DEVICE AND METHOD FOR PACKAGING BULK MATERIALS IN OPEN BAGS

Abstract

Apparatus and method for filling bulk materials into open-mouth bags, including the following steps: a) an open-mouth bag is appended from beneath to a filling spout of a filling station by way of an at least partially upwardly motion, so that the bottom end of the open-mouth bag is freely suspended; b) the filling process is started and bulk material is introduced into the open-mouth bag so that the freely suspended bottom end of the open-mouth bag unfolds; and c) the filling spout is lowered, so that the unfolded bottom end of the open-mouth bag is supported.

Claims

1. A method for filling bulk materials into open-mouth bags comprising the following steps: a) an open-mouth bag is appended from beneath to a filling spout of a filling station by way of an at least partially upwardly motion, so that the bottom end of the open-mouth bag is freely suspended; b) the filling process is started and bulk material is introduced into the open-mouth bag so that the freely suspended bottom end of the open-mouth bag unfolds; and c) the filling spout is lowered, so that the unfolded bottom end of the open-mouth bag is supported.

2. The method according to claim 1, wherein the filling spout with the appended open-mouth bag is lowered onto a conveyor device.

3. The method according to claim 1, wherein the bottom end of the open-mouth bag is supported at least during part of the filling process.

4. The method according to claim 1, wherein the method step c) is carried out during the filling process.

5. The method according to claim 1, wherein the bulk material in the open-mouth bag resting on the conveyor device is compacted during the filling process.

6. The method according to claim 1, wherein in the method step a), holding grippers grasp the open-mouth bag and in the method step c), are lowered together with the filling spout.

7. The method according to claim 1, wherein after filling and method step c) are completed, the holding grippers release the open-mouth bag and travel upwardly together with the filling spout, while the open-mouth bag rests on the conveyor device.

8. The method according to claim 1, wherein, after filling is completed, the open-mouth bag is conveyed further by means of the conveyor device.

9. The method according to claim 1, wherein during the further transport the open-mouth bag is guided by its head end by discharge grippers.

10. The method according to claim 1, wherein the open-mouth bag is formed from tubular film prior to appending.

11. The method according to claim 10, wherein the tubular film is unwound from a film roll and a bottom seam is first made in the tubular film. and wherein the tubular film is thereafter conveyed further by one index length, and wherein the tubular film is cut off at the head end to form an open-mouth bag.

12. The method according to claim 1, wherein the head end of the open-mouth bag is pre-opened prior to being appended to the filling spout.

13. The method according to claim 1, wherein the filling spout configured as a flap spout and having entered the pre-opened head end, tips open and opens the head end wider.

14. An apparatus for filling preferably gusseted open-mouth bags, with a control device and a filling station including a filling spout for filling the open-mouth bags and including a plurality of grippers, wherein the grippers comprise at least feed grippers for holding the empty open-mouth bags during feeding to the filling station, holding grippers for holding the open-mouth bags in the filling station and discharge grippers for holding the filled open-mouth bags during discharge from the filling station, and with a conveyor device extending up to beneath the filling station for supporting and for transporting the filled open-mouth bags, comprising: the filling station accommodates the filling spout together with the holding grippers in a height-adjustable supporting structure; the filling station is suitable for lowering and elevating the supporting structure with the filling spout and the holding grippers; and the filling station is suitable for lowering the supporting structure with an appended open-mouth bag during the filling process, so that the bottom end of the open-mouth bag is firstly freely suspended above the conveyor device and thereafter put down on a support.

15. The apparatus according to claim 14, wherein the filling station is suitable for lowering the supporting structure with the appended open-mouth bag onto the conveyor device.

16. The apparatus according to claim 15, wherein the filling station is suitable for lowering the supporting structure with the appended open-mouth bag after filling begins so that the bottom end of the open-mouth bag rests on the conveyor device at least for part of the filling process.

17. The apparatus according to claim 14, wherein the control device and the filling station are configured and set up to elevate the supporting structure with the filling spout and the holding grippers so as to take over the open-mouth bag with the holding grippers in the elevated position, for the bottom end of the open-mouth bag to be freely suspended above the conveyor device as filling begins; and to lower the supporting structure with an appended open-mouth bag, so that the unfolded bottom end of the open-mouth bag is supported from beneath during the filling process.

18. The apparatus according to claim 17, wherein the control device and the filling station are set up and configured to lower the supporting structure with an appended open-mouth bag for the bottom end of the open-mouth bag to rest on the conveyor device in particular at least during part of the filling process.

19. The apparatus according to claim 14, wherein at least one compacting device is comprised, and/or wherein a compacting device is disposed beneath a bearing surface of the conveyor device.

20. The apparatus according to claim 14, wherein the filling station comprises a drive for elevating and lowering the supporting structure.

21. The apparatus according to claim 14, wherein the feed grippers and the discharge grippers are fastened to a support frame of a conveying device.

22. The apparatus according to claim 14, wherein the conveying device comprises swing arms and a pendulum drive.

23. The apparatus according to claim 14, wherein the open-mouth bag can be appended by way of a pendulum motion of a pendulum unit.

24. The apparatus according claim 14, wherein the filling spout is configured as a flap spout suitable for entering an open-mouth bag, and/or wherein a roll accommodation for accommodating a tubular film roll is comprised, and/or wherein a bag forming station is comprised, and/or wherein a bottom seam station for generating a bottom seam and/or a top seam station for closing the open-mouth bag is comprised, and/or wherein at least one cooling station for cooling a closing seam is comprised.

Description

[0046] The figures show in:

[0047] FIG. 1 the apparatus according to the invention in a schematic side cross section in a first position while forming an open-mouth bag;

[0048] FIG. 2 the apparatus according to FIG. 1 in a second position after appending the open-mouth bag;

[0049] FIG. 3 the apparatus of FIG. 1 in a third position;

[0050] FIG. 4 a simplistic horizontal cross section of the filling station;

[0051] FIG. 5 a side view of another filling station; and

[0052] FIG. 6 the apparatus according to FIG. 1 in a fourth position;

[0053] FIG. 7 a schematic view of a pendulum unit with a pre-opening station.

[0054] FIGS. 1 to 4 each show the same apparatus in a schematic side cross section in various positions or states. In all the figures, components and parts of the real apparatus have been omitted to simplify viewing. Although the FIGS. 1, 2, 3, 6 and 7 show the same apparatus, not all the figures illustrate all the components and not all the figures show all the reference numerals.

[0055] The apparatus 1 illustrated in the FIGS. 1, 2, 3 and 6 serves for filling bulk materials into open-mouth bags 2. Preferably the open-mouth bags 2 are manufactured in a bag forming station 27 of the apparatus 1. To this end the apparatus 1 comprises a roll accommodation 24 for a tubular film roll 25. The roll accommodation 24 may be mounted to, or placed separately in front of, the apparatus 1.

[0056] A variety of deflection rollers 31 shown in simplistic views provide intermediate storage, not illustrated in detail, to enable the tubular film roll 25 to unwind quasi continuously. Alternately it is possible to feed prefabricated open-mouth bags to the apparatus 1.

[0057] The apparatus 1 comprises a frame 40 to which the various components of the apparatus 1 are mounted. A bottom seam station 29 is disposed at the bag forming station 27, presently comprising a pair of welding jaws 41 for making a bottom seam in the supplied tubular film 32. After indexing the tubular film 32 one bag length further, the cutting knife 33 (see FIG. 2) cuts the bag off at the head end so as to provide a separate open-mouth bag 2 intended for filling. Grippers 10 (empty-bag grippers) hold the open-mouth bag 2. Meanwhile the bottom seam of the open-mouth bag 2 may be cooled in the cooling station 28 for the bottom seam to show the required stability for the quantity of product intended for filling.

[0058] The bag forming station 27 is followed by a variety of processing stations, including in particular the pre-opening station 39, the filling station 5 and the top seam welding station 42 with welding jaws 41. The open-mouth bags 2 are transported between each of the stations (5, 27, etc.) by means of a conveying device 20 which ultimately conveys the open-mouth bags 2 linearly or horizontally through the apparatus 1. The conveying device 20 comprises a support frame 21 to which various sets of grippers 10 are mounted. The support frame 21 is held by a pair of swing arms 22 to swing between two pivot positions. The conveying device 20 is driven by means of a pendulum drive 23 in the shape of an electric motor which by means of an eccentric member 19 allows pendulum motions between forwardly pivoted and rearwardly pivoted support frame 21 positions. The filling station 5 comprises a drive 18 for elevating and lowering the supporting structure 8.

[0059] Upstream, a separate pendulum unit 44 may be installed where the pre-opening station 39 and feed grippers 11 are attached. The pre-opening station 39 pre-opens the open-mouth bags and by means of a pivoting motion successively appends the pre-opened open-mouth bags to the filling spout 6 from beneath. The open-mouth bags are moved in the horizontal and vertical directions.

[0060] In the forwardly pivoted position illustrated in FIG. 1 the shown open-mouth bag 2 can thereafter be appended to the filling spout 6, which is presently configured as a flap spout 26. The feed grippers 11 take over and then open the open-mouth bag previously formed in the bag forming station 27.

[0061] Thereafter the open-mouth bag 2 is conveyed further from the bag forming station 27 to the next station. The bag forming station 39 may be followed by another cooling station 28. The head end 30 of the open-mouth bag 2 is (pre-) opened e.g. by suction banks in the pre-opening station 39. The filling station 5 is reached by way of a pendulum motion of the pendulum unit 44 (see FIG. 7) as is illustrated in FIG. 2.

[0062] The one or more feed gripper(s) 11 and the pre-opening station 39 may be identical in all the configurations (as in the exemplary embodiment illustrated). In another variant, first feed grippers 11 first take the empty bag to another cooling station 28, and the pre-opening station 39 (another pre-opening station, or with further feed grippers 11) takes over the empty bag by way of the pendulum lift motion, guiding it pre-opened to the transfer position of the filling spout 6.

[0063] In the position illustrated in FIG. 2 the pre-opened open-mouth bag 2 is positioned beneath the filling spout 6. The bottom end of the open-mouth bag 2 is suspended above the support 45 (see FIG. 3) and presently, above the conveyor device 7. In the positions illustrated in the FIGS. 1 and 2, the filling spout 6 is in an elevated position.

[0064] The conveyor device 7 is height-adjustably disposed on the frame 40 for compensating and setting different bag lengths by way of height adjustment 38. The conveyor device 7 is not height adjusted for each single filling so as to enable considerable ease of driving and a considerably simple configuration of height adjustment.

[0065] Optionally the conveyor device 7 may be separately disposed on the floor. The conveyor device 7 comprises a belt section 15 that is in particular configured as a conveyor belt. The surface of the belt section 15 forms a bearing surface 17 for example for filled open-mouth bags 2.

[0066] The belt section 15 is diverted by deflection rollers 14. An electric motor 37 may serve for driving.

[0067] The conveyor device 7 extends up to beneath the filling station 5 and up to beneath the filling spout 6, such that a compacting device 16 received or disposed on the conveyor device 7 is likewise positioned beneath the filling spout 6 in the vertical direction.

[0068] The compacting device 16 is received on the conveyor device 7 such that the compacting device 16, while it is active, acts on the carrying belt section 15 of the conveyor device 7 and on the bearing surface 17 of the conveyor device 7. This allows processing (after lowering the filling spout) an open-mouth bag 2 resting on the conveyor device 7 respectively an open-mouth bag 2 supported by the conveyor device 7, by means of the compacting device 16. This enables compacting the bulk material in the open-mouth bag 2 already during the filling process.

[0069] First, however, the open-mouth bag 2 is appended to the flap spout 26, as FIG. 2 illustrates. In the appending motion, which is, at least relatively, also directed upwardly, the tips of the flap spout already enter the pre-opened head end of the open-mouth bag 2. In the same way the holding grippers 12, not recognizable in FIG. 2, take over the open-mouth bag 2 in the gusseted region of the open-mouth bag, so that on the pendulum unit 44 the grippers 10 can release the open-mouth bag 2 intended for filling. The bottom end 9 of the open-mouth bag 2 intended for filling does not rest on the conveyor device 7. This is significant so that as filling begins the bottom end (always) unfolds properly.

[0070] This is achieved because, prior to beginning filling respectively after finishing a preceding filling, the supporting structure 8 with the filling spout 6 and the holding grippers 12 is transferred to the elevated position 34 illustrated in the FIGS. 1 and 2. In this way the distance from the conveyor device 7 becomes large enough for the bottom end 9 of a subsequently appended open-mouth bag to not make contact with the conveyor device 7. However, there is at least a (small) gap between the bottom end 9 of the open-mouth bag 2 intended for filling and the bearing surface 17 of the conveyor device 7. At least the degree of freedom of the bottom end 9 is large enough so that the bottom can freely unfold with the first product (product thrust) entering.

[0071] In FIG. 3 the flap spout 26 is furthermore tipped up so that the filling process can start. The flap spout together with the supporting structure 8 and the holding grippers 12 is in the elevated position 34. The supporting structure 8 is still in the elevated position 34. The bottom end 9 of the open-mouth bag 2 is freely suspended.

[0072] Thereafter the filling process starts, wherein bulk material is introduced into the open-mouth bag 2. The timed coordination is such (in particular based on empirical values) that the product thrust first entering the open-mouth bag 2 unfolds the bottom end 9 of the open-mouth bag 2 (as far as possible wrinkle-free). An unfolded bottom end 9a is schematically shown in broken lines in FIG. 3.

[0073] Lowering the supporting structure 8 may be initiated thereafter or previously, by coordination, so that the conveyor device 7 in particular supports the bottom end 9 of the open-mouth bag 2 as soon as possible following unfolding the bottom end 9 of the open-mouth bag 2. This allows for the compacting device 16 accommodated there to act on the bottom end 9 of the open-mouth bag 2 and to effectively compact already during filling any bulk material that is already present.

[0074] FIGS. 4 and 5 show two variants of the arrangement of the holding grippers 12 on the supporting structure 8 of the filling station 5. FIG. 4 shows a horizontal cross section of the filling station with the schematic, cross sectional view of the filling spout 6 to which an open-mouth bag 2 is appended. The supporting structure 8 retains the filling spout and also the holding grippers 12. The holding grippers 12 are shown in the closed state, gripping the gussets 3 of the open-mouth bag 2 for controlled retaining of the open-mouth bag 2 during the filling process. A holding gripper 12 in the opened state is also shown in broken lines. The holding gripper 12 needs to be pivoted outwardly far enough to allow discharging (and feeding) an open-mouth bag intended for filling between the holding grippers 12.

[0075] FIG. 5 shows another variant with holding grippers 12 pivotable, not by vertical but by horizontal axes 36. The holding grippers 12 can pivot within the supporting structure 8 and they in turn serve to seize the gusseted regions 3 of the open-mouth bags 2. Again, the open-mouth bag 2 is received on the filling spout 6.

[0076] FIG. 6 finally shows a schematic side cross section of the apparatus of FIG. 1, with a filled open-mouth bag 2 schematically inserted.

[0077] The lowered position 35 of the supporting structure including the filling spout 6 and holding grippers 12 shown in FIG. 6 is taken shortly after beginning filling, so that the bottom end 9 of the open bag 2 intended for filling can already be processed by the compacting device 16 during a considerable portion of the filling process so as to achieve effective compaction of the bulk material intended for bagging.

[0078] Upon completion of the filling process, the filled open-mouth bag is closed and discharged by the conveyor device 7. The filling spout 6 respectively the supporting structure including the filling spout 6 is transferred upwardly to the elevated position 34, so that the bottom end 9 of the next open-mouth bag 2 intended for filling is once again freely suspended above the conveyor device 7.

[0079] FIG. 7 shows a simplistic side view of the pendulum unit 44 with the pre-opening station 39 attached thereto. In the position shown in broken lines the open-mouth bag 2, also shown in broken lines, is in a downwardly position and has already been pre-opened by the pre-opening station 39. A pivoting or pendulum motion pivots the pre-opened open-mouth bag 2, presently to the right and upwardly, so that the pre-opened open-mouth bag 2 is pulled over the filling spout 6 from beneath. Relatively speaking, the filling spout 6 dips into the pre-opened open-mouth bag 2 from above. The open-mouth bag 2 is then opened completely by tipping the flap spout open.

[0080] Since the apparatus shown is a high-performance machine which allows to manufacture and fill up to 2600 open-mouth bags and more per hour, the index time per each index is just slightly longer than 1 second. Thus, only a duration of mostly less than 1 second is available for the filling process proper. This is why an early beginning of effective compaction is considerably advantageous.

[0081] On the whole the apparatus according to the invention and the method according to the invention offer considerable advantages since the efficiency of filling bulk materials into open-mouth bags can be increased considerably, involving little complexity and ease of operation, by way of a single and indexed “simple spout lift”. The conveyor device may and should be disposed up to beneath the filling spout so that a compacting device disposed there acts on the bottom end of the open-mouth bag already during filling. It is not required to have a drop-down conveyor belt as is provided in the prior art. It is sufficient to elevate the filling spout with the appended open-mouth bag and to start the filling process. During the filling process the open-mouth bag is lowered back down on the conveyor device and the compacting device contained therein. It has even been found that the drive for elevating the filling spout including the holding grippers does not need to be configured more powerful than the drive for elevating the filling spout used thus far, although now the supporting structure 8 does not only hold the filling spout 6 and the empty open-mouth bag 2 during the filling process but also holds a considerable portion of bulk material before the partially filled open-mouth bag 2 is deposited on the conveyor device 7.

[0082] Furthermore, no thrust flaps are required for pulling the open-mouth bag 2 off a separate vibrator. This releases the load on the drive for the conveying device somewhat. The drive for the conveyor device 7 does not need to be designed more powerful since a filled bag had to be accelerated previously.

[0083] The bulk materials bagged are preferably granular products. It is also possible to bag cement or similar products using the apparatus according to the invention.

[0084] Another advantage is that a separate drive for elevating and lowering a compacting device can be dispensed with. The compacting device does not require elevating and lowering in operation.

[0085] It is also advantageous that the compacting device can be integrated in the conveyor device or in the bag discharge belt where it may be positioned immediately beneath the carrying belt side. A considerable advantage is that the conveyor device is generally static and there is no drop-down section.

TABLE-US-00001 List of reference numerals:  1 apparatus  2 open-mouth bag  3 gusset  4 control device  5 filling station  6 filling spout  7 conveyor device  8 supporting structure  9 bottom end  9a unfolded bottom 10 gripper 11 feed gripper 12 holding gripper 13 discharge gripper 14 deflection roller for 15 15 belt section 16 compacting device 17 resting surface 18 drive for 8 19 eccentric member 20 conveying device 21 support frame 22 swing arm 23 pendulum drive 24 roll accommodation 25 tubular film roll 26 flap spout 27 bag forming station 28 cooling station 29 bottom seam station 30 head end 31 deflection roller for 32 17 tubular sheet 33 cutting knife 34 elevated position 35 lowered position 36 pivot point of 12 37 drive for 7 38 height adjustment of 7 39 pre-opening station 40 frame 41 welding jaw 42 top seam welding station 44 pendulum unit 45 support