DE102007015251A1 - Machine for filling and closing sacks - Google Patents

Abstract

The invention relates to a machine for filling and closing sacks, which have a first gripper pair (50) for holding the sack (8) in the filling station (60) and a second gripper pair for further transport of the filled sack, wherein the gripper means pairs are arranged such that they keep the bag (8) in its desired position on both sides of its main axis of symmetry (Hs). At least one gripping means (50, 52) of the first pair of gripping tongs is arranged such that its inner edge (55) is closer to the main axis of symmetry (Hs) of the bag (8) when holding the bag than the inner edge (56) of the gripping means (52). of the second pair of gripping means provided for gripping the bag (8) on the same side of the main axis of symmetry (Hs) of the bag (8).

Description

The The invention relates to a machine for filling and closing of sacks and a method of manufacturing, filling and sealing plastic bags with filling material and to close the filled sacks.

Such a device is for example from the DE 93 01 355 U known. 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 Fill and Seal) category.

at the filling of dusty bulk materials Machines of the named category via gravity or by free fall, the product displaced, dusty air can escape from the bag. In the escape The air often causes contamination in the upper edge areas of the bag. Due to the contamination with product dust can the bag by means of the usual in this type of packaging generally Welding can not be closed securely. About that In addition, the dust pollutes the environment and must be extracted separately become.

Further performs the filling of dusty goods the known filling method described in the rule to a significantly inflated product volume or to a significant reduction in bulk density, since the product accumulates strongly in the free fall with air. This, in turn, leads to bottling the product initially significantly more packaging material is needed. In addition, the air must be back can escape from the bag, since he is not otherwise can be stacked or stored.

There The escape of air usually takes a long time, the Vent not already before closing the sack take place. The bag must therefore have a perforation. This additionally pollutes the environment because of the perforation the packaging the fine-grained, dusty products to Part can get outside.

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. The EP 1 459 981 A1 suggests, therefore, to introduce the filler neck of a metering of an FFS machine in the opening of a bag. In the WO 2006/053627 A1 on the other hand, the relative movement between the bag and the filler neck is accomplished by a movement of the bag.

In Both of the aforementioned publications Dosierorgane be presented, containing the snails. These screws promote the filling material in the sacks. The preferred conveying direction in These screws corresponds to the effective direction of gravity. By the screws are left free fall of the filling material in the bag. Therefore, snails are often used for bagging dusty Filling goods used. Their use, however, is - too in relation to the present invention - by no means mandatory.

In particular - but not exclusively - when filling and then closing sacks with dusty filling goods show up again and again Problems with the formation of a clean weld. Often The weld is formed so that permanently Form wrinkles in the bag. If the wrinkles already when creating the weld, that is, when closing of the bag were present in the bag material, it may happen that the wrinkles extend into the weld. Such Wrinkles remain permanently in the closed bag and can even lead to leaks.

The The object of the present invention is a machine to propose that prevents formation of such wrinkles.

The Task is solved by claim 1. Often, such becomes one Machine is a so-called FFS machine, which is also a sack making part, in the hose pieces are provided with a bottom seam, includes. The pieces of hose are in turn to such Machine formed in which a hose unwound from a settlement and to pieces of tubing or sacks is isolated.

The invention is based inter alia on the finding that folds often form in the filling station due to the increasing load of the filling material. At least a large part of these wrinkles starts at the Main axis of symmetry of the bag facing side of the gripping means, which holds the bag while it is being filled. This first gripping means has taken over the bag usually before the filling station. In any case, it has seized the bag before the second pair of gripping means makes contact with it.

By the measure according to the invention is avoided that the folds of the second gripping means pair and fixed in be supplied to this form of welding station.

One Gripping means in the sense of this document is each to grasp the bag suitable device. Often, grabbers are used as gripping means used. However, it is also possible to bag material between pinch two jaws not connected by a forceps joint and to take it.

It is advantageous if at least parts of the first gripping means pair the bag above the contact area of the second gripping means pair attack.

Testing have shown that the mentioned wrinkles are preferred in one Area between a line and the main axis of symmetry occur. This line begins at the point of contact of the gripping means of the first pair of gripping means, in the lowest level of the contact area closest to the main axis of symmetry. The line is running diagonally down until it reaches the bag wall. Between This line and the main axis of symmetry is an angle of 30 ° to 60 °. It is advantageous if the effective range of the active agent of the second active agent pair on the same side of the main axis of symmetry entirely outside this fold area, the means between the line and the sack edge, remains.

If be used as gripping means gripper tongs, it is advantageous To arrange these pliers so that the forceps joints of the first pair of gripper tongs above of the bag are arranged, while those of the second gripper pair are arranged next to the desired position of the bag.

If the active or contact surface of a first gripping means to the contact area of the associated second gripping means extends or in the vertical direction (down) over this still extends, this is advantageous.

The Word gripper pair indicates that sacks are in such FFS machines usually seized and held on its two edges be because a Befüllgutstrom in the central area of the bag must be introduced. If carrying the bag with a plurality of contact surfaces on both sides of the Befüllgutstromes accomplished by suitable gripping means is, these gripping means are still pairs of gripping means in the sense of the present document.

Further Embodiments of the invention will be apparent from the subject Description and claims.

The individual figures show:

1 A side view of a FFS machine

2 A detail view of 1

3 A first embodiment of two gripper pairs

4 A second embodiment of two gripper pairs

5 A third embodiment of two gripper pairs

6 A side view of a claw pliers

A tubular film web 15 , preferably with inserted gussets, is initially a preferred roll system 9 in a horizontally movable transport, such as a pair of grippers 18 promoted.

The foil web 15 is, after the preference has pulled the section according to the desired bag length, from the knife 17 cut across. At the same time the bottom welding takes place 13 , The closed at the lower end empty bag 11 is a horizontally movable transport, such as a gripper 18 , transferred and transported to the filling station.

In the filling station takes over another means of transport 4 which is off 3 . 4 . 5 exists, the bag section. The empty bag is now with a suction system 16 open. For this purpose, the or the gripper 4 moved in z-direction (sack-in). The connecting piece of the transport system 3 is moved into the sack and protects the sack inner surfaces from contamination by possible product adherence to the dosing tube 2 . 21 ,

The opened sack is from the transport system 3 . 4 . 5 over the metering tube 2 . 21 pulled until the lower end of the bag is approximately equal to the Füllgutaustrittsöffnung 31 located. The bag bottom support device 32 . 33 . 34 is driven in the embodiment shown below the sack floor. A bag bottom support device 32 . 33 . 34 however, is not essential. 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 indicated by the double arrow 35 shown. In this embodiment of the invention, therefore, the bag is opposite the Befüllorgan 2 . 21 emotional. It is also conceivable, of course, the relative movement between sack 8th and metering by a movement of the metering or even by a movement of bag 8th and dosing 2 bring about. As a rule, it is sufficient in this case if the bag in this case by claw-like means of transport 4 is held at its upper end. The mentioned bag bottom support device 32 . 33 . 34 Offers optional additional protection against cracking of the just-welded sack bottom.

The sealing tube 21 is raised and gives the product outlet 31 free. The product / bulk material 24 is filled in the bag. Meanwhile, the transport system lowers 3 . 4 . 5 the bag in such a way that the product outlet opening 31 at any time below the filling level. Even before the end of the dosage of the product / bulk material 24 can the product outlet 31 but at least once above the fill level 38 are located. After completion of the filling, the sealing tube 21 lowered and closes the product outlet 31 by making contact with the closure 20 receives. The connecting piece is pulled out of the bag. The gripper (s) 4 of the transport system 3 . 4 . 5 is or will now be moved counter to the Z-direction (out of bag) and pulls or pull the opening area at the top 25 of the previously opened sack tight. Another means of transport takes over the filled bag 8th , By means of the closing device 14 will now be the top of the bag 25 locked. If necessary, it can be combined with the dosing process in the sealing tube 21 be sucked integrated filter. The required vacuum is transferred via the connection piece 23 initiated. 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 to 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 achieved by the additional use of vibration generators / knockers 29 to be reinforced. Here it is advantageous, the dosing 2 . 21 by means of a vibration generator 29 to vibrate, since it is located during the filling at least with parts of its lateral surface within the product. The vibrations are from the dosing tube 2 . 21 to the filling material 24 transferred, in which then takes place a compression. Another advantage of the "vibrating dosing tube" 2 . 21 is that the formation of product adhesion to the dosing tube 2 . 21 thereby largely avoided. The shaker 29 could also at the "Sackbodenunterstützungsvorrichtung" 34 be arranged!

A particularly advantageous embodiment of the carriage is the frame 5 together with neck 3 , Mode of Transport 4 as well as the absorption 16 to store on sensors. The sensors send their signal to a weighing electronics, which ultimately controls the dosing process.

To mention is still the guide or support 6 that the frame 5 and thus the means of transport 4 wearing. In the metering or pipe 2 there is a snail 7 , with the filling material 24 out of the funnel 1 without much dust in the bag 8th can be promoted. The different sensors 26 (Especially weighing sensors or load cells) indicate advantageous locations for attaching such sensors. The conveyor belt 27 transports the filled sacks ( 8th ). In its surroundings are the checkweigher 30 and the vibration generator 29 appropriate.

3 shows a first embodiment of the invention. The bag 8th , which already up to Füllgutpegel 38 with contents 41 is filled by the gripping means 50 and 52 held in the filling station at the same time. The gripping means are here Greiferzangenpaare, which in each case the actuators 51 and 53 are assigned, which act on the gripper tongs with force to their operation. Between the different contact zones of the gripping means 50 . 52 grips a filler neck 54 in the bag. Through this, a Befüllorgan 2 engage in the bag and direct the product flow in this. The filler neck 54 and the connecting piece 3 correspond therefore largely in their function. A gripping means pair is any gripping means which is suitable for gripping the bag on both sides of the product flow.

The gripping means 50 and 52 each have inner edges 55 and 56 , The inner edges of the gripping means 50 of the upper gripper pair are in relation to the bag 8th further inside (= closer to the main axis of symmetry thereof) than the lower pair of gripping means 52 , Between the selected point 64 which is in the lowest level of the contact area of the gripping means 50 and here the main symmetry axis Hs is closest, and the side wall 65 of the bag forms a fold 59 out. That the two gripping means 52 by its squeezing movement this fold 59 fix, is not optimal. Despite the embodiment of the machine according to the invention according to the first embodiment, there may still be slight wrinkles.

In 4 this condition is already corrected. The second gripping means are moved further outwards. In this way, their entire contact area is with the bag 8th outside the line 66 , This connects the point 64 with the bag edge or the bag side wall 65 , The point 64 is located in the lowest level of the contact area of the respective gripping means of the first gripping means pair. In this plane is the point 64 the point closest to the main axis of symmetry Hs.

Between the line 66 and the main axis of symmetry should be an angle between 30 ° and 60 °. Tests have shown that the folds preferably form between this line and the main axis of inertia Hs.

In 5 another, even more advanced embodiment is shown. The contact areas of the first gripping means 50 with the bag 8th extend in the vertical direction y "down" still on the effective range of the second gripping means 52 out. Despite these circumstances, wrinkles develop 59 out. However, these can not be determined by the second gripping means as the figure shows. In the illustrated embodiments, gripper pair pairs 62 used. The first pair of gripping means 50 grasps the bag "from above" and has a forceps joint 62 which is above the bag. It is in the 3 to 5 Not shown. The forceps joint of the second gripping means 52 lies next to the bag (x-direction). The mode of action of such a forceps is in 6 shown. The forceps 62 has a forceps joint 61 and two grippers 63 , The arrow 58 indicates the forceps movement of the grippers 63 at. LIST OF REFERENCE NUMBERS 1 funnel 2 metering 3 spigot 4 Mode of Transport 5 frame 6 guide 7 slug 8th Filled sack 9 drawing rollers 10 Mode of Transport 11 empty bag 12 guide 13 bottom weld 14 Kopfnahtschweißung 15 Blown film web 16 sucker 17 knife 18 Mode of Transport 19 unwinding 20 shutter 21 Closing pipe with filter 22 filter 23 Support 24 Product / bulk 25 Upper edge of the bag 26 sensors 27 conveyor belt 28 Directed flow 29 vibration generator 30 checkweigher 31 product discharge opening 32 guide 33 joint 34 Sack ground support 35 Double arrow (movement of the frame 5 with the bag 8th ) 36 Arrow (deviation from setpoint, sack crack) 37 Arrow (deviation from setpoint) 38 Füllgutpegel 39 bag bottom 40 level sensor 41 filling 50 Gripper of the first pair of pliers 51 Actuator of the first pair of pliers 52 Gripper of the second pair of pliers 53 Actuator of the second pair of pliers 54 sealing element 55 Inner edge of a pair of pliers of the first pair of pliers 56 Inner edge of a pair of pliers of the second pair of pliers 57 Protruding part of a pair of pliers of the first pair of pliers 58 Arrow in the direction of movement of the gripper of the pliers 62 59 wrinkle 60 filling station 61 pliers joints 62 tongs 63 Gripper of a pair of pliers 64 Selected point 65 Sidewall of the bag 66 line hs Main axis of symmetry of the bag y Vertical direction x Horizontal direction α Angle between line 66 and principal axis of inertia Hs

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 9301355 U [0002]
• EP 1459981 A1 [0006]
• WO 2006/053627 A1 [0006]

Claims (9)

Machine for filling and closing sacks comprising a first pair of gripping means ( 50 ) for holding the bag ( 8th ) in the filling station ( 60 ) and a second gripping means pair for further transport of the filled bag, wherein the gripping means pairs are arranged such that they the bag ( 8th ) in its desired position on both sides of its ( 8th ) Main axis of symmetry (Hs), characterized in that at least one gripping means (Hs) 50 . 52 ) of the first gripper pair of tongs is arranged such that its inner edge ( 55 ) holding the bag closer to the main axis of symmetry (Hs) of the bag ( 8th ) is located as the inner edge ( 56 ) of the gripping means ( 52 ) of the second gripping means pair, which is used to grasp the bag ( 8th ) on the same side of the main axis of symmetry (Hs) of the bag ( 8th ) is provided. Machine according to claim 1, characterized in that the first pair of gripping means ( 50 ) is arranged such that it has a contact area with the bag, which starts above the contact area of the second gripping means pair. Machine according to the preceding claim, characterized in that - at least one gripping means ( 52 ) of the second gripping means pair is arranged such that its ( 52 ) Contact area with the bag located in the desired position ( 8th ) entirely between a line ( 66 ) and the bag sidewall ( 65 ) on the side of the at least one gripping means ( 52 ), where the line ( 66 ) a connecting line between a selected point ( 64 ) and the bag sidewall ( 65 ) on the side of the at least one gripping means ( 50 ) which has an angle (α) of 20 ° to 60 °, but preferably 40 ° to 50 °, to the main axis of symmetry (Hs), and wherein the selected point (P) is that point in the contact area of the gripping means ( 50 ) of the first gripper pair on the same side of the main axis of symmetry (Hs), which in the lowest plane of the effective range of this gripping means ( 50 ) is closest to the main axis of symmetry (Hs). Machine according to one of the preceding claims, characterized in that the gripping means pairs ( 50 . 52 ) Are pairs of gripper tongs, and that the forceps joints ( 61 ) of the pliers ( 62 ) one of the two gripper pairs in the filling station above the position of the bag ( 8th ) while the forceps joints ( 61 ) of the other gripper pair next to the bag ( 8th ) are arranged. Machine according to the preceding claim, characterized in that the forceps joints ( 62 ) of the first gripper pair above the position of the bag. Machine according to one of the preceding claims, characterized in that the effective range of at least one gripping means ( 50 ) of the first gripper pair ( 50 ) extends in the vertical direction of the bag (y) into the region in which the contact region of the second gripper pair ( 52 ) is located. Machine according to the preceding claim, characterized in that the effective range of the first gripping means pair ( 50 ) in the vertical direction of the bag (y) at least up to the lower end of the contact region of the second gripping means pair ( 52 ). Machine according to the preceding claim, characterized in that the contact area of the first pair of gripping means ( 50 ) extends in the vertical direction of the sack (y) at least beyond the lower end of the contact region of the second gripping means pair. Method for filling and closing bags, in which a first pair of gripping means ( 50 ) the bag ( 8th ) in the filling station ( 60 ) and a second gripping means pair the filled bag ( 8th ), wherein the pairs of gripper means the bag ( 8th ) in its desired position on both sides of its ( 8th ) Main axis of symmetry (Hs), characterized in that - at least one gripping means ( 50 . 52 ) of the first pair of gripper tongs the bag in the filling station ( 60 ) holds such that its inner edge ( 55 ) closer to the main axis of symmetry (Hs) of the bag ( 8th ), as the inner edge facing the main axis of symmetry (Hs) ( 56 ) of the gripping means ( 52 ) of the second gripping means pair, which is used to grasp the bag ( 8th ) on the same side of the main axis of symmetry (Hs) of the bag ( 8th ) is provided when this gripping means ( 50 . 52 ) the bag ( 8th ) takes.