EP2132093A1

EP2132093A1 - Multifunctional sealing element

Info

Publication number: EP2132093A1
Application number: EP08734774A
Authority: EP
Inventors: Martin Kölker; Oliver Huil; Ludger Schulten; Thomas Knoke
Original assignee: Windmoeller and Hoelscher KG
Current assignee: Windmoeller and Hoelscher KG
Priority date: 2007-03-27
Filing date: 2008-03-26
Publication date: 2009-12-16
Anticipated expiration: 2028-03-26
Also published as: EP2132093B1; PL2132093T3; ATE494216T1; DE502008002211D1; WO2008116638A1; DE102007015298A1

Abstract

The invention relates to a machine for filling and sealing bags, characterised by at least the following: a filling station (60) in which the bags (11) are filled; grip means (10, 18) for transporting the bag (8, 11) between processing stations; a dosing element (2) which protrudes into the bag (11) during a dosing process; movement means for creating a relative movement between the bag (11) and the dosing element (2) in the filling station, in order to enable the dosing element (2) to protrude into the bag; and a connecting piece (3, 112) which surrounds at least parts of the dosing element (2), and can be positioned between the inside wall of the bag and the dosing element (2). The relative position of the dosing element (2) and the connecting piece (3, 112) can be modified. The machine especially comprises clamping means (107, 108, 117) for gripping the bag (11) at least in a target region (118) located at least in the region of the side walls (102, 103) of the bag, at least in the upper region of the bag. Said clamping means are positioned in such a way that they can grip the bag in the nominal position in the filling station (60), and comprise actuators (117) which pull the target regions (118) of the bag away from the main axis of symmetry (120) of the bag (8).

Description

Multifunctional sealing element

The invention relates to a machine for filling and closing of bags and a method for filling of plastic bags with filling material and for closing the filled bags.

Such a device is known for example from DE 93 01 355 U. Here is already a device for producing, filling and closing unilaterally open, preferably provided with gusseted bags of thermoplastic described in which a first welding and separation station to form the bag with bottom seam, a filling station and a second welding station for closing the bag available. Generally, these filling machines are classified in the FFS (Form FiII and Seal) category.

When filling dusty bulk materials on machines of the named category by gravity or by free fall, the dusty air displaced by the product must be able to escape from the bag. The escape of air often leads to contamination in the upper edge areas of the bag. Due to the contamination with product dust, the bag can not be securely closed by means of the welding which is generally customary in this type of packaging. In addition, the dust pollutes the environment and must be separately extracted.

Furthermore, the filling of dusty goods according to the described known filling method usually leads to a significantly inflated product volume or to a significant reduction in bulk density, since the product accumulates heavily in the free fall with air. This in turn means that significantly more packaging material is needed to fill the product. In addition, the air must be able to escape from the bag again, otherwise it can not be stacked or stored.

Since the escape of air usually takes a long time, the venting can not take place before closing the bag. The bag must therefore have a perforation. This additionally pollutes the environment, as the fine-grained, dusty products can partially escape through the perforation of the packaging.

Over time, the volume of bulk material decreases again. The sack packaging is now, compared to the packaged bulk material volume, significantly too large. Such filled sacks are difficult to stack on pallets because they are too unstable.

EP 1 459 981 A1 therefore proposes to introduce the filler neck of a metering device of an FFS machine into the opening of a bag. In WO 2006/053627 A1, however, the relative movement between the sack and the filler neck is accomplished by a movement of the sack.

In both of the aforementioned publications Dosierorgane are presented which contain screws. These screws transport the filling material into the bags. The preferred conveying direction in these screws corresponds to the effective direction of

Gravity. Due to the screws, there is no free fall of the filling material in the bag. Therefore, snails are often used for bagging dusty

Filling goods used. However, their use is by no means mandatory - also in relation to the present invention.

In particular - but not exclusively - when filling and then closing bags with dusty filling goods show up again and again Problems with the discharge of filling material when infecting the bags. The discharge of filling material will dirty and damage the machine.

Therefore, the object of the present invention is to propose a machine in which the discharge of filling material proceeds with less dust.

The object is solved by the claim 1.

As a rule, the clamping means will comprise grippers or suckers which grasp or suck in parts of the bag material and pull them outwards, that is, away from the main axis of symmetry of the bag. In this way, the bag material is stretched and nestles in a better way to the connection piece and / or the metering tube. Therefore, the clamping means comprise, in addition to any gripping means actuators, so devices apply the force that pull the gripping means and the bag material in the manner described. Often, linear actuators or working pistons will be used for this purpose.

In this way, the bag material is stretched, nestles against the connecting piece, so that less Füllgutstaub escapes from the bag. This effect can be further enhanced by pressing sealant against the sack and the filler neck surrounded by the sack during the filling process. This need not be done in relation to the entire circumference of the bag or the filler neck. Rather, it may be advantageous if portions of the circumference remain free, so that bag material that is not jammed between the filler neck and the sealing elements or, continues to be held without excessive pulling forces from the tensioning device to train.

In particular, in the area between the clamping elements and a sealing element, such an area makes a positive impact. It may be advantageous if the surfaces in opposition are matched in shape to one another so that they interlock when the sealing elements are employed. This is easy if the elements are just pronounced on the surfaces where they touch the bag material.

The spigot should have at least two passages for elements that pass through it. Then, in addition to a metering, for example, one or more vent tubes engage through the metering in the bag. The venting of the bag during the filling process is of great advantage, since air, which can not escape at first, means overpressure. Such an overpressure may discharge to the outside during filling and may lead to dusty contents again. The or the vent tubes can then be followed by filters that prevent leakage of Füllgutstaub. Alternatively or additionally, the vent pipes can be made of sintered material.

It is advantageous if the connecting piece has at least one corner. In addition, it is to be welcomed if at least one of these corners points in the direction of action (= pulling direction) of a tensioning element. The tension member then pulls the bag material into a shape that spans the corner. If then - which is usually advantageous - the employment of the sealing elements takes place against the already tensioned or prestressed film, the film nestles very well on the sealing element.

The direction of action of the clamping element is the direction in which the sack material is actually pulled during the clamping movement. This direction can also be influenced by other additional machine elements such as the density elements - that is, deflected.

It has proven to be particularly advantageous if two clamping elements, of which at least one performs a relative movement to the filling nozzle, each one corner of the filler neck - which may have even more corners - are assigned. For a clean process, in which the filler neck is cleanly guided into the bag opening, it is advantageous to open the bag before any relative movement between the bag and the connecting piece brings these two objects to each other in their working position.

Subsequently, the metering is usually perform a further relative movement relative to the connecting piece to advance into the interior of the bag and here to fill the bag with filling. If a suitable pre-positioning between the bag and dosing, the two aforementioned relative movements can also coincide. In general, however, any possible sequence of these relative movements between the sack, the dosing member and the connecting piece is advantageous or encompassed by the present invention.

It is advantageous if the bag is brought with first gripping means into the working position in which the connecting piece moves into the bag, and is conveyed out of this working position again with second gripping means. Often, both types of gripping means will be adapted to grip the sack at its upper edges, not blocking the central area of the sack opening, since this central area is reserved for sack filling. As a rule, the gripping means are gripper pair.

The provision of opening means for the sack opening is advantageous. Often these are also assigned directly to the filling station. They often include suckers or other grippers. You should open the sack before the nipple through one

Relative movement is introduced into the bag.

Advantageously, then carried out the tensioning of the bag. It is also from

Advantage, when the bag material is pressed with sealing means against the connecting piece. This is best done after tensioning the bag material.

Further embodiments of the invention will become apparent from the description and the claims. The individual figures show: Fig. 1 is a side view of an FFS machine

2 is a detail view of Figure 1

3 view according to III - III in Figure 2

Fig. 4 view as in Figure 3, but with suckers shown

Fig. 5 view as in Figure 3, but with the bag open

Fig. 6 view as in Figure 3, but with connecting pieces

Fig. 7 view as in Figure 6, but drawn outwards

bag walls

Fig. 8 view as in Figure 7, but with employed clamping elements

9 view IX - IX according to FIG. 7

A tubular film web 15 (see FIG. 1), preferably with inserted side folds, is initially conveyed by a preferred roll system 9 into a horizontally movable transport means, for example a pair of grippers 18.

The film web 15, after the preference has pulled the section according to the desired bag length, cut by the knife 17. At the same time, the bottom welding takes place 13. The empty bag 11, which is closed at the lower end by the bottom of the bag 39, is transferred to a horizontally displaceable transport means, for example a gripper 18, and transported to the filling station 60.

In the filling station 60 takes over a further transport 4, which consists of 3,4,5, the bag section. The empty bag is now opened with a suction system 16. For this purpose, the grippers 4 are moved in the Z direction or in the -Z direction (inwardly). The connecting piece of the transport system 3 is moved into the bag and protects the sack inner surfaces from contamination by possible product adherence to the metering tube 2,21.

The opened bag is pulled by the transport system 3, 4, 5 on the metering tube 2,21 until the lower end of the bag is approximately equal to the Füllgutaustrittsöffnung 31. The bag bottom support device 32,33,34 is in the embodiment shown below the bag floor hazards. However, a bag bottom support device 32, 33, 34 is not absolutely necessary. Rather, the relative movement of the bag relative to the Befüllorgan 2,21 mainly caused by the fact that the frame 5 along the guide 6 moves. This is represented by the double arrow 35. In this embodiment of the invention, therefore, the bag is moved relative to the Befüllorgan 2,21. Of course, it is also conceivable to bring about the relative movement between bag 8 and metering element 2 by a movement of metering element 2 or even by a movement of bag 8 and metering element 2. As a rule, it is sufficient in this case if the bag is held by claw-like transport means 4 at its upper end. The mentioned bag bottom support device 32, 33, 34 offers optional, additional protection against a crack of the just welded bag bottom.

The closure tube 21 is lifted and releases the product outlet opening 31. The product / bulk material 24 is filled in the bag. Meanwhile, the transport system 3,4,5 lowers the bag in such a way that the product outlet opening 31 is always below the filling level. However, even before the end of the metering of the product / bulk material 24, the product outlet opening 31 may be located at least once above the filling level 38. After completion of the filling, the closure tube 21 is lowered and closes the product outlet opening 31 by making contact with the closure 20. The connecting piece is pulled out of the bag. The gripper (s) 4 of the transport system 3, 4, 5 is now moved counter to the Z direction (out of the bag) and tightens the opening area at the upper edge 25 of the previously opened bag. Another transport means 10 takes over the filled bag 8. By means of the closing device 14, the upper edge of the bag 25 is now closed. If necessary, it can be sucked out by the filter integrated in the closure tube 21 together with the dosing process. The required vacuum is introduced via the pipe 23. The integration of the filter in the closure tube allows a very compact design, which makes it possible to fill even relatively small bags. The suction of the air leads to a certain extent a compression of the bulk material. As a result, a sack size appropriate to the product quantity can be selected.

This effect of product compaction can be further enhanced by the additional use of vibration generators or beaters 29. It is advantageous here to set the dosing tube 2, 21 in vibration by means of a vibration generator 29, since it is located within the product at least with parts of its lateral surface during filling. The vibrations are transmitted from the dosing 2.21 to the filling material 24, in which then takes place a compression. A further advantage of the "vibrating metering tube" 2.21 is that the formation of product adhesions on the metering tube 2, 21 is thereby largely avoided, and the vibrator 29 could also be arranged on the "bag bottom support device" 34.

A particularly advantageous embodiment of the carriage is to store the frame 5 together with the neck 3 and the transport 4 on sensors. The sensors send their signal to a weighing electronics, which ultimately controls the dosing process. The absorption 16 may also be mounted on the sensors, but should advantageously be stored elsewhere, since the suction 16 is usually no longer in contact with it during the filling of the bag 11.

To mention is still the guide or support 6, which carries the frame 5 and thus the transport 4. In the metering or pipe 2 is a screw 7, can be promoted with the filling material 24 from the hopper 1 without much dust in the bag 8. The various sensors 26 (in particular weighing sensors or load cells) indicate advantageous locations for attaching such sensors. The conveyor belt 27 transports the filled bags (8). In the vicinity thereof, the checkweigher 30 and the vibration generator 29 are mounted.

FIGS. 3 to 8 show a plan view of the elements of the filling station which are essential for the sack opening and bag filling in a device for Forming, filling and closing sacks. This view is shown in Figure 2 by the view III - III.

FIG. 3 shows a still unopened empty bag 11, which comprises two outer walls 102, 103. In the case shown, a sack with gussets 104, 105 can be seen. The empty bag 11 has been taken over in the region of its lateral folds 104, 105 by grippers 106 and 107 by the feed device 18 (not shown here) (see FIG. 1). The grippers 106, 107, which are rotatably mounted in the holders 108, 109 in a manner not shown, hold the bag during the entire filling process. The holders 108, 109 are based on the frame 5, which is likewise not shown here in detail, and are displaceable relative to this frame 5 in a manner described below.

FIG. 4 shows the same elements as FIG. 3, but opening means, which in the present exemplary embodiment are in the form of suckers 110, 111, are made from outside against the bag walls 102, 103 and suck them up.

FIG. 5 illustrates the opening process of the empty bag 11. For this purpose, the teat 110 is moved in the direction Y and the teat 111 in the direction -Y. At the same time, the holders 108 and 109 are moved in directions Z and -Z, respectively, to compensate for the reduction of the lateral extent of the bag 11. In this way, a filling opening at the upper end of the bag 11 is formed. This situation has also already been described in connection with FIG.

FIG. 6 shows a situation similar to FIG. 5. Only one sealing element 112 was introduced into the interior of the bag 11. The sealing element 112 has already been referred to above in connection with Figures 1 and 2 and in the introductory description as a connecting piece. In the context of this application, the words "sealing element" and "connecting piece" thus refer to the same element. The contour of the sealing element 112 in the plan view is similar in this embodiment, the cross section of a Convex lens. The sealing element 112 only needs to be introduced into the interior of the bag 11 approximately so far that the surface of the sealing element lies on a plane or slightly below the upper edges of the walls 102 and 103 (see FIG. 9). After the introduction of the sealing element 112, the negative pressure, which is applied to the outer walls 102 and 103 via the suction cups 110 and 111, can be removed and the suction cups 110, 111 can be removed. The sealing element 112 has at least two passage openings. In the present embodiment, three such openings can be seen. The largest opening represents the filling opening 113, which is preferably arranged centrally. Through this filling opening, the product can be filled into the interior of the bag 11. In a first embodiment, however, the sack is moved relative to a fixed in the device filling tube. In a second embodiment, the sack can be held immovable while the filling tube is moved into the interior of the sack 11 through the filling opening. A combination of both embodiments is, as described, conceivable. In all embodiments, the sealing member 112 surrounds the filling tube and closes the space between the filling tube and the walls 102 and 103. The bag walls 102 and 103 are therefore not immediately adjacent to the filler neck. The bag 11 is raised so far that the distance between the bottom of the bag 39 and the lower outlet end 31 of the filling tube 2 is very small. After the filling process has begun, the bag 11 is lowered continuously, so that the distance between the lower outlet end 31 of the filling tube 2 and the level of the contents 38 remains very small. The distance can assume a negative value. This means that the outlet end 31, as already described above, below the Füllgutpegels 38 is located. In this way, a dust development during the filling process is avoided. It should be noted at this point that the filling process takes place only after the step shown in Figure 8 has been performed.

The sealing element 112 further comprises two passages 114 through which, for example, suction nozzles are introduced into the interior of the bag 11 can be. With such suction can register the registered during the filling process air and compress the product in this way.

FIG. 7 now shows that the holders 108 are again moved outward in the directions -Z and Z. The walls 102 and 103 lie partially outside from the outside to the edge of the sealing element 112. However, the space between the walls 102 and 103 and the sealing element 112 is not completely closed.

In order to achieve this, clamping elements 115 (see FIG. 8) are also set against the sealing element 112 from the outside, so that the walls 102 and 103 are clamped between sealing element 112 and clamping elements 115 or between two clamping elements 115. In the region of the sealing element 112, therefore, a single wall of the bag is respectively clamped between this and a clamping element. Between two clamping elements 115, however, both walls 102 and 103 are clamped lying on each other. As can be seen from FIG. 8, the clamping elements 115 have two regions. A first area presses against the sealing element 112, so that a bag wall 102 or 103 is clamped. In a second area, a clamping element 115 presses against a second clamping element, which clamp the bag walls 102 and 103 between them. Since the bag walls are biased by the holder 108, results in an extremely high tightness of the bag interior with respect to the bag exterior. This applies even to the region 116 of the bag, in which neither a clamping element 115, nor the sealing element 112, nor the holder 108 attack. Due to the fact that not all areas of the bag wall must attack a device element in order to produce sufficient tightness, the format of the bags, in particular their width, can also be varied. The contour of the clamping elements is adapted to the contour of the sealing element, so that no free space remains. The holders 108 are thereby acted upon by an outwardly directed force which, however, is less than the force with which the walls 102 and 103 according to FIG. 7 are applied to the sealing element 112. This situation is shown in FIG. 8 symbolized by compared to Figure 7 shorter arrows Z and -Z. The holders 108 are moved by means of actuators, which may be arranged on the frame 5. Such actuators may be, for example, linear motors. In particular, pneumatic pistons are conceivable for this purpose. Preference is given to three-stage pneumatic cylinder, which can be acted upon by three different air pressures, so that they can beauchlage the holder 108 and thus the gripper with 107 with three different forces in Z and -Z direction. The actuators are represented in FIG. 8 by the reference numeral 117 and, which is not shown, are advantageously supported on the frame 5. The material of the bag 11 can be pressed against the sealing element 112 by the clamping elements 115, without being damaged by the holders 108 due to excessive tension. However, the force with which the holders 108 are acted upon is nevertheless so great that the regions 116 of the walls 102 and 103 abut one another without the clamping elements 115 exerting a force here. Even in such areas 116, the interior of the bag 11 is sufficiently sealed against the environment.

In the figure 8, the line L is still shown in dashed lines, on which the corners of the sealing element 112 lie. Likewise, both the median plane between the grippers 106 and the median plane between the grippers 107 lie on this line, as well as the direction of force exerted by the actuators 117 on the holders 108 and 109. The line L is thus a symmetry line.

FIG. 9 shows the view IX-IX from FIG. 7. In this FIG. 9, the sealing element 112 can be seen in a solid line before it is introduced into the bag. After being displaced in the direction of the arrow X, the sealing element 112 is located inside the bag 11 just below the upper edge 117 of the bag 11. In this position, the sealing element 112 is shown with broken lines.

From Figure 9, the target areas 118 can be seen in addition, in which the grippers 106 and 107 engage. In this figure, only the front grippers 106 and 107 can be seen, which engage the wall 103. As can be seen from FIGS. 3 to 8, the rear grippers 106 and 107 grip the wall 102. The target areas are far outward. For example, in a gusseted bag these outboard areas are the gusset areas. The target area 118 is also arranged as close as possible to the sack top 25. Since the bag 11 can only be filled to a region that lies well below the target area 118 in which the grippers 106 and 107 engage, any bag material that projects upwards beyond the grippers 106 and 107 is useless and should be saved become. In a simple embodiment, the target areas 118 are located in the right and left upper corners of the bag 11, respectively.

The directions -Z and Z are again shown in FIG. 9, in which the forces with which the actuators 117 apply the holding means 108 are shown. These force directions are directed away from the main axis of symmetry 120 of the bag. The main axis of symmetry 120 lies along the longitudinal direction of the bag and, as a rule, centrally between the two outer edges of the bag 11.

Claims

claims

A sack filling and closing machine which has at least the following features:

a filling station (60) in which the sacks (11) are filled,

Gripping means (10, 18) for transporting the bag (8, 11) between processing stations,

- A metering member (2) which engages in the dosing process in the bag (11),

- Movement means for causing a relative movement between the bag (11) and dosing (2) in the filling station, so as to allow the grasping of the dosing (2) in the bag,

- A connecting piece (3, 112), which engages around at least parts of the dosing (2), between Sackinnenwandung and metering (2) can be positioned, wherein the relative position of metering (2) and connecting piece (3, 112) is variable, characterized by

at least one tensioning means (107, 108, 117) for gripping the sack (11) at least in a target area (118) which lies at least in the upper area of the sack at least in the area of its sack sidewalls (102, 103),

- Which are positioned so that they can take the bag in its desired position in the filling station (60) and which comprise actuators (117) which pull the target areas (118) of the sack away from the main axis of symmetry (120) of the sack (8).

2. Machine according to claim 1, characterized in that

Sealant (115) are provided, which in the filling station (60) from the outside to the bag wall (102, 13) are adjustable.

3. Machine according to the preceding claim, characterized in that the sealing means (115) are shaped and dimensioned such that they touch only partial areas of the circumference of the bag (11) during their employment.

4. Machine according to one of the preceding claims, characterized in that the sealing means (115) and the connecting piece (112) are positioned to each other such that they are adjustable against each other.

5. Machine according to one of the preceding claims, characterized by a connecting piece (3,112) having at least two passages (13,14).

6. Machine according to the preceding claim, characterized in that through at least one of the passages (13,14) engages an air exhaust pipe.

7. Machine according to one of the preceding claims, characterized in that the connecting piece (3,112) has a concave, trapezoidal or konvexlinsenar- term form.

8. Machine according to one of the preceding claims, characterized in that the connecting piece (3,112) has at least one corner which points to the gripping means (10, 18).

9. Machine according to one of the preceding claims, characterized in that the actuators (117) of the clamping means are arranged and arranged such that they the target areas (118) of the bag (11) substantially along a line (L) of the main axis of symmetry (120 ) of the bag (8), which passes through the at least one corner of the connecting piece (3, 112) and the gripping means (10, 18).

10. Machine according to the preceding claim, characterized in that two gripping means (106, 107) are each associated with a corner of the connecting piece (3,112).

11. Machine according to one of the preceding claims, characterized by

Means (110,111) for opening the sack (11) positioned to open the sack.

12. Method for filling and closing sacks, which has at least the following process characteristics:

the filling of the sacks (8, 11),

the transport of the bag (8, 11) between different processing stations,

- the grasping of a dosing (2) through the bag opening in the bag (8, 11),

a relative movement between sack (8, 11) and dosing member (2), which allows the dosing member (2) to reach into the sack,

- A relative movement between a connecting piece (3,112) which engages around at least parts of the dosing (2) and is positioned between the bag inner wall and dosing (2), and dosing (2), characterized in that

- At least parts of the bag wall (102,103) are stretched when the filler neck (2) engages in the bag (11) into it.

13. Method according to the preceding claim, characterized in that

- That the bag (11) are transported before filling of gripping means (18) in the Befüllstati- on (60) into, and

- That the bag (11) after filling by other gripping means (10) from the filling station (60) is transported out.

14. The method according to any one of the preceding claims, characterized in that the bag in the filling station (60) with opening means (110,111) is opened.

15. The method according to the preceding claim, characterized in that the connecting piece (3,12) is moved into the opened bag.

16. The method according to the preceding claim, characterized in that the bag (8,11) is tensioned after the connection piece has been retracted into the opened bag.

17. The method according to any one of the preceding claims, characterized in that

Sealant (115) are driven against the opened and tensioned bag (8,11) that bag material (8) between the sealing means (115) and the connecting piece (3,112) are clamped.

18. The method according to any one of the preceding claims, characterized in that

Air is sucked out of the filling material (41) during and / or after it is filled into the bag (11).