EP0781707B1 - Transversal sealing device for a vertical bag forming, filling and closing machine - Google Patents

Description

The present invention relates to a vertical tubular bag machine with the characteristics of the generic terms of claims 1 and 11.

Vertical form, fill and seal machines are known. They work in such a way that the enveloping material coming from a roll as a flat web the feed system is transported around the filling pipe. Of the Envelope is formed into a tube, after which the longitudinal seam is welded. After that, a lower one Cross weld seam generated, and the bag formed is over the filling tube is filled with the material to be packed. Finally, the upper cross weld is formed, and the finished, filled bag is separated from the tube.

In known vertical tubular bag machines proceeded so that a transverse seam welding device at the same time the lower cross weld seam around the filling pipe guided hose and the upper cross weld of the   filled bag below.

The fill tube can be round or rectangular. The term "welding" used here is intended to mean both Welding as well as sealing the enveloping material, with both a continuous seam and with interrupted seam. Commercially available envelopes come and common films for use, for example polypropylene, Polyethylene, aluminum combinations, paper and others Multi-layer films in a wide variety of bag formats can be processed. In addition to the Welding devices can be corresponding folding devices, Air extractors or other elements, for example Knives may be provided.

Many well-known vertical Tubular bag machines have the disadvantage that this the upper cross welds only in a relatively large Arrange the distance from the product surface so that the tubular bags are roof-shaped in the upper area are. This is due to the fact that in manufacturing the upper cross weld seam that is hanging freely on the filling pipe The film is exposed to tension by retracting the welding jaws becomes. In other words, by retracting the Welding jaws must be made up of foil material from below, to bring the two sides of the film together over the contents to be able to. As a rule, when merging the film sides only angles up to achieve at 45 °, i.e. a smooth fit of the foils the filling material is not reached. Rather, one remains relative large air space above the product.

It is also known to provide appropriate air extractors, which removes the unwanted air, however even with these measures, no close adjustment of the   Foil in the upper area of the tubular bag on the contents reached. Disadvantages had to be accepted, that the packaged contents move in the tubular bag could, which caused stacking problems etc.

In order to remedy this and to achieve that the film as close as possible to the formed body from the Filled goods nestle, you go from the FR-A2 251 476 known device that has the features of the preamble of claims 1 and 11, so that the Container then, when the welding jaws of the welding position approach, exposed to a vacuum so that the film in the container around the formed body of powdered Material hugs. However, this is relatively expensive additional facilities required.

The invention has for its object a vertical To create tubular bag machine of the specified type with the tubular bag can be produced in a particularly simple manner are the smallest possible air space above the product surface exhibit.

a. die Quernahtschweißvorrichtung in zwei getrennte Einheiten aufgeteilt ist, von denen eine die untere und eine die obere Querschweißnaht eines Schlauchbeutels erzeugt;

b. die Maschine eine Hebevorrichtung für den gefüllten, noch nicht mit der oberen Querschweißnaht versehenen Schlauchbeutel aufweist;

c. die Einheit zur Erzeugung der oberen Querschweißnaht auf- und abbewegbar ist; und

d. die Hebevorrichtung und die Einheit zur Erzeugung der oberen Querschweißnaht so angetrieben und/oder gesteuert sind, daß die Einheit und der gefüllte Schlauchbeutel zur Erzeugung der oberen Querschweißnaht relativ zur Einheit zur Erzeugung der unteren Querschweißnaht und zum Füllrohr angehoben werden.

This object is achieved according to a first solution of the invention in a tubular bag machine of the type described above in that

a. the transverse seam welding device is divided into two separate units, one of which produces the lower and one the upper transverse weld seam of a tubular bag;

b. the machine has a lifting device for the filled tubular bag which has not yet been provided with the upper transverse weld seam;

c. the unit for generating the upper transverse weld seam can be moved up and down; and

d. the lifting device and the unit for producing the upper cross weld are driven and / or controlled in such a way that the unit and the filled tubular bag for producing the upper cross weld are raised relative to the unit for producing the lower cross weld and to the filling pipe.

The solution according to the invention is therefore based on the principle that the filled, not yet with the upper cross weld provided tubular bag together with the unit for generation the upper cross weld relative to the filling pipe and raised to the unit for generating the lower cross weld around the envelope forming the tubular bag to relax and in the area of the upper cross weld arrange more enveloping material so that the enveloping material in the essentially stress-free from the unit to the generation the upper cross weld (welding or sealing jaws) can be guided radially inwards. Because in this area enough material is available, the Fold the wrapper tightly onto the product surface so that almost no air space remains above the product surface. The upper cross weld seam can therefore be special in one short distance from the product surface become.

To the above described two movements of the lifting device and the unit for producing the upper cross weld To achieve both elements can be the same Drive or have different drives. The speeds with which both elements are moved, can be the same or different. There is one here A series of special cases, which are explained below.

In the simplest case, the lifting device and the unit so driven to produce the upper cross weld and / or controlled that both the same distance be raised. In this case there is no relative movement between the upper generation unit Cross weld seam and the product surface in the vertical direction instead of. But that means that in this embodiment the unit for generating the upper cross weld   must be located relatively close to the product surface, around a close-fitting fold in this area to reach the cross weld seam attached to the product surface. This embodiment is therefore essentially suitable only for machines where almost always the same Filling level can be ensured, which at relative dimensionally stable filling materials and / or very precisely working Machines is the case. It goes without saying that in this case the unit for creating the upper cross weld approaches the side of the tubular bag and the Envelope coming from the side over the product surface sets. With filling levels of different heights problems can occur.

In a further embodiment of the invention, the The lifting device is the rule for practical use and the unit for producing the upper cross weld driven and / or controlled so that the unit only raised over part of the lifting distance of the lifting device becomes. In other words, in this embodiment takes place during the lifting movement of the filled tubular bag a relative movement between the product surface and the unit for generating the upper cross weld in Vertical direction instead. The speed of the lifting device executed lifting movement is greater than that of the unit for producing the upper cross weld, because the lifting device covers a longer distance. It is understood that in this embodiment the unit to create the upper cross weld in the lower Position of the lifting device and the unit at a distance must be arranged above the product surface so that in the upper end position is the unit for generating the upper Cross weld seam lies close to the product surface. At In this embodiment, the unit for generation is thus eliminated the upper cross weld from above against the   Product surface, since it is also during the lifting movement moved radially inward. The wrapper can therefore be almost ideally be folded inward with absolutely no tension.

It is understood that any combination of the two Embodiments shown above are possible.

A solution in which the lifting device is particularly preferred is raised over a distance that is the width of the tubular bag. This solution can work for both of the cases shown above apply. in the the former case then becomes the unit for generation the upper cross weld over a distance that corresponds to the width of the tubular bag. In the second case becomes the unit for creating the upper cross weld preferably raised over a distance that is half Corresponds to the width of the tubular bag. It has already been mentioned that the unit for generating the upper cross weld preferably so driven and / or controlled is that they move radially inward during the upward movement emotional. At the conclusion of the upward movement of the lifting device and the unit for producing the upper cross weld has the unit for creating the upper cross weld also reached its end point of inward movement, so that the folding process of the filler is completed and the cross weld can be created. With in other words, the two welding or sealing jaws of the Then have a unit for generating the upper cross weld reaches its most radially inner point and can weld the two sides of the casing together or seal.

The unit for generating the upper cross weld can be designed as a pure welding or sealing device   and pork or sealing jaws to produce a continuous Weld or sail seam or to produce a have interrupted seam. Preferably the unit is but provided with a suitable folding device, the one or more folding members, for example side butterflies, may include. Such folding organs are known. Hereby there is a perfect fold in the area of the upper cross weld ensured.

Of course you can, for example, two cross welds can be arranged one above the other to form a handle. Here is a suitable separation device Opening or slot in the area between the two Cross welds made. It is always essential that the envelope is folded to match the level, in order to achieve packaging that is as air-free as possible. How mentioned, the air space above the product should be minimized, in order to achieve a particularly stable product, which means better packing density and better Stackability go hand in hand.

In a development of the invention, the unit for generation the upper cross weld relative to the lifting device adjustable in height. In this embodiment, can react flexibly to level fluctuations, i.e. the unit for generating the upper cross weld seam can through height adjustment, for example depending on a sensor supplied by a level sensor Signal to be adapted to the respective level, around a fold close to the surface of the filling material to reach.

a. unterhalb der Quernahtschweißvorrichtung eine Faltvorrichtung für den Hüllstoff am oberen Schlauchbeutelendbereich vorgesehen ist;

b. die Maschine eine Hebevorrichtung für den gefüllten, noch nicht mit der oberen Querschweißnaht versehenen Schlauchbeutel aufweist;

c. die Faltvorrichtung auf- und abbewegbar ist; und

d. die Hebevorrichtung und die Faltvorrichtung so angetrieben und/oder gesteuert sind, daß die Faltvorrichtung und der gefüllte Schlauchbeutel zum Falten des Hüllstoffs relativ zur Einheit zur Erzeugung der Querschweißnähte und zum Füllrohr angehoben werden.

The above object is achieved according to a second solution of the invention in a tubular bag machine of the type specified in that

a. a folding device for the enveloping material is provided at the upper end of the tubular bag below the transverse seam welding device;

b. the machine has a lifting device for the filled tubular bag which has not yet been provided with the upper transverse weld seam;

c. the folding device can be moved up and down; and

d. the lifting device and the folding device are driven and / or controlled in such a way that the folding device and the filled tubular bag for folding the wrapping material are raised relative to the unit for producing the transverse weld seams and to the filling tube.

This embodiment is essentially like that above described embodiment formed. Deviating is essentially only that instead of moving up and down Unit for generating the upper cross weld seam one up and down movable folding device is provided. The Unit for generating the upper cross weld seam can be used this embodiment in a conventional manner together with the unit for generating the lower cross weld be, i.e. stationary in the vertical direction. Only the folding device is filled together with the Tubular bag raised so that the wrapper in the top Area of the tubular bag without tension on the product surface can be folded. The real top Cross weld seam is then created over the folding device, i.e. in this area the tubular bag has a somewhat longer flag than the one described above Embodiment. However, the air is expelled by folding pressed out this area, so that despite the higher order upper transverse weld seam a relatively dimensionally stable Pack is reached.  

Otherwise, all variants of the above also apply described embodiment to the present embodiment to. As mentioned, this leads to the first Embodiment as a unit for producing the upper cross weld designated device a pure folding process through, while the upper cross weld in conventional Way can be generated by a device that forms both the lower and the upper cross weld. In this embodiment, several upper Cross welds are generated; the folding device ensures in any case for a close contact of the wrapping material on the Surface of the product and thus effects the desired air pressure.

The folding device itself can preferably have two folding jaws have and be designed like that welding unit described above. However, it can other embodiments of folding devices use Find. It is only essential that the folding device in Connection with the filled tubular bag accordingly is raised.

Figur 1

eine schematische räumliche Darstellung eines Teiles einer vertikalen Schlauchbeutelmaschine, wobei die Hebevorrichtung und die Einheit zur Erzeugung der oberen Querschweißnaht in einer ersten abgesenkten Stellung dargestellt sind;

Figur 2

eine entsprechende Darstellung wie Figur 1, bei der jedoch die Hebevorrichtung und die Einheit zur Erzeugung der oberen Querschweißnaht in einer zweiten angehoben Stellung dargestellt sind;

Figur 3

einen Vertikalschnitt durch einen Teil der vertikalen Schlauchbeutelmaschine der Figuren 1 und 2, wobei die linke Hälfte der Figur den abgesenkten und die rechte Hälfte der Figur den angehobenen Zustand der Hebevorrichtung und Einheit zur Erzeugung der oberen Querschweißnaht zeigt;

Figur 4

eine entsprechende Darstellung wie Figur 3, wobei jedoch eine andere Ausführungsform der Erfindung gezeigt ist;

Figur 5

einen Horizontalschnitt durch die Einheit zur Erzeugung der unteren Querschweißnaht; und

Figur 6

einen Horizontalschnitt durch die Einheit zur Erzeugung der oberen Querschweißnaht.

The invention is explained in detail below using exemplary embodiments in conjunction with the accompanying drawing. Show it:

Figure 1

is a schematic spatial representation of a part of a vertical tubular bag machine, wherein the lifting device and the unit for producing the upper cross weld are shown in a first lowered position;

Figure 2

a representation corresponding to Figure 1, but in which the lifting device and the unit for producing the upper cross weld are shown in a second raised position;

Figure 3

a vertical section through part of the vertical tubular bag machine of Figures 1 and 2, the left half of the figure shows the lowered and the right half of the figure the raised state of the lifting device and unit for producing the upper cross weld;

Figure 4

a representation corresponding to Figure 3, but showing another embodiment of the invention;

Figure 5

a horizontal section through the unit for producing the lower cross weld; and

Figure 6

a horizontal section through the unit for generating the upper cross weld.

Figure 1 shows the essential parts of a vertical Flow pack machine for the present invention are of interest. A suitable wrapper 2, for example made of polyethylene, is via a feed system, (not shown) placed around a rectangular filling tube 1, so that a hose 3 is formed. Suitable funding facilities 4, which are shown as endless belts, move the hose cyclically in the figure from top to bottom. A longitudinal seam welding device 5 welds the edges the wrapper together.

At a short distance from the lower end of the filling pipe 1 is a unit 6 for producing a lower cross weld   (Bottom seam) arranged. This unit has two side butterflies 8 assigned. The unit 6 for generating the lower Cross weld seam has two welding jaws 7, the by a radially inward movement the two Press sides of the hose 3 formed against each other and weld them together. Together with the welding jaws 7 the side folders 8 have moved inwards, so that a perfect conclusion at the bottom of the Tubular bag results.

Figure 2 shows the welding jaws 7 in the retracted and the side folder 8 in the retracted state.

After the creation of the lower cross weld seam, the filling material is filled into the still open hose 3. The filling device with a suitable weighing device is not shown and does not form part of the present invention represents.

Simultaneously with the creation of the lower cross weld becomes the upper cross weld of the one below Tubular bag generated. This upper cross weld seam forms the upper end of the tubular bag then finished, the then separated from the hose via a suitable separation device becomes. As shown in Figure 1, there is a unit 9 for producing the upper transverse weld seam (head seam) under the unit 6 for generating the lower cross weld. The unit 9 also has two radially inwards and outwardly movable welding jaws 10. This unity 9 a side folder 11 is also assigned.

The one with a cross weld at the lower end and tubular bag filled with filling material 13 rests in a lifting device 12. To produce the upper cross weld the tubular bag with the filling material 13   and the unit 9 for producing the upper cross weld raised so that the position shown in Figure 2 is reached becomes. The two drive during the stroke movement Welding jaws 10 of the unit 9 for producing the upper one Cross weld seam radially inwards so that the enveloping material is folded radially inwards. At the end of the stroke movement the welding process takes place. The Seitenfalter 11 (only shown from one side) is moved inwards accordingly been. The fact that both the tubular bag with contents as well as the unit 9 for performing the welding process is a tension-free folding of the Envelope in the upper tubular bag area and a tension-free Welding possible, so that the Envelope as close as possible to the surface of the product bring up. It can therefore be extremely dimensionally stable packs getting produced.

After the upper cross weld has been created, the separation takes place of the finished tubular bag from the tube. Of the The tubular bag is noticeable when the lifting device is opened a suitable belt for removal.

Figure 3 shows the operation of the lifting device 12 and the unit 9 for generating the upper cross weld in individual in a first embodiment. On the left Side of the figure are the lifting device 12 and the unit shown in the lowest position while on the shown on the right side of the figure in the uppermost position are. To carry out the folding and welding process lifts the lifting device 12 is provided with the filling material 13 Tubular bag by the distance B, which is the width of the Tubular bag corresponds to. At the same time also the unit 9 for producing the top cross weld raised by distance B, i.e. the one in the figure right and left welding jaws 10 are raised. While   the stroke movement of the unit 9 drive the two welding jaws 10 radially inward and get into the one on the right Half of the figure shown innermost end position, in the the welding process is carried out. In this position, which corresponds to the uppermost position are the Welding jaws 10 slightly below the welding jaws 7 the unit 6 for producing the lower cross weld. In the lowest shown in the left half of Figure 3 Position, the welding jaws 10 are only slightly over the surface of the filling material 13 so that the folding process of the enveloping material essentially by a purely lateral Movement of the welding jaws 10 is carried out. There both the lifting device 12 and the unit 9 to move the distance B, a single drive 14 for both parts are used. Figure 3 finally shows nor the lifting device 12 in the opened state.

The embodiment shown in Figure 4 corresponds to essential of that of Figure 3, with the only difference, that here the lifting device 12 and the unit 9th to create the upper cross weld by different Stretch and therefore at different speeds move. In this embodiment, the Lifting device 12 as in the embodiment in FIG. 3 by the route B, while the unit 9 is only the Line B / 2 moves. In the bottom shown in Figure 4 Position of the lifting device 12 and the unit 9 is the Unit 9 at a distance of B / 2 from the product surface arranged. As shown in the right half of Figure 4, this distance is in the uppermost position of the unit 9 and the lifting device 12 almost consumed. Also here the two welding jaws 10 of the unit 9 move during lifting radially inwards into the in the right half of Figure 4 end position shown. One notices, that the welding or folding jaws in this   Place the embodiment from above on the product surface and do not perform an exclusive sideways movement as in the embodiment of Figure 3. The envelope can thus tight to the product surface without tension be adjusted.

Figure 5 shows a cross section through the machine in the area the unit for generating the lower cross weld. The two are in the upper half of the figure Welding jaws 7 shown in the closed position, while in the lower half in the open position are shown. A drive device 15 ensures that corresponding transverse movement of the welding jaws 7. You can see further triangular butterfly 8, which in the figure of up and down to move the wrapper in appropriately fold.

Figure 6 shows a cross section of the machine in the area of Unit 9 for producing the upper cross weld. Also here are the two welding jaws in the upper area of the figure 10 shown in the closed state while it are shown in the lower area in the open state. One notices also the hanging hose 3 through the Welding jaws 10 are folded radially inwards from both sides becomes. A corresponding drive device 16 ensures the in and out movement of the welding jaws 10. On Side folder 11, which consists of two elements, is also shown.

The embodiment described above also applies to the embodiment of the invention, in which instead of Liftable unit to create the upper cross weld a folding device is provided. This will be the Element 9 formed by the folding device, and the element 6 is by a unit for generating the lower and the   upper cross weld. Otherwise, it is the same Structure and the same functionality exist.

In the case of those described above and in FIGS. 1 to 6 Embodiments shown was assumed that Unit 6 only the lower cross weld seam (bottom seam) of a not yet filled tubular bag. It understands however, that this unit 6 next to this lower Seam (bottom seam) also an upper seam (head seam) of the underneath Manufacture the existing tubular bag as standard can. For this purpose, the unit 6 preferably has two double jaws, the two welding jaws arranged one above the other exhibit. This is in addition to the invention made with the unit 9 upper cross weld a further transverse weld seam arranged above it is produced. There is then a separation between the two by the Double jaws 7 produced cross welds.

In principle, therefore, the unit 6 can only the lower one Cross weld seam (bottom seam) of a not yet filled Tubular bag or this lower cross weld and an additional upper cross weld seam (head seam) one generate the filled tubular bag underneath. This is independent of that generated with the unit 9 upper cross weld or independently of one instead this unit provided folding unit.

In addition, with the machine according to the invention additionally provided knives above the upper cross weld remaining bag flag shortened as desired become.

Claims (12)

1. A Vertical bag forming, filling and sealing machine comprising a feed system for a wrapping web forming the flexible tube bags, a filling tube around which the wrapping web is fed for the formation of a flexible tube and which serves for filling a material which is to be packed into the tube, a longitudinal seam welding device, a cross seam welding device for the formation of a lower and an upper cross weld seam on a tube, and a lifting device for the filled bag which is not yet provided with the upper cross weld seam, characterized in that

   a. the cross seam welding device is divided into two separate units (6, 9) independent from one another of which one (6) produces the lower and one (9) produces the upper cross weld seam of a tube bag;

   b. the unit (9) for producing the upper cross weld seam is movable up and down relative to the unit (6) for producing the lower cross weld seam; and

   c. the lifting device (12) and the unit (9) for producing the upper cross weld seam are driven and/or controlled in such a manner that the unit (9) and the filled tube bag are lifted relative to the unit (6) for producing the upper cross weld seam and to the filling tube (1) for producing the upper cross weld seam.
2. The machine according to claim 1, characterized in that the lifting device (12) and the unit (9) for producing the upper cross weld seam are driven and/or controlled in such a manner that both are lifted for the same distance.
3. The machine according to claim 1, characterized in that the lifting device (12) and the unit (9) for producing the upper cross weld seam are driven and/or controlled in such a manner that the unit (9) is lifted only for a part of the stroke distance of the lifting device (12).
4. The machine according to one of the preceding claims, characterized in that the lifting device (12) is lifted for a distance which corresponds to the width (B) of the tube bag.
5. The machine according to claim 3 or 4, characterized in that the unit (9) for producing the upper cross weld seam is lifted for a distance which corresponds to half of the width (B/2) of the flexible tube.
6. The machine according to one of the preceding claims, characterized in that the unit (9) for producing the upper cross weld seam is provided with a folding device (11).
7. The machine according to one of the preceding claims, characterized in that the unit (9) for producing the upper cross weld seam is driven and/or controlled in such a manner that it moves radially inwardly during upward movement.
8. The machine according to one of the preceding claims, characterized in that the unit (9) for producing the upper cross weld seam is provided with a cutting device for the wrapping web.
9. The machine according to one of the preceding claims, characterized in that the unit (9) for producing the upper cross weld seam is adjustable in its height relative to the lifting device (12).
10. The machine according to one of the preceding claims, characterized in that in the lower position of the lifting device (12) the unit (9) for producing the upper cross weld seam is spaced from the surface of the filling material by a distance which is taken up by the lifting movement of the lifting device (12) and of the unit (9).
11. A vertical bag forming, filling and sealing machine comprising a feed system for a wrapping material forming the flexible tube bags, a filling tube around which the wrapping material is fed for the formation of a flexible tube and which serves for filling of the material which is to be packed, a longitudinal seam welding device, and a cross seam welding device for the formation of a lower and an upper cross weld seam at a flexible tube bag, and a lifting device for the filled tube bag which is not yet provided with the upper cross weld seam, characterized in that

    a) a folding device for the wrapping material is provided below the cross seam welding device at the upper end portion of the tube bag;

    b) the folding device is movable up and down relative to the unit for producing the upper cross weld seam; and

    c) the lifting device and the folding device are driven and/or controlled in such a manner that the folding device and the filled tube bag are lifted relative to the unit for producing the cross weld seams and to the filling tube for folding the wrapping material onto the surface of the filling material.
12. The machine according to claim 11, characterized in that the folding device has two fold jaws.