HUE035090T2 - Device and method for producing bags - Google Patents

Description

Description [0001] The invention relates to a device for the production of bags, which may be transported transversely to their direction of extension through the device, according to the preamble of claim 1 and a method according to the preamble of claim 13.

[0ÖÖ2J Such devices are known and have been available on the market for a iong time. As a rule, they initially comprise a separating device for separating a supplied hose into hose pieces. This hose preferably comprises a fabric of stretched plastic strips, which may also be coated. The separated hose pieces consist of two superposed material layers. After separation, the hose pieces are taken over by at least one transport device In order to transfer them into the individual processing stations. One of these processing stations Is the so-called bottom opening station. In this case at least one end of a hose piece is applied so that a bottom may be formed on this end. As a rule, both ends of a hose piece are precessed in this way, [0ÖÖ3J A device with which such bags may be produced is disclosed In DE 195 02 251 A1. In this device, the hose pieces are moved forwards in clocked operation, wherein they are transported lying flat transversely to their main axis so that laterally arranged processing means may process both ends of the hose piece. The hose pieces are held in the bottom opening station. Then the upper layer is raised by means of a suction piece at the ends of the hose piece so that a plate, which is horizontally displaceable in the direction of the main axis, may be inserted between the two material layers of the hose section. The lower material layer of the hose section is held down by vacuum on the table on which the hose section rests during transport. The upper matériái layer is folded back onto the outer side of the upper material layer by inserting the plate in order to form corner Inserts. After folding, the plate is withdrawn again and the bag is transported further. As a result, the hose pieces are successively taken up by a further transport device, which feeds them to a bottom closure device at a uniform speed, s.e, continuously. (GÖG4J in particular, in the case of hose pieces which comprise a fabric of stretched plastic strips, the tendency is for the open parts to fold back again. In order to counter this effect, in the afoovementioned disclosure, pressing means in the form of forming stamps are proposed, which may be lowered onto the corner inserts in order to emboss the folding lines more strongly and fix the opened bottoms. These forming stamps have the shape of the corner inserts created upon opening.

[ÖÖ05] However, the named device has a number of disadvantages with respect to tbe fixing of the opened bottoms. Particularly serious is the time required to fix the opened bottoms within the opening station. According to DE 195 02 251 A1, it is provided that the hose piece is transported further after the opened bottom is fixed. This period may even represent an upper limit to the performance of the entire bag forming apparatus.

[GOGS] However, it is already known in the field of paper bags that during the further transport, pressing means act on the opened bottoms, while the folding edges have already previously been fixed in a pre-folding station. Thus, DE 1 121 447 A1 discloses a pressing means formed as a pair of pressing rollers for pressing the opened bottoms. Furthermore, DE 1 121 447 A1 provides at least one transport means by means of which the hose piece may be transported further in the direction of transport (x) after the opening of one end of this hose piece and before the action of the pressing means.

[ÖÖG7J DE 0 898 887 discloses a similar device.

[GOGS] DE 1 273 315 discloses a still further improved device, which presses the second triangular pockets more rekabiy by applying a holding down rod to the second triangular pockets, [GOGS] In the area of the plastic bags, however, pre-folding for the precise fixing of the folding edges is not sufficient, so that pressing known from the area of the paper bags nevertheless leads to defective bottoms.

[0010] The object of the present invention is therefore to propose a device and a method for the production of bags with which the opened bottoms are fixed more quickly.

[0011] The object is achieved according to toe invention though a device with the characteristic features of claim 1 and through a method with the characteristic features of claim 13.. Accordingly, it is provided that the pressure toiler (23, 23’} has an adjustable gap with a counter layer, but wherein the gap has a fixed dimension through which at least parts of the opened bottom may be passed. After opening at least one end of the hose piece, this may thus be immediately transported further, so that space for a further hose piece may be quickly created again in the bottom opening station in order to allow at least one end to be opened. Ultimately, the efficiency, i,e. the number of bags completed per unit of time, may be significantly increased with this measure.

[0012] As already described, it is provided according to the invention that the pressing means is designed as a rotatabie pressure roller. Such pressure rollers have various advantages. DE '195 02 251 teaches that forming stamps may be formed to be lowered and raised. For this purpose, however, a targe mechanical effort is necessary. For this purpose, pressure medium piston cylinder units are proposed in the named publication for this purpose. Furthermore, in a device according to DE 195 02 251, It is a disadvantage that the forming stamps must have the shape of the corner inserts in order to work effectively. In the case of a change in format, the replacement of the forming stamps Is therefore necessary. These disadvantages are reduced by the provision of pressure rollers. [0013] The mode of operation of a pressure roller is as follows: The opened bottom is threaded under the pressure roller. The pressure roller may then exert a compressive pressure on the bottom and fix It In this way. Such a roller no longer needs to be towered or raised, which Is why the mechanical effort for fixing the bottom may be omitted, A pressing roller may be placed close behind the bottom opening station so that the bottom has no opportunity to fold back again. As soon as the bottom Is completely opened, this may be fed to the pressing roller by means of further movement with the transport means.

[9014] Advantageously, the invention has an effect when the hose pieces are not transported In a clocked manner, as described in DE 195 02 251 A 1, but are continuously transported within the device for the production of bags, if the forming stamps proposed in the aforementioned publication were adapted to continuous transport, the mechanical effort would be even considerably greater. [0Ö1S] in an advantageous embodiment of the invention, If is provided that the rotational axis of the pressure roller runs parallel to the direction of extension of the hose pieces, in this case, the opened bottom of the hose pieces is thus guided during its transport under the pressure roller, wherein, as described at the outset, the transport direction lies transversely to the direction of extension of the hose pieces. The pressure roller may thus be mounted to be stationary with respect tc the device. It does not need to be moved relative to the production device during operation. This minimizes the mechanical effort.

[ÖÖ16| In a particularly preferred embodiment of the invention, if is provided that the pressure roller extends at least completely over the entire width of the opened end of a hose piece, in this case, the width is the width of the bottom rectangle, which is often referred to as the bottom square, viewed In the direction of extension of the hose piece. This ensures that the pressure roller rolls on all sections of the fold edges of the corner Inserts and thereby optimally fixes the corner inserts and consequently the complete opened end. The width of the pressure roller should therefore be greater than the width of the bottom square of the bag with the greatest possible bottom width that may be produced on the device, in particular, when the bottoms or the ends of the hose piece lie in the plane of the hose pieces after opening, the present invention and, in particular, the last-mentioned embodiment offer particular advantages. In this case, It Is possible to apply a pressing pressure not only to areas of the folding edges of the corner inserts, but also to the tips of the corner inserts and the folding edge in the region of the bottom center line around which the one material layer is folded to be folded back onto itself.

[0017] In order to achieve an optimum pressing action of the pressure roller, if Is provided that the pressure roller forms with the counter layer a gap with an adjustable but fixed gap, through which et least parts of the opened bottom may be passed. In other words, the gap dimension is adjustable but fixed when It has been set. The pressure roller Is then adjustable in such a way that a plurality of superimposed layers of the material, which are generally connected to one another via folding edges, ere pressed. Overall, a very high contact force may be provided by such a fixed arrangement, [0018] It is particularly advantageous if the pressure roller Is rotatably mounted in at least one lever arm, which is Itself pivotally mounted in the machine frame or in mounted parts of the machine frame. With this arrangement it is possible to adjust the distance between the pressure roller and the counter layer in a particularly simple manner. For this purpose, the lever arm may be fixed, for example clamped, on an axle, which may be fixedly and non-rotatably connected to the machine frame, [Ö819] The pressure roller may also be mounted in a different manner in an adjusting device, by means of which the pressure roller may be moved relative to the counter layer. For example, it is conceivable for the pressure roller to be mounted in at least one slide, which is displaceable on rails. Other adjusting devices are conceivable, [ÖÖ2Ö] In other embodiments, the counter layer may be embodied in different ways. In a first embodiment, it Is provided that the counter layer comprises a bearing surface on which the hose pieces rest during their transport through the device for producing the bag. The opened bottoms are thus pressed in the gap between the pressure roller and the supporting surface, the latter being a tablelike plate. In a second embodiment, the counter layer may comprise at least one counter-pressure roller. This counter-pressure roller is preferably rotatable in order to prevent displacement of the material layers of the opened bottom against one another. However, It is aiso conceivable to combine both embodiments in order to provide a uniform contact pressure over the entire width of the bottom, even If a different number of material layers is present in the different regions.

[ÖÖ21] In a further embodiment of the invention, it is provided that the peripheral surface of the pressure rosier has at least partially a steel surface or a rubberized surface. Thus the adhesion friction between the hose material and the pressure roller may be adjusted. The at least one counter-pressure roller may also comprise such surface materials.

[ÖÜ22] It Is particularly advantageous If the at least one pressing roller and/or at least one counter-pressure roller may he driven. The drive may be a motor which drives a pressing roller and a counter-pressure roller. However, the drive of the bottom opening station upstream of the pressure roller may also be responsible for the drive. The main drive of the entire apparatus for producing bags may also he used as a drive. Further drive configurations are conceivable. If pressing roilers and/or counter-pressure rollers are provided at both ends of the hose pieces, the rollers may be driven at the respective end independently of the rollers at the other end of the hose piece, [8G23J Further exemplary embodiments of the invention may be gathered from the description and the claims.

[8G24] The individual figures are as follows:

Fig. 1 shows a schematic diagram of a device for producing fabric bags

Fig. 2 shows a perspective view of a bottom opening station in a device according to the Invention,

Fig, 3 shows the view ill ~ hl from Fig. 2

Fig. 4 shows the view IV - IV from Fig. 3

Fig. 5 shows the view V - V from Fig. 2

Fig, 8 shows a perspective view of an embodiment of a device according to the Invention

Fig, 7 shows a perspective view of a further embodiment of a device according to the invention

Fig. δ shows a perspective view of a further embodiment of a device according to the invention

Fig, 9 shows a view IX IX from Fig: 5 [002S] Fig. 1 shows schematically Individual steps for processing a fabric hose info bags, as effected in the bag-making device 1.

[002δ] First, the fabric hose £ is fed to the bag -making device 1. This is advantageously done by unwinding the fabric hose forming a roil 3 in an unwinding device 4. Subsequently, the hose 2 experiences the so-called opening in the separation station 5. The fabric roll is passed around an Inner tooi which separates the two layers from one another, so that the layers, If they were previously glued together during one of the production steps of the hose, are separated. Only in the case of separate layers may It be ensured that the following production steps are carried out correctly. Subsequently, the separated materia! layers of the hose are placed one on top of the other.

[0027] The fabric hose is now fed to the cross-cutting device 8, which separates the fabric hose into individual hose pieces.

[GG28] Subsequently, a change in the original transport direction z, in which the hose or the hose pieces were transported in the direction of their longitudinal axes, takes place In the new transport direction x so that the hose pieces are now no longer transported in the direction z of the hose longitudinal axis but transversely thereto, so that the ends of the hose pieces are laterally accessible to form the bottoms.

[0029] in the following station, s.e. the bottom opening station 8, both ends of each hose piece are opened and the so-called ground square is laid, in the following valve station 9, a valve is placed and fastened on one of the two open ends. The opened bottoms are now closed in the bottom closing station 10, wherein two tabs are laid one upon the other and permanently connected to one another, for example by welding. The end of the actual bag production process is the application of a bottom cover sheet to the bottoms In the cover sheet station 11. For this purpose, the cover sheets may also be welded on. The finished hags are subsequently deposited on the bag stack. 12 and are transported away from there in a manner not described in detail.

[0Ö30] Fig. 2 shows details of a bottom opening station 8 in a device according to the Invention. The hose pieces 13 are transported by means of a transport device (not shown in detail) in the direction x on the surface of a support 14, for example on the surface of a table, lying flat, preferably horizontally. In order to open one end 15 of the hose piece, this end is first brought into a vertical position from the horizontal position, in order to enable this folding, the nose piece must be subjected to a counter force. For this purpose, the hose piece 13 is threaded under a foiding band 18. This folding band may be moved relative to the hose pieces at rest, and thus relative to the support. However, the hose pieces may also move relative to the folding rape 16. This is, for example, the case when the folding hand is at rest. The folding band may consist of a flexible but highly stressed material. Preferably, however, fhese folding bands are made of steel plates which are connected in a manner not shown with the support 14 or with the machine frame. Steel plates have the advantage, compared to other components, of a smaller thickness with the same load capacity. When the hose piece 13 is threaded, it is then guided pest a guide element 17, for example a guide plate, and is thereby foided over.

[ÖÖ31] After the end 15 of the hose piece 13 has been brought into the vertical position, it reaches the actual bottom opening device 18, which is shown only schematically in this figure. In this bottom opening device 18, two suction bars are provided, which engage on both sides of the folded-up end and are guided in or against the direction a, sc that the material layers are separated from each other. In addition, the suction bars are guided in the direction x, i.e. in the transport direction of the hose pieces, so that the opening may also take place during the transport of the hose pieces. The interior of the end 15 of the hose piece 13 is now accessible. Spreading elements are Inserted into this interior space, and press the matériái layers further apart until they lie horizontally again. This situation is Illustrated with the aid of the opened bottom 19.

[0032] The second end 15* of the hose piece 13 is opened in the same way but spatially and thus offset in time relative to the opening of the first end 15. The first end is already opened in the bottom opening device 18, while the second end 15’ is led under the folding band 18'. By means of the guide element 17' and the bottom opening device 18‘, the opened bottom 19* is produced in the manner described above. A displaced arrangement of the components is advantageous if bags with very small bottom center distances A are to be produced.

[0933] When the bottom opening station 8 is exited, the hose piece Is located with the bottoms 19, 19' open, wherein all the components of the opened bottoms lie essentially in the plane of the support 14.

[ÖÖ34J A particular aspect of the bottom opening station 8 is that each bottom opening device 18, 18’ is supplied with torque by its own drive. This is illustrated by the motor 22 on the bottom opening device 18. The corresponding motor on the bottom opening device 18' is not visible in the view shown. The motor of a bottom opening device 18. 18' mainly supplies the suction bars with a driving torque so that they may move the material iayers away from one another, in addition, the spreader elements are supplied with torque by this motor.

[8035] The closing rollers 23, 23' form the end of the bottom opening devices 18, 18’, which serve the purpose of compressing the freshly opened bottoms and thus fixing them in their position. The bend edges created within the framework of the bottom opening are then aligned to form correct folding edges so that the tendency of the bottoms to reestablish themselves decreases. The support 14 or the counter-pressure rollers 24, 24' serve as a counter-pressure element to the pressure rollers 23, 23'. The pressure rollers 23, .23’ are arranged at the same height In Fig. 2 when viewed in the transport direction x. However, these rollers 23, 23' may also be offset with respect to one another, so that the opened bottoms may also he pressed in the described manner immediately after the opening process. The pressure rollers 23, 23' and the counterpressure rollers 24, 24’ may be driven. The driving torque may be provided by the motors of the bottom opening stations. Alternatively, they may be driven via the main drive of the device, which, infer alia, also drives the transport devices.

[0038] Fig. 3 shows the view III HI in Fig, 2. In Fig, 3, details of the bottom opening station 8 may be seen. In order to defect, the material positions of the end 15 of the hose piece 13, suction pads are provided, of which the suction bar 20 facing the observer may be seen. On the side of the suction bar 20 facing away from the observer, suction devices are arranged which are able to detect the side of the end 15 of the hose piece 13 feeing the observer.

[8037] Since bags with different bottom widths may be produced with the device 1 according to the invention, the possibility exists that the foided~up ends 15 of the hose pieces 13 have different heights. In order to achieve proper opening of the ends by means of the suction piece, they should be able to engage close to the upper end of the end 15, For this purpose, the suction bars 28, 20' are detachably fastened to vertical guides 21, 2Γ, so that the suction bars may be displaced In the direction of the double arrow y along the folded-υρ ends 15 and may be adjusted according to their heights H,

The guides may be designed in various ways. They may have circular or rectangular profiles which are solid or hollow.

[0038] Fig. 4 shows the view IV - IV of Fig. 3. in addition to the front suction bar 20 and the front guide 21, the suction bar 20' and the guide 2T may now also be seen, [0030] Fig. 5 shows the view V V of Fig. 2. The pressure roller 23 is mounted in a lever arm 25 or in a pair of levers. The lever arm 25 itself is pivotally mounted In the machine frame or in mounting parts 25 of the machine frame. In one embodiment, the lever arm 25 is pivotable about an axle 27, which is fixedly connected to components, and may be fixed on this axle. For this purpose, a suitable clamping device (not shown) may be provided. By means of the fixing of the lever arm 25 on the axle 27, the distance of the peripheral surface to the counter-pressure roller or to the support 14 may be fixed. In this way, the opened bottom is subjected to a strong pressure force.

[0040] In a further non-inventive embodiment, it may be provided that the lever arm is mounted to be freely rotatable on the axle 27. As an alternative to this, It may be provided, not according to the invention, that the sever arm 25 is fixedly connected to a shaft, which is rotatably mounted in the attachments, in the mentioned embodiment, the pressure roller 23 may now act on the opened bottoms with a predetermined force, for example the force of its own weight. However, additional forces may also be provided with which the pressure roller acts on the bottoms. For this purpose, at least one spring or at least one pneumatic cylinder may be provided. Simple weights may also serve this purpose.

[0041] The support 14, which is shown in Fig. 2, may serve as a counter layer for the pressure roller to press the opened bottom. A further possibility, however, is to provide a counter-pressure roller 24 with which the pressure roller 23 forms a roller gap In which the opened bottoms 19 may be pressed. The counter-pressure may can be arranged rotatably, but in a fixed manner.

[0042] Fig, 6 shows an embodiment of a bag-making machine. The individual processing stations are only shown schematically here. The hose section 13 is guided In the x-direction transversely to its longitudinal axis, which runs in the z-direcfion, first along a bottom opening station 8 on the operating side BS. The corresponding pressure roller 23 smoothes the bag opening which has just been formed. While the hose piece is still being transported In the x direction, a bottom opening 19' is formed at its second end 15' by a bottom opening station 8' on the drive side AS. This 8! is offset In the x-direction relative to the bottom opening station 8 of the operating side. The associated pressure rosier 23' also smoothes the bottom i9‘ which has just been opened. Fig, 6 clearly shows that, in addition to the bottom opening stations 8, 8’, the pressure rollers 23 and 23' are also offset relative to each other. By means of this offset arrangement of the bottom opening stations 8, 8' on the operating and drive side, space problems with respect to the installation space at these processing stations are, for example, avoided, In order to keep the overall length also low, the pressure roller 23, as viewed in the transport direction x, is then overlapped with the base opening station 8’.

[0043] Subsequently, the hose piece is guided to a valve-feeding station 9 which applies a valve to the bottom opening 19, through which the filling material may be introduced later into the bag by means of a suitable filling device.

[0044] Deviating from Fig. 8, the valve-feeding station 9, which is arranged only on one side, preferably the operating side, may also be arranged opposite one of the bottom opening stations 8, 81. In the preferred exemplary embodiment, the valve-loading station 9 is thus opposite, or at least partially overlaps, the bottom opening station 8'. In this configuration, it is possible to produce bags with very small bottom center distances. In addition, the device has the smallest possible overall length.

[0Ö4S] In the feed stations 10, T0‘, the bottom openings 19, 19' are then inflated before the cover sheets are welded at. the bottom cover station 11, 1Γ by means of the latter 19, 19' and/or coated with a suitable adhesive (extrudate, cold glue, etc.). The two feed stations 10, 10’ are arranged opposite one another In the present exemplary embodiment. The same is true fer the bottom cover sheet stations 11. IT.

[0046] Fig. 7 shows a further embodiment of a bag-making machine 1. The hose pieces 13 are first guided transversely to their longitudinal axis in the x-direction, by means of a first transport device 30, successively to the processing stations 8, 9, 10 on the operator side BS of the machine 1. A closed bag bottom with valve is formed on the hose piece 13 at Its end 15. Thereafter, the semi-finished bag Is transferred to a second transport device 31, which is located on the drive side AS of the machine 1. By means of the processing stations S', If)1, IT, the other end 15' of the hose piece 13 or the semi finished bag is formed info a finished bag bottom. This embodiment makes.it possible to produce very email bag formats. In the case of these small formats, the conveyor belts of the transport devices 30 and 31 would overlap if they extended in the χ-directíon on both sides over the entire machine extension. (0047] Fig. 8 shows a further embodiment of a device 1 for producing bags. The similar processing stations 8, 8’, 10, 10', 11, 11' are arranged alternately offset on the operating and drive side. This tear-shaped arrangement of the processing stations 8, 8', 10, 10', 11, IT is interrupted oniy by the valve station 9, which is arranged between the bottom opening and feed station 10 on the operating side BS, In the case of this machine arrangement, ali processing steps for the bag production on the hose piece 13 are alternately carried out. initially on the operating side BS and then on the drive side AS. By this arrangement, ail processing stations are easily accessible for maintenance purposes.

[0Ö48] Fig. 9 shews a detaii from the top view of a device according to the invention according to Fig, 2. The viewing direction may be seen in Fig. 2. The hose piece 13 is thereby transported by means of the transport devices 30 and 31 In the direction x, white it rests on the support 14. The bottoms 19, 19’ are fully open. In the opening process of the bottoms orthogonal to the bag body 42, the upper layers 44, 44' of the ends of the hose piece 13 are folded back over the folding edge 43, 43’ onto the surface of the bag body 42, while the lower layers 45, 45’ rest on the bearing surface 14. The folding edges 43 and 43' are thereby defined by the outer edges of the devices 30 and 31, Even if these devices 30 and 31 are components of transport devices, they may be designed as steel plates around which the upper layers may be folded. By the extension and the laying of the layers 44, 44', 45, 45’ on the support surface 14 or the hag body 42, i.e. in the plane of the bag body 42, front comer notches 40, 40' and rear corner notches 41, 41’ are formed, wherein these are connected to the layers 44, 44’, 45, 45' by means of foidlng edges. These folding edges and also the folding edges 43, 43’ are more strongly fixed under the pressure roller 23 In the direction x by the further transport of the hose piece 13, in that the pressure roller covers the corner stops 40, 40’, 41, -41’ and the upper layers 44, 44' in the direction on the support 14. Instead of the support 14, a counter-pressure roiler (not shown) may also serve as a counter-pressure for the pressing. The pressing roller 23 and/or 23’ may be arranged directly behind one of the opening stations 8, 8' (not shown In this figure) so that at least one of the front corners of the corner stops 40, 40’ is immediately detected by the pressure roiiers. It Is conceivable that the pressing roiiers may be heated in order to increase the quality of the pressing, The length L of the pressure rollers 23, 23' exceeds the maximum width B of the bottom which is to be produced by means of a device according to the invention. The height H of the end 15 is shown In Fig. 9 and corresponds to half the width B.

List of reference numbers 1 Bag manufacturing device 30 First .'transport device 2 Fabrie höW 31 Second transport device 3 Roil 33 A Unwinding· device 33 § Separating station 34 6 Cross-cutting device 3$ 7 Device for changing the őiraotiöftöf 33 transport 37 6 Botiem opening station 33 9 Vaive station 39 10 Bottom olosing station 40,40’ Front corner insert 11 Cover sheet station 41 Roar corner insert 12 Bag stack 43 Bag bcoiy 13 Hess section 43.43’ Folding ©less 14 Support 44.44' Upper layer 15, IS’ End of the hose section 4S. 46' 16. IS’ Folding band A Bottom Clearance distance 17.. 17’ 'Guide element Width of the open end of the hose piece 18,18’ Bottom opening device 13 19,18’ Opened bottom H Haight of the end 1§ 20,20’ Suction Oat L LengUitolthe pressure roller 23,23' 21.21’ Vertical guide x Biteeiion of transport of the hose pieces 23 Motor 13 23,33’ Pressure roller y Birociien OrthegOils! to the plane which Is 24 Counter-pressure roller stretched’ by the transport pitectioo x and 25 Lever arra the extension direction z 26 Mounting pari x Extension direction of the hose pieces 13 27 Axle AB Drive side 28 BS Operating side 16 23

Claims (13)

EQUIPMENT AND PROCEDURE FOR THE MANUFACTURING OF BAGS E Equipment for the production of bag bags (1) can be supplied in the transport direction (x) of the device in a direction transverse to its longitudinal direction, where the material of the hose pieces contains tensioned plastic strips and two. they consist of a layer of braked material which contains at least the following components; - at least one means for opening the end of the hose piece by which a portion of the end of the hose piece can be folded back onto a scarf by a hose piece, so that the "open end" can be fitted to a base and - at least one press means which is rotatable as a roller (23, 23 '). formed at least a portion of the open end being pressed against the folded edges to form a counterweight, at least one conveying means for transporting the stem piece further after opening the end of the hose piece and in the transport direction (x) before the penetration of the pressure means. characterized in that the pressure gauge (23. 23 '} with the counterweight is an adjustable, but fixed slot gap, through which at least a portion of the open base can be passed. Device according to the preceding claim, characterized in that the rotation axis (2?) Of the pressure roller (23, 23 ') runs parallel to the extension direction of the hose piece. Apparatus according to the preceding claims, characterized in that the pressure roller (23, 23 ') extends over at least the entire width of the open end; Apparatus according to one of the preceding claims, characterized in that the pressure roller (23,23 ') can be adjusted by an adjusting device relative to the counterweight, Apparatus according to one of the preceding claims, characterized in that the compression roller (23, 23 ') is bearable on a lever arm (25), which is itself fixedly secured in the machine frame or in the structure of the machine frame. Apparatus according to one of the preceding claims, characterized in that the counter-mass comprises a bearing surface, such as a table pot, on which the hose piece is provided with a snap-through through the apparatus. 7, Herend / es according to one of the preceding claims. characterized in that the counter-mask comprises at least one counter pressure roller 24}. Apparatus according to one of the preceding claims, characterized in that the circumferential surface of the compression roller has at least partially a projected or rubberized surface, Device according to one of the preceding claims, characterized in that the circumferential surface of the backpressure roller (24) has at least partially a steel or rubberized surface. Apparatus according to one of the preceding claims, characterized in that at least one pressure roller and / or at least one counter pressure roller (24) can be folded. An apparatus according to the prior art eavike, characterized in that at least one pressure roller is disposed at each end region of the base piece; Apparatus according to one of the preceding claims, characterized in that the pressure roller arranged in one of the end areas is arranged offset relative to one another by a nozzle array arranged on the opposite end portion. 13. A method of making bags from a hammock, which may be transported in the direction of delivery tx in a direction transverse to its longitudinal direction, wherein the material of the hollow sections comprises stretched plastic strips and consists of two layers of clay laid on one another, and wherein: · the ends of the end of the hollow piece at the end of at least one hollow piece by means of a device for opening the jar, so that the open end can be laid on a base, and - at least a portion of the open end being pressed with a pressing means formed by at least one rotatable pressure roller (23, 23 ") to form the folded edges - the jar of cuttings, after opening an end of the jaw piece and before the compression, in the direction of delivery, (x) (ova; characterized in that the compression roller (23, 23 ') forms an adjustable but fixed gap with the front support; through it, at least a portion of the open base.