up at previous heating stages, glue the parts together, and the folded-up outer edge of the end member remains permanently inside the U-folded upper edge.

At the second end sealing station I, the same operational stages are carried out at different points than at the previous station, so that the seal is even around the whole perimeter of the casing, which at this stage is already in its finished can-shaped form.

At the last processing station, removal station J, the can-shaped casing is lifted off the wrapping mandrel 2 and transferred to the next stage of the process PV, particularly to the filling unit of the packaging machine, where it is also closed, which explains why the filling unit can also be called the filling and closing unit.

After the finished can has been removed from the wrapping mandrel 2, the mandrel advances to the wrapping station A by a short rotational movement of the table 1 , to receive a new sidewall portion blank, and the above-described processing stages are repeated.

The typical processing time at each of the stations A-J may be in the range of 500 ms, including the transfer from one station to the next. Therefore, a can may be produced and finished in the container-forming unit in approximately 5 seconds, and the production capacity is 1 can/0.5 s, equalling approximately 120/min.

From the last processing station, the removal station J, the casings OP advance along the transfer track in the direction of the longitudinal axis of the sidewall portion towards a storage magazine W. The direction of transfer is substantially parallel to the direction of the longitudinal axis of the sidewall portion. The length of the transfer track depends on the placing of the different stations and other machine parts and on the distance between the different units of the packaging machine, but its horizontal length, that is the track's horizontal transfer distance, is several times the length of a casing, usually more than 0.5 metres, normally more than one metre.

Fig. 3 illustrates in more detail an embodiment of the method according to the invention. Here, the first aperture 12 of the flow channel 11, i.e. the inlet, is placed at the location of the removal station J. The flow channel 11 forms the first part of a transfer track, which is arranged to transfer the formed casings to the packaging machine unit that forms the next process stage. The casings OP are transferred directly upwards from the mandrel 2 into the first aperture 12 of the flow channel, at which point the longitudinal central axis of the vertical mandrel 2 meets the central axis of the first vertical portion 11a of the flow channel 11. The flow channel 11 in the embodiment presented here is thus comprised of the first vertical portion 11a used to move the casings OP to a suitable height for the apparatus and its proper functioning, and in the top part of which the casings are turned towards the horizontal section 11b of the flow channel 11 , thus enabling the horizontal transfer to a storage magazine W necessary for the process and for the structure of the apparatus. In the upper part of the storage magazine W, acting as an extension of the horizontal portion 11b and as the closing part of the transfer track thus produced, there may be a bumper 14, which stops the longitudinal movement of the casing OP as the casing is transferred from the tube to the storage magazine. In the storage magazine W, which forms the end part of the transfer track, the casing OP, perpendicular to its longitudinal axis, with the sidewall portion first, is moved vertically downwards by force of gravity. In practice, after the casings OP hit the bumper 14, they fall down and land on top of one another in a horizontal position to form a stack in the storage magazine W. The lower part of the storage magazine has opening and closing devices 15, 16, that can if desired be regulated so as to open or close. The upper closing device 15 is used to stop the free fall of the casings OP, and the joint action of the closing devices 15, 16, serves to control the precise forward movement of the casings in the process. At the end of the transfer track, that is at the lower end of the storage magazine W, the casing OP is moved in the direction of its longitudinal axis onto a conveyor track leading to the filling and sealing stages, i.e. onto the conveyor PV of the filling and sealing unit, to be described later in more detail, by a pusher arm 17 performing a reciprocating linear movement. There may be several casings OP simultaneously in the storage magazine W on top of one another, the sidewall portions O of the casings being against one another, whereby the lowest package is the first to be moved onto the conveyor track PV.

It is obvious that the design of the flow channel 11 may differ from the above within the scope of the functional demands of the apparatus and the process. The cross-sectional shape of the flow channel 11 corresponds to the shape of the horizontal cross-section of the casing OP, and on grounds relating to flow technology, the cross-section of the flow channel 11 has been chosen to be somewhat larger in size than that of the casing OP.

According to the invention, whichever mandrel 2 is at the removal station J is connected to the next stage PV of the process by the flow channel 11 for the gaseous transmission medium. In this case, the first aperture 12 of the flow channel 11 , that is the inlet for the casing OP, faces in the direction of the end face 2a of the mandrel 2, i.e. is in a horizontal position, at a distance from and above the end face (Fig. 3). The second aperture 13 of the flow channel, that is the outlet for the casing OP, is connected to the storage magazine W.

As illustrated in Fig. 3, the transfer is carried out essentially in the direction of the longitudinal axis of the sidewall portion of the casing OP (excluding the direction change 11a- 11b which takes place in the curve, where the longitudinal axis is parallel to the tangent of the direction-changing curve, but also follows the direction and the curve of the transfer track).

It is preferable that the energy for transferring the casing OP is created by a gaseous transmission medium. This is particularly preferable for the reason that a suction effect can be generated at the first aperture 12 in order to bring the casing into the flow channel 11, in particular by employing an ejector structure as marked IV in Fig. 3, and known from Finnish patent application 981221. The casing OP is brought within range of the suction effect created by the gaseous transmission medium acting on the first aperture 12 in the flow channel 11, by removing the casing OP at least partly from the mandrel 2 by means of a releasing force exerted on the casing OP and separate from the suction effect. This releasing force, which is separate from the suction effect, may be a force directed from the mandrel preferably onto the inner surface of the casing OP, particularly onto the end member P, and created by a gaseous pressure medium. It is also possible to conceive of an alternative, wherein the releasing force used to lift the casing OP off the mandrel 2 is so powerful that the kinetic energy of the casing is enough to transfer the casing OP into the flow channel 11 , within range of the gaseous transmission medium. It must be noted that persons skilled in the art have the knowledge to select the flow rates and pressure levels that will generate sufficient kinetic energy of the casing, which combined with a sufficient suction effect, will ensure the functioning of this process stage. Fig. 4 illustrates one preferable embodiment of the storage magazine VV. When the casing OP advances from the package-forming unit via the flow channel 11 through the outlet 13 to the storage magazine W, the kinetic energy in the direction of the longitudinal axis of the casing is stopped essentially by means of the bumper 14. The bumper 14 can at its simplest be a flexibly mounted plate structure that stops the casing with a flexible motion conforming to the movement of the casing OP. Thereafter, the casing advances to the storage magazine VV, which is essentially a vertical shaft, where the casings are arranged to move down by force of gravity. In the storage magazine, the casings OP are stored one on top of another with the sidewalls O against one another (horizontally). The shaft of the storage magazine is dimensioned so that only one casing OP can be at the same level at a time. It should be noted that a person skilled in the art has the knowledge to select such dimensions as to obtain adequate movement of the casing OP, so as to ensure the functioning of this process stage.

In Fig 5, the connection of the end portion of said flow channel 11 to said storage magazine is illustrated in more detail. The flow channel narrows towards its end portion through a cone-like portion in such a way that prior to the storage magazine, the diameter of the flow channel is smaller than the diameter of the initial portion of the flow channel. At the end of the flow channel, the narrower end portion ends in an outlet 13, after which there is an extension of the upper part of the flow channel's narrower end portion that forms an obstacle to the upward movement of the casing OP. The smaller-diameter end portion stabilises the movement of the casing OP before it hits the bumper 14. The walls of the end portion of the flow channel 11 are permeable to air in order to remove the transmission air from inside the flow channel. In practice this is achieved by arranging at least the conelike narrowing portion of the flow channel to be permeable to air. In the figure, the air-permeable wall is executed by placing at certain intervals around the flow channel's circumference longitudinal ribs or corresponding means, which begin already at the wider portion of the flow channel. In the narrow portion of the flow channel, the ribs or corresponding means end in the area of the lower half in the outlet 13, and in the upper half said ribs are located above the storage magazine W acting as a kind of roof.

Fig 4 shows the opening and closing devices 15, 16 in the lower portion of the storage magazine, which are regulated to open and close in accordance with the timing required by the conveying capacity of the conveyor track PV leading to packaging and sealing stage. The upper closing device 15 is used to stop the free fall of the casings OP, and the joint action of the closing devices 15, 16, serves to control the precise forward movement of the casings in the process. The lowest closing device 16 of the storage magazine W allows one casing OP at a time to move in front of the pusher arm 17, which moves the casing with a linear motion in the direction of the casing's longitudinal axis towards the conveyor PV leading to the packaging and sealing stage. The pusher arm moves the container to a reception point on the conveyor (e.g. a hole or corresponding point) for the casing OP, which has arrived opposite the pusher arm at the turning point of the conveyor loop. After this, the casing rises into an upright position due to the effect of the conveyor's transfer motion. In one preferable embodiment, the conveyor is a so-called walking beam conveyor, which has successive transverse beams that are provided with recesses or corresponding spaces as reception points for casings and arranged to convey casings stepwise between the different stages of the filling unit (sterilising, filling and sealing) in order to produce the finished sales package.

Fig 6 shows a front view of an embodiment with six parallel storage magazines W or "magazines". From the figure it can be seen that the closing devices 15, 16 are located in the lower portion of the storage magazine and that the shaft of the storage magazine is dimensioned so that only one casing OP can be at the same level at a time. In order to implement this, the inside width of the storage magazine W can be dimensioned to be somewhat larger than the diameter of the casing OP. In one preferable embodiment, the closing devices 15, 16 of different storage magazines are controlled by the joint control devices of the storage magazines, whereby the closing devices on the same level in different storage magazines can be made to operate simultaneously. The lower portion of each storage magazine VV is equipped with its own pusher arm 17 to push the casing to the corresponding point on the conveyor beam. Thus, several casings are placed on the conveyor simultaneously, and the conveyor moves them on simultaneously to the same processing stage in the filling and sealing unit.

Fig. 7 shows a series of illustrations describing the operating principle of the closing devices 15, 16 in one of the storage magazines W. The illustration begins with the situation where there are five casings OP in the storage magazine, the bottom-most of said casings being situated in the pusher station, and the closing devices 15, 16 being closed. A pusher arm transfers the bottom- most casing OP to the conveyor leading to the next process stage (2nd illustration), after which the pusher arm retracts and the lower closing device 16 opens and allows the casing to fall into the pusher station (3rd illustration). After the lower closing device 16 has closed (4th illustration) the upper closing device 15 is opened (5th illustration), after which the casings OP in the storage magazine move downwards (6th illustration) and the upper closing device 15 is closed (7th illustration), as a result of which there is one casing in the space delimited by the closing devices 15 and 16. More casings OP are transferred into the storage magazine W from the container-forming unit at the rate determined by the production capacity of the container-forming unit and the flow channel (8th illustration), and because the filling potential of the storage magazine does not depend on the functioning of the closing devices 15, 16, the filling of said storage magazine can be performed at any stage of the closing devices' operation (illustrations 1-7), although the stage of filling the storage magazine is shown only in the 8th illustration. Consequently, there is "buffer capacity" in the upper part of the storage magazine to even out fluctuations caused by variations in the production rate and possible disturbances of short duration. The closing devices 15, 16 in the lower part of the storage magazine are used for controlled steering of the casings OP to bring them within range of the pusher arm, so that it is possible to implement a feeding rate corresponding to the stepping rate of the filling and sealing unit conveyor by means of the closing devices and the pusher arm, which operate in a synchronised manner with the conveyor.

Fig. 8 illustrates another alternative, in which the flow channel 11 is tumable around the longitudinal axis of its initial portion, whereby the pivot axis forms the centre point of an aperture 12, and the said aperture remains at the same point in the removal station J. By turning the flow channel 11, it is possible to change the storage magazine W for the casings OP.

Although this can be implemented in practice by means of one continuous flow channel 11 , the end portion of which moves and distributes the casings OP to adjacent storage magazines W, as the casings advance through said flow channel at a frequency determined by the production rate, a preferable structure is illustrated particularly in Fig. 9, where the initial portion 11a+b of the flow channel 11 is turnable, and the end part of the initial portion is connected to a series of fixed-position end portions 11 b, each of which feeds its own storage magazine W through its own outlet 13. Otherwise the storage magazines have the same structure and operating principle as in Figs. 3-7. The end portions 11b are placed so that their inlets are adjacent to one another approximately along the circumference of a circle drawn with the pivot axis as its centre point and the said inlets meet with the outlet of the initial portion in a suitable order. The initial portion 11a+b, through which one casing OP advances at a time, is rotated to meet the appropriate end portion 11b, and the casing OP is steered into it. The distribution can be made according to an appropriate diagram so as to distribute the casings into adjacent storage magazines W. After feeding the previous casing OP, the initial portion can be rotated rapidly past one or more inlets of the end portions 11 b to a subsequently chosen inlet, so that the distribution is not necessarily conducted one aperture at a time going from one edge to the other. The turnable structure is smaller and the extent of the turning motion is shorter compared to a complete rotation of the flow channel. In Figs. 8 and 9, the break point of the flow channel 11 , where the outlet of the initial portion and the inlet of the end portion meet, is in the horizontal portion 11 b. It can be seen, especially from Fig. 8, that the transfer channel 11 does not otherwise differ in shape from that shown in Fig. 3, and that the gap between the portions may be very short, so that the portions of said channel form a functionally continuous tube.

The structure that rotates the initial portion of the channel is known from the Finnish patent application 981221.

Although the figures have shown essentially cylindrical casings, the present invention is not limited to the transfer of such casings, but it can be used with any casings that can be formed by wrapping a sidewall portion around an appropriately shaped mandrel and attaching an end member to the end of the said sidewall portion. The present invention is therefore also suitable for casings that do not have exactly circular cross-sections but may deviate from the said shape, being for example polygon-shaped with rounded corners, for example, square-shaped. Similarly, the diameter of the cross-section need not be the same at every point in the axial direction of the sidewall portion, but the sidewall portion may be more or less conically tapering towards the end member.

The present invention is suitable particularly for food packaging machines, especially for liquid foods such as beverages. Thus the casing is filled with food in the filling and sealing unit, to which the casings are transferred from the storage magazine W, after which the sealing of the said casings takes place. If the containers are filled with liquid food in the filling and sealing unit, the casings OP may be manufactured, for example, from liquid packaging board.

Claims

Claims:

1. A method in a packaging machine, in which method a casing (OP), after being formed, is transferred to a filling and sealing unit, characterised in that before the transfer to the filling and sealing unit, the casings (OP) are stored temporarily on top of one another with the sidewall blanks (O) against each other, essentially in a horizontal position, in one or more storage magazines (W).

2. A method according to claim 1, characterised in that the casings are transferred to the storage magazine (W) essentially in a direction parallel with the longitudinal axis of the sidewall portion (O) of the casing (OP).

3. A method according to claims 1 or 2, characterised in that the casings are transferred from the storage magazine (W) essentially in a direction parallel with the longitudinal axis of the sidewall portion (O) of the casing (OP) onto a conveyor track (PV) leading to the filling and sealing stages.

4. A method according to any of the above claims, characterised in that at the storage magazine (W), the casings (OP) are transferred, peφendicular to their longitudinal axis, with the sidewall portions (O) first, essentially vertically downwards.

5. A method according to claim 4, characterised in that at the storage magazine (W), the casing (OP) moves downwards by force of gravity.

6. A method according to claims 4 or 5, characterised in that the free fall and the advancing of the casings in the process is controlled by means of the opening and closing devices (15, 16) situated in the lower part of the storage magazine.

7. A method according to claim 6, characterised in that the closing devices (15, 16) allow one casing (OP) at a time to be transferred further by a pusher arm (17).

8. A method according to any of the above claims, characterised in that the transmission energy of the transfer track bringing the casings towards the storage magazine (W) is at least on part of the transfer track generated by means of a gaseous transmission medium.

9. A method according to any of the above claims, characterised in that the casings are stored temporarily in one or more parallel storage magazines (W)

10. A method according to claim 9, characterised in that moving the transfer track, such as a flow channel (11), that brings the casings towards the storage magazines W, at least for part of its length, changes the storage magazines (W) for the casings (OP).

11. A packaging machine incoφorating a container-forming unit for forming the casing (OP) into an essentially finished form and a transfer track arranged to steer the casings in succession to the filling and sealing unit, characterised in that the transfer track incoφorates a storage magazine

(W), to which the casings can be transferred to await transfer to the next process stage, to the filling and sealing unit.

12. A packaging machine according to claim 1 1 , characterised in that the storage magazine (W) is essentially a vertical shaft where the casings are arranged to move downwards by force of gravity.

13. A packaging machine according to claim 12, characterised in that at least at the lower end of the storage magazine (W) there are opening and closing devices (15, 16) arranged to move so as to obstruct the free-falling movement of the casings.

14. A packaging machine according to claims 12 or 13, characterised in that the storage magazine (W) is arranged to store the casings (OP) on top of one another, with the sidewall portions (O) against each other, essentially in a horizontal position.

15. A packaging machine according to any of the above claims 1 1-14, characterised in that the transfer track leading to the storage magazine (W) is anranged to steer the casings in succession, essentially in a direction parallel to the longitudinal axis of the sidewall portion (O) of the casing (OP).

16. A packaging machine according to any of the above claims 11-15, characterised in that the storage magazine (W) is provided with an operating device, such as a pusher arm (17), performing a linear reciprocal movement and arranged to transfer the casing (OP) in a direction parallel to its longitudinal axis onto the conveyor track (PV) leading to the filling and sealing unit.

17. A packaging machine according to any of the above claims 11-16, characterised in that the storage magazine (W) is provided with a damper (14) arranged to stop the longitudinal movement of the casing (OP), as it is transferred from the transfer track preceding the storage magazine to the storage magazine

18. A packaging machine according to any of the above claims 11-17, characterised in that the transfer track comprises a source of the gaseous transmission medium arranged to transfer the casings onto the transfer track leading from the container-forming unit to the storage magazine (W).

19. A packaging machine according to any of the above claims 11-18, characterised in that has two or more storage magazines (W).

20. A packaging machine according to claim 19, characterised in that the conveyor track leading to the storage magazine (W) is arranged to be moved at least in a part of its length in the position transverse to its longitudinal axis for changing the storage magazines (W) during the transfer of the casings.

21. A packaging machine according to claim 20, characterised in that the transfer track (11) comprises a movable initial portion (11a+b), which at its end is connected with a series of fixed-station end portions (1 1b), which are connected in turn with the storage magazines (W), the outlets of which are linked to the conveyor track (PV) leading to the filling and sealing unit.