Method and apparatus for making medium-filled packages

There is disclosed a method and an apparatus for making a medium-filled packing of two superposed heat-sealable elongated webs of plastic film (3) which are thermally sealed in longitudinal and transverse directions of the film webs for forming packings (11), and where the formed packings are filled by medium and closed. The film webs (3) are passed between a pair of rollers (6) which are pressed against each other, retaining the film webs therebetween. Thermal sealing across part of the width of the film webs is performed so that unbroken longitudinal areas (9) without any thermal sealing appear in the longitudinal direction of the film webs (3). The medium is filled into the packing before closing it for the formation of the medium-filled packing.

This application claims the benefit of Danish Application No. PA 2007 00109 filed Jan. 24, 2007 and PCT/DK2008/000027 filed Jan. 24, 2008, which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention concerns a method for making a medium-filled packing of two superposed heat-sealable elongated webs of plastic film which are thermally sealed in longitudinal and transverse directions of the film webs for forming packings, and where the formed packings are filled by medium and closed. The invention furthermore concerns an apparatus for use in making a medium-filled packing of two superposed heat-sealable elongated webs of plastic film which are thermally sealed in longitudinal and transverse directions of the film webs for forming packings, and where the formed packings are filled by medium and closed.

BACKGROUND OF THE INVENTION

It is prior art to make bags into which medium is filled afterwards. For example, this is known by making ice cube bags where medium in the form of water is filled into bags.

Furthermore, apparatuses by which packings that may be filled with medium in the shape of liquid are formed from two plastic film webs, which are either formed by a folded/U-shaped film or by using two superposed separate films, are known. In these designs, a packing is formed at first, which is subsequently filled with the liquid via a filling opening. Then the filling opening is closed, and the liquid-filled packing is ready for further handling.

Furthermore, there is also so-called form-fill-and-seal machines where a film is drawn over a shaping tube, whereby the film is folded for the formation of a packing tube. This packing tube is closed by a welding, and filling of the packing tube is effected through the shaping tube around which the film is folded. Common to the prior art machines is the application of strong and thick films for providing a sufficiently strong packing.

It is thus commonly known that bags are filled with medium in the form of liquid, while they are on a supporting surface, as the film is inadequate for carrying the weight of the bags.

Particularly in connection with bags that are thermally sealed or welded, a softening and weakening of the material occurs, so that there is less load-bearing ability in the heated and softened material. This puts greater demands on the support of the packing during and after the filling of medium.

Common to the techniques described in these publications is the use of thick plastic films and/or use of complicated equipment for application in the making of medium-filled packings.

From U.S. Pat. No. 4,598,529 is also known a method and an apparatus for forming flexible plastic bags with two sides which are formed by superposed plastic webs and for filling the bag with liquid. The system described includes, however, the formation of a bag. This bag is subsequently provided with a slit at one side for filling liquid by means of a filling nozzle. The slit is subsequently closed by thermal sealing means that welds the to sides together. According to this technique, the packing is thus not formed successively while simultaneously being filled. Moreover, according to this art thermal sealing occurs across the entire width of the plastic webs so that a weakening of the material appears such that the web cannot carry a filled packing. There is no indication of the possibility of placing a liquid-filled packing directly in a sales unit and/or distribution unit.

For many years there has been a wish of providing packings filled by medium, preferably a liquid in the shape of water. Also, is has been desired to be able to make such medium-filled packings in the form of ice cube bags, where ice cubes are formed after freezing.

Furthermore, for many years it has been a wish to be able making ice cubes where the risk of bacterial growth is avoided, as known from traditional ice cube machines where the ice cubes are formed in a freezing compartment.

Moreover, there has also existed a wish for making water containers where the risk of bacterial growth is avoided by distributing water directly from a flexible liquid container. In the prior art containers, air penetrating into the container will cause the introduction of oxygen. Thereby a risk of bacterial growth is present.

OBJECT OF THE INVENTION

It is the object of the present invention to indicate a method and an apparatus which is technically simple and which enables the making of medium-filled packings by using thin films. It is thus an object that the method and the apparatus can be used for making medium-filled packings which during the making of the packing can be filled with the medium irrespectively whether it is a solid medium or a liquid medium, and irrespectively whether the medium after filling into the packing is to be treated or is ready for distribution and/or use, so that it is possible to avoid using ready-made packings/bags and thereby to use cheaper packings/bags and to avoid changing magazine with the finished packings/bags.

It is furthermore a particular object to indicate a method and an apparatus where such medium-filled packings can be used for making ice cubes, for making liquid-filled packings/containers for water machines and for use in filling ice cubes directly into a packing during the formation of such a packing, as the risk of bacterial growth is avoided hereby.

DESCRIPTION OF THE INVENTION

According to the present invention, this is achieved by a method of the kind mentioned in the introduction, which is peculiar in that the film webs are passed between a pair of rollers, that they are pressed against each other, retaining the film webs therebetween, that thermal sealing is performed at a position downstream of the rollers, that the thermal sealing is performed across part of the width of the film webs so that at least one and preferably two or more unbroken longitudinal areas, where no thermal sealing occurs, appear in longitudinal direction of the film webs, that the medium is filled into the packing before it is closed for forming the medium-filled packing, and that the medium-filled packing is subsequently separated from the film webs.

The apparatus according to the invention is peculiar in that it includesa pair of rollers between which the film webs are passed;means for pressing the rollers against each other for retaining the film webs therebetween;means for performing thermal sealing, the means being disposed at a position after the rollers as seen in the conveying direction of the film webs;means for filling medium into the packing before the packing is closed for formation of the medium-filled packing; andmeans for separating the medium-filled package from the film webs;

that the width of the thermal sealing means is adapted for performing a thermal sealing extending across a part of the width of the film webs, so that at least one and preferably two or more unbroken longitudinal areas where no thermal sealing occurs appear in the longitudinal direction of the film webs.

By a system according to the present invention it is possible to have a film storage, either in the form of film which is folded into U-shape for forming two superposed packing webs, or alternatively a storage of two separate films that are joined for forming the superposed elongated webs. Alternatively, the film may be provided as a tube which is pressed together, forming two superposed film layers. The two superposed heat-sealable elongated webs of plastic film are thus formed either by folding a film or by superposing two films.

By the system according to the invention it thus becomes possible to avoid using readymade packings/bags. This will enable making the packing/bag directly in or in direct connection with a distribution unit/sales unit while simultaneously filling it with the medium. Hereby, cheaper packings/bags can be used, and the user may avoid changing magazine with the finished packings/bags.

From the film storage, the film webs are passed between one or more pairs of rollers for controlling and unwinding the film in the ordinary way. However, only one pair of rollers is needed where the film webs are passed through, as the roller pair exert a squeezing force around the film web. The squeezing force exerted against the film is to be adapted so that the film web does not slide between the rollers when the packing to be formed is filled with medium.

Means for medium filling and thermal sealing can be provided immediately after the rollers.

The medium filling means may be of any type for filling liquids or solids and wherein there are blocking means for controlling the medium filling action.

The medium filling means may e.g. be a liquid supply pipe with shut-off valves for controlling the filling.

The medium filling means may e.g. be a water supply pipe with shut-off valves for controlling the filling.

The medium filling means may be a funnel or a screw conveyor, the outlet of which being provided with shut-off means for controlling the filling.

The medium filling means may be an ice cube machine, the outlet of which being provided with shut-off means for controlling the filling.

The thermal sealing means may e.g. be welding jaws that are reciprocatingly moved into and out of contact with the film webs.

Alternatively, heated rollers may be used which perform a longitudinal heating/thermal sealing of the two webs to each other. The film web is advanced by the rotation of the rollers which operate continuously or stepwise.

If the method is used for the formation of packings containing a compartmentation, as e.g. in ice cube bags, welding jaws for the formation of the compartmentation are actuated alternating with liquid filling, so that compartments are formed continuously which are filled with liquid before closing the packing for the formation of the liquid-filled packing.

The method may also be used with actuating welding jaws for the formation of one compartment, the volume of which being enlarged by actuation alternating with medium filling, so that continuously there is formed a larger compartment which is filled by medium before the closing of the packing for forming the liquid-filled packing.

Irrespectively whether the method is applied for the formation of a compartmentalised packing or a packing with one compartment, the volume of which being enlarged by actuation alternating with medium filling, e.g. an ice cube bag, the weight of the medium filled into the partly formed packing at first will contribute to pulling the packing and ensuring its movement during the filling before closing the packing for the formation of the medium-filled packing.

Alternatively, a packing may be filled with liquid, and then a compartmentation can be performed in that the film webs are pressed together and welded through the liquid.

By using the method, the forming of packings containing one large compartment, firstly a transverse thermal sealing is performed and subsequently a longitudinal thermal sealing is performed simultaneously with the medium filling before closing the packing for forming the medium-filled packing. The longitudinal sealing may be performed in one or more steps. Closing of the packing will usually be effected by a further transverse thermal sealings running between the longitudinal thermal sealing so that one or more closed compartments are formed between the longitudinal and transverse thermal sealings.

The transverse thermal sealings will always have a length adapted for a thermal sealing extending across a part of the width of the film webs, so that the above mentioned unbroken longitudinally extending areas where no thermal sealing occurs appear in the longitudinal direction of the film webs are established.

The thermal sealing means and the medium filling means are actuated synchronised with the rollers and thereby the movement of the film web. The packing thus formed will therefore be suspended in the film web extending between the two rollers. As the thermal sealing of the film web does not extend across the entire width of the film web, longitudinal areas will appear in longitudinal direction of the film webs in which no weakening occurs due to thermal sealing/heating. It is thus possible to use film where the widths of these longitudinal areas are dimensioned with such thickness of film and width of the areas in order to carry the weight of the packing when it is filled with the medium in the position where it is suspended by the rollers. After the medium has been filled into the packing, a closing will be performed for forming of the medium-filled packing. Then the medium-filled packing is separated from the film webs.

The unbroken longitudinally extending areas in which no thermal sealing is performed may be provided at any area across the width of the film webs. However, in a particularly simple embodiment it is preferred that these longitudinal areas is an edge area adjoining each longitudinal edge of the film webs. A welding formed in the longitudinal direction of the film webs in order to form sides in the formed packing may thus be made at a distance from the width of the film webs in the case of two superposed webs. At both side edges there will hereby be an area where no welds appear. Between the two longitudinal weldings forming side edges in the packing, transverse weldings are formed which form bottom and top in the packing.

Alternatively, between bottom and top there may be performed a transverse thermal sealing extending across the width of the film between the two longitudinal weldings. Hereby may be provided a division into compartments or sections of the formed packing which thus would be suited for use in making ice cubes, but which also may have individual chambers containing another medium. In such a situation it is preferred that thermal sealing of the film webs and medium filling are performed alternatingly, as the medium is successively filled into the packing during the formation of the packing for forming medium-filled compartments or sections in the packing before final closing of the medium-filled package.

It will thus be possible to make ice cube bags filled with liquid and which may subsequently be moved directly to a freezing unit where a complete or partial freezing of the ice cubes is performed. The ice cubes may then be moved directly to a storage compartment, either intended for immediate sale/distribution or from where they may be sold/distributed after a shorter or longer period of storage.

The method and apparatus according to the invention may thus be suited for application in the making of ice cube bags that are frozen, as the parts of the apparatus in a simple way may be disposed over a freezer used for storing and distributing the ice cubes. Hereby is achieved the advantage that the production of the liquid-filled packing and the freezing itself for the formation of the ice cubes can be moved out into a retail store.

Thus is achieved advantages of the keeping qualities of the filled product, and furthermore there will be far less requirements to the strength of film material as the filled product does not have to be handled through the usual distribution chains from producer to retailer.

The requirement to strength of the film will thus be significantly reduced. In principle, the films can be made so thin as technically possible, if only the plastic can protect the formed ice cubes.

The plastic film does not need to have a strength so that it can resist the loads arising during transport, where liquid-filled packings from producer to retail may be subjected to considerable pressure actions.

If the system according to the invention is used for making water packings for water machines/distribution units, the filling will normally occur in a separate bottlery, and the water-filled packings are subsequently to be transported to the retailer. In such a situation of use, the water-filled packings may be provided with drawing taps so that they are adapted to be placed immediately in a distribution unit.

The thickness of the film to be used for such liquid-filled packings is to be dimensioned according to the load occurring during the filling with the liquid-filled containers suspended in the rollers as well as the load that may occur during transport.

In practice it has appeared that the decisive dimensioning factor will be the weight that may be carried during production, as a film product has very inferior carrying ability if the film is heated and thereby softened. Also in connection with liquid-filled packings for water containers, which may have a volume of 5-10 liters or even larger volume, it will be advantageous to use the system according to the present invention.

By the making of the medium-filled packings, these may either before or immediately after being separated from the film webs be conveyed to subsequent treatment.

Subsequent treatment in the form of freezing of liquid is mentioned above. Freezing may thus be effected before the individual packings are separated from the film webs. In some situations, this may be an advantage. Possible leakages occurring in welds in the transverse direction of the film webs will therefore not give rise to leaking of liquid if freezing is performed before dividing into transverse separation areas between the transverse weldings.

Other subsequent treatment may e.g. be packing, radiation treatment, heating or other kinds of subsequent treatment performed before the liquid-filled packings are distributed/sold.

A particular embodiment of the method according to the invention is peculiar in that the longitudinal sealings are formed by a series of L-shaped sealings, where the small leg of the L is superposed the long leg of the L in a subsequent sealing action. In a safe way is hereby achieved a longitudinal sealing without any perforations, even if the film webs will be drawn downwards due to the suspended weight, so that they assume a profile with side edges which are directed inclining downwards and inwards.

In a special embodiment of the apparatus used for making ice cubes, the heat sealing means will include welding jaws which can reciprocate between an active position for contact with the film webs in order to thermally seal the latter, and an inactive position wherein the film webs may be moved freely between the welding jaws. The reciprocating movement of the welding jaws may thus be performed synchronously with the conveying and the filling of liquid.

If the medium filling means are provided with blocking means, it is possible that the medium may be filled successively into the packing during the formation. Thus thermal sealing of the film webs and medium filling for the formation of medium-filled compartments or sections may be performed alternatingly before a final closing is performed. This enables a rapid filling of packings to be used as ice cube bags, where otherwise there would be a slow filling if a liquid was to run through the entire packing and through a long series of chambers interconnected by small passages for forming the final liquid-filled packing.

This embodiment will thus be particularly suited for making liquid-filled packing which is moved directly to a freezer and then to a storage compartment in a distribution unit which may be located in a retail store.

According to the invention, any medium-filled packing can be brought via a treatment unit to a storage compartment in a distribution unit that may be disposed in a retail store, or directly to such a storage compartment in a distribution unit which can be placed in a retail store.

In such a situation, the apparatus according to the invention may be combined with special monitoring means so that it is only activated when the level of medium-filled packings, e.g. filled ice cube bags, go below a certain value in the distribution unit.

By the system according to the invention, it will be possible to provide a germ-free medium-filled packing. This will be the case by filling any packing with liquid or solid. It is thus possible both in the situation where ice cube bags are produced and in the situation where liquid-filled containers are produced for use in water machines.

Identical or corresponding features below will be provided with the same references throughout the various Figures of the drawing.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a roll1rotating about a journal2for unwinding two superposed film webs3which are advanced in direction of arrow4. The film webs have longitudinally extending side edges5. The film webs are passed between two rollers6which are pressed against each other for compressing and retaining the film webs3therebetween.

Under the rollers6, a water supply pipe7is disposed, connected to a water supply source7′ in the interspace between the superposed film webs3. At a position downstream of the rollers6, as seen in the conveying direction4of the film webs, there is provided a welding station8with which a thermal sealing can be performed for welding the superposed film webs.

The welding station8is provided with welding jaws (27,28seeFIGS. 3 and 4) extending across part of the distance between the side edges5of the film webs, so that two unbroken longitudinal areas9are left in the longitudinal direction of the film webs.

In the shown embodiment, the two longitudinal areas9in which no welding is present are provided adjacent to the side edges5of the film webs. In the interspace there between, weldings are provided, forming ice cube pockets10in the packing11.

In the welding station8, transverse weldings12are also established for mutual separation of the individual packings11. The packings11can be conveyed to a storage13which in the shown form is illustrated as a roll. Alternatively, there may be a storage where separate packings11are disposed in random order or stacked.

In the shown embodiment, there is illustrated a freezing station14after the welding station. This means that after the freezing station, packings11will contain frozen ice cubes, as the water filled into the packings via the water supply pipe7is frozen to ice in the freezing station14.

Alternatively, it is possible that the welding station only performs longitudinal welds and transverse welds for forming packing containers containing a single compartment for the liquid. Likewise, it will be possible to omit the freezing station. By an alternative method there will thus be filled containers with water.

In the shown embodiment, the unbroken longitudinal areas9where no welding appears will enable support of the film webs in the nip between the rollers6. Thus there is no need for other support means by the filling of the packings11.

FIG. 2shows an upright freezer15. At the bottom of the freezer there is provided a supply roll1with double-layered film web3. The film web is passed up along a side edge16in the freezer to an upper part17of the freezer. As shown inFIG. 1, the rollers6and the welding station8are provided at an upper part in the area18.

The film web is conveyed from the welding station8down on a conveyor belt19which is passed around two rollers20. The packings11are placed on the upper run of the belt19. In this embodiment, the division into separate packings may be effected at the welding station8.

Alternatively, the separation may occur at a separate separation station21which is provided at the end of the belt19. The liquid-filled packing11will thus first be separated from the web in the station21so that they fall down into a freezing compartment22as individual frozen packings.

The compartment22will be a freezer compartment. A compartment23wherein the film web is placed will be outside the freezing compartment as well as a compartment24with the upper part17being frost-free. The upright freezer will thus be provided with insulation of the compartment22in which freezing temperature is maintained by commonly known techniques. The upright freezer15may be cabinet located in a shop, and the customers will have access to take out the frozen packings via doors25.

FIGS. 3 and 4show how the film web3is passed around a roller26before it goes between the rollers6pressing against each other and retaining the film web. In this design, the welding station is formed by a first welding jaw27which provides a welding forming single chambers, and which does not extend across the entire film web. Furthermore, there is a second welding jaw28which is intended for a transverse termination and separation of the packings11from the film web3.

The weight to be carried by the rollers6will thus be weight of the liquid-filled packings11located between the water supply pipe7and the lower end of the welding jaw8, where separation is performed.

The separate liquid-filled packings11are then laid on the conveyor belt19and conveyed in direction of arrow29to subsequent treatment and/or storage.

As alternative to welding jaws for separation, scissors, knives or similar may be used, provided in separation station21which is located at the end of the belt19(seeFIG. 2).

As it particularly appears fromFIG. 4, spot weldings are formed in the welding jaw28, forming pockets10for the formation of ice cubes.

At the outer side edges, the sealings in longitudinal directions are formed by L-shaped sealings or weldings30. As it is clearly seen in lower part ofFIG. 4, the L-shaped sealings are made with slightly greater length in longitudinal direction of the film webs than the other longitudinal weldings33for the formation of the pockets. The small leg31of the L will thus be superposed the long leg32of the L in a subsequent sealing. This ensures that a tight and unbroken sealing is provided in longitudinal direction, irrespective of the tension occurring in the film due to the liquid-filled containers. Such a tension will cause a somewhat downwards tapering orientation of the film web as indicated onFIG. 4. The L-shaped configuration of the sealings30will thus compensate for the tapering formation of the film webs.

Between the L-shaped sealings30are formed punctiform sealings33running in longitudinal direction of the film and punctiform sealings34extending in transverse direction of the film. The length of the sealings33corresponds to the length with the film web is displaced before performing a subsequent thermal sealing with welding jaw27. Thus there will appear a welding pattern as illustrated in lower part ofFIG. 4with the longer L-shaped sealings30in superposed condition.

FIG. 5shows a partial, however more detailed view of the apparatus according to the invention. It appears that the water supply pipe7is provided with a valve mechanism35which is used for disconnecting and connecting the water supply concurrently with the stepwise conveying of the film webs3.

It appears that the apparatus includes a cabinet36in which water supply pipes, rollers and welding jaws are disposed. In the Figure appears a shaft37for one of the rollers6. The roller6is pressed into abutment against the other roller6(not shown) by means of a spring bracket38which is mounted between two anchoring points39in the cabinet36. A corresponding spring bracket38is provided in order to press the second roller in direction against the first roller6.

Alternatively, it will be sufficient with a single spring bracket, if only the spring force is adjusted so that the squeezing force between the two rollers6is sufficient to retain the two superposed film webs by the squeezing of the unbroken longitudinal areas where no thermal sealing occurs.

Furthermore is seen a spring bracket40which is fastened at anchoring points41. The spring bracket40serves to urge shafts42supporting drive wheels43for wires44. The wires are connected with the welding jaws27,28and driven by a motor for establishing a reciprocating movement of the welding jaws27,28at the thermal sealing of the film webs.

The welding jaws27,28are provided with a Teflon film45which is replaceable and which prevents the film webs3from adhering to the welding jaws27,28.

Moreover, inFIG. 5two lateral guides46are seen for ensuring the reciprocating movement of the welding jaws27,28.

FIG. 6illustrates the pattern on a welding jaw27. The welding jaw27has a pattern with a size which is less than the width of the film webs3, as also indicated in this Figure. The pattern of the welding jaw includes projections47intended for disposition transversely of the film web, and projections48intended to run in the longitudinal direction of the film web. At the outer ends, two L-shaped projections49are provided, having an elongated part50which is longer than the projections48and intended to be disposed in longitudinal direction of the film web, and a short transverse part51intended to be in the transverse direction of the film web. By the special design of the welding jaw27is achieved the above mentioned L-shaped sealing of the film web.

FIG. 7illustrates a further embodiment of a method according to the invention, where ice cubes152are filled into the formed packings instead of liquid.

FIG. 7illustrates a roll101rotating about a journal (not shown) for unwinding two superposed film webs103which are advanced in direction of arrow4. In the shown embodiment, the film webs103are produced by folding a film edge around one edge area marked with105. The film webs thus have two longitudinally extending side edges105and105′. At the side edges105, the film webs are not joined when located in the roll101. The film webs103are passed between two rollers106which are pressed against each other for compressing and retaining the film webs103therebetween.

Under the rollers106is disposed an feeding unit107for introducing ice cubes152into the interspace between the superposed film webs103. At a position downstream of the rollers106, as seen in the conveying direction104of the film webs, there is provided a welding station108with which a thermal sealing can be performed for welding the superposed film webs together.

The welding station108, which will be explained in more details in the following, is provided with two welding jaws127,128. These extend across part of the distance between the side edges105,105′ of the film webs, so that an unbroken edge area109is left in longitudinal direction of the film web at the side edge105. Welding jaw127performs welding129which is largely running in parallels with the side edge105. Transverse weldings are performed with the welding jaw128. A transverse welding112extending from the side edges105to the side edges105′ is performed. However, the welding jaw is also intended for making transverse weldings130which do not extend across the entire width, but stop at the welding129. By the welding is thus formed a packing111with an inner compartment110in which the ice cubes152are placed. As seen such a compartment110will be surrounded by an unwelded edge area along the entire circumference, except at the side edges105′.

As an alternative to the above described method, the superposed sheets103may be formed by two separate sheets, like in the previously described embodiment.

In an alternative embodiment, it will also be possible to provide the welding station108with a further welding jaw extending in longitudinal direction of the film web, corresponding to the welding jaw127. Such an additional welding jaw may perform a welding in longitudinal direction of the film web close to the side edges105′, so that two unbroken edge areas are formed in longitudinal direction of the film webs.

The feeding unit107includes a funnelshaped part131into which the ice cubes152fall down from a supply source107′. At the bottom of the funnelshaped part there is a U-shaped channel132in which is provided a screw133driven by a motor134. The ice cubes152will thus be introduced between the film webs103by means of the screw133.

The introduction of the ice cubes152is effected interchanging with activation of the welding jaws127,128of the welding station108.

The welding station108has two welding jaws127and128that may be applied/activated independently of each other.

When thus a first packing is to be formed, the welding jaw128is activated, establishing the transverse welding112and the partly transverse welding130. At the same time, the vertical welding jaw127is activated, forming a first part of the longitudinal weld129. At this time, ice cubes152may be filled into the (partly formed) packing. After a filling, the film webs103are conveyed in direction of arrow104.

Then the welding station108is activated again. However, at this time only the welding jaw127will be activated. Hereby, the weld129is extended. Hereafter additional filling is performed. Such extending of the weld129may take place one or more times, depending on which content is wanted in the formed packing. When a packing has been filled with desired contents as defined by the rotation of the screw at each sequence in which ice cubes are filled into the formed packing, the welding station108is activated again.

In this situation the welding jaw128is activated. By the welding, transverse welds are formed, as the welding jaw may contain several welding wires128a,128bso that by the same activation of the transverse welding jaw128a transverse welding112and two adjacent partial welds130are formed at each side for the formation of the side edges of the packing.

After the welding station108, the filled packings may be transferred directly to a sales unit.

By the embodiment shown inFIG. 7, it will thus be possible to provide a packing which substantially corresponds to the one previously described, however with bags in which ice cubes are disposed loosely without the use of freezing pockets.

It is to be noted that by activation of the welding jaws128, the transverse welding112may either establish an intersection126or just such a perforation that the individual packings111may be separated from each other afterwards.

By applying the method illustrated inFIG. 7, it is thus possible to perform a partial filling after the first welding step with a limited amount of ice cubes in the packing. Then these ice cubes will provide a weight which contributes to producing a pull advancing the film webs103.

However, it is also to be noted that the conveying of the film webs will be controlled by a stepwise advancing of the film. Such a stepwise advancing may e.g. occur by stepwise advancing of a support upon which the packing rests, or by stepwise advancing of driven rollers106.

Also, stepwise conveying may also be established by using the welding station in a situation where the welding jaws are not activated, but only performing a pulling action in the film webs.

In use, the welding jaws will be moved to a position from each other in order to avoid cooling of the welding jaws by the ice located in the packing. The welding jaws will thus be disposed with such mutual spacing that they do not prevent the downwards travel of the partial packing between the opposed welding jaws.

Even though there is described a method and an apparatus inFIG. 7in which ice cubes152are filled into the formed packing111, it will also be possible to fill the packing111with other solid media.

Likewise, it will be possible to use a feeding unit107which is designed differently from the one shown, when only it is ensured that the introducing of medium through the not welded side edges of the two superposed film webs103under the rollers106and at a position above the welding station108can be controlled.