EP1167191A1 - Method and apparatus for folding back and attaching the bottom seam of a self-standing bag in a bag packaging machine - Google Patents

Abstract

The procedure to lay round and fasten the bottom seam of a flat bottomed bag includes folding and sealing the bottom (27) of the next bag (28) to be filled together with folding and sealing of the top seam of the previous bag (30), forming a connecting link (31) between them. The link is then separated by the cutting movement of a knife, with a transverse sealing device (10) closed, after which the knife returns to its starting position. The transverse sealing device is then opened and the previous bag freed by movement of one of the transverse sealing tools (18,19), forming a gap between both tools which is at least as large as the bottom seam width. An Independent claim is included for a device for carrying out the proposed procedure.

Description

The present invention relates to a method for using the bottom seam on a Folding organs equipped pouch packaging machine manufactured stand pouch fold and pin to the bottom and a device for carrying out the Method as defined in the preamble of claims 1 and 2, respectively.

It is in the manufacture of bags on the known bag packaging machines known to also produce so-called "stand-up pouches". Stand-up pouches are, in the sense this invention, such bags, which, starting from a flexible film web, on a likewise known bag packaging machine equipped with folding members getting produced. They are characterized in that they have a flat bottom have, in the sense of a footprint, and are therefore able to stand upright Take position and keep stable. Bag packaging machines like those for the production of such stand-up pouches are best in practice known, as well as the corresponding stand-up pouches. It’s machines, which are also known in the patent literature (see, inter alia, DE-C 303 1399) and are equipped with special folding elements. Such bag packaging machines basically consist of a housing in which the working elements are fixed. The most important organs are the film web feed with film roll and guide and conveyor roller, the so-called format set with filling tube for filling the product in from a flexible film web to be manufactured bag and a shape shoulder, about which the film web is pulled to form a tube, a Longitudinal closing device to produce the longitudinal seam of the bag and a Cross closure device to create the cross seam, i.e. the bag too closure. To these organs, which are present in every bag packaging machine are, come, in the case of the production of stand-up pouches, additional, too known folding organs, which have the function of the bag after the filling tube to deform and give it a rectangular footprint. In such a case the end of the filling tube is not round (as is usual for normal "pillow bags"), but shaped rectangular, which helps to produce the stand-up pouch. That is all however state of the art and is carried out in practice on an ongoing basis and therefore needs not to be explained in detail here. The present invention is concerned not with the formation of the stand floor and with the necessary facilities in a bag packaging machine, which must be considered known, but specifically with the folding and tacking of the bottom seam to the bottom itself, so that the bottom results as flat as possible and the bottom seam does not interfere when placing the bag on a surface. It is about So here it’s just a matter of tacking the bottom seam to the bottom of the bag.

According to the current state of the art, which is known from practice, it is common for the The bottom seam is folded using sliding plates or with an air jet (so-called air allocation). With this method it is possible fold the bottom seam, but not pin it to the bottom of the bag. Further the expert knows from a known bag packaging machine (so-called Butler 3 from PMB-UVA, NL), a reassembly and attachment technology, which is that after the cross-lock device is made the bottom seam and the previous bag has been dropped, the entire format set is pneumatic is lowered onto the cross-locking device. The fact that the closing device is warm, the bottom seam is folded over and tacked to the bottom, because the film material becomes thermally soft (it is usually a Plastic film). This known method, which in principle is correct Unfortunately, there are still some major disadvantages which are given by the shift of the entire format set. The corresponding device is complicated and expensive, the speeds that can be achieved are deep (as a result of the relatively large masses that have to be moved), each type of format set requires an adjustment of the lowering and lifting movement the same and, what is particularly serious, the film is localized by high Tensions heavily stressed, since the film pull-off belts are not taken along with the format set become (which would complicate the whole thing) and thus on the strap high tensile stresses are generated. In addition there are difficult to solve Synchronization problems, since the vertical movement of the format set is pneumatic is realized, and everyone knows that such a drive is always imprecise control is.

The present invention aims to overcome the above drawbacks of the prior art To fix technology and to propose a method and the corresponding device, which is the production of a perfectly folded and tacked bottom seam allow a stand-up pouch, and this without restrictions on the production of Machine and with high precision the movements of the elements involved Machine. The machine should also be simple and cheap.

All of these purposes are carried out using a procedure for transferring and pinning the Loot (near a stand-up pouch according to the preamble of claim 1 and achieved by the features of the characterizing part of claim 1. The for the Implementation of the inventive method necessary device, according to the The preamble of claim 2 is characterized by the features of the characterizing part of the Claim 2 characterized.

The main feature of the invention, both as a method and as a device, is in the vertical movement of the locking tools between one lower closing position and an upper tacking position and vice versa. thanks this movement - and assuming a systematic folding of the bottom seam - you can attach the bottom seam precisely and quickly to the bottom of the bag without - as known from the prior art - lower the entire format set and to have to lift.

The invention will now be illustrated in more detail using an illustrated embodiment, further advantages are to be clarified by the description.

Fig. 1

eine schematische Darstellung der Hauptelemente einer Beutelverpackungs-Maschine, wie sie für die Realisierung des erfinderischen Verfahrens ausge-bildet ist;

Fig. 2a und 2b

eine Frontansicht bzw. einen Grundriss der für die Bildung von Standbeuteln nötigen Arbeitselemente der Maschine in schematischer Darstellung und im offenen Zustand der Querverschliessvorrichtung gezeigt;

Fig. 3a und 3b

die gleiche Darstellung der Fig. 2a und 2b, aber im geschlossenen Zustand der Querverschliessvorrichtung, d.h. während der Nahtbildung, gezeigt;

Fig. 4a bis 4h

zeigen die einzelnen Verfahrensschritte des erfinderischen Verfahrens in in symbolischer Darstellung.

The figures show:

Fig. 1

a schematic representation of the main elements of a bag packaging machine, as it is designed for the implementation of the inventive method;

2a and 2b

a front view or a plan view of the working elements of the machine necessary for the formation of stand-up pouches shown in a schematic representation and in the open state of the locking device;

3a and 3b

the same representation of Figures 2a and 2b, but shown in the closed state of the cross closure device, ie during the seam formation;

4a to 4h

show the individual process steps of the inventive method in a symbolic representation.

1 first allows a summary description of the bag packaging machine, however shown only in the main elements which are necessary for the implementation of the inventive method are necessary and characterize the inventive device. In particular, the base frame of the machine, the film feed with the Foil roll and the scale have been omitted, as well as all elements of a conventional Bag packaging machine which are known to any person skilled in the art and therefore do not need to be described separately here.

In Fig. 2, 1 is the shoulder of a so-called format set 2, on which the Packaging film is converted from a flat film to a tube. 3 with a funnel is designated, which with the filler tube 4 below connected is. The hopper 3 receives the material to be packaged from the balance (not shown) and forwards it to the filler pipe. The filler pipe 4 is open at the bottom and can have a square cross section in its lower part exhibit; this is not a requirement if the machine is for normal production Pillow bags are provided. On the other hand, if the machine (as in the case of the present Invention) is provided for the production of stand-up pouches, then the filler tube 4 at its lower, open end 5 a rectangular cross section, because to create better conditions for a stand-up pouch. In such a case So the cross section of the filler tube changes from its upper part to its lower part gradually from the round to the rectangular shape. However, this is for the present invention is not relevant.

The entire format set 2 is fixed on a yoke 6, which has two vertical supports Columns 7 (only one of them is visible) connects to one another and no further shown frame of the machine belongs.

Guides 8 are placed parallel to the vertical columns 7, in such a way that each column 7 has its guide 8. In the guides 8 are a longitudinal locking device 9 and a cross locking device 10 out. Such Devices are known in principle from the prior art, as in any conventional Bag packaging machine available. The longitudinal closing device 9 consists essentially of two tools, one heated, vertical lying tool 11 and a fill pipe counter holder 12. The two tools 11 and 12 lead a common, opposite movement to the filling pipe 4 out. Their function is to seal the longitudinal seam of the bag. All of this is conventional and has nothing in common with the present invention. The method, like the tools 11 and 12 of the longitudinal closing device synchronously with one another moving to and from each other is not critical to the present invention. In principle, all known methods can be used for this purpose use, although of course the most modern drive technologies are also advantageous here with e.g. Servomotors and direct drive should be used. Such a suitable drive method is in a separate patent application same applicant, to which we want to refer here. After this The tools 11 and 12 are system by means of parallel guides 13 and 14 guided, with the guides 13 and 14 (usually two per tool) as racks 15 are formed and each driven by a pinion 16. On Motor 17 (preferably a digital synchronous motor with fiber optic cable for real-time operation) e.g. drives each pinion 16. However, it should be emphasized that others Drive methods for tools 11 and 12, e.g. conventional mechanical Methods with cam disks or pneumatic or hydraulic drive are conceivable are, provided that they are drive systems that have the necessary kinematic properties to achieve a high output of the machine exhibit.

The transverse closing device 10 is also, in principle, of conventional construction, to however to a point which plays a crucial role in the context of the present Invention plays and therefore deserves special attention. The cross locking device 10 basically consists of two horizontal, heated tools 18 and 19 conventional design with folding elements, which are in a horizontal Plane can be moved to and from each other using suitable drive means. These tools 18 and 19 can also be equipped with guides, racks and pinions, similar to the tools 11 and 12 are driven. For them, too, is the way they are driven to the closing movement, not essential to the invention, provided it is an efficient and low-mass method.

However, what is critical in the context of the present invention is the fact that the cross closure device 10 has means for movement of the cross locking tools also in the vertical direction to open and close Downward movement, is equipped. This, to the actual closing movement in The horizontal level additional movement is critical to the realization of the inventive goals, as will be shown later. A preferred type of this additional movement device is shown in Fig. 1 as an example.

The tools 18 and 19 are with horizontal guides (only the guide 20 of the tool 19 is, however, shown in Fig. 1), which in one Carriages 21 are let in. The carriage 21 is a plate which in the two vertical, parallel guides 8 is guided. With two pinions, not shown, which engage in a corresponding rack of each guide 8 can now Carriage 21 by means of a motor 22 up and down, that is up and down, be moved by motor. This vertical movement of the locking device 10, which are basically realized with other drive methods can, is critical in the present invention as it is closer to be explained. It is understood that such an up and down movement with drive means other than those described can be implemented, the described Solution, as experience has shown, offers the important advantage of mass poverty.

Figures 2a and 2b show in a detailed representation the specific for Forming a stand-up pouch necessary for the machine's work organs: this affects above all the cross-closure device 10, which must be equipped with folding members.

FIGS. 2a and 2b show the cross-locking device in the open state. With 18 and 19, the locking tools are further designated, while with 23 and 24 the folding organs are indicated. These consist of folding corners 25 and folding fingers 26. The folding members move transversely to the closing tools 18 and 19, driven by suitable drive elements in synchronism with the Closing tools 18 and 19. The folding corners 25 form the for molding of the bottom of the next bag folds, while the folding fingers 26 upside down fold the previous filled bag. This technique of forming a stand-up pouch is known to every specialist and does not need to be specifically explained here.

The folding members 25 and 26 and the closing tools are shown in FIGS. 3a and 3b 18 and 19 in the closed position, i.e. during the sealing of the Bottom seam of the next bag and the top seam of the previous bag, shown.

Figures 4a to 4h now serve to explain the inventive method steps. Only the elements necessary to describe the process are shown are, the folding members 23 and 24 (with the folding fingers 26 and the folding corners 25) have also been omitted because they are narrow, as shown in Figures 2 and 3 are connected to the transverse locking device 19 and in particular their must follow vertical movement. The procedure relates to the reallocation and Attach the bottom seam to the bottom of a stand-up pouch and therefore does not fall into it Concerning the formation of the stand-up pouch itself. This happens namely after conventional Type and is not the subject of this invention.

4a shows the first step of the method. In this step the Bottom 27 of the next stand bag 28 to be refilled, folded and closed, what together - in one go - with the folding and closing of the Head seam 29 of the previous stand-up pouch 30 already filled occurs. Doing so a connecting web 31 between the previous stand-up pouch 30 and the next stand-up pouch 28 is formed.

4b shows the second step of the method. By moving the cutting knife 32, which is installed in the cross-closure device 10, the Connecting web 31 separated. The two standing bags 28 and 30 are separated with the transverse closing device 10 closed.

4c shows the third step of the method. This consists in the repatriation of the Knife 32 in its starting position (i.e. from right to left in Fig. 4c) at still closed transverse locking device 10. In this position, the previous one Stand-up pouch 30 still held.

In the next (fifth) step (shown in FIG. 4d), the cross-locking device is now 10 opened, with which the previous standing bag 30 freed and dropped becomes. It has already disappeared in FIG. 4d. The step is that one of the two locking devices (e.g. tool 18 in Fig. 4d) in the sense of its Distance from the other tool. It arises immediately, between the two tools 18 and 19, one gap, at least as large as the bottom seam width.

Now, in the next step shown in FIG. 4e, the second cross-locking tool (Tool 19 in Fig. 4e) in the same direction of movement of the previous step moved tool 18, namely (as shown in Fig. 4f is) up to an at least approximate closure of the previously formed one Gap 33 between the two cross closing tools 18 and 19. By this movement becomes the bottom seam 34 of the next stand-up pouch 28, as a result the entrainment by the last shifted cross-locking tool 19. 4f clearly shows that, in this position, the bottom seam 34 to the right inclined, i.e. "turned over". Now all she needs is on floor 27 of the next Bag 28 to be pinned, what happens in the next step and is to be regarded as the core of the invention.

Was it previously known to tack the bottom seam 34 to the bottom 27, the whole bag 28 to lower a small distance and the bottom 27 on the to deposit the upper surface of the two tools 18, 19 of the cross-locking device 10, this movement is now happening according to the present invention vice versa. Instead of lowering the bag 28, the entire cross-sealing device is new 10, or both tools 18 and 19 together, in closed Condition raised by the distance necessary to the top Surface of the cross locking tools 18, 19 with the base 27 of the to bring the next pouch 28 still in the filling position into contact (see Fig. 4g). Thanks to the fact that tools 18 and 19 are warm the bottom seam 34, under the influence of heat, on the bottom 27 of the bag 28 firmly attached, in the sense of a fusion or a bond. The precision the movement of the closing device is very important for the implementation a perfect attachment. The most modern drive and control systems help here to create the necessary conditions for the success of the operation.

Now comes the next process step, which is shown in Fig. 4g. Now will the cross closure device 10 is fully open, i.e. tools 18 and 19 are shifted in the opposite direction by a total distance (s), which is greater than the width (b) of the stand-up pouch 28. The bag 28 is now lowered in the closing position of the head seam and with the one to be filled Material filled, with which his head seam to lie in the position shown in Fig. 4a comes.

As the last step of the method, the cross-closure device 10 is again used lowered to its initial position and the cross-locking tools 18 and 19 are closed, so that the situation of Fig. 1a is reached again. The cycle can with start closing the next top and bottom seam again.

The advantage of the inventive method lies in the fact that for the reallocation and tacking the bottom seam only small masses can be moved along small paths must, and this without having to move (lower) the format set 2. The The result is a higher output of the machine with a perfectly tacked bottom seam.

The device for performing the method has a format set 2 and a longitudinal closing device 9, which in the lower zone of the filling tube 35, is placed parallel to the axis of the tube and is equipped with means to the Longitudinal closing tools 11 and 12 a counter-rotating and synchronized To give movement to form the longitudinal seam. It also has a cross locking device 10, which is in the immediate vicinity of the free end 5 of the filling tube 35 is placed and equipped with means to the cross-locking tools 18 and 19 an opposing and synchronized movement up and down to Issue formation of the transverse seam of the bag, the transverse seam being both the head seam of the next bag as well as the bottom seam of the previous bag. Both are made at the same time, as is clear from the description of the method evident.

The device also has conventional folding members 23, 24 to create a flat one To produce the bottom of the bag 27. These folding organs (as folding corners 25 and folding fingers 26) are immediately above and below on the cross locking tools 18 and 19 attached.

The inventive feature of the device now consists in the fact that the Means 20 for the opening and closing of the locking tools 18, 19 also one smooth and synchronized movement of the individual tools 18 and 19 allow - to perform the process steps of FIGS. 4e and 4F - and further in that means 22 are also provided for the entire cross-locking device 10 to move up and down vertically. These means 22 can, in addition to the engine, other Include items such as gears, racks, etc.

According to a further preferred solution, it is provided that each cross-locking tool 18, 19 with its own drive (not shown) for the opening and Movement is equipped, with all guides 20 together in one and movable carriage 21 are housed. The drive of the cross locking tools 18 and 19 can be made using known means such as pneumatic or hydraulic Cylinder / piston systems (not shown) can be realized. According to a preferred Variant is, however, provided that each guide 20 as a rack (not shown) is formed and by means of its own toothed pinion (also not shown) is opened and closed. This type of drive, in which the pinion - after a further preferred variant of the invention - with a digital servo motor and fiber optic cables for real-time operation is the subject of a to this parallel invention of the same applicant, to which expressly here is referred. The application of such very precise drive systems, which one Positioning of the parts within 1 / 100th of a mm and extremely fast accelerations and allow delays has proven to be very beneficial in the present context Invention proven. According to a further preferred variant of the invention it is provided that the carriage 21, in which all the guides 20 of the cross-locking tools 18, 19 are housed with at least one digital Servo motor 22 with fiber optic cables for real-time operation, for its up and down movement is driven. The advantages of this type of drive correspond to those which above in connection with the drive of the transverse locking device 10 have been described and therefore need not be repeated here.

According to a further preferred variant of the present invention, that the vertical up and down movement of the locking device 10 a Distance of less than 6 mm. Just the brevity of this route, which only must be sufficient to cover the bottom seam length (strictly speaking, only part of the bottom seam length, since at the moment the bottom seam 34 is attached to the bottom 27, the bottom seam is already inclined by approximately 45 ° - see Fig. 4f) tacking on the floor plays one important role with regard to the rapid execution of the movement and thus to the Delivery of the bag packaging machine.

Figure designation

1

shoulder

2

format set

3

hopper

4

filler pipe

5

rear end of the filler pipe

6

yoke

7

pillar

8th

guide

9

Längsverschliessvorrichtung

10

Querverschliessvorrichtung

11

Tool

12

Füllrohrgegenhalter

13

guide

14

guide

15

rack

16

pinion

17

engine

18

closure tool

19

closure tool

20

guide

21

dare

22

engine

23

folding member

24

folding member

25

Faltecke

26

folding fingers

27

ground

28

next stand-up pouch

29

head seam

30

previous stand-up pouch

31

connecting web

32

separating knife

33

gap

34

bottom seam

35

filling pipe

Claims (8)

Process for folding over the bottom seam of a stand-up pouch produced on a bag packaging machine equipped with folding elements and tacking it to the bottom,
characterized by the following process steps : Folding and closing the bottom (27) of the next stand-up pouch (28) to be filled, together with the folding and closing of the top seam of the previous stand-up pouch (30) to form a connecting web (31) between the previous (30) and the next stand-up pouch (28) Separation of the connecting web (31) between the above-mentioned stand-up pouches (28 and 30) by a separation movement of the knife (32) with the transverse sealing device (10) closed; Returning the knife (32) to the starting position with the transverse locking device (10) still closed; Opening the cross-closure device (10) and releasing the previous stand-up pouch (30) by moving one of the cross-closure tools (18) or (19) in the sense of its distance from the other tool (19 or 18) and formation of a gap (33), at least as large like the bottom seam width, between the two locking tools; Displacement of the second cross-closing tool (19 or 18) in the same direction of movement of the first moving cross-closing tool (18 or 19) up to an at least approximate closure of the previously formed gap (33) between the two cross-closing tools (18, 19) and simultaneous folding the bottom seam (34) of the next stand-up pouch (28) by being carried along by the last locking tool (19 or 18) moved; joint lifting of the two cross-closing tools (18, 19) in the closed state by the distance that is necessary to cover the upper surface of the cross-closing tools (18, 19) with the base (27) of the next bag (28 ) to bring into contact and to accomplish the bottom seam (34), under the influence of heat, on the bottom (27) of the bag (28); Opening the cross-closure tools (18, 19) by moving them in the opposite direction by a total distance (s) greater than the width (b) of the stand-up pouch (28) and lowering the next pouch (28) in the closed position of the head seam by photo transport; joint lowering of the two locking tools (18 and 19) to their initial position. Device for carrying out the method according to claim 1 with a format set (2) for shaping and filling a stand-up pouch and a longitudinal closing device (9), which is placed in the lower zone of the filling tube (35), parallel to the axis of the tube and is equipped with means for the longitudinal closing tools (11, 12) to have an opposing and synchronized movement for the formation of the longitudinal seam To give, with a cross-locking device (10), which is placed in the immediate vicinity of the free end (5) of the filling tube (35) and is equipped with means for the cross-locking tools (18, 19) an opposing and synchronized movement up and down for formation to give the cross seam of the bag; with folding members (23, 24) to produce a flat bottom (27) of the bag, which are placed immediately above and below on the cross-closing tools (18, 19), characterized in that
the means (20) for moving the cross-closing tools (18, 19) also permit the individual tools (18 and 19) to move in a synchronized and synchronized manner
and that further
Means (22) are provided in order to move the entire cross-closing device (10) vertically up and down. Device according to claim 2,
characterized in that
each cross locking tool (18, 19) is guided in guides (20) and that the guides (20) of each cross locking tool (18, 19) are equipped with their own drive for opening and closing and that all guides (20) together in an up and down movable carriage (21) are housed. Device according to claim 2,
characterized in that
each guide (20) is designed as a toothed rack and is moved up and down by means of its own toothed pinion. Device according to claim 4,
characterized in that
each pinion is driven by a digital servo motor with fiber optic cables for real-time operation. Device according to claim 3,
characterized in that
the carriage (21) is driven by at least one digital servomotor (22) with optical fiber cables for real-time operation for its up and down movement. Device according to claim 1,
characterized in that
the vertical up and down movement of the transverse locking device (10) makes up a distance of less than 6 mm. Device according to claim 3,
characterized in that
the carriage (21) is driven pneumatically or hydraulically with a cylinder / piston unit for its up and down movement.

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