System and method for corrugated cardboard

Abstract

A system comprises a corrugator (1) having a first corrugated-cardboard production device (2) for producing a first corrugated cardboard web (21) which is laminated on one side, a laminating-web unrolling device (67) for unrolling a laminating web (72), and a joining device (88) for joining the first corrugated cardboard web (21) which is laminated on one side and the laminating web (72) together to form a corrugated cardboard web (91) which is laminated on both sides and which has a first outer web (21, 72) and a second outer web (72, 21). The corrugator (1) also has at least one cutting device (97) for producing corrugated cardboard sheets (102) from the corrugated cardboard web (91) which is laminated on both sides, the cutting device being downstream of the joining device (88). The system additionally comprises a processing assembly (108), which is designed to automatically adapt a tension of the second outer web (72, 21) to a tension of the first outer web (21, 72) if necessary, so that, at least in the transport direction of the corrugated cardboard sheets (102), the corrugated cardboard sheets (102) are flat or adhere to flatness target values.

Description

[0001] SYSTEM AND PROCESS FOR CORRUGATED CARDBOARD

[0002] This patent application claims priority from German patent application DE 10 2022 205 208.0, the contents of which are incorporated herein by reference.

[0003] The invention relates to a system with a corrugator for producing corrugated board. Furthermore, the invention is directed to a method for producing corrugated board.

[0004] The production of corrugated board is well known due to prior public use. It often happens during the production of corrugated board that the resulting sheets exhibit a curvature, which is disadvantageous and undesirable.

[0005] The invention is based on the object of providing a system comprising a corrugated board plant capable of producing particularly high-quality, particularly (essentially) flat, corrugated board sheets with extreme reliability and efficiency. Furthermore, the system should be comparatively simple. A corresponding method should also be provided.

[0006] This object is achieved according to the invention by the features specified in independent claims 1 and 15. The core of the invention lies in the adjustment of the (mechanical) tension / web tension of the second outer web, if necessary, to the mechanical tension / web tension of the first outer web by the processing arrangement. At least the tension of the second outer web is adjustable. Absolute control of a web tension level is preferably unnecessary.

[0007] The aim is in particular to coordinate the tension of the first outer web and the second outer web in such a way that the flatness of the corrugated cardboard sheet is constant, at least in the running direction, without any upward or downward curvature of the corrugated cardboard sheet.

[0008] The tension level depends, for example, on the material's properties and / or any additional necessary interventions, which preferably (must) be performed by an operator. A tension level that is as low as possible is advantageous, which ideally lies within certain or predetermined limits for a minimum and / or maximum tension. The tension level is preferably matched to the paper base material of the webs (grade, basis weight, or the like).

[0009] It is expedient if it is selectable, preferably by an operator, which web is the first outer web. An outer web here is or comprises a web that is on the outside of the double-sided laminated corrugated board (web) or of the finished corrugated board sheets and is thus visible from the outside. The first outer web forms, for example, an outer or inner cover, while the second outer web forms the corresponding other cover. The web that does not form the first outer web thus forms the second outer web. The outer cover is preferably facing upwards during corrugated board production or in the finished, deposited corrugated board sheet or is arranged above the corresponding inner cover.

[0010] It is advisable for the finished corrugated board sheets to be flat both in the direction of transport and perpendicular to it in the transverse direction, or to comply with the flatness target values.

[0011] The processing system is, in particular, an information or data processing system, preferably an electrical or electronic one. It is preferably designed as a control system and, for example, is a component of the corrugated board system. Alternatively, the processing system is, for example, superordinate to the corrugated board system and is at least temporarily in signal communication with it.

[0012] The first corrugated cardboard production device preferably comprises a first corrugating arrangement for producing a first corrugated web from a first material web and a first glue application device for applying glue to the first corrugated web. It is expedient if the first corrugated cardboard production device also has a first pressing device for pressing another material web and the glued first corrugated web against each other to form the single-sided laminated first corrugated cardboard web.

[0013] It is expedient if a first and second unwinding device for unwinding the first and further material webs are arranged upstream of the first corrugated cardboard production device. The unwinding devices are preferably designed as splicing devices for unwinding endless material webs. It is expedient if the lamination web unwinding device is designed as a lamination web splicing device for unwinding an endless lamination web.

[0014] The joining device is preferably designed as a heating and pulling device. It is preferably capable of pressing the single-sided laminated first corrugated cardboard web and the laminated web toward each other and bonding them together, directly or indirectly, by gluing.

[0015] The at least one cutting device is preferably designed as a cross-cutting device. It is expedient if it comprises at least one cutting means, such as a cutting knife, cutting blade, or the like.

[0016] Further advantageous embodiments of the invention are specified in the subclaims.

[0017] The presetting arrangement according to subclaim 2 results in a particularly user-friendly system. It is advantageous if the system or the corrugated board plant is operated via the presetting arrangement. It is expedient if the presetting arrangement has an input device for entering a target tension for the first outer web. The input device comprises, for example, a slider, a rotary wheel, or the like, in particular to arrange a curvature correction of the corrugated board sheets or to adjust a tension difference between the outer webs. The tension is entered only or exclusively for the first outer web.

[0018] It is advantageous if the predefined arrangement is superordinate to the corrugator. Alternatively, it is part of the corrugator.

[0019] It is expedient if a specification is made via the specification order at the start of a quality. If the tension difference between the first outer web and the second outer web was not zero during a last storage operation, particularly a quality storage operation, then the corresponding tension difference should ideally be taken into account. Preferably, at least one minimum and / or maximum tension value is stored as a standard value to be defined and can preferably be manipulated for all qualities as needed. Specified data can ideally be adjusted by manual intervention in the laminating area. If an adjustment is to be adopted generally, the operator can request the data in the specification order. If the result is a one-off, it is expedient if the change is ignored.

[0020] The system according to subclaim 3 is particularly simple. Only the target tension for the first outer track is required. The processing arrangement automatically or independently adjusts the tension of the second outer track. It is capable of doing so.

[0021] According to subclaim 4, a master-slave relationship exists for adjusting the voltage of the second outer track to the voltage of the first outer track.

[0022] The voltage comparison unit according to dependent claim 5 preferably determines a voltage difference between the voltage of the first outer track and the voltage of the second outer track. This allows for particularly good voltage adjustment or matching.

[0023] The system according to subclaim 6 is extremely reliable.

[0024] The system according to subclaim 7 results in comparatively easy-to-flatten corrugated cardboard sheets. The aim is always to achieve mutually adjusted web tensions, with which a good flatness of the corrugated cardboard sheets has already been achieved.

[0025] According to subclaim 8, the system has a voltage difference control arrangement, which is particularly efficient and leads to high-quality corrugated board.

[0026] According to dependent claim 9, the first outer web is formed by the lamination web or is a component of the one-sidedly laminated first corrugated cardboard web. The second outer web is formed by the other web or is a component thereof. The at least one lamination web tension-changing device according to dependent claim 10 is designed, for example, as a braking and / or driving device. For example, it is a component of the lamination web unwinding device and is capable of correspondingly influencing the unwinding of the lamination web. By increasing the unwinding braking force during the unwinding of the lamination web, the tension of the lamination web is increased. By reducing the unwinding braking force during the unwinding of the lamination web, the tension of the lamination web is reduced.

[0027] Alternatively, the at least one laminated web tension-changing device is designed, for example, separately, in particular from the laminated web unwinding device, and is capable of acting accordingly on the laminated web. It is then designed, for example, as a laminated web tension-changing roller. To brake the laminated web, i.e., to increase the tension of the laminated web, the circumferential speed of the respective laminated web tension-changing roller is reduced such that it is lower than the prevailing transport speed of the laminated web. Alternatively or additionally, the wrap angle of the laminated web around the respective laminated web tension-changing roller can be increased.To drive the lamination web, i.e., to reduce the tension of the lamination web, the peripheral speed of the respective lamination web tension adjustment roller is increased such that it exceeds the prevailing transport speed of the lamination web. Alternatively or additionally, the wrap angle of the lamination web around the lamination web tension adjustment roller can be reduced.

[0028] The at least one first corrugated cardboard web tension-changing device according to dependent claim 11 is preferably designed as a braking and / or driving device and is capable of acting accordingly on the single-sided, first corrugated cardboard web. It is advantageously formed by at least one first corrugated cardboard web tension-changing roller. It is advantageous if the at least one first corrugated cardboard web tension-changing device is arranged on a bridge of the corrugating system. To brake the single-sided, first corrugated cardboard web, i.e., to increase the tension of the single-sided, first corrugated cardboard web, the peripheral speed of the respective first corrugated cardboard web tension-changing roller is reduced such that it is lower than the prevailing transport speed of the single-sided, first corrugated cardboard web.Alternatively or additionally, the wrap angle of the single-sided, first corrugated cardboard web around the respective first corrugated cardboard web tension-adjusting roller can be increased. To drive the single-sided, first corrugated cardboard web, i.e., to reduce the tension of the single-sided, first corrugated cardboard web, the peripheral speed of the respective first corrugated cardboard web tension-adjusting roller is increased such that it is greater than the prevailing transport speed of the single-sided, first corrugated cardboard web. Alternatively or additionally, the wrap angle of the single-sided, first corrugated cardboard web around the respective first corrugated cardboard web tension-adjusting roller can be reduced.

[0029] The at least one laminated web tension measuring device according to dependent claim 12 is designed, for example, as a laminated web tension measuring or sensor roller. It is advantageous if the at least one laminated web tension measuring device is directly connected to the laminated web. It is preferably capable of measuring the tension of the laminated web or of providing a measured value correlating with the tension of the laminated web. The measurement is carried out, for example, continuously or at cyclical intervals. It is expedient if the at least one laminated web tension measuring device has at least one integrated or attached force transducer, force measuring block, force measuring bearing, and / or tensile force sensor. It emits a corresponding measurement signal. Laminated web tension measuring devices of other designs can be used alternatively.

[0030] The at least one first corrugated cardboard web tension measuring device according to subclaim 13 is advantageously designed as a first corrugated cardboard web tension measuring or sensor roller. It is advantageous if the at least one first corrugated cardboard web tension measuring device is directly applied to the single-sided laminated first corrugated cardboard web. It is preferably capable of measuring the tension of the single-sided laminated first corrugated cardboard web or of providing a measured value correlating with the tension of the single-sided laminated first corrugated cardboard web. The measurement is carried out, for example, continuously or at cyclical intervals. It is advantageous if the at least one first corrugated cardboard web tension measuring device has, for example, at least one integrated or attached force transducer, force measuring block, force measuring bearing, and / or tensile force sensor. It emits a corresponding measurement signal.Differently designed first corrugated board web tension measuring devices can be used alternatively.

[0031] The at least one curvature-determining device according to dependent claim 14 preferably operates contactlessly. It is expedient if it is designed as a sensor, camera, or the like and is capable of delivering a corresponding measurement signal. Such a system is particularly user-friendly and requires extremely low personnel expenditure. Alternatively or additionally, the curvature of the corrugated cardboard sheets can be determined manually.

[0032] The developments according to subclaims 2 to 14 also relate to preferred developments of the method according to independent claim 15.

[0033] For example, the corrugated board plant has several corrugated board production devices for producing several corresponding single-sided laminated corrugated board webs. It is expedient if the double-sided laminated corrugated board web is three-ply, five-ply, or seven-ply.

[0034] It is expedient if the corrugated board system comprises at least one second or further corrugated board production device for producing at least one single-sidedly laminated second / further corrugated board web and preferably at least one second / further corrugated board web tension-changing device assigned to the at least one single-sidedly laminated second corrugated board web and at least temporarily in signal communication with the processing arrangement in order to optionally change the tension of the at least one single-sidedly laminated second corrugated board web. Such a system allows the efficient production of high-quality corrugated board sheets that have more than three layers and are flat. It is expedient if the at least one second corrugated board production device is designed like the first corrugated board production device.Advantageously, the at least one second corrugated cardboard web tension-changing device is designed like the at least one first corrugated cardboard web tension-changing device. Alternatively, these differ from one another. It is advantageous if at least one second / further corrugated cardboard web tension-measuring device is also present for measuring the tension of the at least one single-sidedly laminated second corrugated cardboard web, which is preferably designed like the first corrugated cardboard web tension-measuring device. Alternatively, these differ from one another. Preferably, the at least one single-sidedly laminated second corrugated cardboard web, if present, is located inside the double-sidedly laminated corrugated cardboard barge or the finished corrugated cardboard sheet.

[0035] A preferred embodiment of the invention is described below by way of example with reference to the accompanying drawings. In the drawings:

[0036] Fig. 1 shows a first part of a corrugated board plant which is part of a system according to the invention,

[0037] Fig. 2 a second part of the corrugated board plant, which is connected to the first part,

[0038] Fig. 3 shows the detail III marked in Fig. 1 on an enlarged scale, showing a preheating device arranged upstream of the connecting device together with its surroundings,

[0039] Fig. 4 shows the detail IV marked in Fig. 1 on an enlarged scale, illustrating an example of an outlet of an elevated transport facility including its surroundings,

[0040] Fig. 5 shows the detail V marked in Fig. 2 on an enlarged scale, showing, among other things, a processing arrangement,

[0041] Fig. 6 is a perspective view of a tension measuring device which is part of the illustrated corrugator,

[0042] Fig. 7 is a perspective view of an alternative tension measuring device, which is part of the corrugated board machine shown and is mounted in a holder,

[0043] Fig. 8 is a perspective view illustrating a stacking device of the corrugated board plant shown, including a curvature determining device,

[0044] Fig. 9 shows a simplified control of the system, Fig. 10 is a block diagram illustrating a voltage difference control of the system shown, and

[0045] Fig. 11 is another block diagram showing the voltage difference control process of the system shown

[0046] A corrugated board plant 1 shown in its entirety in Figures 1, 2 comprises a first corrugated board manufacturing device 2 for producing a one-sidedly laminated endless first corrugated board web.

[0047] A first cover web splicing device 3 and a first material web splicing device 4 are arranged upstream of the first corrugated board manufacturing device 2.

[0048] The first cover web splicing device 3 comprises a first unwinding unit 6 for unwinding a finite first cover web from a first cover web roll 5 and a second unwinding unit 8 for unwinding a finite second cover web from a second cover web roll 7. The finite first cover web and second cover web are connected to one another to provide an endless first cover web 9 by means of a connecting and cutting unit (not shown) of the first cover web splicing device 3.

[0049] The first material web splicing device 4 is designed correspondingly to the first cover web splicing device 3. This comprises a third unwinding unit 11 for unwinding a finite first material web from a first material web roll 10 and a fourth unwinding unit 13 for unwinding a finite second material web from a second material web roll 12. The finite first material web and second material web are connected to one another to provide an endless first material web 14 by means of a connecting and cutting unit (not shown) of the first material web splicing device 4.

[0050] The endless first cover web 9 is fed via a first heating roller 15 to a first heating device 16 and a first tension control device 17 of the first corrugated cardboard production device 2. The first heating device 16 is capable of heating the endless first cover web 9. The first tension control device 17 is capable of changing or controlling the tension of the endless first cover web 9. The endless first material web 14 is fed via deflection rollers to the first corrugated cardboard production device 2.

[0051] The first corrugated cardboard production device 2 comprises a first corrugating roller arrangement 18 with a first corrugating roller 19 and a second corrugating roller 20 for producing a continuous, corrugated first web from the continuous first material web 14. The corrugating rollers 19, 20 form a first corrugating roller gap for passing and corrugating the continuous first material web 14. The rotational axes of the corrugating rollers 19, 20 run parallel to one another and perpendicular to the continuous first material web 14.

[0052] To join the endless first cover web 9 to the endless corrugated first material web or fluted web 14 to form a one-sided laminated endless first corrugated board web 21, the first corrugated board manufacturing device 2 has a first glue application device 22, which preferably comprises a first glue metering roller, a first glue container, and a first glue application roller. To guide and apply glue to the endless first fluted web 14, the first glue application roller forms a first gluing gap with the first fluted roller 19. The glue located in the first glue container is applied to the peaks of the fluting of the endless first fluted web 14 via the first glue application roller. The first glue metering roller rests against the first glue application roller and serves to form a uniform layer of glue on the first glue application roller.

[0053] The endless first cover web 9 is then joined to the endless first corrugated web 14, which is provided with glue from the first glue container, in the first corrugated cardboard production device 2. To press the endless first cover web 9 against the glue-provided, endless first corrugated web 14, which in turn rests partially against the first corrugating roller 19, the first corrugated cardboard production device 2 has a first pressing module 23, which is advantageously designed as a pressing belt module. It is arranged above the first corrugating roller 19 and has two first deflecting rollers and an endless first pressing belt that is guided around the two first deflecting rollers. The first corrugating roller 19 engages partially from below in a space between the two first deflecting rollers of the first pressing module 23, whereby the first pressing belt is deflected by the first corrugating roller 19.The first pressure belt presses against the endless first cover web 9, which in turn is pressed against the endless first corrugated web 14 provided with glue and lying against the first corrugating roller 19.

[0054] For intermediate storage and buffering of the one-sidedly laminated endless first corrugated cardboard web 21, it is fed via a first overhead transport device 24 to a first storage device 25 of the corrugating cardboard plant 1, where it forms or can form loops.

[0055] The first storage device 25 has a first transport device for transporting the one-sidedly laminated, endless first corrugated cardboard web 21. The first transport device forms a transport path for the one-sidedly laminated, endless first corrugated cardboard web 21. A first impeller 106 is rotatably or rotatably mounted in the first transport device. When the one-sidedly laminated, endless first corrugated cardboard web 21 is transported by the first transport device, it is conveyed along the first transport wheel 106, thereby causing it to rotate.

[0056] Furthermore, the corrugated cardboard plant 1 has a second corrugated cardboard production device 26, which is designed correspondingly to the first corrugated cardboard production device 2 and serves to produce a one-sidedly laminated endless second corrugated cardboard web.

[0057] A second cover web splicing device 27 and a second material web splicing device 28 are arranged upstream of the second corrugated board manufacturing device 26.

[0058] The second cover web splicing device 27 comprises a fifth unwinding unit 30 for unwinding a finite third cover web from a third cover web roll 29 and a sixth unwinding unit 32 for unwinding a finite fourth cover web from a fourth cover web roll 31. The finite third cover web and fourth cover web are joined together to provide an endless second cover web 33 by means of a connecting and cutting unit (not shown) of the second cover web splicing device 27. The second material web splicing device 28 comprises a seventh unwinding unit 35 for unwinding a finite third material web from a third material web roll 34 and an eighth unwinding unit 37 for unwinding a finite fourth material web from a fourth material web roll 36.The finite third material web and fourth material web are joined together to provide an endless second material web 38 by means of a connecting and cutting unit (not shown) of the second material web splicing device 28.

[0059] The endless second cover web 33 is fed via a second heating roller 39 to a second heating device 40 and a second tension control device 41 of the second corrugated cardboard production device 26. The second heating device 40 is capable of heating the endless second cover web 33. The second tension control device 41 is capable of changing or controlling the tension of the endless second cover web 33. The endless second material web 38 is fed via deflection rollers to the second corrugated cardboard production device 26.

[0060] The second corrugated board manufacturing device 26 comprises a second corrugating roller assembly 42 with a third corrugating roller 43 and a fourth corrugating roller 44 for producing a continuous, corrugated second web from the continuous second material web 38. The corrugating rollers 43, 44 form a second corrugating roller gap for passing and corrugating the continuous second material web 38. The rotational axes of the corrugating rollers 43, 44 run parallel to one another and perpendicular to the continuous second material web 38.

[0061] To join the endless second cover web 33 to the endless corrugated second material web or fluted web 38 to form a one-sided laminated endless second corrugated board web 45, the second corrugated board manufacturing device 26 has a second glue application device 46, which preferably comprises a second glue metering roller, a second glue container, and a second glue application roller. To guide and apply glue to the endless second fluted web 38, the second glue application roller forms a second gluing gap with the third fluted roller 43. The glue located in the second glue container is applied to the peaks of the fluting of the endless second fluted web 38 via the second glue application roller. The second glue metering roller bears against the second glue application roller and serves to form a uniform layer of glue on the second glue application roller.The endless second cover web 33 is then joined to the endless second corrugated web 38, which is provided with glue from the second glue container, in the second corrugated cardboard production device 26. To press the endless second cover web 33 against the glue-applied, endless second corrugated web 38, which in turn rests partially against the third corrugating roller 43, the second corrugated cardboard production device 26 has a second pressing module 47. The second pressing module 47 is advantageously designed as a pressing belt module. It is arranged above the third corrugating roller 43. The second pressing module 47 has two second deflection rollers and an endless second pressing belt that is guided around the two second deflection rollers. The third corrugating roller 43 engages in a space between the two second deflection rollers of the second pressure module 47 in regions from below, whereby the second pressure belt is deflected by the third corrugating roller 43.The second pressure belt presses against the endless second cover web 33, which in turn is pressed against the glue-coated, endless second corrugated web 38 lying against the third corrugating roller 43.

[0062] For intermediate storage and buffering of the one-sidedly laminated endless second corrugated cardboard web 45, it is fed via a second overhead transport device 48 to a second storage device 49 of the corrugating cardboard plant 1, where it forms or can form loops.

[0063] The second storage device 49 has a second transport device for transporting the one-sidedly laminated, endless second corrugated cardboard web 45. The second transport device forms a transport path for the one-sidedly laminated, endless second corrugated cardboard web 45. A second impeller 107 is rotatably or rotatably mounted in the second transport device. When the one-sidedly laminated, endless second corrugated cardboard web 45 is transported by the second transport device, it is conveyed along the second transport wheel 107, thereby causing it to rotate.

[0064] The single-sided, endless first corrugated cardboard web 21 is fed via the first overhead transport device 24 to a bridge 50 of the corrugator 1 for further conveying. The single-sided, endless second corrugated cardboard web 45 is also fed via the second overhead transport device 48 for further conveying to the bridge 50. The bridge 50 carries, in a downstream end region, a first delooping device 51 with first delooping rollers 52, which ensure delooping of the single-sided, endless first corrugated cardboard web 21. The first de-looping rollers 52 are arranged substantially horizontally spaced from one another at a common height and extend transversely to a transport direction of the one-sidedly laminated endless first corrugated cardboard web 21. The one-sidedly laminated endless first corrugated cardboard web 21 is guided through the first de-looping device 51.

[0065] The bridge 50 also carries, in its downstream end region, a second delooping device 53, which is designed like the first delooping device 51 and ensures delooping of the single-sided, endless second corrugated cardboard web 45. The second delooping device 53 is arranged below the first delooping device 51 and comprises second delooping rollers 54. The second delooping rollers 54 are arranged substantially horizontally spaced from one another at a common height and extend transversely to a transport direction of the single-sided, endless second corrugated cardboard web 45. The single-sided, endless second corrugated cardboard web 45 is guided through the second delooping device 53.

[0066] Downstream of the first delooping device 51, a first guide device 55 for guiding the single-sided, endless first corrugated cardboard web 21 is arranged on the bridge 50. The first guide device 55 detects a transverse position of the single-sided, endless first corrugated cardboard web 21. If necessary, it corrects the transverse position of the single-sided, endless first corrugated cardboard web 21 and, in particular, if necessary, ensures a transverse alignment of the single-sided, endless first corrugated cardboard web 21 to a system center or to the single-sided, endless second corrugated cardboard web 42 or to a lamination web.

[0067] Arranged in or adjacent to the first guide device 55 is a first splice detection device 57, which is capable of detecting a change in the width of the single-sided, endless first corrugated cardboard web 21 and / or directly detecting a splice point in the single-sided, endless first corrugated cardboard web 21. For this purpose, the first splice detection device 57 has a rotatable first detection web roller 58 resting on the single-sided, endless first corrugated cardboard web 21 and a contactless first scanning device for scanning side regions of the single-sided, endless first corrugated cardboard web 21.

[0068] Downstream of the second de-looping device 53, a second guide device 56 for guiding the single-sided, endless second corrugated cardboard web 45 is also arranged on the bridge 50. The second guide device 56 detects a transverse position of the single-sided, endless second corrugated cardboard web 45. If necessary, it corrects a transverse position of the single-sided, endless second corrugated cardboard web 45 and, in particular, if necessary, ensures a transverse alignment of the single-sided, endless second corrugated cardboard web 45 to the center of the system or to the single-sided, endless first corrugated cardboard web 21 or to the lamination web.

[0069] A second splice detection device 59 is arranged in the second guide device 56 or adjacent thereto. This second splice detection device 59 is designed like the first splice detection device 57 and is capable of detecting a change in the width of the single-sided, endless second corrugated cardboard web 45 and / or directly detecting a splice point in the single-sided, endless second corrugated cardboard web 45. For this purpose, the second splice detection device 59 has a rotatable second detection web roller 60 resting on the single-sided, endless second corrugated cardboard web 45 and a contactless second scanning device for scanning side regions of the single-sided, endless second corrugated cardboard web 45. The splice points can be synchronized.

[0070] Downstream of the first guide device 55, a first tension-changing roller 61 is arranged on the bridge 50, which is preferably rubberized and can be driven and / or braked by a first drive 62, in particular a servo drive. The first drive 62 has a first torque-measuring unit, or a first torque-measuring unit is assigned to the first drive 62. The first tension-changing roller 61 ensures, in particular, a taut or tensioned, one-sidedly laminated, endless first corrugated cardboard web 21, the tension of which is preferably kept constant. The one-sidedly laminated, endless first corrugated cardboard web 21 is guided around the first tension-changing roller 61. Deflection rollers 63 are arranged upstream and adjacent to the first tension-changing roller 61.

[0071] Downstream of the second guide device 56, a second tension-changing roller 64 is arranged on the bridge 50. This second tension-changing roller is preferably rubberized and can be driven and / or braked by a second drive 65, in particular a servo drive. The second drive 65 has a second torque-measuring unit, or a second torque-measuring unit is assigned to the second drive 65. The second tension-changing roller 64 ensures, in particular, a taut or tensioned, one-sidedly laminated, endless second corrugated cardboard web 45, the tension of which is preferably kept constant. The one-sidedly laminated, endless second corrugated cardboard web 45 is guided around the second tension-changing roller 64.

[0072] Upstream and adjacent to the second tension changing roller 64 are deflection rollers 66.

[0073] The corrugated board plant 1 also has a lamination web splicing device 67, which comprises a ninth unwinding unit 69 for unwinding a finite first lamination web from a first lamination web roll 68 and a tenth unwinding unit 71 for unwinding a finite second lamination web from a second lamination web roll 70. The finite first lamination web and finite second lamination web are connected to one another to provide an endless lamination web 72 by means of a connecting and cutting unit (not shown) of the lamination web splicing device 67.

[0074] The ninth unwinding unit 69 and the tenth unwinding unit 71 each have an unwinding brake 69a and 71a, respectively, in order to optionally apply an unwinding braking force to the finite first and second lamination webs or the first and second lamination web rolls 68, 70, respectively, which braking force preferably (also) depends on a currently existing diameter of the first lamination web roll 68 and second lamination web roll 70.

[0075] Downstream of the tension-changing rollers 61, 64 and the lamination web splicing device 67, the corrugated board system 1 has a preheating device 73 comprising three stacked preheating rollers 74, 75, 76. The single-sided, endless corrugated board webs 21, 45 and the endless lamination web 72 are fed to the preheating device 73. The single-sided, endless first corrugated board web 21 wraps around the first preheating roller 74 and is heated. The single-sided, endless second corrugated board web 45 wraps around the second preheating roller 75 and is heated. The endless lamination web 72 wraps around the third preheating roller 76 and is heated.

[0076] Downstream and adjacent to the first preheating roller 74 is a first tension-measuring roller 77, which is in direct mechanical contact with the single-sided, endless first corrugated cardboard web 21 and is capable of measuring its mechanical (web) tension. The first tension-measuring roller 77 extends perpendicular to the single-sided, endless first corrugated cardboard web 21. It runs horizontally.

[0077] Downstream and adjacent to the second preheating roller 75, a second tension measuring roller 78 is arranged, which is in direct mechanical contact with the one-sidedly laminated endless second corrugated cardboard web 45 and is capable of measuring its mechanical

[0078] (Web) tension measurement. The second tension measuring roller 78 extends perpendicular to the one-sidedly laminated, endless second corrugated cardboard web 45. It runs horizontally.

[0079] Downstream and adjacent to the third preheating roller 76 is a third tension-measuring roller 79. The endless laminating web 72 is guided around the third tension-measuring roller 79. The third tension-measuring roller 79 is in direct mechanical contact with the endless laminating web 72 and is capable of measuring its mechanical (web) tension there. The third tension-measuring roller 79 extends perpendicular to the endless laminating web 72 and runs horizontally.

[0080] As Fig. 6 shows, each tension measuring roller 77, 78, 79 has a force measuring bearing 80 on both sides, which is capable of detecting occurring bearing forces and thus determining the mechanical tension of the respective web 21, 45, or 72. Advantageously, each force measuring bearing 80 comprises a radial force sensor. As Fig. 7 shows, a guide roller 81 for guiding the respective web 21, 45, or 72 can be assigned to the first tension measuring roller 77, second tension measuring roller 78, and / or third tension measuring roller 79. The tension measuring roller 77, 78, or 79 and the guide roller 81 are held by a holder 82 and run parallel to one another.

[0081] Downstream of the tension-measuring rollers 77, 78, 79, the corrugated board system 1 has a gluing unit 83 with a first gluing roller 84 and a second gluing roller 85, each partially immersed in a corresponding glue bath. A glue metering roller 86 is located on each gluing roller 84, 85 to form a uniform layer of glue on the corresponding gluing roller 84 or 85. The continuous first corrugated board web 21, laminated on one side, is in contact with the first gluing roller 84 with its corrugation path 14, so that its corrugation is coated with glue from the corresponding glue bath. The one-sidedly laminated, endless second corrugated board web 45 is in contact with the second gluing roller 85 via its corrugation web 38, so that its corrugation is coated with glue from the associated glue bath. The endless laminated web 72 remains uncoated in the gluing unit 83.

[0082] The gluing unit 83 also includes a fourth tension measuring roller 87, which is configured, for example, like the tension measuring rollers 77, 78, or 79. The endless lamination web 72 is guided around the fourth tension measuring roller 87 and is in direct mechanical contact with it, so that the fourth tension measuring roller 87 is able to measure its mechanical (web) tension there. The fourth tension measuring roller 79 extends perpendicular to the endless lamination web 72. It runs horizontally.

[0083] Downstream of the gluing unit 83, the corrugated board system 1 comprises a connecting device 88 with a horizontally extending heating table 89. Adjacent to the heating table 89, the connecting device 88 has an endless pressure belt 90 guided around guide rollers. Between the pressure belt 90 and the heating table 89, a pressure gap is formed through which the single-sided, glued, corrugated board webs 21, 45 and the endless lamination web 72 are guided to form a double-sided, endless corrugated board web 91. The double-sided, endless corrugated board web 91 is five-sided in total. The single-sided, endless first corrugated board web 21 forms an upper first outer web of the double-sided, endless corrugated board web 91. The endless lamination web 72 forms a lower second outer web of the double-sided laminated endless corrugated cardboard web 91. The single-sided laminated endless second corrugated cardboard web 45 is arranged intermediately or inside.

[0084] Downstream of the connecting device 88, the corrugated board system 1 comprises a short cross-cutting device 92, which comprises at least one cross-cutting roller. The short cross-cutting device 92 is capable, for example, of cutting out rejects from the double-sided laminated endless corrugated board web 91 and / or of creating connecting cuts during a format change between correspondingly modified longitudinal cuts in the double-sided laminated endless corrugated board web 91.

[0085] Downstream of the short cross-cutting device 92, the corrugated board system 1 has a longitudinal cutting / creasing device 93 for longitudinally cutting and creasing the double-sided, endless corrugated board web 91. The longitudinal cutting / creasing device 93 has two consecutively arranged creasing stations and two consecutively arranged longitudinal cutting stations. In the longitudinal cutting / creasing device 93, endless partial webs 94, 95 can be produced from the double-sided, endless corrugated board web 91 by at least one longitudinal cut. These partial webs initially run parallel to one another.

[0086] Downstream of the longitudinal cutting-creasing device 93, the corrugator 1 comprises a switch 96 for conveying the endless partial webs 94, 95 to different levels.

[0087] Downstream of the switch 96, the corrugated board machine 1 comprises a cross-cutting device 97 with two cross-cutting devices 98, 99 arranged one above the other. Each cross-cutting device 98, 99 has two paired cutter bar rollers with radially projecting cutter bars. To cross-cut the endless partial webs 94, 95, the cutter bars of the cutter bar rollers of the corresponding cross-cutting device 98, 99 cooperate.

[0088] Each cross-cutting device 98, 99 is followed by a conveyor belt device 100 or 101, respectively, for conveying corrugated cardboard sheets 102 produced from the endless partial webs 94, 95 by the cross-cutting devices 98, 99. Each conveyor belt device 100, 101 is followed by a storage device 103, which is advantageously height-adjustable. In the storage devices 103, the corrugated cardboard sheets 102 can be stacked one above the other to form stacks 104.

[0089] The system further comprises curvature-determining devices 105, which are arranged above the stacks 104 in the storage devices 103 and are capable of determining or measuring a prevailing curvature of the corrugated cardboard sheets 102 in the longitudinal direction. The curvature-determining devices 105 can be part of the corrugating system 1. The corrugated cardboard sheets can, for example, be curved upwards or downwards. S-shaped curvatures are also possible.

[0090] The system also comprises a processing arrangement 108, which is designed as an electrical or electronic control arrangement and serves in particular to control the web tensions.

[0091] The first impeller 106 is at least temporarily connected to the processing assembly 108 via a first signal line 109. Signals or information relating to the rotational speed of the first impeller 106 are thus supplied to the processing assembly 108. The length of the currently stored, one-sidedly laminated, endless first corrugated cardboard web 21 can be calculated via the first impeller 106.

[0092] The second impeller 107 is at least temporarily connected to the processing assembly 108 via a second signal line 110. Signals or information relating to the rotational speed of the second impeller 107 are thus supplied to the processing assembly 108. The length of the currently stored, one-sidedly laminated, endless second corrugated cardboard web 45 can be calculated via the second impeller 107.

[0093] The first roll brake 69a is at least temporarily connected to the processing arrangement 108 via a third signal line 111 and is capable of receiving actuation signals from the processing arrangement 108. The second roll brake 71a is at least temporarily connected to the processing arrangement 108 via a fourth signal line 112 and is capable of receiving actuation signals from the processing arrangement 108.

[0094] The first detection web roller 58 is at least temporarily in signal communication with the processing arrangement 108 via a fifth signal line 113 in order to supply the processing arrangement 108 with signals relating to a time of detection of a splice point in the one-sidedly laminated endless first corrugated cardboard web 21.

[0095] The second detection web device 60 is at least temporarily in signal communication with the processing arrangement 108 via a sixth signal line 114 in order to supply the processing arrangement 108 with signals relating to a time of detection of a splice point in the one-sidedly laminated endless second corrugated cardboard web 45.

[0096] The first tension measuring roller 77 is at least temporarily in signal communication with the processing arrangement 108 via a seventh signal line 115 in order to supply the processing arrangement 108 with signals relating to the currently existing mechanical tension of the one-sidedly laminated endless first corrugated cardboard web 21 at the first tension measuring roller 77.

[0097] The second tension measuring roller 78 is at least temporarily in signal communication with the processing arrangement 108 via an eighth signal line 116 in order to supply the processing arrangement 108 with signals relating to the currently existing mechanical tension of the one-sidedly laminated endless second corrugated cardboard web 45 at the second tension measuring roller 78.

[0098] The third tension measuring roller 79 is at least temporarily in signal communication with the processing arrangement 108 via a ninth signal line 117 in order to supply the processing arrangement 108 with signals relating to the currently existing mechanical tension of the endless lamination web 72 at the third tension measuring roller 79.

[0099] The fourth tension measuring roller 87 is at least temporarily in signal communication with the processing arrangement 108 via a tenth signal line 118 in order to supply the processing arrangement 108 with signals relating to the currently existing mechanical tension of the endless lamination web 72 at the fourth tension measuring roller 87.

[0100] Each curvature determination device 105 is at least temporarily in signal communication with the processing arrangement 108 via an eleventh signal line 119 in order to supply the processing arrangement 108 with signals relating to a curvature in the longitudinal direction of the last detected corrugated cardboard sheet 102.

[0101] The first drive 62 is at least temporarily in signal communication with the processing arrangement 108 via a twelfth signal line 129 and is capable of receiving actuation signals from the processing arrangement 108.

[0102] The second drive 65 is at least temporarily in signal communication with the processing arrangement 108 via a thirteenth signal line 130 and is capable of receiving actuation signals from the processing arrangement 108.

[0103] In addition to the corrugated board system 1, the system also comprises a higher-level electrical or electronic setting arrangement 120, which is at least temporarily in signal connection with the processing arrangement 108 for a voltage setting.

[0104] The operation of the system, or rather the control of the corrugated board system 1, is briefly explained below. The control system is illustrated in a highly simplified form in Fig. 9. As already mentioned, electrical signals or information are fed to the processing arrangement 108 from the corrugated board system 1, the curvature determination devices 105, the presetting arrangement 120, and possibly also from a quality data memory 121. The processing arrangement 108 processes this information.

[0105] The control system is shown in more detail in Fig. 10. Tension difference control is performed by means of the processing arrangement 108. A tension difference is preferably specified via a slider of the setting arrangement 120 of the corrugated cardboard system 1. The processing arrangement 108 receives corresponding signals or information from the setting arrangement 120 and is capable of actuating the lamination web splicing device 67, in particular its unwinding brakes 69a and 71a, the first drive 62, and / or the second drive 65, if necessary. The lamination web splicing device 67, in particular its unwinding brakes 69a and 71a, the first drive 62, and the second drive 65 form actuators. In this way, the mechanical tension of the one-sided laminated endless first corrugated cardboard web 21, the one-sided laminated endless second corrugated cardboard web 45 or the endless laminated web 72 is changed or adjusted as required or to the required extent.specifically influenced.

[0106] The control system contains the one-sidedly laminated endless first corrugated cardboard web 21, the one-sidedly laminated endless second corrugated cardboard web 45, and / or the endless laminated web 72 up to the tension measuring rollers 77, 78, 79, and 87, respectively. This control system is assigned the reference numeral 122 in Fig. 10. The controlled variable here is the mechanical tension of the one-sidedly laminated endless first corrugated cardboard web 21, the one-sidedly laminated endless second corrugated cardboard web 45, and / or the endless laminated web 72, which is controlled or specifically influenced.

[0107] Signals can be fed to the control system 122, which is illustrated by the reference numeral 123 in Fig. 10. These signals can relate to a quality of the corrugated cardboard sheets 102, an at least regional speed change of the corrugator 1 and / or operating signals of the lamination web splicing device 67.

[0108] An output variable of the control system 122 is preferably fed to the third tension measuring roller 79, the fourth tension measuring roller 87, the first tension measuring roller 77 and / or the second tension measuring roller 78.

[0109] Measurement signals from the third tension measuring roller 79, fourth tension measuring roller 87, first tension measuring roller 77, and second tension measuring roller 78, which correlate with the corresponding measured mechanical web tension, are fed to the processing arrangement 108. The processing arrangement 108 processes the measurement signals or the information. A control loop is present. The mechanical tensions of the first outer web and second outer web measured by the tension measuring rollers 77, 78, 79, and 87, respectively, are then compared with one another and, if necessary, controlled. The processing arrangement 108 determines a control variable via a control deviation or control difference, which then acts accordingly on the controlled system 122.

[0110] The master outer track is defined as the controlled variable. The slave outer track is automatically adjusted and controlled to the same value or adjusted to the same value, ie, the same difference or deviation is maintained as originally intended.

[0111] With reference to Fig. 11, the principle of the web tension difference control process in the laminating area of ​​the corrugated board plant 1 is described in more detail. The corrugated board plant 1 is in operation.

[0112] First, a freely selectable voltage setting for the master outer track is made via the setting arrangement 120. As mentioned, the voltage of the slave outer track is automatically adjusted or adjusted.

[0113] The curvature of the corrugated cardboard sheets 102 is then determined using the curvature determination devices 105. As mentioned, this can alternatively be done manually.

[0114] Thereafter, in a step 124, a check is carried out to determine whether the corrugated cardboard sheets 102 have or maintain a desired flatness in the longitudinal direction.

[0115] If the corrugated cardboard sheets 102 have or maintain the desired flatness in the longitudinal direction, a check is carried out in a step 125 to determine whether the tensions of the single-sided, endless first corrugated cardboard web 21, the single-sided, endless second corrugated cardboard web 45, and / or the endless lamination web 72 are appropriate. As mentioned, the tensions are measured via the third tension measuring roller 79, fourth tension measuring roller 87, first tension measuring roller 77, and second tension measuring roller 78, respectively. If the tensions of the single-sided, endless first corrugated cardboard web 21, the single-sided, endless second corrugated cardboard web 45, and / or the endless lamination web 72 are not appropriate, a web tension level is adjusted in a step 126.

[0116] If the check in step 125 reveals that the tensions of the single-sided, endless first corrugated cardboard web 21, the single-sided, endless second corrugated cardboard web 45, and / or the endless lamination web 72 are acceptable, no change in the web tension level is necessary, as illustrated in step 127. The control process is terminated.

[0117] If the check in step 124 reveals that the flatness of the corrugated cardboard sheets 102 in the longitudinal direction is not correct or is not being maintained, the web tension difference is adjusted in a step 128 by means of a corresponding web tension difference control by the processing arrangement 108. This continues until the flatness of the corrugated cardboard sheets 102 in the longitudinal direction is correct or maintained. The lamination web splicing device 67, in particular its unwinding brakes 69a and 71a, the first drive 62 and the second drive 65, if necessary, are actuated accordingly.

[0118] If the flatness of the corrugated cardboard sheets 102 in the longitudinal direction is correct or maintained, the correction data are stored in the quality data memory 121. They can be retrieved by the specification device 120 as needed.

[0119] When creating a new quality for which experience is still lacking, it is preferable that the tension of the first outer lane is equal to that of the second outer lane.

[0120] If loose edges are present on the one-sided laminated, endless first corrugated board web 21, the one-sided laminated, endless first corrugated board web 21 requires a higher tension. This is preferably adjusted by the operator.

[0121] For example, if the first outer web exhibits wrinkles, this may require a change in the tension of the second outer web and is requested accordingly by the operator. The second outer web requires more or less tension. If the endless liner web 72 or the single-sided, endless first corrugated board web 21 flutters, a higher tension is necessary.

[0122] If the corrugated cardboard sheet 102 moves upwards (upward curvature), the tension of the inner liner is reduced and / or the tension of the outer liner is increased depending on the distance from a maximum or minimum limit. The value that is farther away from the respective limit is preferably changed. The measured tensions in the lamination area serve as control variables. Therefore, it is first determined whether the outer liner or the inner liner is closer to the limit values.

[0123] If the corrugated cardboard sheet 102 bends downwards (downward curvature), the tension of the inner liner is increased and / or the tension of the outer liner is reduced depending on the distance from a maximum or minimum limit. The value farther from the respective limit is preferably changed. The measured tensions in the lamination area serve as control variables. Therefore, it is first determined whether the outer liner or the inner liner is closer to the limit values.

[0124] The signal connections specified here are, for example, wireless or wired. Not all signal lines of the corrugator 1 are shown. The terms "downstream," "upstream," "upstream," "downstream," or the like generally refer to the transport direction of a corresponding web.

Claims

Patent claims 1. System a. with a corrugated board plant (1) comprising i. a first corrugated board manufacturing device (2) for producing a first corrugated board web (21) laminated on one side, ii. a laminating web unwinding device (67) for unwinding a laminating web (72), iii. a connecting device (88) downstream of the first corrugated board manufacturing device (2) and laminating web unwinding device (67) for joining the first corrugated board web (21) laminated on one side and the laminating web (72) together to form a double-sided laminated corrugated board web (91) comprising a first outer web (21, 72) and a second outer web (72, 21), and iv. at least one cutting device (97) downstream of the connecting device (88) for producing corrugated sheets (102) from the double-sided laminated corrugated board web (91), and b.with a processing arrangement (108) which is designed to automatically adjust the tension of the second outer web (72, 21) to a tension of the first outer web (21, 72), so that the corrugated sheets (102) are flat at least in the transport direction of the corrugated sheets (102) or comply with flatness target values.

2. System according to claim 1, characterized by a preselection arrangement (120) that is at least temporarily in signal communication with the processing arrangement (108) for preselection of the voltage of only the first outer track (21, 72).

3. System according to claim 1 or 2, characterized in that the tension of the second outer track is not specified (72, 21).

4. System according to one of the preceding claims, characterized in that the first outer track (21, 72) forms a master outer track and the second outer track (72, 21) forms a slave outer track and a master-slave voltage matching takes place.

5. System according to one of the preceding claims, characterized in that the processing arrangement (108) has a voltage comparison unit which compares the currently prevailing voltage of the first outer track (21, 72) and the currently prevailing voltage of the second outer track (72, 21).

6. System according to one of the preceding claims, characterized in that a voltage difference between the currently prevailing voltage of the first outer track (21, 72) and the currently prevailing voltage of the second outer track (72, 21) is adjustable.

7. System according to one of the preceding claims, characterized in that the processing arrangement (108) adjusts the voltage of the second outer track (72, 21) to the voltage of the first outer track (21, 72).

8. System according to one of the preceding claims, characterized in that a regulation of a voltage difference between the currently prevailing voltage of the first outer track (21, 72) and the currently prevailing voltage of the second outer track (72, 21) takes place.

9. System according to one of the preceding claims, characterized in that the laminating web (72) or the first corrugated board web (21) laminated on one side forms the first outer web and the other web (72, 21) forms or comprises the second outer web.

10. System according to one of the preceding claims, characterized in that the corrugated board system (1) comprises at least one laminating web tension changing device (69a, 71a) associated with the laminating web (72) and at least temporarily in signal communication with the processing arrangement (108) in order to change the tension of the laminating web (72) if necessary.

11. System according to one of the preceding claims, characterized in that the corrugated board system (1) is assigned at least one of the first corrugated board webs (21) laminated on one side, and is at least temporarily in signal connection with the processing arrangement (108). The standing first corrugated board tension-changing device (61, 62) is comprised to optionally change the tension of the first corrugated board laminated on one side (21), wherein preferably at least one first corrugated board tension-changing device (61, 62) is arranged between the first corrugated board manufacturing device (2) and the joining device (88).

12. System according to one of the preceding claims, characterized in that the corrugated board system (1) comprises at least one laminating web tension measuring device (79, 87) associated with the laminating web (72) and at least temporarily in signal communication with the processing arrangement (108), wherein preferably at least one laminating web tension measuring device (79, 87) is arranged between the laminating web unwinding device (67) and the connecting device (88), preferably downstream of a laminating web preheating device (76) for preheating the laminating web (72).

13. System according to one of the preceding claims, characterized in that the corrugated board system (1) comprises at least one first corrugated board tension measuring device (77) associated with the processing arrangement (108) and at least temporarily in signal communication with the processing arrangement (108) for measuring the tension of the first corrugated board (21), wherein preferably at least one first corrugated board tension measuring device (77) is arranged upstream of the connecting device (88), preferably downstream of a corrugated board preheating device (74) for preheating the first corrugated board (21).

14. System according to one of the preceding claims, characterized in that the corrugated board system (1) comprises at least one curvature determination device (105) associated with the corrugated board sheets (102) and at least temporarily in signal communication with the processing arrangement (108) for determining a currently prevailing curvature of the corrugated board sheets (102).

15. Method for manufacturing corrugated board, comprising the steps - Producing a first corrugated board web (21) laminated on one side using a first corrugated board manufacturing device (2), - Unwinding a laminating web (72) from a laminating web unwinding device (67), - Joining the first corrugated board web (21) laminated on one side and the laminating web (72) together to form a corrugated board web (91) laminated on both sides using a joining device (88) downstream of the first corrugated board manufacturing device (2) and laminating web unwinding device (67), wherein the corrugated board web (91) laminated on both sides has a first outer web (21, 72) and a second outer web (72, 21), - Producing corrugated board sheets (102) from the corrugated board web (91) laminated on both sides using at least one joining device (88) downstream of the joining device (88) Cutting device (97), and - if necessary, adjusting the tension of the second outer web (72, 21) automatically to a tension of the first outer web (21, 72) by means of a processing arrangement (108), so that the corrugated sheets (102) are flat at least in the transport direction of the corrugated sheets (102) or comply with flatness target values.

Images