EP0603704B1 - Method and device for continuously making foil containers - Google Patents

Abstract

A method and a device serve for continuously making filled foil containers. By V-shaped folding of a soft foil (3) until the foil halves lying on both sides of the folding line (8) lie one on top of the other and by subsequent joining of the foil halves by first sealing seams (10), individual pockets (12) are formed within a string of containers. By filling the pockets between the first sealing seams (10) and by closing the pockets by sealing by means of second sealing seams (29), filled foil containers are formed, these containers subsequently being cut off individually or in groups. To increase the filling volume of the pockets in this case, the initially still superjacent wall elements of the pockets (12) are plastically deformed after applying the first sealing seams (10), to form a distance between the wall elements. For processing the foil, the device has a supply station (1), a folding station (7), a first sealing station (9), a filling station (23), a second sealing station (28), a transporting means (32) and a punching station (30). The first sealing station (9) is in this case followed downstream by a forming station (16) for the plastic deformation of the wall elements of the pockets (12). Filling and plastic deformation may in this case also be carried out in a combined forming and filling station. <IMAGE>

Description

The invention relates to a process for the continuous production of a filled film container by folding a V-shaped sealable film according to the preamble of claim 1.

Methods are known which lead to film containers, the level of which itself Wall elements are inflated through the contents of the container, so that the filled Foil containers have the shape of so-called "pillows". For this reason such containers have an unfavorable ratio of the amount of product and Surface, i.e. it becomes a for a given quantity of product disproportionately large film area required. This doesn't just lead to one disproportionately large share of the cost of packaging, but also represents an unnecessary environmental impact because the emptied foil containers in the garbage land or have to be recycled. Such "Pillows" are not suitable for installation.

It is known from EP-A 0 343 266 by the same applicant, in one To form film web on both sides of the folding line, deep-drawn container parts, then fold the two film halves together along the fold line, to be sealed on a partial circumference of the container parts by first sealing seams, to spread the unsealed film edges again and through that formed openings to fill with the contents, whereupon the film edges in Area of the previously existing filling opening with second sealing seams be closed. By forming the film container from a single one Foil is eliminated from the containers otherwise found in the bottom area of such containers Sealed seam, so that so-called "stand bottles" due to the known measure getting produced. Although the known method is not specific to Film thicknesses and film materials is bound, it serves primarily to produce relatively rigid bottles, which are preferably for Sample packs and serve for advertising purposes. However, with that known methods also stand bottles with a filling volume of 1000 ml and can be manufactured clearly above.

From DE-AS 1 133 114 it is known in a preliminary stage to Packaging machine in a continuous sequence of process steps to produce individual empty containers that are separated and in additional Working steps sealed, filled and on another machine must be closed. In the manufacture of the container folded film in the riding seat, i.e. with the fold line up, on one Guide plate guided, heated on it and inflated in a mold. The The specified PVC film is at the temperatures mentioned from 80 to 110 ° C neither inherently sealable nor can it be sealed by the edges of the unheated mold halves are sealed as these edges the Cool film immediately when touched. So the containers are carried upwards Directed bottom inflated from below and with open edges separated and must subsequently in a manner not described be sealed. Because the later fill opening during manufacture below filling is not possible in the course of the manufacturing process. The separated individual containers are for a mechanical filling process not or only difficult to handle; they would have to be upside down first be put on the ground.

The invention has for its object a method of the beginning described genus to improve that with this method the ratio of filling volume using thin and soft foils to the surface is further improved, so that one per unit volume significantly less amount of film material is required. Besides that Manufacturing process and the mechanical effort compared to the prior art Technology can be simplified or reduced.

The problem is solved with the generic Process thereby the features of claim 1.

In contrast to the prior art, the Wall elements of the so-called "bags" after the formation of the bags deformed. The film material comes thermally and / or mechanically deformable films in question, preferably soft films with a thickness between 50 and 500 µm, the volume of the container finally produced can be between 5 and 5000 ml. The film material is polypropylene, Polyethylene, polyamide and polyurethane in question, in one or multilayer design, with multilayer films in particular to such with a barrier against steam and aroma loss. For certain uses, for example for the packaging of General cargo such as cheese, meat, sausages etc. are preferably shrinkable Foils are used, which are shrunk onto the product after filling. When using materials that are not themselves sealable, must multi-layer or multi-layer films are used, whose through the V-shaped Wrinkles on top of each other are sealable.

Through the V-shaped unfolding of the two sides of the fold line In this case too, wall elements become a so-called bottom seam not necessary, so that a targeted shaping of the wall elements at least substantially flat bottom area of the container can be achieved can. Despite the high flexibility of the film and the relatively low required Wall thicknesses are created in an amazingly simple manner sufficient even when filled with a thin liquid Have stability.

The plastic deformation of the wall elements between the first Seal seams can preferably be carried out in a hollow shape, so that all containers have the same filling volume. The plastic deformation the wall elements can either by mechanical expansion bodies Vacuum deformation or by simply inflating. This bloat can take place in a molding station upstream of the filling station. It is but also possible by the deformation of the wall elements in the filling station bring pressurized contents. The expansion medium can to make it easier to find the bags before placing them on a bag Temperature above the softening temperature of the film material be heated.

In order to "freeze" the deformation state of the containers the hollow shape when deforming heated wall elements in particular advantageously cooled.

The invention also relates to a device for performing the The method described above according to claim 10.

The molding station described above also makes it possible existing devices for the production of the so-called pillow packs retrofit so that the inventive method on such Devices can be run.

Further advantageous configurations of the subject matter of the invention result from the other subclaims.

An embodiment of a device according to the invention and individual parts this device and the method itself and one by the method Foil containers produced are described below with reference to FIGS. 1 to 5 explained in more detail.

Figur 1

eine Seitenansicht einer vollständigen Vorrichtung in Form einer Prinzipskizze,

Figur 2

eine Draufsicht auf den Gegenstand gemäß Figur 1,

Figur 3

einen Schnitt durch eine Formstation senkrecht zur Transportrichtung der Folie,

Figur 4

einen Horizontalschnitt durch den Gegenstand nach Figur 3, und

Figur 5

eine perspektivische Darstellung eines nach dem Verfahren und auf der Vorrichtung nach den Figuren 1 bis 4 hergestellten Folienbehälters.

Show it:

Figure 1

2 shows a side view of a complete device in the form of a schematic diagram,

Figure 2

2 shows a top view of the object according to FIG. 1,

Figure 3

a section through a forming station perpendicular to the transport direction of the film,

Figure 4

a horizontal section through the object of Figure 3, and

Figure 5

a perspective view of a film container produced by the method and on the device according to Figures 1 to 4.

In Figures 1 and 2, a storage station 1 is shown, in which a Film roll 2 is located, of which the film 3 in the initially vertical direction is withdrawn via a deflection roller 4. The axis of the deflection roller 4 lies horizontal.

On the way to two vertical guide rollers 5, one include narrow nip 6 between them, there is a folding station 7, in which the film 3 along a lengthwise direction of the film Folding line 8 is unfolded in a V-shape, to the point of congruence The film halves 3a located on both sides of the fold line 8 lie one on top of the other and 3b.

The first folding station 7 is followed by a first sealing station 9 Sealing tools 9a and 9b. The sealing tools are towards the Double arrows in Figure 2 movable and provided with heating elements 9c. The Sealing tools 9a and 9b are designed in such a way that through them strip-shaped first sealing seams 10 are formed which extend from the fold line 8 extend to the two film edges 11, which is not necessarily take place in a straight line and perpendicular to the fold line 8 and to the film edges 11 got to.

Through the first sealing seams 10 are within the film composite intermediate pockets 12 delimited, being between the first Sealing seams 10 filling openings 13 and wall elements 14 and 15 are formed be what will be explained in more detail with reference to Figures 3 and 4. On the sealing station 9 is followed by a molding station 16 with a hollow mold 17 there are two mold halves 17a and 17b in the direction of the two double arrows are movable in Figure 2. A pressure medium generator belongs to the forming station 16 18, which leads via a line system 19 to two nozzles 20, which from above into the Bags 12 can be inserted. So these nozzles are vertical arranged movably. The pressure medium generator 18 is in this case as Hot gas source 21 executed, which is indicated by a heating resistor 22 is. By blowing hot air into the pockets 12, these are defined deformed, which will be explained in more detail with reference to Figures 3 and 4.

The molding station 16 is in turn followed by a filling station 23, the one Dosing device 24 is assigned, which has two further nozzles 25 which in the pockets 12 still open at the top can be inserted. For this purpose, the Metering device 24 can be raised and lowered in the sense of the double arrow. To the Open pockets 12 in the area of the film edges 11 are on both sides of the Transport path of the film arranged in pairs suction cups 26, which the Pull wall elements 14 and 15 apart at this point so that the Nozzles 25 are inserted into the filling openings 27 formed thereby can.

It is understood that analog suction cups 26 also form station 16 are assigned to the pockets 12 in the area of the film edges 11 as far to be able to open that the nozzles 20 can be inserted. However, this is not shown in detail. For this purpose, the area of Forming station 16 mechanical guides and a sequence control provided, through which the mold halves 17a and 17b are first lowered, whereupon the Foil edges spread by the suction cups, not shown, and the nozzles 20th be introduced. The suction cups are then raised and / or withdrawn and the mold halves 17a and 17b likewise raised and closed and thereby brought into a position that will be explained in more detail with reference to Figures 3 and 4.

A second sealing station now again connects to the filling station 23 28, to which second sealing tools 28a and 28b belong, each with one Heating element 28c are provided. These sealing tools are also in the Movable sense of the double arrows in Figure 2. They are designed in the way that by the action of the sealing tools in the area of the film edges 11 second sealing seams 29 are formed which the pockets 12 through Bridging the gaps between the first sealed seams 10 bridge. In this way, a series of filled and all-round is created sealed film containers, which are subsequently a punching station 30 are supplied, which include punching tools 30a and 30b. These are in Direction of the double arrows of Figure 2 across the transport path of the film flexible and divide the hitherto endless container chain into individual ones Foil container 31. The cut lines run through the middle of the first Sealing seams 10, so that the film container 31 of equal width on both sides Sealing seams are formed. Such a film container is shown in FIG. 5 shown.

It goes without saying that in addition to the device according to FIGS. 1 and 2 Transport device 32 belongs, which is only indicated by an arrow. By this transport device becomes the film or film composite and finally the container chain is gradually transported through the device, the stride length being the dimensions and number of each corresponds to simultaneously manufactured film container. It is possible to carry the bags or to manufacture foil containers individually. It is still possible, as in the Figures 1 and 2 shown, the bags or film containers at the same time to produce twice (in two-up); but it is also possible at the same time produce three, four or more bags or film containers if the individual stations are equipped with appropriate multiple tools. Regarding the number of bags or 1 and 2 are to be evaluated only as examples.

The processes in the molding station 16 are now described with reference to FIGS. 3 and 4 explained in more detail: The initially still and superimposed Film halves 3a and 3b are introduced into the forming station 16, the Foil edges 11 lie in a plane through the dash-dotted line E-E is indicated. Then the film edges 11 on one by the Distance of the sealing seams 10 given length by the already described but not shown suction cups spread, so that between the spread film edges, the nozzle 20 of the hot gas source 21st can be introduced from above. After removing the suction cups the two mold halves 17a and 17b in that shown in Figures 3 and 4 Position driven, the film edges 11 between the nozzle 20 and Mold halves 17a and 17b are clamped in the manner shown. The both mold halves are for this purpose with an elastomeric lining 33 provided, which has the shape of a hollow half cylinder for each mold half, so that the nozzle 20 is tightly enclosed with the film edges.

The mold halves are each provided with a cooling device 34 which consists of Cooling channels within the metal halves formed. How 4 can be seen, are in the mold halves 17a and 17b numerous ventilation channels 17c through which the between the film and the Air trapped in mold halves can escape.

First of all, the film or pocket still has that in FIG. 3 in its central region Shape and position shown in dashed lines. With increasing penetration of hot compressed air through the nozzle 20, the wall elements 14 and 15th these pockets, however, roughly in the direction of the arrows the boundary walls of the hollow mold 17 are pressed until they are pulled out reach the position shown. At this moment the cooling effect of the cooled mold halves effective, and the film solidifies to a certain extent Requirement of the inner volume of the hollow form 17. The hot gas supply is now interrupted and the mold halves 17a and 17b are now in Pulled apart in the direction of the outer arrows, and then the Pulled nozzle 20 upwards. The now prefabricated bags can now be transported further in the direction of arrow 35 in FIG to the filling station 23.

Should the energy content used by the nozzle 20 to inflate Hot gas is not sufficient to adequately soften the To ensure wall elements 14 and 15, the nozzle 20 can be as coaxial Arrangement of two pipes are carried out, one of which Pipe for introducing the hot gas and the other is used for gas removal. In this case, a larger amount of hot air can be created realized pocket 12 are introduced because the blowing process is not timed is limited by the volume of the mold. Of course it is possible to carry out the same process using two juxtaposed nozzles or Pipelines.

It is of course also possible according to the above statements that Functionally summarize molding station 16 and the filling station 23. In this Case the drawing in Figures 3 and 4 also corresponds to that Filling station, i.e. the nozzle 25 of the filling station replaces the nozzle 20, and it is heated and / or pressurized in the respective pocket Filled product, which results in the same process can until the filling process by contacting the wall elements 14 and 15 on the Walls of the mold cavity is terminated. Because of warmed product of course a larger amount of heat is stored in the pockets of the The cooling process of the film material takes a correspondingly longer time individual consider whether in terms of the manufacturing capacity of the Device separate molding and filling stations according to Figures 1 and 2 should be applied or not.

Practically all liquid or flowable substances come in as filling material Question like liquids, pastes, powders flowing through a pipe get funded.

From Figure 5 it is also evident that the permanent or frozen deformation of the wall elements 14 and 15 on both sides of one imaginary plane through the fold line 8 and the sealing seams 10 and 29 is defined, a filling volume of considerable size is formed, which too leads to a very favorable ratio of filling volume to film area. Of the Filled film container is also stable, as can be easily done from a Consideration of Figure 5 results.

For foil containers for liquids, in particular for liquid containers Larger volume, it can be advantageous to improve the stability be part of their height with a cardboard sleeve or a comparable material in the form of a "support corset" to surround Bottom edge is on the same level or lower than the bottom of the Foil container. This cover is useful only in places and detachable connected to the film container so that the container parts after loosening them "Stapling" separate different disposal methods or To be able to supply recycling processes. The cover can also be used Contents etc. are printed.

Claims (16)

1. Process for the continuous production of foil containers (31) filled with a filling material by folding a sealable foil (3) in a V shape along a folding line (8) running in the transport direction of the foil until the foil halves (3a, 3b) lying on both sides of the folding line come to lie at least partially on one another, by subsequently joining the foil halves by strip-shaped first sealing seams (10), which extend from the folding line (8), are separated from one another and also have interstices (Z) between one another on the foil edges (11) and in the region of the folding line and form individual pockets (12) inside a container chain, by filling the pockets from above through the interstices (Z) between the foil edges (11) and the first sealing seams (10), by closing the pockets by sealing the foil halves by means of second sealing seams (29), which lie in the edge region of the foil halves and bridge said interstices between the first sealing seams (10), and by subsequently separating the filled pockets into individual foil containers (31) or containers connected to one another in groups, said foil containers having a suitable base region for standing upright, characterised in that after the first sealing seams (10) have been attached, the initially still flat wall elements (14, 15) of the pockets (12) lying one on top of the other are plastically deformed in opposing directions, at least in some parts, forming a space (D) between the wall elements, whereby the base region suitable for standing upright is constructed, and that the pockets (12) are filled either simultaneously or subsequently and are then closed.
2. Process according to Claim 1, characterised in that the plastic deformation of the wall elements (14, 15) of the pockets (12) is respectively restricted by a hollow form (17).
3. Process according to Claim 1, characterised in that the plastic deformation of the wall elements (14, 15) of the pockets (12) is performed by mechanical spreading members before filling.
4. Process according to Claim 2, characterised in that the plastic deformation of the wall elements (14, 15) of the pockets (12) is performed by vacuum deformation before filling.
5. Process according to Claim 1, characterised in that the plastic deformation of the wall elements (14, 15) of the pockets (12) is performed by inflation.
6. Process according to Claim 5, characterised in that the plastic deformation of the wall elements (14, 15) of the pockets (12) is performed by vacuum deformation by inflation by means of a heated gas before filling.
7. Process according to Claim 1, characterised in that the plastic deformation of the wall elements (14, 15) of the pockets (12) is performed by expanding by means of the pressurised filling material during filling.
8. Process according to one of Claims 2 to 7, characterised in that the spreading medium is heated to a temperature lying above the softening temperature of the foil material before being inserted into the pockets (12).
9. Process according to Claim 2, characterised in that the hollow form (17) is cooled during the deformation of heated wall elements (14, 15).
10. Device for carrying out the process according to Claim 1, with a storage station (1) for the foil (3), with a folding station (7) for folding the foil in a V shape along a folding line (8) running in the longitudinal direction of the foil until the foil halves (3a, 3b) lying on both sides of the folding line (8) come to lie at least partially on one another, with a first sealing station (9) with first sealing tools (9a, 9b) for forming the strip-shaped first sealing seams (10), which extend from the folding line (8), lie between the folding line (8) and the foil edges (11), and serve to define pockets (12) lying between them and with filling openings (27) lying at the top and with wall elements (14, 15) without forming a base seam, with a filling station (23) with a dosing means (24) for filling the pockets (12) from the top, with a second sealing station (28) with second sealing tools (28a, 28b) for closing the filled pockets by means of second sealing seams (29), which bridge the interstices (Z) between the first sealing seams (10) in the region of the filling openings (27), with a transport means (32) for transporting the foil through the device and with a stamping station (30) with stamping tools (30a, 30b) for separating individual foil containers (31) or containers joined together in groups, characterised in that the first sealing station (9) is connected downline of a forming station (16) for the plastic deformation of the wall elements (14, 15) in opposing directions and for constructing a base region of the pockets (12) suitable for standing the foil containers (13) upright, forming a space (D) between the wall elements (14, 15).
11. Device according to Claim 10, characterised in that the forming station (16) has at least one hollow form (17) for restricting the deformation.
12. Device according to Claim 11, characterized in that the hollow form (17) is provided with a cooling means (34).
13. Device according to Claim 11, characterised in that the hollow form (17) is a vacuum form.
14. Device according to Claim 10, characterised in that the forming station (16) has mechanical spreading members.
15. Device according to Claim 11, characterised in that the forming station (16) has a hot gas source (21) and at least one nozzle (20), which may be inserted into a respective pocket (12), whereby a seal may be formed between the nozzle and the hollow form (17).
16. Device according to Claim 11, characterised in that the forming station is constructed as a filling station (23) and has a means for heating and pressurising the filling material.

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