EP0802025A2 - Method and apparatus for producing and stacking sheets cut from a web, in particular from carton webs - Google Patents

Abstract

The method includes the steps of cutting a material path (7) in a longitudinal direction to form at least two partial paths (7a, 7b) with predetermined width, cutting each of the partial paths in an orthogonal direction to form a predetermined number of sheets of a certain length corresponding to a respective order, and stacking the produced sheets. At a format change of the width of the first (7a) partial path due to a new order, the running order of the second (7b) partial path is interrupted, if the running order of the second partial path can not be processed simultaneously with the new order of the first partial path. The second partial path is cut in both the longitudinal and orthogonal direction, according to a new order with regard to the width of the second partial path, which can be processed simultaneously with the new order of the first partial path. The material sheets of the new order of the second partial path are stacked separately from the material sheets of the interrupted order.

Description

The invention relates to a method and a device for producing and depositing sheets cut from a material web, in particular a corrugated cardboard web, with the features of the preamble of claim 1 and claim 9.

In systems for the production of corrugated cardboard sheets of a certain format, a continuous web of material is first produced and then cut into sheets of the desired format by means of cutting devices. This requires at least one longitudinal cutting device for cutting individual partial webs from the continuously supplied web and at least one cross-cutting device which cuts the final sheets with the desired format from the partial webs.

These sheets are then deposited in the form of stacks by means of a depositing device. Such a depositing device for depositing corrugated cardboard sheets generally includes a conveyor device for each partial web, on which the individual sheets cut from the relevant partial web are deposited after the cross-cutting in the form of a scale-like overlapping sheet stream.

Each sheet stream is fed to a stacking device, a so-called stacker. In a stacker of this type, the sheets are combined into stacks of a predetermined height, the stack being conveyed out of the stacker after the desired stack height or the desired number of sheets per stack has been reached, in order to produce the next stack therein. A such a storage device is described for example in EP 0 211 996 A1.

Since a certain period of time is required to remove a finished stack from the stacker, a sufficient gap must be created in the sheet stream fed to the stacker, since otherwise an incorrect stacking process would be brought about. However, the requirement for gap formation in the sheet stream limits the production speed of the entire system.

Storage devices with two stackers were therefore created, between which it is possible to switch back and forth by means of a switch arranged in the conveyor device.

In this way, there is the advantage that the gap to be created in the sheet current only has to correspond to a time period which the switch requires for the switching process from one stacker to the other stacker.

If not only a single partial web of predetermined width is cut from the continuously produced corrugated cardboard web, but at least two partial webs, which of course can have different widths, a depositing device is usually used, which has a conveying device for the sheets cut from each partial web, each for Conveyor at least one stacker must be provided.

For optimal use of the continuously produced corrugated cardboard web, it is necessary to assign the individual orders of each sub-web to one another as possible so that the least possible waste is produced. An order is defined by a predetermined number of sheets Format. An order therefore corresponds to a certain total length of a partial web.

So far, the simultaneous processing of at least two partial orders from an original single corrugated cardboard web has been carried out in such a way that the orders to be processed in parallel are selected from a plurality of orders to be processed in such a way that both in the transition from an order of a partial web to the relevant exclusion order and As little waste as possible occurs during the processing of two orders.

If the orders to be processed on the individual partial webs end at very different times or at correspondingly different locations with regard to the web length and an order with a smaller sheet width follows the earlier job, a large intersection point is regularly created.

In addition, this known method has the disadvantage that in the event that very large orders have to be processed on both partial webs, there is no possibility of interposing an order of higher priority on at least one partial web.

Based on this prior art, the present invention has for its object to provide a method and an apparatus for producing and storing sheets cut from a material web, in particular a corrugated cardboard web, the waste, in particular after a format change after the completion of an order Partial web to be reduced compared to the known method. In addition, the possibility is to be created to make the processing of orders flexible.

The invention solves this problem with the features of claims 1 and 9, respectively.

The possibility of being able to interrupt the current order of the second of the at least two partial webs at least then when the format of the width of the first of the at least two partial webs as a result of a new order from the first partial web can be interrupted if the current order of the second partial web does not coincide with the order the first partial web can be processed, the advantage of an overall lower cut is achieved or a more flexible reaction to production specifications is made possible. Since orders do not have to be processed in one piece, orders to be processed in parallel can be combined more flexibly. The possibility is also created to postpone priority orders immediately after the end of the order of the first partial web and thereby to keep the waste low by interrupting the current order on the second partial web and interposing a suitable order.

According to the preferred embodiment of the method according to the invention, the interruption of the new order to be processed after the interruption of the order of the second partial web is prevented.

This has the advantage that only two stackers have to be assigned to this partial web or the transport device for this partial web. After interrupting the current job of the second partial web, the other stacker is switched over and the intermediate job completely processed. You can then switch back to the original stacker and continue processing the interrupted job.

If necessary, an order can of course also be interrupted several times in the method according to the invention, preferably each interposed order is not interrupted.

In one embodiment of the method according to the invention, the order of one, several or all partial webs can also take place independently of a format change in the width of another partial web, in order to enable the processing of higher priority orders. In this case, only a single partial web can be cut from the material web supplied.

In the case of two partial webs, it is of course also possible that the interruption of one order also interrupts the other order if it cannot be processed together with the higher priority order. Since both orders have to be interrupted in this case, it is necessary that at least two stackers are assigned to each partial web.

In the preferred embodiment of the method according to the invention, a partial web is used as the master partial web, wherein the orders of the at least one further partial web can be interrupted depending on the orders of the master partial web.

In the preferred embodiment, the orders of the master partial web cannot be interrupted. This ensures that only a single stacker has to be assigned to the master partial web.

If the orders of the master sub-lane are to be interrupted for the processing of orders of higher priority, so As already mentioned, at least two stackers must also be assigned to the master partial web.

Although the method according to the invention will generally be used in conjunction with stackers for stacking the material sheets, it is of course also conceivable that the material sheets of an order are combined and stored in a different way.

The device for carrying out the above method according to the invention comprises in a known manner a slitter, at least one cross cutter and a storage unit for stacking the sheets with at least three stacking devices, two stacking devices being assigned to one of the at least two partial webs. The method according to the invention is implemented by means of a control unit which effects the slitter, the cross cutter and the switching of the feed device between the two stacking devices assigned to a partial web in a corresponding manner.

The two stacking devices assigned to a partial web can, in the event that none of the stacking devices is occupied for buffering an interrupted job, be controlled in a known manner to increase the speed in such a way that a switch is made to the free stacking device when the capacity of the other stacking device is in each case is exhausted and must be emptied.

If, on the other hand, one of the two stacking devices is occupied for buffering an interrupted job, the control unit can control a device for the shedding of the material sheets of this partial web in such a way that such a gap in the shingled one is used up when the capacity of the active stacking device is exhausted Arc current is generated that there is sufficient time for emptying the stacking device.

If only a single partial web is to be cut from the supplied material web and an order produced thereon can be interrupted for the intermediate pushing of a higher priority order, the corresponding device must of course only have two stackers between which it is possible to switch back and forth.

Further embodiments of the invention result from the subclaims.

Fig. 1

eine schematische Darstellung einer Ausführungsform der Vorrichtung nach der Erfindung und

Fig. 2

eine schematische Darstellung der Abarbeitung verschiedener Aufträge im Fall von jeweils zwei parallel abzuarbeitenden Aufträgen.

The invention is explained in more detail below with reference to an embodiment shown in the drawing. The drawing shows:

Fig. 1

is a schematic representation of an embodiment of the device according to the invention and

Fig. 2

a schematic representation of the processing of different orders in the case of two orders to be processed in parallel.

The device for producing and depositing sheets cut from a corrugated cardboard web according to FIG. 1 essentially comprises a longitudinal cutting device 1, a transverse cutting device 3 and a depositing unit 5.

An endlessly produced corrugated cardboard web 7 is fed to the longitudinal cutting device 1, which is cut by the longitudinal cutting device 1 into two partial webs 7a and 7b each having a predetermined width. As a rule, the corrugated cardboard web 7 is additionally trimmed at the outer edges in order to ensure a clean cutting edge on the respective outer sides of the partial webs To ensure 7a and 7b. The partial webs 7a, 7b are fed to the cross-cutting device 3 by means of a first guide and transport device 9. As shown in FIG. 1, this can be a duplex cross cutter to which the partial webs 7a and 7b are fed at different heights.

For this purpose, the guide and transport device for each partial web 7a, 7b has an endless conveyor belt 9a, 9b, which enclose a corresponding angle. The cross-cutting device cuts the partial webs 7a, 7b fed to it in each case transversely to the conveying direction in sheets of corrugated cardboard of predetermined length.

The finished cut corrugated cardboard sheets of each partial web are fed by means of a second guiding and transport device 11 to a scale station 13, each of which has a group of brushes 15a, 15b which are assigned to the partial webs 7a and 7b. The incoming corrugated cardboard sheets are delayed by means of the brushes 15a, 15b and formed into a scale-like sheet stream. For this purpose, the shingling station 13 has endless conveyor belts 17a, 17b on the input side, which convey the corrugated cardboard sheets at the same speed as the first and second guide and transport devices. On the output side, the shingling station 13 has endless conveyor belts 19a, 19b which convey at a lower speed than the endless conveyor belts 17a, 17b. Due to the different conveying speeds and the brush groups 15a, 15b acting on the top of the corrugated cardboard sheets, a uniform scale-like flow of the corrugated cardboard sheets cut from each partial web is generated.

The scale-like sheet streams are fed to the storage unit 5, which has a plurality of endless conveyor belts 21 and 23 arranged one behind the other for the sheet stream of each partial web.

The conveyor belts 21 and 23 are each supported in the region of their ends by means of vertically movable supports 25. A chain (not shown in more detail) of a chain drive (also not shown) engages on the superimposed supports 25.

The supports 25 arranged vertically one above the other can each be moved vertically separately from one another. The vertically movable supports 25 belonging to a path are each coupled in such a way that the desired uniform course of the path generated by the successive endless conveyor belts is achieved. For this purpose, the supports 25 belonging to a partial web can be connected to the drive chain, for example, by means of chain wheels of different sizes. Since the vertical adjustment path of the supports 25 belonging to a partial web increases towards the exit of the storage unit 5, the diameter of the chain wheels of the supports 25 assigned to a partial web must increase in the direction of the downstream stackers.

Of course, it would also be conceivable to provide a separate drive for each support 25, the drives having to be controlled accordingly.

In Fig. 1, the coupling of the supports 25 of each partial web consisting of the endless conveyor belts 21 and 23 is shown only schematically, a separate drive being required for each support 25. The coupling of the supports 25 of the partial web consisting of the conveyor belts 21 and 23 is effected by a corresponding control with a control unit 27 for the conveyor belts 21 and a control unit 29 for the conveyor belts 23.

A total of three stacking devices 31, 32 and 33 are provided in the exit area of the storage unit 5. Here is the Stacking device 31, the shingled sheet stream produced from the partial web 7a can be fed by means of the endless conveyor belts 23. The stacking device 31 shown in FIG. 1 is a so-called up-stacker. In this type of stacker, the sheets are formed into stacks on a vertically rigid support 33 in that the endless conveyor belts 23 are slowly and steadily moved upwards by means of the supports 25. The speed of the upward movement corresponds essentially to the speed of the increase in height of the sheet stack 35 formed.

The stacker 32, to which the shingled sheet stream produced from the partial web 7b can be fed by means of the endless conveyor belts 21, is in principle also designed. However, since a further guiding and transport device 37 is provided above the stacker 32, the stacker 32, as shown in FIG. 1, can preferably be designed as a so-called side chamber. With a stacker of this type, only stacks of relatively low height are initially formed and the respective finished stacks are moved laterally out of the chamber and subsequently larger stacks are formed. This technique is particularly suitable for sheet sizes of short length, since in this case only relatively small stack heights can be achieved for reasons of stability. If individual stacks are then placed side by side, higher stack heights can also be realized.

In addition to the stackers 31 and 32 arranged one above the other in the vertical direction, a further stacker 33 is arranged, which is designed as a so-called down stacker. In this type of stacker, the delivery of the shingled sheet stream takes place with a constant vertical position of the supplying conveyor belt of the guiding and transport device 37. The stack in question is formed by the fact that a vertically movable base plate 39 is provided, which essentially begins at the start of the stack construction Feed height of feeder Conveyor belt is controlled. As the stack height increases, the plate 39 is then moved further and further vertically downward, the upper end of the stack preferably always being essentially at the feed height of the sheet stream or just below it. This avoids that the supplied sheets must fall down over a further distance and wedge against one another in this way and prevent the correct stack formation.

To control the entire device, a control unit 41 is provided, which controls both the longitudinal cutting device 1, the cross cutting device 3 and the shingling station 13 as well as the storage unit 5 including the supports 25 and the stackers 31, 32 and 33. The control of the supports 25 takes place by supplying control signals to the control units 27 and 29 assigned to the endless conveyor belts 21 and 25. Furthermore, the control unit 41 controls the base plate 39 of the down-stacker 33 and devices (not shown) for clearing out the Chamber the stacker.

The method according to the invention explained below can be implemented by suitable control of all of the aforementioned components.

In order to explain a preferred embodiment of the invention, reference is made below to FIG. 2. 2 schematically shows the processing of different orders, two orders being processed simultaneously. The processing of the orders takes place from right to left, since in Fig. 2, corresponding to the representation of the device in Fig. 1, a corrugated cardboard web 7 is shown in the direction of the arrow, which depending on the width of the orders to be processed simultaneously in partial webs 7a and 7b is cut.

In Fig. 2 it is initially assumed that an order I is first produced on the first partial web 7a, the sheets having a width B _I and the total length of the order, ie the total length of all sheets being equal to L _I. Simultaneously with order I, a second order II is produced, the sheets of which have the width B _II .

After completion of the processing of the order I, a further order III is processed on the first partial web 7a. This order III has a width B _III which is so large that the order II cannot be processed at the same time as the order III, since the total width would be greater than the width B of the corrugated cardboard web 7.

The invention therefore provides that when the format of the first partial web 7a changes during the transition from the first order I to the third order III, the second order II, which is produced on the second partial web 7b, is interrupted and a fourth order IV instead of the second order II to be produced on the second partial web 7b, which has a width B _IV , which allows the order IV to be processed simultaneously with the order III. After the completion of order III and order IV, a further order V is produced on the first partial web, the width B _{V of which is} such that simultaneous processing of orders V on the first partial web 7a and order II on the second partial web 7b is possible.

In Fig. 2 it was assumed for the sake of simplicity that orders III and IV have the same length. Of course, order IV can, however, also be shorter or longer than order III, whereby there is necessarily a waste, unless an order of a correspondingly short length can be inserted on the respective partial web.

The production of the order sequence according to FIG. 2 by means of the device shown in FIG. 1 is carried out as follows:

First, the jobs I and II are manufactured in such a way that the sheets of the job I, which are cut from the partial web 7a, are stacked in the stacker 31 and the sheets of the job II, which are cut from the partial web 7b, are stacked in the stacker 33 . For this purpose, the control device 41 controls the supports 25 of the storage unit 5 in such a way that the conveyor belts 23 enable up-stacking and the endless belts 21 feed the sheet stream of the partial web 7b to the guide and transport device 37. At the same time, the vertically movable plate 39 of the down stacker 33 is controlled accordingly.

If the length of the job I is so large that the maximum stack height in the stacker 31 is reached one or more times, the control unit 41 controls the stacker 31 with one or more clearing commands, whereupon the respectively finished stack is transported out of the stacker. For this it is of course necessary that a gap is created in the arc stream of the partial web 7a. This is done in a manner known per se by means of a suitable device, not shown, which can also be controlled by the control unit 41.

After order I has ended, the last stack is conveyed out of the stacker 31. The endless conveyor belts 23 are then brought back into the lower position in order to enable the sheets of the order III now to be produced to be stacked again. At the same time, the endless conveyor belts 21 are brought by the control unit 41 into the position in which the sheet stream of the partial web 7b here the processing of the order IV is fed to the stacker 32.

After the control of the longitudinal cutting device 1 and the transverse cutting device 3 by the control unit 41 to the format of the sheets of the orders III and IV now to be finished, the sheets of these orders are stacked in the stackers 31 (order III) and 32 (order IV).

With regard to the times of the control processes described above, the running time between the devices, for example the longitudinal cutting device, the cross cutting device and the stackers, must of course be taken into account.

For stacking the sheets of order IV in the stacker 32, the supports 25 of the endless conveyor belts 21 are controlled in the manner required for the function of the up-stacker 32.

Once the maximum stack height in the stacker 32 has been reached, the endless conveyor belts 21 are moved back into the lower position, the finished stack is conveyed out of the stacker and assembled into an overall stack in the connected side chamber.

Since, at the time of switching from order I to order III, there will generally be a partial stack started in the stacker 33, the stacker 33 serves as a buffer in the stacker 32 during the processing of the order IV.

After completion of the (equally presupposed) orders III and IV, the job V is then processed further by means of the stacker 31 and the job II started is further processed, the sheet stream of the job II being of course again fed to the guide and transport device 37 by means of the endless conveyor belts 21 got to.

In the preferred embodiment of the invention described above, the first partial web 7a therefore serves as the master partial web, the orders of which are not interrupted. For this reason, only a single stacker, namely the stacker 31, has to be assigned to this partial web.

Depending on the format change in the partial web 7a as a result of a new order, an ongoing order of the partial web 7b can be interrupted, the sheets in question being buffered in the stacker 32 or 33.

Of course, a multiple interruption of an order of the partial web 7b is also possible, but in the case of only two stackers assigned to the partial web 7b, the interposed order may not be interrupted.

However, it is also possible to interrupt an order to be processed on the partial web 7b, regardless of a format change in the first partial web 7a. However, this presupposes that the width of the order to be pushed on the second partial web 7b is such that it can be processed simultaneously with the order running on the first partial web 7a. This makes it possible, for example, to postpone high-priority orders if very long orders are running on both partial lanes.

This method can of course also be carried out if only a single partial web is cut from the endless corrugated web 7 fed to the slitter.

Due to the possibility of being able to interrupt an order on at least one partial web, the compilation of the orders to be processed at the same time can be carried out much more flexibly than was previously the case. This applies itself in the event that only a single partial web is cut from the material web 7. This then corresponds to the partial web 7b according to FIGS. 1 and 2.

Claims (11)

Process for the production and storage of sheets cut from a material web, in particular a corrugated cardboard web, according to the a) at least two partial webs (7a, 7b) with a predetermined width are cut from the material web (7) by longitudinal cutting, b) a transverse cut of each of the at least two partial webs (7a, 7b) is used to cut a predetermined number of material sheets of predetermined length corresponding to the respective order (IV) and c) the predetermined number of material sheets corresponding to an order (IV) are stored together,
characterized, d) that in the event of a format change in the width of the first (7a) of the at least two partial webs (7a, 7b) as a result of a new order (III) of the first partial web (7a), the current order (II) of the second (7b) of the at least two Partial webs (7a, 7b) are interrupted at least when the current order (II) of the second partial web (7b) cannot be processed simultaneously with the new order (III) of the first partial web (7a), e) that the second partial web (7b) is cut lengthways and crosswise in accordance with a new application (IV) of the second partial web, which can be processed in terms of width simultaneously with the new application (III) of the first partial web (7a), f) the material sheets of the new order (IV) of the second partial web (7b) being deposited separately from the material sheets of the interrupted order (II), and g) that the rest of the interrupted job (II) after a new format change in the first partial web (7a) as a result of another job (V) is processed further or finished, which allows simultaneous processing with the interrupted job (II). Method according to claim 1, characterized in that the new job (IV) to be processed after the job of the second partial web has been interrupted is not interrupted. Method according to one of the preceding claims, characterized in that the order of one, several or all of the partial webs can also be interrupted independently of a format change in the width of another partial web for processing orders of higher priority. Method according to claim 3, characterized in that only a single partial web is cut from the material web (7). Method according to one of claims 1 to 3, characterized in that a partial web (7a) is used as the master partial web and that, depending on the orders (I, III, V) of the master partial web (7a), the orders (III) of the at least one further partial web (7b) can be interrupted. Method according to claim 5, characterized in that the orders (I, III, V) of the master partial web (7a) are not interrupted. Method according to claim 5, characterized in that the orders (I, III, V) of the master sub-web (7a) can also be interrupted for processing orders of higher priority. Method according to one of the preceding claims, characterized in that the material sheets of an order (IV) are deposited in a stack and that at least one partial web (7b) is assigned two stacking devices (32, 33) between which it is possible to switch back and forth. Device for carrying out the method according to one of the preceding claims, with a) a slitter (1), to which the incoming material web (7) is fed, for the longitudinal cutting of the material web (7) in at least two partial webs (7a, 7b), b) one or more cross cutters (3) for cross cutting the at least two partial webs (7a, 7b) into sheets of a predetermined length, c) a storage unit (5) for stacking the sheets with at least three stacking devices (31, 32, 33), two stacking devices (32, 33) being assigned to one (7b) of the at least two partial webs (7a, 7b) and d) a control unit (41) for controlling the formats of the slitter (1) and the cross cutter (s) (3) and for controlling a switchable feed device (5) for feeding sheets of material to the two stacking devices (32, 33) assigned to the one partial web (7b),
characterized, e) that the control unit (41) controls the slitter (1), the cross cutter (s) (3) and the feed device (5) according to the method according to one of claims 1 to 8, f) wherein the control unit (41) when the order (II) of the partial web (7b), to which the two stacking devices (32, 33) are assigned, switches the feed device (5) to the other stacking device and when the interrupted job (II) switches back to the relevant stacking device. Apparatus according to claim 9, characterized in that the control unit (41) for the two stacking devices (32, 33) assigned to one partial web (7b) in the event that none of the stacking devices is occupied for buffering an interrupted job (II) Speed increase switches over to the free stacking device when the capacity of the other stacking device is exhausted and it must be emptied. Apparatus according to claim 9, characterized in that a device (13) for flaking the material sheets of the partial webs (7a, 7b) is arranged downstream of the slitter (1) and the cross-cutter or cutters (3) and that, in the event, one of the two the stacking devices (32, 33) assigned to a partial web (7b) is used for buffering an interrupted job, the control unit (41) controls the device (13) for the shingling of the material sheets of this partial web to maintain the production speed so that when the capacity of the stacking device in question is exhausted, such a gap is generated in the shingled sheet stream that sufficient time remains for emptying the stacking device.

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