System and method for producing bags or pouches

Abstract

A system for manufacturing sacks or bags includes at least two sack or bag producing machines which control components are assigned to, and which are connected with each other by at least one transport device and/or one storage device. The system includes a control unit configured such that manufacturing speeds of the two sack or bag producing machines can be transmitted to and/or processed by the control unit. The control unit is configured such that it proposes and/or sets the manufacturing speed of the two sack or bag producing machines based on system operating parameters.

Claims

1. A system for manufacturing sacks or bags from a web, comprising: at least a tube extruding machine, which receives the web after an adhesive has been applied thereto, and a bottom jointing machine having control components associated therewith, a transport device that provides for communication between the tube extruding machine and the bottom jointing machine, a control unit configured: such that manufacturing speeds of the tube extruding machine and the bottom jointing machine are transmitted to and/or processed by the control unit, and to propose and/or set the manufacturing speed of the tube extruding machine and the bottom jointing machine based on system operating parameters, the system operating parameters comprising a first part and a second part, with the first part being a parameter which is recorded once before a start of a production run, and the second part being a parameter determined from a current production run, with the manufacturing speed of at least one of the tube extruding machine and the bottom jointing machine being set with the control unit (i) such that a filling level of the transport device approaches a target value and (ii) based on operating values of the tube extruding machine or the bottom jointing machine that are transmitted to and processed by the control unit, with the target value being adjustable by the control unit during the production of the sacks or bags, and with the transport device always being partially full of the sacks or bags.

2. The system according to claim 1, further comprising sensors with which at least one of the manufacturing speeds and other operating parameters are determined and transmitted to the control unit.

3. The system according to claim 1, wherein the first part of the system operating parameter is at least one of a sack format, a type of the adhesive, an order quantity, a diameter of a roll sleeve, a specified cleaning or maintenance interval, a curing time of the adhesive, a maximum acceleration of the machines depending on the bag or sack being produced, a maximum speed of the machines depending on the bag or sack being produced, and a maximum storage volume of the transport device.

4. A method of manufacturing sacks of bags from a web with at least a tube extruding machine, which received the web after an adhesive has been applied thereto, a bottom jointing machine, a transport device, and a control unit, said method comprising: with the transport device, transporting and/or storing the sacks or bags between the tube extruding machine and the bottom jointing machine, reporting to the control unit manufacturing speeds of the tube extruding machine and the bottom jointing machines, and at least one other operating parameter of the tube extruding machine, the bottom jointing machine, and the transport device, the control unit proposing and/or setting the manufacturing speed of at least one of the tube extruding machine and the bottom jointing machine based on the reported speeds and on system operating parameters, the system operating parameters comprising a first part and a second part, with the first part being a parameter which is recorded once before a start of a production run, and the second part being a parameter determined from a current production run, such that a filling level of the transport device approaches a target value, based on operating value of a preceding or a following machine that are transmitted to and processed by the control unit, with the target value being adjustable by the control unit during the production of the sacks or bags, and with the transport device always being partially full of the sacks or bags.

5. The method according to claim 4, wherein the target value ranges between a lower limit and an upper limit within a volume of the transport device.

6. The method according to claim 5, wherein at least one of the lower limit and the upper limit is only exceeded in an event of unplanned changes of operating parameters.

7. The method according to claim 4, wherein at least one of the target value and at least one of the lower limit and the upper limit is adjusted by the control unit based on at least one of impending maintenance deadlines, length of available web material on one or a plurality of rolls, error messages of machine components, degree of occupancy of a pallet, actual value of storage occupancy, sack parameters, and data of follow-up orders.

8. The method according to claim 4, wherein a capacity of the transport device is calculated based on a format of the respective sacks or bags that are being manufactured.

9. The method according to claim 4, wherein the control unit displays at least part of at least one of the operating parameters and information derived therefrom, with the displayed parameters being assigned to a respective system component.

10. A control system for a system for manufacturing sacks or bags from a web that includes a tube extruding machine, which receives the web after an adhesive has been applied thereto, and a bottom jointing machine in communication with each other via a transport device, said control system comprising: control components associated with the tube extruding machine and the bottom jointing machine, and a control unit configured to have transmitted thereto manufacturing speeds of the tube extruding machine and the bottom jointing machine, and to prepare and/or set the manufacturing speed of the tube extruding machine and the bottom jointing machine based on system operating parameters, the system operating parameters comprising a first part and a second part, with the first part being a parameter which is recorded once before a start of a production run, and the second part being a parameter determined from a current production run, (i) such that a filling level of the transport device approaches a target value based on operating values of a preceding or a following machine that are transmitted to and processed by the control unit, with the target value being adjustable by the control unit during the production of the sacks or bags, and with the transport device always being partially full of the sacks or bags.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the individual figures:

(2) FIG. 1 shows a side view of a tube extruding machine in a system according to the invention,

(3) FIG. 2 shows a schematic representation of the manufacturing steps taking place in a bottom jointing machine,

(4) FIG. 3 shows a schematic representation of a storage device,

(5) FIG. 4 shows a view of a palletizer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are give n by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description

(7) FIG. 1 shows a tube extruding machine 1 as component of a system according to the invention. It shows this kind of machine for the manufacture of a four-layered tube. However, it is not restricted to four layers. Tubes with a greater or smaller number of layers may also be producible. The individual webs 6, 7 are pulled off from material rolls 4, 5 arranged in tandem and supported in unreeling devices 2, 3. Only two unreeling devices are illustrated. The material rolls 4, 5 are pivotably supported in cradles 8, 9. The pulled off webs 6, 7 are transported across guide rolls to the pre-stretching devices. The webs 6, 7, 10, 11 are pre-stretched by means of powered pre-stretching devices, each of which consists of the powered pre-stretching roller 12 and the guide roller 13 which enlarges the wrap angle. A device to create needle holes in the web is arranged behind the pre-stretching rollers 12, 13, said device consisting of a back pressure roller 14, which the inserted web runs across and which a porcupine roller 15 can be leaned against, which equips the web with needle holes either across the entire width or in stripe-shape, designed to ventilate the sacks made of the webs.

(8) Each paper web runs from the porcupine roller to the cutter block 16 which can be leaned against the backpressure roller 17. The cutter block 16 creates a transverse perforation representing the future separation line. Next, the paper webs enter a stand 18 in which the webs 6, 7 and 10 are equipped with transverse adhesive strips by means of adhesive application rollers 19 on both sides of the transverse perforations. After pooling the webs by means of the guide rolls 20, they travel across adhesive application rollers 21 by means of which the adhesive substance is applied onto the webs in longitudinal direction. The tube formation station 22 follows, which essentially comprises guide elements such as guide sheets used to fold over and place the outer edges of the webs on top of each other. The tube 23 created in this fashion then enters a separation mechanism 24, in which the tube 23 ruptures along the transverse perforation and is separated into tube pieces 25. This kind of separation mechanism is disclosed for example in EP 0 711 724 A1. A plurality of tube pieces 25 are now used to create tube piece stacks 27 in a stacking device 26, said stacks being transported away by means of a first transport device 28.

(9) The tube extruding machine comprises a plurality of rollers which can be powered. In addition to the previously mentioned pre-stretching rollers 12, other rollers can be designed as powered rollers. The manufacturing speed can be measured with rotary encoders provided on the powered rollers (not illustrated) or with rotary encoders provided on an idle roll. As an example, the idle roll 29 comprises a rotary encoder 30. It is also conceivable to measure the transport speed of a web directly.

(10) The circumference of the material rolls 4 and 5 can be measured with sensors 31, 32. If the diameter of the winding sleeves 35 is known, this information can be used to determine the residual amount of material and hence to predict the time of the future roll exchange. Alternatively, rotary encoders 33, 34 which measure the rotating speeds of the material rolls are an option. The time of the roll exchange can be determined taking into account the manufacturing speed.

(11) Another sensor 36 determines the number of tube pieces 25 in the tube piece stack 27. The data of the sensors and rotary encoders 30-34 and 36 can be made accessible to the control unit 38 via a data line 37. Additional sensor and/or measuring devices in different locations of the machine are possible. They too, would be connected to the control unit 38 via the data line 37. The control unit 38 activates the drives via the control line 39. As an example, it is shown that the control line 39 activates the idle roll 12.

(12) Also, the transport speed of the first transport device 28 is controlled by the control device 38 via a control line 40. At least one occupancy sensor 41 can be provided in order to be able to determine the filling status of this first transport device 28.

(13) It is not illustrated that at least one printing machine can be arranged between the unreeling devices 2, 3 and the pre-stretching rollers 12, said printing machine being used to print the unreeled webs, usually one of the webs. Operating parameters can also be defined or calculated on or in said printing machine. Sensors may be available for this purpose, which monitor for instance the filling level of the print color in the color tanks. Operating parameters of the printing machine can be transmitted to the control unit via not illustrated data lines. These operating parameters can subsequently be used to set or propose manufacturing speeds of machines.

(14) FIG. 2 shows a bottom jointing machine 50, to which tube piece stacks 27 are fed via the first transport device 28. The first transport device 28 can consist of different elements. For example, a plurality of transport devices can be provided. Some of them can be used for the vertical transport or for changing the orientation of the tube pieces, relative to their transport direction. Furthermore, one or a plurality of storage elements can be provided inside which the tube pieces can remain for some time. This kind of storage element is described for example in EP 1 593 614.

(15) The bottom jointing machine 50 takes the tube pieces 25 over in such a way that their orientation, i.e. the orientation of the longitudinal adhesive seam is transverse to the transport direction. The tube pieces 25 are removed one-by-one from the tube piece stack by a separation device 51, which can be designed as a rotational feeder unit, as indicated in FIG. 2. An alignment and transport device 52 transports the tube pieces 25 further while at the same time ensuring the proper orientation of the position of the tube pieces 25.

(16) A twin-belt conveyor 53 takes over the individual tube pieces 25 and transports them to the individual processing stations which create bottoms on one or both ends of the tube pieces 25 in a known fashion. In the process, the ends are put on in a first step, thus creating rectangular bottoms while triangular pouches are formed on the sides. Next, a valve patch 54 can be glued on. For this purpose, adhesive from a so-called glue application mechanism is applied to the valve patch and/or areas of the tube piece 25. The valve patches 54 normally consist of paper and are created by cutting off individual patches from the material 55, which is provided as a material web roll 56. Analogous to the material web rolls 4 and 5 in the tube extruding machine 1, sensors 57 and/or rotary encoders 58 can be provided in this position, which are connected with the control unit 38 via data lines 59, in order to ultimately be able to determine the time of the impending roll exchange in advance. Moreover, components of the adhesive application mechanism, such as for example an adhesive tank, can also be equipped with sensors. Amongst other things, the control unit 38 controls the circumferential speed of the powered wheel 61 of the twin-belt conveyor 53 and hence the manufacturing speed of the bottom jointing machine 50 by means of the control line 60. The pre-stretching speed of the material web 55 is also controlled in a similar fashion, which is however not illustrated.

(17) After the valve patch 54 has been glued on, the bottom is folded shut and glued, if necessary. Finally, a bottom cover sheet 62 can be glued on to reinforce the finished bottom. The bottom cover sheets 62 are separated from a material web 63 provided by a material web roll 64. Like in the case of the valve patches 54, corresponding sensors, rotary encoders, data lines and/or control lines are provided here as well, which is not illustrated for simplicity's sake.

(18) The sacks 65 manufactured from the tube pieces 25 in this fashion are taken over and transported away by a second transport device 66. The sacks 65 are often arranged in streams (see FIG. 3) for this purpose. As illustrated in FIG. 3, the streams are transmitted from the second transport device to a so-called deposition device 67. Said deposition device 67 transports the sacks 65 across defined pathways, while at the same time compressing the freshly created bottoms to ensure a permanent strong adhesive bond. The transport distance inside the deposition device is relatively long in order to allow the sufficient drying of the adhesive bond. The second transport device 66 can again be divided into a plurality of transport and/or storage devices. After passing through the deposition device 67, the sacks 65 reach a third transport device 68, which transports the sacks 65 to a stream counting and separation device which is not illustrated. The latter separates the streams and arranges the sacks 65 to sack stacks 69 with a defined number of sacks 65. This kind of stream counting and separation station is illustrated and explained for example in DE 10 2004 055 325 B4. The stream counting and separation station is often followed by one or a plurality of other transport and/or storage devices, for instance devices as they were described for the area between the tube extruding machine 1 and the bottom jointing machine 50. In the area behind the stream counting and separation station, individual sacks or sack stacks are often randomly withdrawn, subjected to quality control, and re-inserted into the transport chain. The time spent for the control can also be considered storage.

(19) FIG. 4 shows a palletizer 70 as an exemplary embodiment of a device used to arrange a plurality of sacks to a transportable sack combination. Another device is one in which sacks arranged as streams are reeled onto rolls by means of ribbons or strips.

(20) The palletizer 70 comprises a fourth transport device 71, which brings the sack stacks 69 within the range of motion of a gripping device 72. In each case, the gripping device 72 grabs one sack stack 69 and arranges it on a pallet 73. Sensors can also be provided inside the palletizer, for example for monitoring the current occupancy of the pallet 73. The sensors are connected with the control unit 38 via not illustrated data lines. The control unit 38 can propose and/or set the palletizing speed of the palletizer in consideration of operating parameters and manufacturing speeds of other machines.

(21) The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims.

(22) TABLE-US-00001 Reference list 1 Tube extruding machine 2 Unreeling device 3 Unreeling device 4 Material roll 5 Material roll 6 Web 7 Web 8 Cradle 9 Cradle 10 Web 11 Web 12 Pre-stretching roller 13 Guide roller 14 Back pressure roller 15 Porcupine roller 16 Cutter block 17 Back pressure roller 18 Stand 19 Adhesive application roller 20 Guide rolls 21 Adhesive application roller 22 Tube formation station 23 Tube 24 Separation mechanism 25 Tube piece 26 Stacking station 27 Tube piece stack 28 First transport device 29 Idle roll 30 Rotary encoder 31 Sensor 32 Sensor 33 Rotary encoder 34 Rotary encoder 35 Winding sleeve 36 Sensor 37 Data line 38 Control unit 39 Control line 40 Control line 41 Occupancy sensor 42 43 44 45 46 47 48 49 50 Bottom jointing machine 51 Separating device 52 Alignment and transport device 53 Twin-belt conveyor 54 Valve patch 55 Material web 56 Material web roll 57 Sensor 58 Rotary encoder 59 Data line 60 Control line 61 Powered wheel 62 Bottom cover sheet 63 Material web 64 Material web roll 65 Sack 66 Second transport device 67 Deposition device 68 Third transport device 69 Sack stack 70 Palletizer 71 Fourth transport device 72 Gripping device 73 Pallet