EP2498984B1 - Bottom-cover-sheet subassembly for periphery-free gluing - Google Patents

Description

The invention relates to a device for adhering pieces of material to parts of bags or sacks according to the preamble of claim 1 and to a corresponding method according to the preamble of claim 12.

Such devices and methods have been used in the manufacture of bags or sacks for many years. Bags, particularly block bottom bags with gussets, are often made in a longitudinal process in which a piece of tubing is conveyed to the bag in its longitudinal direction for processing. At the leading end of the hose piece is a bottom, often a block or block bottom, formed. The layout DE 1 245 699 shows a complete device for the production of bags of web-shaped materials. Often such bags are provided with bottom cover sheets to increase the stability of the soil. At the same time, the bottom cover sheets can be designed so that the user of this bag is a carrying handle available. Such bags with differently designed cover sheets are in the DE 41 02 548 shown and described.

The DE 1 245 699 indicates a device for sticking pieces of material on parts of bags or sacks. The device is called there cover sheet sticker. However, it is not described in detail in the cited document.

Such device for adhering pieces of material initially comprises a provision device for providing pieces of material. This can be one Be magazine with which individual pieces of material, ie, for example, cover sheets, are provided as a stack. Often, however, one finds web rolls, of which individual pieces of material are to be separated. This takes place in a separating device in which individual pieces of material can be separated from the roll. Such separating devices usually comprise a smooth-cutting or perforating knife with which separating cuts can be introduced into the material web. For individual, stacked pieces of material, the singulator is designed so that it can remove a piece of material from the stack. The separated piece of material is taken over by a first transport cylinder which guides the piece of material past an adhesive application device. The piece of material provided with adhesive is then stickable to parts of bags or sacks, in practice usually the floors.

The adhesive application device comprises an adhesive reservoir and an adhesive removal roller, which draws adhesive from the adhesive reservoir. Said roll then delivers the adhesive to an adhesive applicator roll. This roller carries a to be glued surface of the piece of material corresponding format piece, which is often referred to as a cliché. Only this format piece takes over the adhesive from the adhesive removal roller and transfers it to the meter slot.

Since often intended for the separation cutting blade is integrated in the Trensportzylinder, there is the problem of contamination by the adhesive.

• ein zweiter Transportzylinder (6) vorgesehen ist, mit welchem die Materialstücke vom ersten Transportzylinder übernehmbar sind, und mit welchem die Materialstücke auf die Telle der Beutel (2) oder Säcke aufbringbar sind, und
• die Klebstoffauftrageinrichtung (19) mit dem zweiten Transportzylinder (6) zusammenwirkt, so dass Klebstoff auf das Materialstück auftragbar ist, wenn sich dieses auf dem zweiten Transportzylinder (6) befindet.

The publication BE 489 863 A discloses a device in which deviating

• a second transport cylinder (6) is provided, with which the pieces of material from the first transport cylinder can be taken over, and with which the pieces of material on the Telle the bag (2) or bags can be applied, and
• the adhesive application device (19) cooperates with the second transport cylinder (6), so that adhesive can be applied to the material piece when it is located on the second transport cylinder (6).

For the provision of adhesive and the application of the material piece to the bags or sacks so a second transport roller is provided, which takes over the piece of material from the first transport roller. Only then is the piece of material provided with adhesive. In this way, an unforeseen Klebstoffiübertrag on the first transport roller and thus on the cutting blade or other means for singling is avoided.

It has been found, however, that blanket bonding of the piece of material with adhesive is in fact not possible with prior art devices. If the cliché corresponds exactly to the contour of the piece of material to be glued, because of the necessary contact pressure, adhesive passes beyond the edges of the piece of material, which leads to the said anti-wear problems. A very well fitting reduction of the cliché to avoid this problem is not or only very cumbersome.

The object of the present invention is to propose an apparatus and a method for adhering pieces of material to parts of bags or sacks, which avoids the said and other disadvantages.

According to the invention, this object is achieved by the addition of the features of the characterizing part of claims 1 and 12.

According to the invention, it is provided that the second format cylinder comprises a format part whose surface contour corresponds to the region of a material piece to be provided with adhesive and that the material piece rests on this format part during transport with the second transport cylinder.

With the invention, the problem described is now circumvented by the material piece is now raised above the outer surface by the format part on the outer surface of the second transport cylinder. If now the adhesive is applied by means of a roller, So this can only stick to the piece of material and does not reach the second transport cylinder. Thus, on the one hand pollution of the transport cylinder is avoided and on the other hand a more complete - a so-called borderless - adhesive application achieved. Especially the latter point is important if the bag is to be filled automatically in a filling device. In bags made in conventional devices, the bottom deck often has an edge that is not glued to the bag or bag. This edge can unfold in a filling device and then disturbs the proper transport of the bag through such a device. Machine downtime can not be ruled out in such cases. The device according to the invention can now be used to produce bags or sacks which can be transported more reliably in filling devices.

In a further advantageous embodiment of the invention, it is provided that the format part comprises recesses or depressions. This embodiment is advantageous if the cover sheet is to comprise one or more carrying handles. Such carrying handles can be created by cutting the piece of material so that the subsequent user can reach under the area delimited by the cuts. Of course, these areas must not be coated with adhesive. With the recess or depressions in the format part, the region of the later carrying handles can now be pulled slightly inwards as seen in the radial direction of the second transport roller, so that this area is not provided with adhesive.

The piece of material can be held in different ways on the surface of the second transport cylinder. A practicable solution would be holding tongs or other mechanically acting devices. Magnetic or electrostatic forces would also be possible, depending on the material. However, it is preferred that the second transport cylinder comprises openings, which can be acted upon by negative pressure. This vacuum is sufficient to hold pieces of material of very different materials on the cylinder can. Furthermore, it can be provided that the openings not only with negative pressure, but also with overpressure can be acted upon. The piece of material can thus be sucked in with negative pressure or repelled with overpressure. The latter is advantageous at the moment when the piece of material is to be dispensed from the second transport cylinder and applied to the bag.

It is advantageous if at least a part of the openings continues through the format part, so that a piece of material can also be reliably retained on the format part.

The adhesive application roller needs, if the second transport roller carries a format part, itself no longer be subjected to a cliché. It is now sufficient to use an adhesive applicator roll, which has the same surface structure over the entire outer circumference. So it can be especially smooth. It is also advantageous if the adhesive application roller at least partially comprises a metal surface.

In a preferred embodiment, an adhesive application device is provided, with which hot-melt adhesive, ie hot-melt adhesive, can be provided. In addition to the procedural advantages (no drying of the adhesive to fear during breaks, no long drying time for glued together workpiece parts necessary) is to be mentioned as an advantage that now not only paper materials can be glued. Now plastic bags can be made in the same way. Also bags that include both paper and plastics are producible. In general, bags made of any materials can be produced with it.

In an advantageous embodiment of the invention, the adhesive application device by means of a parking device from an operating position in which adhesive can be applied to a piece of material, off, so that no contact with the piece of material, or if this is missing, can be produced with the format part. In this way, the unforeseen contamination of the transport cylinder can be avoided. The parking device may comprise at least one compressed air cylinder. Advantageously, two such cylinders. A first short stroke cylinder can be for a very fast Ensure that the adhesive applicator is stopped when a piece of material fails. The parking distance only needs to be a few millimeters. A Weithubzylinder can convey the adhesive applicator in a maintenance position, which may for example be several 10 cm above the operating position. Pneumatic cylinders are an example of suitable lifting devices. Other devices are equally applicable.

Particularly advantageous is a sensor with which the presence or absence of a material section can be detected. The sensor may provide its "observations" to a controller that actuates the shedder in the event of the absence of a portion of material.

In a further embodiment of the invention it is provided that the adhesive application device comprises an adjusting device, with which the minimum radial position is adjustable relative to the second transport cylinder. By an optimal adjustment of the adhesive applicator roller relative to the second transport cylinder of the adhesive transfer can be optimized so that no adhesive reaches the format part or the second transport roller. In addition, it can be used to set the amount of adhesive to be transferred to the piece of material.

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

Fig. 1

Seitenansicht einer erfindungsgemäßen Vorrichtung zum Aufkleben von Materialstücken

Fig. 2

Ansicht des Schnitts II-II in Fig. 1

Fig. 3

Ansicht des Schnitts III- III in Fig. 2

Fig. 4

Ansicht des Schnitts IV-IV in Fig. 2

The individual figures show:

Fig. 1

Side view of a device according to the invention for adhering pieces of material

Fig. 2

View of the section II-II in Fig. 1

Fig. 3

View of the section III-III in Fig. 2

Fig. 4

View of the section IV-IV in Fig. 2

Fig. 1 shows a device 1 for adhering pieces of material not shown on parts of bags 2. The bags are transported by means of a so-called storage cylinder 3, which has the task to a To put down finished bag 2 on a bag stack, not shown. The bag 2 is initially transported by the storage cylinder along a first pressure roller 4. This has the task, the bag bottom 5, which has just been formed in the previous steps, to press again to get the gluing of the piece of material (here: a ground cover sheet) as flat as possible. Immediately thereafter, the bottom cover sheet provided by the second transport cylinder 6 and already provided with adhesive is accurately applied to this floor. For this reason, the second transport cylinder can also be referred to as transfer cylinder 6. The operations required to provide the ground cover sheet are described below. After application of the bottom cover sheet, the bag 2 is guided past a second pressure roller 7, which again presses the ground, so that the bottom cover sheet is as firmly as possible connected to the ground.

The bottom cover sheets are provided in the form of a roll 8, from which the material web 9 is unwound. The web 9 passes through the nip of a punch 10. A first roller 11 carries one or more punching blades, a second roller 12 comprises a counter-layer. With this punch cuts can be introduced into the web 9, which later separate the carrying handles from the rest of the bottom cover sheet.

The web 9 now passes through the nip of a feed roller pair 13. Subsequently, the web 9 reaches the peripheral surface of a cutting cylinder 14, which carries a cutting knife 15, usually in the form of a slitter knife. The knife 15 cooperates with the fixed counter blade 16 and separates individual pieces of material, the later ground cover sheets, from the material web 9. The cutting cylinder transports the so-isolated ground cover sheets on and therefore can also be referred to as the first transport cylinder 14. In order to hold the bottom cover sheet on the outer circumference of the cutting cylinder 14, this is preferably designed as a suction cylinder. This means that this cylinder comprises on its peripheral surface openings which can be acted upon by negative pressure. The structure of the cutting cylinder 14 will be explained later with reference to the transfer cylinder 6, the advantageously has the same functionality with respect to the retention of the bottom cover sheet.

For this purpose, the openings, which were previously subjected to negative pressure, now subjected to an overpressure, so that the corresponding area of the bottom cover sheet is pressed away from the cutting cylinder 14 in the direction of the transfer cylinder 6. The transfer cylinder is acted upon at the same time with a negative pressure, so that a secure transfer of the ground cover sheet comes about.

The transfer cylinder 6 carries on its outer surface at least one format part 17. This is interchangeable and corresponds to the extent of the bottom cover sheet. After having been taken over by the cutting cylinder, the bottom cover sheet occupies exactly the format part 17. The format part 17 has through holes which correspond to the openings of the transfer cylinder 6 that can be subjected to negative pressure, so that a bottom cover sheet can be securely fixed to the format part 17 by the negative pressure. In the further course, the bottom cover sheet is pressed by a pressure roller 18 against the format part 17, wherein not only the bottom cover sheet is again fixed on the format part 17 and smoothly painted, but the later grip strip is pressed slightly into an introduced into the format part recess. On the recess of the format part and the lowering of the grip strip will be discussed later in more detail. Now only areas of the bottom cover sheet, which do not belong to the later grip strip, are in an exposed position, so that only these areas are provided with adhesive. For this purpose, an adhesive application device 19 is provided, which comprises at least one glue reservoir 20 and an adhesive application roller 21. The adhesive applicator roll 21 can directly remove the adhesive from the reservoir. But it can also - as known - be provided an adhesive transfer roller, which takes over the task of adhesive removal and applies the adhesive to the adhesive applicator roll. The adhesive application roller 21 is positioned relative to the transfer cylinder so that they just rest on the raised areas of the format part 17 Touched parts of the bottom cover sheet and only provides these parts with adhesive. Thus, neither the peripheral surface of the transfer cylinder 6 nor the lower regions of the bottom cover sheet, ie in particular the later grip strip, are covered with adhesive. In contrast, since the adhesive applicator roller 21 rolls on the exposed portions of the bottom cover sheet, the bottom cover sheet is covered with adhesive without leaving an uncovered portion. For adjusting the position of the adhesive applicator roll 21, it can advantageously be provided slidably in the direction of the double arrow 22, advantageously together with the adhesive reservoir.

During the transfer of the bottom cover sheet, the negative pressure acting on the openings is switched off and an overpressure is switched on, so that the adherence of the bottom cover sheet to the bag 2 is still supported.

It may happen that a ground cover sheet is not transferred or at least not properly from the cutting cylinder 14 to the over-cylinder 6. In order to prevent the adhesive application roller 21 from coming into contact with the format part 17, a sensor 23 is provided which detects the presence or absence of a bottom cover sheet. The corresponding signals can now be processed by a control device (not shown). This can now cause a displacement of the adhesive application roller 21 in the direction of the double arrow 22. The shift takes place by means of a parking device, which on the basis of FIG. 2 will be explained.

In the FIG. 2 that the view II - II off FIG. 1 shows, various other details of the device 1 are shown. In this figure it can be seen that the adhesive reservoir 21 is displaceable along a rail 24 in the direction of the double arrow 22. It can also be provided a plurality of parallel rails. Preferably, two rails 21 are disposed at each end of the adhesive reservoir 21. The rails 24 are supported on brackets 25, which may be connected in a manner not shown to the machine frame. In addition, a stop 26 is supported on a bracket 25. This is adjustable so that the operating position in which the adhesive application roller 21 applies the adhesive to the ground cover sheet, is changeable. As an example of a stop 26, a pin 50 is shown, which is a portion 51 with a hexagonal plan, to which a wrench can engage, and a threaded portion 52 which is screwed into the bracket 25, is provided. By rotating the pin so its height and thus the operating position can be varied.

On the console 25 continues to support a first piston-cylinder unit 26, which is designed as a quick-release cylinder unit. This is actuated by the control device when the absence of a bottom cover sheet has been detected by means of the sensor 23. In addition, a second piston-cylinder unit 27 is arranged on the console 25, which is designed as a Weithubzylindereinheit. With this cylinder unit 27, the displacement of the adhesive applicator 19 in a maintenance position is possible.

In the FIG. 2 the outer surface 31 of the transfer cylinder 6 is shown. It can be seen that this comprises a plurality of openings 30. In order to be able to apply this to overpressure or negative pressure, a disk 32 is arranged at least on one end side of the transfer cylinder 6 and does not rotate together with the transfer cylinder. This disc 32 comprises an overpressure port 33 and a vacuum port 34. In this context, overpressure and negative pressure mean that a fluid is provided which is exposed to a higher or a lower pressure relative to the ambient pressure. Preferred fluid is air, so that can be spoken of overpressure of compressed air and negative pressure of a vacuum.

In the FIG. 3 the essential details are shown, which are required to pressurize the openings 30 with positive or negative pressure. The transfer cylinder 6 has a comparatively thick jacket, which comprises a plurality of axial bores 35, which in turn may be configured as through-bores. Each of these axial bores 35 may communicate with a plurality of radial bores 30 that represent the openings 30. If individual openings 30 are not supposed to overlap with or negative pressure can be applied, 35 bolts 37 can be inserted in the corresponding axial bores, whose length is dimensioned so that the desired number of openings 30 is covered. In the FIG. 3 the open holes 35 are white and the holes sealed with bolts 37 shown in black.

In the FIG. 4 the disk 32 is shown in more detail. This comprises a circular arc-shaped recess 38 which communicates with the vacuum port. The radial position of the recess 38 is dimensioned so that it can communicate with the holes 35. The recess 38 includes, for example, an angle in a range of 200 to 270 degrees. A bore 35, which is located in this angular range, is subjected to negative pressure. Upon further rotation of the transfer cylinder 6, the bore 35 leaves after a certain time the recess 38. Shortly thereafter, the bore 35 reaches a second circular arc-shaped recess 39. This is supplied via the compressed air connection 33 with an overpressure, so that the overpressure now the bore 35th detected. In the manner described so switching the openings of negative pressure to overpressure, if the ground cover sheet is no longer held, but rather repelled and handed over. The procedure described does not only refer to the transfer cylinder. It can also be provided in the cutting cylinder 14. LIST OF REFERENCE NUMBERS 1 Device for sticking pieces of material 2 bag 3 storage cylinder 4 First pressure roller 5 bag bottom 6 Second transport cylinder / transfer cylinder 7 Second pressure roller 8th reel 9 web 10 punch 11 First roll 12 Second roller 13 Preferred roller pair 14 cutting cylinder 15 separating knife 16 against knife 17 format part 18 pressure roller 19 Adhesive application device 20 adhesive reservoir 21 Adhesive applicator roll 22 Displacement direction of the adhesive applicator roller 21 23 sensor 24 rail 25 console 26 First piston-cylinder unit 27 Second piston-cylinder unit 28 29 30 openings 31 Outer surface of the transfer cylinder 6 32 disc 33 Compressed air connection 34 vacuum connection 35 Axial bore 36 Rotary axis of the transfer cylinder. 6 37 bolt 38 Circular arc-shaped depression 39 Second circular arc-shaped depression 40 41 42 43 44 45 46 47 48 49 50 pen 51 Section with hexagonal floor plan 52 Threaded section

Claims (11)

1. Apparatus for adhesively bonding material pieces (1) onto parts of bags (2) or sacks, comprising:

   - a supply device, by way of which contiguous material pieces can be supplied,

   - a separating device, by way of which individual material pieces can be supplied,

   - a first transport cylinder, by way of which separated material pieces can be transported further,

   - an adhesive application device (19), by way of which adhesive can be applied to in each case one material piece,

   a second transport cylinder (6) being provided, by way of which the material pieces can be accepted from the first transport cylinder, and by way of which the material pieces can be applied to the parts of the bags (2) or sacks, and the adhesive application device (19) interacting with the second transport cylinder (6), with the result that adhesive can be applied to the material piece when the latter is situated on the second transport cylinder (6),
   characterized
   in that the second transport cylinder (6) comprises at least one format part (17), the surface contour of which corresponds to that region of a material piece to be provided with adhesive, and
   in that, during the transport by way of the second transport cylinder (6), the material piece rests on the said format part.
2. Apparatus according to the preceding claim,
   characterized in that
   the format part comprises cut-outs or depressions (38, 39).
3. Apparatus according to one of the preceding claims,
   characterized in that
   the second transport cylinder (6) comprises openings (30) in its circumferential wall, which openings (30) can be loaded with vacuum, with the result that the material piece can be held on the transport cylinder.
4. Apparatus according to one of the three preceding claims,
   characterized in that
   at least some of the openings (30) continue through the format part.
5. Apparatus according to one of the preceding claims,
   characterized in that
   hot-melt adhesive can be supplied by way of the adhesive application device (19).
6. Apparatus according to one of the preceding claims,
   characterized in that
   the adhesive application device (19) comprises an adhesive application roller (21), by way of which the adhesive can be applied to a material piece, the adhesive application roller (21) comprising a metal surface at least in regions.
7. Apparatus according to one of the two preceding claims,
   characterized in that
   the adhesive application device (19) can be set away from the second transport roller (6) from an operating position by way of a disengagement device.
8. Apparatus according to the preceding claim,
   characterized in that
   the disengagement device comprises at least one pneumatic cylinder.
9. Apparatus according to one of the preceding claims,
   characterized in that
   a sensor (23) is provided, by way of which the presence or the absence of a material section can be determined, with the result that the disengagement device can be actuated if a material section is absent.
10. Apparatus according to one of the preceding claims,
    characterized in that
    the adhesive application device (19) comprises a setting device, by way of which the minimum radial position relative to the second transport cylinder (6) can be set.
11. Method for adhesively bonding material pieces to parts of bags (2) or sacks, in which method

    - contiguous material pieces are supplied by way of a supply device,

    - individual material pieces are supplied by a separating device,

    - the separated material pieces are transported further by way of a first transport cylinder,

    - adhesive is applied to in each case one material piece by way of an adhesive application device (19),

    the material pieces being accepted from a second transport cylinder (6) and being applied to the parts of the bags (2) or sacks, and
    adhesive being applied to the material piece by way of the adhesive application device (19) when the said material piece is situated on the second transport cylinder (6),
    characterized
    in that the second transport cylinder (6) comprises at least one format part (17), the surface contour of which corresponds to that region of a material piece to be provided with adhesive, and
    in that, during the transport by way of the second transport cylinder (6), the material piece rests on the said format part.

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