EP2268481B1 - Device and method for producing bags - Google Patents

Abstract

A device for production of bags that preferably consist mostly of paper includes a perforation device for cross perforation of a material web, a tube formation device for formation of a tube from the material web, a first separation device to separate individual tube sections, a device to form a bottom on one of the ends of the tube section, and a second separation device with which individual material sections can be torn off from the tube sections or bags.

Description

The invention relates to a device for producing bags according to the preamble of claim 1 and to a method for producing bags according to the preamble of claim 11.

Devices and methods of the type mentioned are already known for many years. Thus, the German patent publication DE 720 665 a machine for producing flat or side-folding bags, in which a material web unwound from a roll, folded into a tube and separated into individual pieces of hose, which are then provided in each case with a bottom.

In one embodiment shown there, a web is first provided with transverse perforations, wherein at each perforation individual perforation sections are offset in the direction of travel of the web relative to other sections. After creating the tube and the tearing off of individual tube sections, this offset perforation results in parts of the rear wall projecting beyond the front wall at one end of the tube section. This over the front wall going beyond part of the rear wall is also referred to as a tab. Accordingly, the front wall towers over the rear wall at the other end. In general, the perforation is designed so that at the leading end of the hose section, the rear wall projects beyond the front wall. This procedure is chosen because then easily folded back the tab and attached to the front wall, for example, glued, can be. Often, parts of the front wall are folded back together with the tab and glued, which is the tightness of the bag and the durability of the soil increases. For example, the back wall needs only run on a stationary resistance. These bags produced in this way are referred to below as "conventional bags".

More recently, however, bags have been increasingly requested in which a strip of transparent material is longitudinally incorporated in the front wall. The folded back wall on the front wall is usually printed, since in comparison to conventional bags, the printable area on the front wall is lower overall. However, it is also often desirable in this type of bag that at the rear, open end also the rear wall projects beyond the front wall in order to fill such a bag in a simple manner.

Conventional bags were simply rotated about the longitudinal axis so that the back wall became the front wall and vice versa. But then the tab with which the bag is closed, on the - then new - rear wall arranged. For bags with a transparent strip but then printable area is lost.

In order to create a desired bag, it is therefore necessary to remove a piece of material at the open end of the front wall, so that here also the rear wall then projects beyond the front wall.

From practice machines are already known, with which this material portion of the front wall of the trailing end is removable. This is done together with the step of separating a tube section from the tube. The leading end of the tube is detected by the nip of a pair of rollers, which is often referred to as Abreißwalzenpaar. Since the rolls of this pair of rolls have a higher peripheral speed than the rolls of the last pair of feed rolls, the hose section tears off along the perforation line. At the same time, the part of the front wall projecting beyond the rear wall is grasped and held, so that this part is covered both by the disconnected hose section as well as the then new leading end of the hose tears off. To hold this part another roller pair is used in which the peripheral speed of the rollers is smaller than the peripheral speed of the rollers of the Abreißwalzenpaares, but greater than the peripheral speed of the rollers of the feed roller pair. These other rollers can be considered as an additional tear-off. Such devices are from the document DE 647 889 B known.

The device described operates very slowly in comparison to devices for the production of conventional bags. Also, the separated part can often not be removed reliably, so it can lead to malfunction of the machine to stoppages. The setting of the three mentioned pairs of rollers to each other is very difficult. In addition, the required speed differences often create problems and limit the possible section lengths.

The object of the present invention is therefore to propose an apparatus and a method for the production of bags, wherein a material part of the front wall is removed, which overcomes the mentioned disadvantages of the described device of the prior art.

The object is achieved by a device comprising the characterizing features of claim 1, and a method having the characterizing features of claim 11.

Accordingly, it is provided that the additional tear-off device is spaced in the transport direction of the hose from the separating device, wherein the material portion is torn off by means of the tear-off device when the hose section or bag has left the first separator. The basic idea of the present invention is, in principle, not to change the separating device for separating individual tube sections of machines for producing conventional bags in comparison with the described machine known from practice. Order now To be able to separate material section, a further separating or tearing device is provided. This further tear-off device operates independently of the first separating device for separating individual tube sections, but according to the same functional principle. It can even be identical to the first separator. The separation of a hose section from the hose and the separation of the material section thus takes place in two separate steps in two separate stations. With the invention, therefore, the processing speed, which is known from machines for the production of conventional bags, can be maintained, since not only the separating device for separating individual tube sections can be operated at this speed, but also the additional separating device. In addition, a device according to the invention operates much more reliably, since no complex, the torn-off material portion removal device must be provided within the first separator. The material section can be removed from one of the rollers separating the material section. It is preferably torn from a bag or hose portion of the material portion which runs in front of a separation section just isolated hose section or a to be singulated in the separator hose section. The bag or hose portion from which the material portion is torn off may directly precede the latter hose portion, or other lengths of hose may pass therebetween. Between two tube sections or two bags, in which the material sections are to be separated, so there is a gap. This gap is characterized in that no components of the first tube section or the first bag with components of the subsequent tube section or the subsequent bag overlap. In particular, the material section to be separated of the section of tube that is running ahead does not overlap with the tab of the subsequent tube section which is in advance.

In an advantageous embodiment of the invention, it is provided nachordnen the additional tear-off device of the device for molding the soil. Such a device is particularly easy from a Construct apparatus for making conventional bags by coupling an additional tear-off device. The additional tear-off device can be produced, for example, as an additional module, which can optionally be offered and sold or even retrofitted later. If such an additional tear-off device is present at said position, it can also be put out of operation if conventional bags are to be produced. A device according to the invention can therefore also be used very flexibly when it comes to producing different kinds of bags.

In an alternative embodiment, it is provided to pre-store the additional tear-off device of the device for molding the soil. A device manufactured according to this embodiment is more compact than the machine described in the previous paragraph. In this embodiment, it is even conceivable that the material portion from the front end of the hose portion can be torn off. This is only possible in the first-mentioned embodiment, when the bottom is formed at the trailing end of the hose section, which is, however, apart from the rule due to the relatively complicated procedure.

In a further embodiment of the invention, a device for removing material sections is provided in the additional tear-off. This has the task of safely removing the material section from the transport path of the tube sections or bags, so that there are no shortcomings in the bag production. This device may include suction devices, pliers or a combination of suction and pliers. However, it is preferred that the device for removing material sections comprises at least one needle roller. The said device for removing material sections can simply consist of needles which are associated with one of the rollers of the Abreißwalzenpaares, so that no additional needle roller is required. These needles may be disposed within the roller and slidably mounted relative to this roller. This makes it possible for the Extend needles when the material section is to be taken, and retract the needles again when the material section is to be removed again from the roller. The removal of the abzunehmenden of the roller material sections is advantageously carried out by means of a suction device.

In an advantageous embodiment, it is provided that the first separating device for separating individual tube sections, which is also referred to as a first tear-off device in this patent application, comprises holding means with which or which the material section to be torn off later is fixed. Such holding means are moved so that the material portion is at rest relative to the piece of tubing to which this portion of material belongs. Thus, if the material section is at the trailing end of the hose section to be torn off, the retaining means must move with the circumferential speed of the rollers of the roller pair, which accelerates the hose section to be torn off. However, should the material portion remain at the leading end of the hose from which the hose portion is torn off, the retaining means must move at the transport speed of the hose. As holding means are preferably the peripheral surfaces of other rolls in question. Optionally, can be dispensed with additional holding means when the Abreißwalzenpaar or Vorzugswalzenpaar detect the abstressed tube section or the following hose directly in the region of said material section.

In this context, it should be mentioned that at all points in this application, where rollers are mentioned, any circulating transport means are conceivable, such as conveyor belts, which are guided over several rollers or rollers and ultimately fulfill the same purpose as the aforementioned rollers.

In a preferred embodiment of the invention, it is provided that the second tear-off station can be driven by a drive separated from the drive of the main machine. In order to be able to extend the said device by a second tear-off station, there is no need for a geared connection be made between the drive of the actual machine to the second tear-off. This facilitates the assembly work.

It is equally advantageous if the second tear-off station is arranged in a machine frame which is independent of the machine frame of the main machine. Both machine frames can then be interconnected via fasteners such as screws, but ultimately form independent units. Incidentally, the main machine is understood to mean the machine part with which "conventional bags" can be completely produced.

In a further embodiment of the invention it is provided that a storage cylinder in the machine frame, in which the second tear-off is arranged, is mounted.

Further embodiments of the invention will become apparent from the subject description and the other claims.

Fig. 1

Seitenansicht einer ersten Ausführungsform einer erfindungsgemäßen Vorrichtung

Fig. 2

Seitenansicht einer ersten Ausführungsform einer erfindungsgemäßen Vorrichtung

Fig. 3

Seitenansicht einer weiteren Ausführungsform einer erfindungsgemäßen Vorrichtung

Fig. 4

Detailansicht der zweiten Abreißstation

Fig. 5

Detailansicht der ersten Abreißstation

Fig. 6

Draufsicht auf eine Materialbahn, die mit Perforationen versehen ist

Fig. 7

Aufsicht auf ein Schlauchstück, welches vereinzelt wurde.

Fig. 8

Aufsicht auf ein Schlauchstück, bei welchem ein Materialabschnitt abgerissen wurde.

Fig. 9

Aufsicht auf einen fertigen Beutel

Fig. 10

Längsschnitt durch eine Nadelwalze in einer erfindungsgemäßen Vorrichtung

Fig. 11

Ansicht XI - XI aus Fig. 10

Fig. 12

Nadelwalze aus Fig. 10, jedoch um 90 Grad gedreht

Fig. 13

Ansicht XIII- XIII aus Fig. 12

The individual figures show:

Fig. 1

Side view of a first embodiment of a device according to the invention

Fig. 2

Side view of a first embodiment of a device according to the invention

Fig. 3

Side view of another embodiment of a device according to the invention

Fig. 4

Detail view of the second tear-off station

Fig. 5

Detail view of the first tear-off station

Fig. 6

Top view of a material web, which is provided with perforations

Fig. 7

Top view of a piece of tubing, which was isolated.

Fig. 8

Top view of a piece of hose in which a piece of material was torn off.

Fig. 9

Top view of a finished bag

Fig. 10

Longitudinal section through a needle roller in a device according to the invention

Fig. 11

View XI - XI off Fig. 10

Fig. 12

Needle roller off Fig. 10 , but rotated 90 degrees

Fig. 13

View XIII-XIII Fig. 12

Fig. 1 shows a device 1 for the production of bags. In this figure, the essential components of this device are shown schematically. The device 1 comprises an unwinding device 2, to which a material web 3 in the form of a roll 4 is fed. Starting from this winding 4, the web 3 is fed via guide rollers 5 to the cross-cutting station 6 or perforating station 6. This station 6 comprises one or more cross-cutting or transverse perforating blades, not shown in detail, which rotates on a roller 7. The web 3 runs in this station 6 via a counter-pressure roller 8, which has the main purpose to provide the necessary for the cutting or perforating counter pressure. In this cutting or perforating the web is not severed, but provided with weakening cuts or perforations along which later breaks the tube to be formed for singulation in pieces of hose. The perforations for later tearing of the material sections are introduced in the described station 6 in the web. For this purpose, the roller 7 in certain areas on knives, which are arranged parallel to each other.

Subsequently, the material web 3 passes through a nip formed by a further guide roll 5 and a roller formed as a longitudinal glue 26. This applies glue on a side region of the material web 3, so that both side regions after the hose formation, which will be described below, permanently connected to each other.

In the subsequent tube forming station 9, a tube 10 is formed from the material web 3, by the web 3 by means of guide elements, such as guide plates, taken laterally, so that the edges of the web subsequently overlap. The subsequently overlapping regions were already provided by means of the longitudinal glue 26 with a suitable adhesive. During the wrapping of the paper web also gussets can be inserted. The insertion of the gussets can also be done after the hose formation. The tube 10 is now usually continued in the transport direction z.

After the tube 10 has been produced, this is singulated in the tear-off 11 to pieces of tubing 12. For this purpose, the tube 10 is guided through the nip of a first pair of rollers 13. During the further advancement of the hose this passes into the nip of a second pair of rollers 14. The rollers of the second pair of rollers have constantly or at least temporarily a greater peripheral speed than the rollers of the first pair of rollers 13 whose peripheral speed advantageously coincides with the transport speed of the tube 10. When the next perforation seen from the leading end of the tube has passed the nip of the first pair of rollers 13, the second pair of rollers 14 engage the tube 10. This can be done by entering the leading end of the tube in the nip of the second pair of rollers. However, the rollers of the second nip 14 can also be moved relative to the hose 10, for example vertically, and applied to the hose. As the rolls of the second nip 14 abut the tube, the tube ruptures along the cut or perforation introduced into the web at station 6.

The piece of tubing 12 torn off from the tube now enters the floor gluing and floor folding station 15. For this purpose, the piece of tubing 12 is held on the floor maker cylinder 16. By a suitable element, for example by a rod, the forward-running tab of the tube piece, which is usually components of the underside and the top dominates, folded, so that parts of the lower layer rests after folding on the outside of the upper layer. Previously, the tab and / or the region of the outer side of the upper layer on which the tab rests after folding over, provided with an adhesive, such as glue. Serves the glue applicator, which in the FIG. 1 symbolized by the glue cylinder 17.

After the bag has been completed so far, this passes through a second tear-off station 18. This tear-off station 18 is thus arranged downstream of the bottom maker cylinder 17. This station is basically constructed like the first tear-off station 11 and operates analogously. The distances between the two nips are set so that the nip of the pair of rollers 19 detects only the material portion of the upper layer, which protrudes beyond the lower layer, while the pair of rollers 20 ensures an accelerated further transport of the bag. This portion of material is then removed in an advantageous manner. After tearing off said material section of the bag is placed on a table 22 by means of a storage cylinder 21. The bags are usually arranged vertically. Vorr this table 22, the bags can then be removed in batches in a suitable manner.

The FIG. 2 shows a further embodiment of a device according to the invention. The basic operating principle does not differ from that of a device according to the FIG. 1 why identical elements have been given the same reference numerals. The second tear-off device 18 is now arranged in the transport direction z in front of the Bodenbeleimungs- and Umklappstation 15. In this case, therefore, only the material section at the rear end of the hose section is torn off before the floor is made. The bags, which with the device according to the in the FIG. 1 shown embodiment, do not differ from the bags, which with a device according to the in the FIG. 2 shown embodiment have been made.

The devices shown in the two embodiments differ not only with respect to the arrangement of the second tear-off 18. Furthermore, in the embodiment according to FIG. 2 the Bodenmacherzylinder 16 at the same time as a storage cylinder, so that it can be dispensed with a separate storage cylinder. However, the second tear-off must be considered from the beginning in the construction of a device according to the invention. According to the embodiment FIG. 1 the second tear-off station 18 can also be provided later or optional. This is in the FIG. 1 indicated by the dividing line 23, which indicates that the second tear-off 18 and consequently also the storage cylinder 21 in a separate from the machine frame of the main engine 24 machine frame, so in the machine frame 25 of the second tear-off can be stored. In principle, the second tear-off station can be provided with its own drive, which supplies the rolls of this tear-off station 18 with torque. Other possibly necessary elements of this tear-off station can be supplied with power from this drive motor. The storage cylinder, if present, can be supplied in this way with power or torque. Of particular advantage is this separate drive when a device according to the invention according to the FIG. 1 is executed. In this case, a full modularity is given, since the second tear-off works completely independently and therefore an existing device for the production of bags can be provided in a simple manner. But also in a device according to the FIG. 2 has a separate drive the advantage that the second tear-off can be retrofitted.

The FIG. 3 shows again a device according to the FIG. 1 , In comparison to FIG. 1 now the roller of the roller pairs 19 and 20 have been provided with reference numerals. The roller 50 of the roller pair 19 is designed as a needle roller, which in FIG. 4 is explained in more detail. The roller 51 is designed accordingly as a counter-pressure roller, which may include depressions into which the needles can dip. These depressions can be configured, for example, as boreholes or as grooves. Above the needle roller 50, a scraper device designed as a suction device is provided, which has the purpose of removing a material section received in the roller nip by the needle roller 50 from the needle roller 50 again. The stripping device is not limited to the interaction with a needle roller. It may also cooperate with other transport means capable of tearing off a section of material from a bag or hose section. Such a transport device may for example be a suction roller.

The FIG. 4 shows enlarged the roller pairs 19 and 20. The roller 50 of the roller pair 19 is equipped with needles 55, two of which can be seen. These needles 55 are slidably mounted within the roller 50 and are moved out of the peripheral surface of the roller 50 just before or when they reach the counter-pressure roller 51. At this moment, the material section 38 should be detected. The tearing of the material portion 38 is carried out either by the holding by means of the needles 55 or by the fact that the material portion in the gap of the rollers 50 and 51 is held or by both. If, after further rotation of the roller 50, the material section has reached the region of the suction device 54, the needles 55 can be retracted again within the body of the roller 50, so that the suction of the material section is facilitated. The extension and retraction of the needles can be done for example by a guide surface, not shown. The needles may be spring-loaded, for example, so that they are in the basic position within the roll body. To extend the needle, these can then run over a guide surface, which is arranged so that the needles are pressed against the spring force to the outside. However, the needles can also be moved in another direction in the direction of the double arrow R, which indicates the radial direction of the roller 50. For example, controllable pneumatic cylinders are conceivable.

While needles 55 have engaged the material portion 38, the bag 39 is already in the nip between the rollers 52 and 53. The peripheral speed of these rollers is substantially equal to the transport speed with which the bags or pieces of tubing are transported through the apparatus. The circumferential speed of the rollers 50 and 51, at least in the period between the detection of the material portion 38 and the tearing off, is smaller than this transport speed, in order to allow the tearing in the first place. However, since the average rotational speed, ie the distance after a complete rotation of the roller 50 divided by the associated time, must be equal to the transport speed, the roller 50 must be non-uniform, that is driven with non-uniform angular or peripheral speed become. This can be done for example via a known non-uniformity gear or a separate servo motor.

The phase angle of the rollers 50 can be adjusted in the direction of the arrows φ and -φ in order to be able to process tube pieces or bags of different formats.

The FIG. 4 was previously described only in connection with an arrangement of the second tear-off behind the Bodenbeleimungs- and Umklappstation 15. A second tear-off station, which is located in front of the ground gluing and folding station 15, can operate in the same way.

The FIG. 5 shows the rollers of the roller pairs 13 and 14 in closer view. The upper roller of the roller pair 13 has on its peripheral surface an increase 56. Only when the elevation enters the nip of the rollers of the roller pair 13, the hose located therein is held between the rollers. In the same way, the roller pair 14 may be configured. Now, if the peripheral speed of the rollers of the roller pair 14 is greater than that of the roller pair 13, so when a perforation has passed through the nip 13, a tearing off. In general, run, at least at the moment of tearing, the rollers of the roller pair 14 at a peripheral speed which is greater than the transport speed, and the rollers of the roller pair 13 at a peripheral speed which is smaller than the transport speed of the hose, the hose pieces or Bag in the device.

The FIG. 6 shows the material web 3 after passing through the perforating 6. The middle region 30 of this material web forms after passing through the tube forming station 9, the lower layer of the tube or the subsequent bag. The two lateral regions 31 and 32, which may each have a different width, later form the upper layer of the finished bag. The lateral region 32 can also be additionally divided into 32 and 32 ', wherein the region 32' may comprise transparent material, preferably transparent plastic film. The material from which the Areas 30, 31 and 32 are made, is a non-transparent material, preferably paper. The connection between the non-transparent material and the transparent material may have already taken place when the material web is wound on the winding, which is later supplied as a winding 4 of the device. However, the merging of the transparent and the non-transparent material can also take place within the device 1 according to the invention.

The material web 3 is provided with Querperforationen 33, which are shown as a dotted line. These transverse perforations are subdivided into a region 34 in which the perforation lies on a single line. This area lies substantially in the middle region 30 of the material web. In the other regions of the transverse perforations, this single perforation divides into two parallel perforations 35, 36. The area between the perforations 35, 36 forms the portion of material which is removed and removed in the second tear-off station 18.

The FIG. 7 shows the hose pieces 12, which by forming a tube from the material web 3 according to FIG. 3 and was produced by dicing. The arrow z illustrates the transport direction. During the singulation process, the advance sack tears along the line of perforations formed by the perforation line sections 34 and 35. In order to ensure that the line section 35 and not the line section 36 actually breaks, holding elements engage the material section 38 and ensure that the hose section and the material section are moved on with the same speed. Even if now the line sections 34 and 35, the hose piece in the FIG. 7 are bounded, they are still drawn, the edge 34 is now shown as a dashed line, as it represents an invisible edge. Seen in the direction of transport, the lower layer 30 now projects beyond the upper layer, for which reason the front flap 37 is visible from the lower layer.

At the trailing end of the tube piece 12 projects beyond the upper layer, by the in the FIG. 6 designated by the reference numerals 31, 32, 32 ' lateral areas is formed, the end of the lower layer. The perforation 36 is visible in this case and therefore still shown with a dash-dotted line. This perforation limits the portion of material 38 which is torn off in the second tear-off station 18 from the piece of tubing 12 or bag.

The FIG. 8 shows this hose section 12, from which now the material portion 38 has been torn off. Now not only towers at the front end, but also at the trailing end of the lower layer, the upper layer. The former perforation 36 now forms the end edge of the upper layer. The previous perforation 34 is now visible as the trailing edge of the lower layer.

The FIG. 9 again shows the tube section 12, which has been closed by folding the front flap 37 on the upper layer and now represents a finished bag 39. It should be noted again at this point that in the FIGS. 7 to 9 a flat bag is shown, which has no gussets. Nevertheless, the described steps can also be applied to gusseted bags, which are customary for packaging, for example, baked goods.

The FIG. 10 shows an embodiment of a needle roller 50 and in particular the control of the displacement of the needles within this needle roller.

The needle roller 50 initially comprises a cylinder body 60, which is configured as a hollow cylinder and which has a central opening 62 at its end faces 61. Externally, another hollow cylinder 63 is attached to one end face. The cylinder body 60 and / or, as in the Fig. 10 is shown, the hollow cylinder 63 are rotatably supported via a bearing 64 in the machine frame 25. At least one of the hollow cylinder 63 is acted upon by a drive with a torque. The drive may, for example, act on a toothed belt which transmits the drive torque to the hollow cylinder 63 by means of gears, which thus acts as a shaft. Another cylinder 65 penetrates both the hollow cylinder 63 and the central opening and thus projects into the interior of the cylinder body 60. About the bearing 66, the hollow cylinder 63 can still be supported on the cylinder 65. This cylinder 65 can be fixed to non-illustrated parts of the machine frame 25, but can also be rotated relative to this. This twisting possibility serves as described below, the adjustment of the needles relative to the outer surface of the cylinder body 60th

In the cylinder body 60, a needle carrier 67 is slidably mounted in guides 68, so that it is displaceable in the direction of the double arrow R relative to the cylinder body 60 (see FIG. 11 ). The guides 68 are in the in the FIG. 10 shown embodiment of two plane-parallel planes, which represent slip planes for the needle carrier. However, they can basically be designed differently for this purpose, as long as they allow the displacement of the needle carrier in the direction of the double arrow R. The needle carrier 67 carries on each of its two side surfaces a row of needles 72 which can pass through recesses 73 of the outer surface 74 of the cylinder body 60. At the end faces 69, the needle carrier 67 has elliptical recesses 70. In these elliptical recesses 70 engage rollers 71 which are fixed to the needle carrier 67 facing the end face of the cylinder 65, wherein the axis 75 of the roller 71 is not aligned with the axis of the cylinder 65, but is arranged eccentrically to this. The roller may be rotatably mounted on the cylinder 65.

So far in relation to the FIG. 10 only the first, right end of the needle roller 50 is described. The second, left end has an analog structure. However, here can be dispensed with facilities for applying the roller with a torque. The FIG. 12 shows the same roller 50 as the FIG. 10 , but further rotated by an angle of 90 °.

The function of the needle roller 50 can be determined by the FIGS. 11 and 13 be explained. In the initial position are the upper needles, which are in the so are located "12 o'clock position" completely sunk within the cylinder body 60. By contrast, the lower needles 72 '("6 o'clock position") are extended as far as possible and project beyond the outer surface 74 of the cylinder body 60. In this position, the needles 72' are able to grip a material section 38. Now, if the cylinder body 60 is rotated in accordance with the arrow D, so remains as described, the roller 71 in position. However, the elliptical recess 70 rolls with the outsides on the roller 71. Since the needle carrier is not freely movable, but only in the direction of the arrow R is displaceable, the needle carrier 67 is acted upon by the action of the roller 71 on the outer sides of the elliptical recess 70 with a resultant constraining force, which points in the direction R.

In order to be able to change the angular position in which the needles 72 or 72 'have extended as far as possible in the direction φ or -φ (see FIG. 4 ), now the cylinder 65 can be rotated relative to the machine frame. This is possible even during operation of the device according to the invention. With the rotation of the cylinder 65 and the axis of rotation 73 of the roller 71 is pivoted by the same angular amount, which has the consequence that also the position in which the needles 72 and 72 'are extended as far as possible, is changed by this angular amount. If, for example, the cylinder 65 is rotated counterclockwise by 30 degrees, the position in which the needles 72 or 72 'are extensible as far as possible is changed to the so-called 5 o'clock position.

The situation after a quarter turn (rotation by 90 °) is in the Fig. 12 shown. Now, the main axis of inertia of the needle carrier 67 is located on the axis of rotation of the cylinder body 67. Thus, the needles 72 and the needles 72 'protrude equidistant out of the cylinder body. In the further course of the rotation, the needles 72 'are pulled further and further into the cylinder body, so that a portion of material held by the needles 72' on the peripheral surface of the cylinder body is released again. The complete release of this material section takes place in the area of
Suction device 54, so that the material portion can be reliably removed from the second separation station. LIST OF REFERENCE NUMBERS 1 Device for producing bags 2 unwinding 3 web 4 reel 5 guide roll 6 Cross-cutting station / perforating 7 roller 8th Backing roll 9 Tube formation station 10 tube 11 first tear-off station 12 hose Connector 13 first pair of rollers / pair of retaining rollers 14 second pair of rollers / Abreißwalzenpaar 15 Floor gluing and folding station 16 Soil makers cylinder 17 Adhesive cylinder / folding blade 18 second tear-off station 19 roller pair 20 roller pair 21 storage cylinder 22 table 23 parting line 24 Machine frame of the main machine 25 Machine frame of the second tear-off station 26 longitudinal gluing 27 28 29 30 middle area / lower location 31 lateral area 32, 32 ' lateral area 33 cross perforation 34 Area of perforation 35 perforation 36 perforation 37 front flap / tab 38 material section 39 bag 50 needle roller 51 Backing roll 52 pulling roller 53 Backing roll 54 suction 55 needles 56 increase 57 58 59 60 cylinder body 61 faces 62 central opening 63 hollow cylinder 64 camp 65 cylinder 66 camp 67 needle carrier 68 guide 69 Front side of the needle carrier 67 70 elliptical recess 71 roll 72 needles 73 recess 74 outer surface 75 Rotary axis of the roller 71 Z Transport direction of the hose A suction direction φ circumferentially R Radial direction; Displacement direction of the needle carrier 67 D Direction of rotation of the cylinder body 60

Claims (11)

1. Apparatus (1) for producing bags which preferably consist mostly of paper, comprising:

   - a perforation device (6) for transversely perforating a material web (3),

   - a tube-forming device (9), for forming a tube (10) from the material web (3),

   - a severing device (11), for severing individual tube portions (12),

   - a device (15, 16, 17) for forming a bottom at one of the ends of the tube portion (12),

   wherein at least one additional tear-off arrangement (18) is provided, and this makes it possible to tear off individual material portions from the tube portions (12) or from the bags,
   characterized in that
   the additional tear-off device (18) is spaced apart from the severing device (11), as seen in the transporting direction (z) of the tube, wherein the material portion can be torn off by means of the tear-off device (18) when the tube portion or the bag has left the first severing device.
2. Apparatus (1) according to the preceding claim,
   characterized in that
   the additional tear-off arrangement (18) is arranged downstream of the bottom-forming device (15, 16, 17).
3. Apparatus (1) according to Claim 1,
   characterized in that
   the additional tear-off arrangement (18) is arranged upstream of the bottom-forming device (15, 16, 17).
4. Apparatus (1) according to one of the preceding claims,
   characterized in that
   the additional tear-off arrangement (18) comprises a device (54) for removing the material portions (38).
5. Apparatus (1) according to the preceding claim,
   characterized in that
   the device (54) for removing the material portions (38) comprises at least one needle roller (50).
6. Apparatus (1) according to one of the preceding claims,
   characterized in that
   the severing device (11) for severing individual tube portions (12) contains at least one retaining means, by way of which the material portion (38) can be gripped and which moves such that the material portion is at rest relative to the tube portion (12) to which the material portion is still assigned.
7. Apparatus (1) according to one of the preceding claims,
   characterized in that
   the additional tear-off device (18) comprises at least two pairs of rollers (19, 20), wherein the rollers of a second pair of rollers - as seen in the transporting direction (z) of the tube portions (12) or of the bags (39) - can be operated at a circumferential speed which corresponds to the transporting speed of the tube portions (12) or of the bags (39), and
   in that the material portion (38) can be gripped by a first pair of rollers (19) which, at least at the moment when the material portion (38) is gripped, can be operated at a circumferential speed which is reduced in relation to the transporting speed of the tube portions (12) or of the bags (39).
8. Apparatus (1) according to one of the preceding claims,
   characterized in that
   the second tear-off station (18) is driven by a separate drive.
9. Apparatus (1) according to one of the preceding claims,
   characterized in that
   the second tear-off station (18) is arranged in a machine framework (25) which is independent of the machine framework (24) of the main machine.
10. Apparatus (1) according to the preceding claim,
    characterized in that
    a set-down cylinder (21) is arranged in the independent machine framework (25).
11. Method for producing bags (39) which consist preferably mostly of paper, wherein the method comprises the following steps:

    - transversely perforating a material web by means of a perforation device (6),

    - forming a tube from the material web using a tube-forming device (9),

    - severing individual tube portions (12) by means of a severing device (11),

    - forming a bottom at one of the ends of the tube portion by way of a bottom-forming device (15, 16, 17),

    characterized in that
    material portions (38) are additionally torn off from the tube portions (12) or from the bags (39) in an additional tear-off arrangement (18) after the tube portion (12) or the bag (39) has left the severing device (11), and has been transported further in the transporting direction, and before the tube portion (12) or the bag (39) passes to the set-down cylinder or the bottom-forming cylinder.

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