Method for producing a corrugated board web by a corrugator, corrugator, and computer program product

Abstract

A method for producing a corrugated board web (4) by a corrugator (2) is shown, in which a plurality of paper rolls (10, 12) each having a paper web made of paper are provided, the paper rolls (10, 12) are each characterized by a number of paper parameters (16) having individual values ​​for each of the paper rolls (10, 12), whereby each of the paper rolls (10, 12) is individually characterized based on the values ​​of the paper parameters (16), and the paper parameters (16) of two paper rolls (10, 12) are compared to each other for the production of the corrugated board web (4). An allocation rule (18) is provided that associates a quality parameter (20) obtained when the paper rolls (10, 12) are combined, and a first paper roll (10) and a second paper roll (912) are selected from the paper rolls (10, 12) using the allocation rule (18) so as to optimize the quality parameter (20), and a corrugated board web (4) is produced by feeding the first paper roll and the second paper roll (10, 12) to a corrugator (2), which then splices the paper webs of the first paper roll and the second paper roll (10, 12) together. Further shown are a corrugator (2) and a computer program product.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a corrugated fiberboard web by means of a corrugator, as well as a corresponding corrugator and computer program product.

[0002] Corrugators are used to produce corrugated board webs. In this case, the corrugator is supplied with several paper webs in the form of paper rolls. The paper rolls are unwound using the respective unwinders of the corrugator, and the resulting paper webs are connected to one another by several processing units to form the corrugated board web. In this case, for example, one of the paper webs (the so-called waves) is corrugated using a corrugating roller and then glued to two non-corrugated paper webs (e.g., outer layers). Multi-layer corrugated board webs with several corrugated paper webs are also possible. Finally, the finished corrugated board web is optionally further processed using the corrugator, i.e., cut into individual sections and, if necessary, further slit and / or grooved.

[0003] The quality of the corrugated board web produced depends on the corresponding selection of values ​​for the operating parameters of the corrugator during operation (i.e., during the production of the corrugated board web), on the one hand, and on the other hand, on the properties of the paper web from which the corrugated board web is produced. The operating parameters are adjusted, for example, manually by an operator during the operation of the corrugator, or automatically in response to measurements by sensors immediately before each processing unit (in-line measurements). In this way, changes in the ambient conditions and the properties of the paper web can be accommodated. For example, temperature and moisture controllers for adapting the temperature and moisture of each paper web can be considered part of the corrugator's control system, immediately before the respective processing unit, in order to influence the processing result of this processing unit as optimally as possible.

[0004] Despite efforts to produce paper webs that are as uniform as possible, the properties of some paper webs can differ significantly, resulting in paper webs with different properties being joined together. Depending on the difference in the properties of the paper webs and the extent of the difference, this can lead to a reduction in the quality of the corrugated web or even the direct production of defective products. For example, distortion (also known as "warping") of a corrugated web is usually due to changes in the properties of the interconnected paper webs. Depending on the moisture content of the paper webs, they may not even be optimally bonded to each other. Essentially, the corrugator can be controlled, i.e., its operating parameters can be adjusted, to compensate for the changes in the properties of the paper webs as much as possible.

[0005] U.S. Patent No. 11,162,226, U.S. Patent No. 10,095,206, European Patent No. 3392649, European Patent No. 3369564, European Patent No. 2572038, European Patent No. 2406616, European Patent No. 2391505, European Patent Application Publication No. 1902833, European Patent Application Publication No. 0936059 , German Patent Application Publication No. 102017219064, German Patent Application Publication No. 102015206650, Chinese Patent Application Publication No. 107458032, Chinese Patent Application Publication No. 107631684, Chinese Patent No. 112644092, Chinese Utility Model No. 207105756, Chinese Utility Model No. 210553357.

[0006] Against this background, the object of the present invention is to improve the production of corrugated board webs, for which a suitable method, corrugator and computer program product for producing corrugated board webs should be provided.

[0007] According to the present invention, the above problem is solved by a method having the features of claim 1, a corrugator having the features of claim 14, and a computer program product having the features of claim 15. Advantageous embodiments, developments and variants are the subject of the dependent claims. Statements relating to the method also apply to the corrugator and the computer program product, and vice versa. Insofar as method steps are described below, advantageous embodiments of the corrugator result from the fact that it is designed to perform one or more of these steps (in particular by means of a control unit of the corrugator). Similarly, advantageous embodiments of the computer program product result from the fact that the computer program product contains commands which, when executed by the corrugator, cause the corrugator to perform one or more of these steps.

[0008] The method is used to produce a corrugated board web by a corrugator. First, a plurality of paper rolls are provided, each having a paper web made from paper. The paper rolls are provided in a roll store, from which they are supplied to the corrugator as needed, and the roll store is replenished from time to time by the delivery of new paper rolls. The roll store is usually located spatially close to the corrugator.

[0009] Each paper roll is characterized by a number of paper parameters, each of which has a distinct value for the paper roll, such that each paper roll is individually characterized based on the values ​​of the paper parameters. In this specification, and generally, "multiple" is understood to mean "one or more" or "at least one." The paper parameters and their values ​​of a single paper roll are also called "paper data," and together form a data set for this paper roll.

[0010] The central idea of ​​the present invention is therefore to combine, among these multiple paper rolls (available for the production of a corrugated board web), those whose paper parameters result in the most optimal production result possible, i.e., the highest possible quality of the corrugated board web, with each other during the production of the corrugated board web. This procedure is also simply called "roll matching" or "roll pairing." To that extent, the method described here also includes a method for selecting paper rolls for producing a corrugated board web. Therefore, paper rolls are not combined with each other randomly, but are instead intelligently selected and combined based on paper parameters. The selection, and preferably the entire method, is performed in an automated manner. Using the paper data, different paper rolls are skillfully combined with each other so that the production of the corrugated board web is optimized overall. In this way, intelligent "roll matching" is achieved, in which two paper rolls are combined with each other taking their paper data into account. Instead of randomly supplying paper rolls, the paper roll to be supplied at a given time is selected depending on how well it matches the currently supplied paper roll or a paper roll that has already been processed.

[0011] Here, an allocation rule is provided that links paper parameters of two (i.e., at least two) paper rolls with quality parameters that are obtained when these two paper rolls are combined to produce a corrugated board web. The quality parameters thus indicate how well the two paper rolls are compatible with each other and, in particular, are also a direct or indirect measure of the quality of the corrugated board web that can be achieved by combining these paper rolls. The allocation rule is therefore used to evaluate specific combinations of two paper rolls, thereby enabling optimization of the selection. In the following, for simplicity and without limiting generality, we start from the assumption that only two paper rolls are combined with each other, but the description applies equally to combinations of three or more paper rolls. The allocation rule thus assigns a quality parameter, or more precisely, a value of the quality parameter, to each combination of paper parameters, or more precisely, to the value of the paper parameter. For different combinations of paper rolls, the quality parameter usually, but not necessarily, varies. The details of the allocation rule are not particularly important for the moment; what is important is simply that the allocation rule links specific combinations of paper rolls with quality parameters based on the paper parameters of the paper rolls. This may be done, for example, by suitable computational models and / or based on historical data.

[0012] In a suitable embodiment, the allocation rules are trained, i.e., generated in advance by machine learning methods, in which the quality parameters are measured as a function of the paper parameters. The allocation rules are then derived from this function. Various approaches to the learning method are suitable, the details of which are not important for the moment. It is not necessarily important to know the correlations or causal relationships; it is essentially sufficient to empirically determine the allocation rules in advance by corresponding experiments, learning methods, and / or big data methods. To this extent, the allocation rules themselves are not necessarily known, and are in particular implemented in a virtual sensor of the corrugator, for example by means of a neural network, which is a kind of black box that simply outputs, for given paper data, the value of the corresponding quality parameter (or, for paper parameters of a first paper roll, the paper data of a second paper roll that is optimal in combination with the quality parameter). Essentially, various solutions that achieve similar or the same results in different ways are conceivable and suitable.

[0013] Within the scope of this method, a first paper roll and a second paper roll are selected from the paper rolls using an allocation rule in such a way that a quality parameter is optimized. The combination of a first and a second paper roll is also called a "roll pair" (or a "roll tuple" if there are more than two rolls). How exactly the quality parameter is optimized is not of great importance for the moment and depends heavily on the specifically used quality parameter. "Optimized" is preferably understood as "minimized", "maximized" or "as close as possible to a target value".

[0014] Basically, various approaches to paper roll selection are possible, each with its own advantages. In a first embodiment, the first paper roll is selected randomly or otherwise specified, e.g., the first paper roll is already stored in the corrugator. In this case, for example, the quality parameters for each combination of the first paper roll with other available paper rolls are then determined using an allocation rule, and the second paper roll is then selected by selecting the correspondingly optimal combination. Alternatively, the entire roll pair, i.e., the first paper roll, is also optimized, i.e., the best roll pair is selected from all available paper rolls. For example, the allocation rule determines the quality parameters of all possible roll pairs, and the roll pair with the highest quality parameter is then used.

[0015] To allow meaningful selection, suitably at least two paper rolls are provided as possible second paper rolls.

[0016] Without limiting generality, we start from the idea that the paper parameters of an actually existing paper roll are fed into the allocation rules, which then determine the optimization parameters. This is also called the "best available result" approach. An equivalent variant is for the allocation rules to determine the optimal paper data for the second paper roll from the paper data of the first paper roll and the predetermined optimization parameters, and then select as the second paper roll from the existing paper rolls the one whose paper data is closest to the optimal paper data. This is also called the "best available match" approach. In both cases, the optimization parameters are optimized.

[0017] Finally, within the scope of this method, the first and second paper rolls are fed to a corrugator, which then connects the paper webs of these first and second paper rolls to each other to produce a corrugated board web. In other words, two paper rolls are fed to the corrugator, which then connects them, possibly with other paper webs from other paper rolls, to produce a corrugated board web. Thus, the paper webs of the first and second paper rolls are connected to each other directly or indirectly via one or more additional paper webs. The first and second paper rolls are fed to the corrugator simultaneously or sequentially. It should be emphasized that the paper webs of the first and second paper rolls are also connected to each other, since only in this case does the interaction of the two paper webs take place in such a way that consideration of paper parameters is important and advantageous.

[0018] A corrugator can be supplied with multiple paper rolls in two ways. On the one hand, multiple paper rolls are supplied to the corrugated web, and the paper webs of the paper rolls are connected to each other as different layers of the corrugated web, i.e., multiple paper rolls of different layers are supplied more or less simultaneously. On the other hand, to achieve continuous operation, multiple paper rolls are supplied to the corrugated web sequentially in time. In the method described here, the paper webs of the first and second paper rolls preferably form different layers of the corrugated web (e.g., corrugations, front / rear cover layers, etc.). In the following, this will be used as a starting point without limiting generality. However, the invention described here is also advantageous in principle when two paper webs form the same layer. This usually occurs during splices, i.e., when the first paper roll is nearly used up and a second paper roll is then spliced ​​onto the first paper roll at its end to ensure continuous operation of the corrugator. In this case, a splice point occurs where two paper rolls are connected to each other, which may potentially benefit from the optimization described here.

[0019] Corrugators have a number of adjustable operating parameters that control the behavior of one or more of the corrugator's processing units. Examples of processing units include unwinders, splicers, printers, single facers, bridges, preheaters, gluers, double facers, dryer sections, cutting units, slitter units, and groove units. However, the details of the processing units are not important here. Examples of operating parameters include conveying speed, tensile stress, ink volume, corrugation roller temperature, glue volume, dampening solution volume, drying temperature, cut and / or groove position, etc. The details of the processing parameters are also not important here.

[0020] Each paper roll is formed in particular by a paper web and a sleeve (also called a bushing) around which the paper web is wound, and the paper web is unwound by an unwinder from a corrugator for producing a corrugated board web and appropriately connected to other paper webs of other paper rolls. Each paper web is made of or consists of paper.

[0021] As already explained, each paper roll is characterized by many paper parameters. More precisely, the paper of each paper roll is characterized by these paper parameters. Thus, the paper parameters specifically characterize the paper of each paper roll, even if sometimes, for brevity, we refer only to the paper roll, in which case we specifically mean the paper of the paper roll. Each paper parameter directly or indirectly represents one or more properties of the paper of the paper roll, whereby different values ​​mean or imply correspondingly different properties. In this case, the term "paper parameter" is particularly broadly interpreted to mean not only the physical, mechanical, and chemical properties of the paper itself, but also any information that allows characterization of the paper, such as, for example, the location, time, and storage period of the paper, or the operating parameters of the paper machine during the paper production. In a suitable embodiment, the paper data is an average value or a position- and / or time-resolved value (e.g., moisture resolved positionally along the length and width of the paper web), or a combination thereof. For example, the paper parameter is the paper fiber orientation of the paper rolls, with associated values ​​a for the first paper roll, b for the second paper roll, and c for the third paper roll.

[0022] Thus, although the values ​​of the paper parameters are different for each paper roll (or, strictly speaking, the paper), this does not exclude the possibility that two paper rolls do not have the same value for a particular paper parameter. However, typically, the paper of two paper rolls differs in one or more paper parameters due to their production, storage, transportation, etc., and therefore has different characteristics, which affect its processing in the corrugator. This individuality of the paper rolls is taken into account and utilized during the production of the corrugated board web in order to optimize the production of the corrugated board web through a skillful combination of paper rolls. In this case, the paper data is not detected for the first time at the corrugator or only at the corrugator, but is detected already in advance, particularly remotely and independently from the corrugator. The paper data preferably includes the paper production process and / or the history of the paper roll, and therefore the paper data is, so to speak, a resume of the paper roll. In particular, the paper data does not necessarily include only paper parameters that can be detected inline at the corrugator, but preferably also includes paper parameters, such as papermaking process parameters, that are, in principle, completely inaccessible to detection within the corrugator. Therefore, the method presented here is correspondingly dynamic in that the individual characteristics of the paper roll are taken into account. The paper parameters themselves, and therefore the entire paper data, are either static, i.e., constant for the paper of the entire paper roll, or dynamic, i.e., change along the paper of the paper roll, so that, for example, the parameter profile changes depending on the portion of the paper web that is currently being unwound, respectively. Combinations are also possible, so that one or more paper parameters are static and one or more other paper parameters are dynamic.

[0023] In general, special adjustments of the supplied paper rolls relative to one another have not been performed to date. This is not even currently necessary, since, for the corrugated cardboard layers, feedback control is generally possible, reacting based on the produced corrugated cardboard web. Any errors or inaccuracies resulting from the combination of the paper roll with changing paper parameters are then readjusted. However, readjustment is not possible in all cases. Furthermore, readjustment typically leads to the production of a defective product or at least one suboptimal product, thereby reducing the economic viability of the corrugator. In contrast, the method presented here allows for the predictive selection of the optimal paper roll, i.e., the paper roll that will provide the best results and therefore require particularly little readjustment. The intelligent combination of paper rolls correspondingly reduces the load on the control system for readjustment.

[0024] Preferably, the values ​​of the used paper parameters of a single paper roll are aggregated as much as possible, i.e., received by the corrugator from as few different sources as possible and preferably only from a single source, and therefore as a cohesive data set as much as possible. Thus, the paper data is preferably not delivered at different points in the corrugator and / or at different times, but is instead collected in a single data set and / or at a single time. Optionally, even the paper data of multiple paper rolls is aggregated in a similar manner, and aggregated in such a way that individual values ​​can be assigned to a single paper roll, preferably by the ID of each paper roll.

[0025] The present invention utilizes, inter alia, the fact that the paper characteristics of each paper roll are actually considered individually, so that starting from a first paper roll with predetermined characteristics, a second paper roll that optimally matches it is selected, thereby producing a cardboard web of the highest quality. Another advantage is that paper rolls with relatively large tolerances can be used, since any deviations from the ideal paper parameter values ​​can be optimally compensated for by skillfully combining them with a correspondingly compatible second paper roll. This makes it possible to produce paper, and paper rolls in general, more simply and cost-effectively. Furthermore, even paper rolls that previously would have been rejected due to too many defects can be used in this case.

[0026] Optimization of production is possible in various ways. Suitably, the production of the corrugated board web is optimized with the aim of improving the properties of the corrugated board web (corrugated board properties) or with the aim of improving the operation, especially the control of the corrugator. Thus, in a first suitable embodiment, the quality parameter is a corrugated board parameter that characterizes the corrugated board web or depends on such a corrugated board parameter (for example, it may be advantageous to combine several corrugated board parameters into a single quality parameter). Suitable corrugated board parameters are generally any corrugated board properties, such as in particular the degree of distortion of the corrugated board web, also known as "camber", strength values ​​of the corrugated board web, and in particular edge crush resistance (e.g. according to ECT = edge crush test) and flat crush resistance (e.g. according to FCT = flat crush test).

[0027] Alternatively or additionally, the quality parameter is a change (e.g., a control range or interval) in an operating parameter of the corrugator during the production of the corrugated board web, or depends on such a change (e.g., it may be advantageous to combine several changes into a single quality parameter). This is based on the consideration that the corrugator has a certain margin in its operating parameters, and in that case, paper rolls are purposefully selected and combined in such a way that they require as little margin as possible. In other words, the margins are minimized. In that case, the corrugator requires particularly few readjustments during operation.

[0028] In an advantageous embodiment, the allocation rules are designed and the quality parameters are selected so that the paper parameters are optimized by a combination of paper rolls that compensate each other. The type of compensation depends, inter alia, on the paper parameters. "Compensating" is understood, inter alia, to mean that two values ​​of a paper parameter of two paper rolls have absolute values ​​but opposite signs, or that the difference between the values ​​is equal to the respective target values, or that the difference between the two values ​​does not exceed a maximum difference. In the case of paper parameters that indicate an orientation or angle, such as fiber orientation, "compensating" is understood, inter alia, to mean that the orientations are perpendicular to each other.

[0029] In a preferred embodiment, one of the paper parameters of each paper roll is moisture (dynamic or static), and the quality parameter is a measure (difference) of the moisture difference, i.e., the quality parameter indicates how much the moisture of two simultaneously processed paper rolls differs. The quality parameter is, for example, simply the difference or ratio of the moisture of the two paper rolls. Alternatively, the quality parameter is a parameter that depends on it, such as the so-called warp (bending or distortion) of the cardboard web produced from the paper rolls. The allocation rule associates the moistures accordingly, for example by subtracting them from each other. The quality parameter is then optimized, for example by minimizing any differences, or at least ensuring that they do not exceed a predetermined maximum value.

[0030] Advantageously, during or after the production of the corrugated board web, the quality parameters of each combination of two paper rolls are repeatedly measured, and the paper parameters of the two paper rolls are stored in a database together with the quality parameters as historical data. In this case, the allocation rule is suitably based on the historical data. In this way, automated "roll matching" is realized based on experience. Such use of historical data is also suitable for learning the allocation rule, as already explained above. A simple match with the historical data is also expedient. For example, given a first paper roll, the paper roll most similar to the first paper roll in terms of paper parameters is searched for in the historical data. A second paper roll with paper parameters that optimizes the quality parameters is then assigned to it. Therefore, the remaining paper rolls most similar to this historical second paper roll are then searched for and selected.

[0031] The specific paper parameters utilized are not particularly important at this stage, and become less important as the number of paper parameters increases. Accordingly, it is preferable to use at least 10, and in particular at least 100, paper parameters. The total amount of paper data is revealed, inter alia, by the number of values ​​stored for each paper parameter. Static paper parameters contain only a single value (e.g., linear meters on a paper roll, production date, or average value of a dynamic paper parameter, average moisture), whereas dynamic paper parameters contain a large number of values ​​(e.g., moisture as a function of the width and length of the paper roll), which, inter alia, depends on the value density / sampling rate (e.g., 1 / cm) and typically ranges from 1,000 to 1,000,000 or more. Paper parameters do not necessarily have to have a directly recognizable causal relationship with quality parameters. Knowing the relationship is not particularly important, especially with the big data techniques mentioned above. However, some paper parameters usually have a greater impact on the quality of the corrugated board web than others, and are therefore preferably used, especially when only a small number (i.e., at most 10) or even only one paper parameter is used. Therefore, in a suitable embodiment, one or more of the paper parameters are selected from the following paper parameters: paper fiber orientation of the paper roll, breaking stress of the paper of the paper roll.

[0032] In a suitable embodiment, at least one of the paper parameters is a dynamic paper parameter, the value of which is shown as a function of the width and / or length of the paper web of the paper roll. In contrast, static paper parameters show the same value along the entire paper web. Suitable dynamic paper parameters are fiber orientation as a function of the width and / or length of the paper web, temperature as a function of the width and / or length of the paper web, for example in the form of a "heat map" showing the temperature at each point on the paper web, and moisture as a function of the width and / or length of the paper web, for example in the form of a "moisture map." Dynamic paper parameters are distinctive in that they may show different values ​​at different points on the paper web and thus represent the non-uniformity of the paper roll. The use of one or more dynamic paper parameters provides a detailed image of the paper roll, which can be advantageously used when combining paper rolls for optimization.

[0033] Papermaking process parameters, i.e., process parameters used during the production of the paper itself of the respective paper roll, are also suitable as paper parameters. Papermaking process parameters are parameters of the production of paper, not the direct and immediate properties of the paper (moisture, fiber orientation, length, width, etc.), and are therefore only indirect or indirect paper parameters. In a suitable embodiment, the paper parameters accordingly include a number of papermaking process parameters used during the production of the paper roll. Papermaking process parameters are, in particular, operating parameters of a paper machine for producing the paper roll and / or for producing the paper of the paper roll. Using papermaking process parameters, a correlation between the production of the cardboard and the production of the paper used therein is appropriately detected, which may not be discernible in the direct paper parameters. Therefore, subsequent determination of other paper parameters, such as breaking stress and fiber orientation, temperature, moisture, etc., may become unnecessary in some cases, and thus may even be omitted completely or partially in advantageous embodiments. In this case, the recognition that the production of the paper roll ultimately has a decisive influence on these properties and that its production is also decisively influenced by the papermaking process parameters is utilized. They are therefore advantageously used directly for the selection and combination of paper rolls.

[0034] Suitable paper parameters are listed below in particular: a) Characteristics of the paper roll - (Exact) Sleeve Outer Diameter - (Accurate) linear meter on paper roll -Splicing position of paper roll b) Paper production process - Production date -Manufacturer name -Manufacturing location -Manufacturing date -Storage period -Storage conditions (e.g. humidity and / or ambient temperature) -Transportation time -Transport conditions (humidity and / or temperature of the surrounding environment, etc.) c) Basic characteristics of paper -Moisture / moisture content -Mass per unit area -Thickness -ash -Fiber orientation (including fiber orientation angle) d) Tensile properties of paper - Breaking force -Tearing length -Elongation at break - Elastic modulus e) Paper surface / printability characteristics - smoothness, e.g. according to Bekk) - roughness, e.g. according to Bendtsen - Breathability, e.g. according to Bendtsen / Gurley f) Characteristics of corrugated board (especially characteristics of base paper) -Flat crush resistance (e.g. CMT = Conchoramedium Test, FCT = Flat Crush Test, etc.) -Short span compressive strength (e.g. SCT = Short span compressive strength test)

[0035] The above list gives preferred paper parameters, but it should be understood that it is not exhaustive: it may already be advantageous to use only a portion of the aforementioned paper parameters (possibly even just one).

[0036] Regardless of whether the paper parameters are static or dynamic, paper parameters that change as little as possible or not at all during the life of the paper roll, i.e. until the paper roll is processed in the corrugator, are particularly suitable.

[0037] Suitably, the values ​​of the paper parameters of each paper roll are already determined during its production, in particular in the case of the above-mentioned papermaking process parameters. Alternatively or additionally, the values ​​of the paper parameters of each paper roll are determined after its production, in particular by laboratory tests. In general, it is advantageous if at least some of the paper parameters are further determined already during production or immediately after production, in particular by the manufacturer of the paper roll itself, and subsequently transmitted to the corrugator, for example by being appropriately stored on a data carrier.

[0038] The corrugator expediently has a data interface via which values ​​of the paper parameters of the paper of each paper roll are transmitted to the corrugator. In the sense of the preferred predictive approach here, all values ​​are preferably transmitted together as a single aggregated data set via the data interface and are then immediately available, i.e., the corrugator can access the paper data while the paper roll is, for example, still stored in a roll storehouse, or even earlier. Suitably, the corrugator is connected to the roll storehouse via the data interface.

[0039] In a particularly preferred embodiment, each paper roll is assigned a data carrier on which individual values ​​of paper parameters for the paper of each paper roll are stored. Thus, each data carrier is assigned to exactly one paper roll and, in particular, contains only the paper data of a single paper roll. Preferably, the data carrier is read by the corrugator for the method described herein. For this purpose, the corrugator has a suitable reader. The reader is, in particular, part of the data interface already mentioned. The data carrier is suitably a code, for example, a QR code or a barcode, a transponder, for example, an RFID tag or an NFC tag, or a volatile or non-volatile memory, for example, a floppy disk, a CD, or a flash memory. Thus, the reader is, for example, a scanner, a receiving unit with an antenna, a drive, a USB port, etc. The data carrier enables an offline solution in which the values ​​of paper parameters are transmitted to the corrugator to receive the data sets for each paper roll without connecting to the Internet or another network.

[0040] The data carrier is attached to the paper roll or is provided separately from the paper roll. According to one embodiment, the data carrier is a label or a kind of data sheet for the paper roll, also called a "roll tag." Furthermore, the data carrier can advantageously be sent together with the paper roll. Therefore, in an advantageous embodiment, the data carrier is attached to the paper roll, for example, glued or printed directly on the paper web of the paper roll or on the packaging of the paper roll, for example on the paper or sleeve. This makes the allocation and handling of the data sets particularly uncomplicated. For example, the data carrier is a code attached to the paper roll and read by a reader upon entry into the roll store.

[0041] It is generally conceivable that a paper roll is used several times (e.g., three times), i.e., it is not necessarily completely used up after being fed into the corrugator, but is only partially used, and then removed from the corrugator again and stored. If necessary, the partially used paper roll is then fed again to the corrugator at a later time. Therefore, the data carrier is preferably designed to be reliably connected to the paper roll even if the paper roll is fed into or removed from the corrugator several times. In a suitable embodiment, the data carrier is detachable for this purpose, being removed when the paper roll is fed and reattached to the paper roll during removal and subsequent storage. In another suitable embodiment, the data carrier is attached to the paper roll so that it does not need to be removed, i.e., it remains on the paper roll when the paper roll is processed in the corrugator. Expediently, the data carrier is attached centrally for this purpose, in particular on or in the sleeve of the paper roll. Contactless or electronically readable data carriers, such as RFID and NFC tags, are particularly suitable for this purpose. Overall, this ensures that the paper parameters remain available over the entire service life of the paper roll, even if it is used several times. The remarks regarding the data carrier apply equally to the already mentioned ID, which will be explained in more detail below.

[0042] Updating paper parameters is particularly advantageous when a paper roll is used multiple times. For this purpose, in a suitable embodiment, one or more paper parameters of a paper roll are updated when the paper roll is only partially used and removed from the corrugator and temporarily stored for later use, particularly away from the corrugator, for example, in a roll storage. The update can either change existing paper parameters or add new paper parameters. For example, it is expedient to update the paper length, i.e., to store the remaining paper length, the diameter of the paper roll, and basically all properties of the paper roll that change during processing in the corrugator. A suitable paper parameter that can be added in some cases is the unwinding direction, i.e., the direction in which the paper roll was unwound during processing (especially in the case of paper for corrugating a cardboard web). In a particularly advantageous embodiment, one or more operating parameters of the corrugator used to process the paper roll are stored during the paper parameter update, so that the operating parameters last used for this paper roll are accessible and available as soon as the paper roll is used again. Once the operating parameters are selected, they are, so to speak, inherited. Alternatively or additionally, it is also stored which other paper rolls the paper roll has been processed with, and optionally under which operating parameters. In this way, advantageously, operating parameters are learned that are particularly advantageous for working with such or similar paper rolls (e.g. from the same batch). The updating is carried out in particular by means of a writer on the corrugator. Optionally, the reader and writer are combined into a writer-reader.

[0043] Instead of or in addition to the offline solutions described above, online solutions, such as cloud solutions, are also fundamentally advantageous. Such online solutions have the particular advantage that, for example, paper parameters can be determined by laboratory tests in parallel (i.e., simultaneously) with the transport of the paper rolls, and then the paper parameters can be transmitted online. In a suitable embodiment, at least some (one or more), in particular all, of the paper rolls have, in particular, individual IDs (also called identifiers or identification marks), which are stored together with the values ​​of the paper parameters of the respective paper rolls in a database (the same as or different from the above-mentioned database), for example, in a data lake. In a suitable embodiment, the database is part of a cloud. The IDs are used to assign specific paper rolls to paper data, which are then determined and / or stored independently of the paper rolls. The paper parameters suitably reach the database and / or the corrugator via a data interface, which is not necessarily connected to a roll storehouse but is therefore connected to a suitable network. The use of IDs to assign a paper roll to one of a number of aggregated data sets has already been outlined above. In a suitable embodiment, the database is designed separately from the corrugator and is connected to the corrugator for data transmission, for example, via the Internet or another network. A design in which the database is part of the corrugator is also suitable. The database is connected to only one corrugator or, alternatively, to multiple corrugators. The corrugator requests the paper data of each paper roll from the database based on its ID. Basically, allocation rules are also stored in the database, which advantageously allow the corrugator to directly output the ID of the second paper roll that best matches a given ID of a first paper roll when the corrugator requests one. The ID is preferably attached to the paper roll; therefore, the above description of the data carrier applies equally to the ID.

[0044] The corrugator according to the invention comprises a control unit designed to carry out the above-mentioned method, in particular to carry out one or more of the above-mentioned steps of the method, and for this purpose the control unit in particular comprises and / or is connected to the above-mentioned database, and expediently the control unit contains the allocation rules.

[0045] Suitably, the corrugator comprises a planning-to-order system, by means of which the selection, combination and supply of paper rolls from the roll store are planned in advance, the planning-to-order system in particular queries the paper data of each first paper roll, for example by means of a reader or ID, and transfers these paper data to a control unit, which then uses allocation rules to determine the optimal second paper roll to combine with the first paper roll.

[0046] A computer program product according to the present invention includes commands that, when executed by a corrugator, in particular when executed as described above, cause the corrugator to select a second roll of paper from a plurality of rolls of paper relative to a first roll of paper using allocation rules in the manner described above such that quality parameters are optimized. In particular, the allocation rules for allocating the two rolls of paper to each other are implemented by the computer program product. Suitably, the computer program product includes commands that, when executed by the corrugator, cause the corrugator to implement the order planning system described above.

[0047] In the following, an embodiment of the invention will be explained in more detail on the basis of the drawings, in which only Figure 1 shows a schematic representation of a corrugator and a roll store therein. [Brief explanation of the drawings]

[0048] [Figure 1]Illustrated is a corrugator 2 for producing a corrugated fiberboard web 4. The corrugator 2 has a number of adjustable operating parameters. Herein, and generally, "a number" is understood to mean "one or more" or "at least one." The operating parameters are used to control the behavior of one or more processing units 6 of the corrugator 2. Examples of processing units 6 are unwinders 8, splicers, printers, single facers, bridges, preheaters, gluers, double facers, drying sections, cutting units, slitter units, groover units, etc.

[0049] Within the scope of the method for producing the corrugated board web 4, a plurality of paper rolls 10, 12 are provided, each having a paper web made from paper. The paper rolls 10, 12 are provided in a roll store 14, from which the paper rolls 10, 12 are supplied to the corrugator 2 as needed, and the roll store is replenished from time to time by the delivery of new paper rolls 10, 12. The roll store 14 is typically located spatially close to the corrugator 2.

[0050] Each paper roll 10, 12 is characterized by a number of paper parameters 16, each having a distinct value for each paper roll 10, 12, such that each paper roll 10, 12 is individually characterized based on the values ​​of the paper parameters 16. The paper parameters 16 and their values ​​for a single paper roll 10, 12, also known as "paper data," together form a data set for that paper roll 10, 12.

[0051] Furthermore, allocation rules 18 are provided that link paper parameters 16 of two (i.e., at least two) paper rolls 10, 12 with quality parameters 20 that are obtained when combining these two paper rolls 10, 12 for the production of the corrugated board web 4. The quality parameters 20 thus indicate how well the two paper rolls 10, 12 are compatible with each other. In what follows, for simplicity and without limiting generality, it is assumed that only two paper rolls 10, 12 are combined with each other, but the description applies equally to combinations of more than two paper rolls 10, 12. The quality parameters 20 usually, but not necessarily, vary for different combinations of paper rolls 10, 12.

[0052] The allocation rules 18 are, for example, trained, i.e., generated in advance by a machine learning method, in which, in particular, the quality parameters 20 are measured as a function of the paper parameters 16. The allocation rules 18 are then derived from this function. The allocation rules 18 themselves are not necessarily known, but are a kind of black box that, in particular, simply outputs for a given paper parameter 16 the value of the corresponding quality parameter 20 (or, for a paper parameter 16 of a first paper roll 10, the paper parameter 16 of a second paper roll 12 that is optimal in combination with the quality parameter 20). For example, the allocation rules 18 are implemented by a neural network or the like.

[0053] Using the allocation rule 18, a first paper roll 10 and a second paper roll 12 are selected from the paper rolls 10, 12 so that the quality parameter 20 is optimized. A combination of the first and second paper rolls 10, 12 is also called a "roll pair." In a possible embodiment, the first paper roll 10 is selected randomly or is otherwise designated in advance, e.g., the first paper roll 10 is already stored in the corrugator 2. In this case, the quality parameter 20 is then determined using the allocation rule 18 for each combination of the first paper roll 10 with the other paper rolls 10, 12 in the available roll storage 14, and the second paper roll 12 is then selected by selecting the correspondingly optimal combination. Alternatively, all roll pairs, i.e., the first paper roll 10, are also optimized, i.e., the best roll pair is selected from all available paper rolls 10, 12. For example, the quality parameter 20 of all possible roll pairs is determined using the allocation rule 18, and the roll pair with the highest quality parameter 20 is then used.

[0054] Here, without limiting generality, it is assumed that the paper parameters 16 of the actually existing paper rolls 10, 12 are fed into the allocation rules 18, which then determine the optimization parameters 20. This is also called the "best available result" approach. An equivalent variant is for the allocation rules 18 to determine the optimal paper parameters 16 of the second paper roll 12 from the paper parameters 16 of the first paper roll 10 and the predetermined optimization parameters 20, and then select as the second paper roll 12 from the existing paper rolls 10, 12 the one whose paper parameters 16 are closest to the optimal paper data 16. This is also called the "best available match" approach.

[0055] Finally, the first and second paper rolls 10, 12 are fed to the corrugator 2, and then the paper webs of these first and second paper rolls 10, 12 are spliced ​​together and, in some cases, to other paper webs of other paper rolls 10, 12 to produce the corrugated board web 4. The first and second paper rolls 10, 12 are fed to the corrugator 2 simultaneously or sequentially.

[0056] In the illustrated exemplary embodiment, the paper webs of the first and second paper rolls 10, 12 form different layers of the corrugated board web 4. However, the description given here also applies semantically to the case where the two paper webs form the same layer, which typically occurs during splicing, i.e., when the first paper roll 10 is nearly exhausted and the second paper roll 12 is then spliced ​​end-on to the first paper roll 10 to ensure continuous operation of the corrugator 2.

[0057] Each paper roll 10, 12 is formed here by a paper web and a sleeve (also called a bushing), the paper web is wound around the sleeve, the paper web is unwound by an unwinder 8 from a corrugator 2 for producing a cardboard web 4, and is appropriately connected to other paper webs of other paper rolls 10, 12.

[0058] Although the values ​​of the paper parameters 16 are different for each paper roll 10, 12 (or, strictly speaking, for each paper roll), this does not exclude the possibility that the two paper rolls 10, 12 do not have the same value for a particular paper parameter 16. However, the paper of the two paper rolls 10, 12 will typically differ in one or more of the paper parameters 16 due to their production, storage, transportation, etc., and therefore have different characteristics that affect their processing in the corrugator 2. This individuality of the paper rolls 10, 12 is taken into account and utilized during the production of the corrugated board web 4 in order to optimize the production of the corrugated board web through a skillful combination of the paper rolls 10, 12. The paper data includes, for example, the production process and / or history of the paper of the paper rolls 10, 12, and thus serves as a resume of the paper rolls 10, 12, so to speak. The paper parameters 16 themselves, and thus the entire paper data, may be static, i.e., constant for the paper of the entire paper roll 10, 12, or dynamic, i.e., changing along the paper of the paper roll 10, 12, so that, for example, the parameter profile changes depending on the portion of the paper web that is currently being unwound, respectively. Combinations are also possible, whereby one or more paper parameters 16 are static and one or more other paper parameters 16 are dynamic.

[0059] Optimization of production is possible in various ways. For example, the production of the corrugated board web 4 is optimized with the aim of improving the properties of the corrugated board web 4 (corrugated board properties) or with the aim of improving the operation and, above all, the control of the corrugator 2. In the first-mentioned case, the quality parameter 20 is, for example, a corrugated board parameter that describes a property of the corrugated board web 4 or depends on such a corrugated board parameter. Suitable corrugated board parameters are generally any corrugated board properties, such as the degree of distortion of the corrugated board web 4, also called "camber", strength values ​​of the corrugated board web 4, and in particular edge crush resistance (e.g., according to the ECT = Edge Crush Test) and flat crush resistance (e.g., according to the FCT = Flat Crush Test). Alternatively or additionally, the quality parameter 20 is, or depends on, a change (e.g., control range or interval) in the operating parameters of the corrugator 2 during the production of the corrugated board web 4.

[0060] In a possible embodiment, the allocation rules 18 are designed and the quality parameters 20 are selected in such a way that the paper parameters 16 are optimized by a combination of mutually compensating paper rolls 10, 12. The type of compensation depends in particular on the paper parameters 16.

[0061] In the exemplary embodiment of FIG. 1 , during or after the production of the corrugated board web 4, the quality parameters 20 of each combination of the two paper rolls 10, 12 are repeatedly measured, here using a sensor 24, and the paper data of the two paper rolls 10, 12 together with the quality parameters 20 are stored as historical data in a database 26. In this case, the assignment rule 18 is optionally based on the historical data. In this way, automated "roll matching" is realized based on experience. The use of such historical data is also suitable for learning the assignment rule 18. A simple match with the historical data is also expedient. For example, given a first paper roll 10, the paper rolls 10, 12 most similar to the first paper roll 10 in terms of paper parameters 16 are searched for in the historical data. The second paper roll 12, whose paper parameters 16 optimize the quality parameters 20, is then assigned to it. Therefore, among the remaining paper rolls 10, 12, the one most similar to this historical second paper roll 12 is then searched for and selected.

[0062] Which specific paper parameters 16 are used is not particularly important for the time being and becomes less relevant as the number of paper parameters 16 increases. For example, at least 10 paper parameters 16 are used. The total amount of paper data is revealed, among other things, by the number of values ​​stored for each paper parameter 16. Static paper parameters 16 contain only a single value (e.g., linear meters on the paper roll 10, 12, production date, or average value of dynamic paper parameters 16, average moisture), whereas dynamic paper parameters 16 contain multiple values ​​(e.g., moisture as a function of width and length of the paper roll 10, 12). However, it is also possible, in principle, to use only a single paper parameter 16, for example, the fiber orientation of the paper of the paper roll 10, 12 or the breaking stress of the paper of the paper roll 10, 12.

[0063] In a possible embodiment, at least one of the paper parameters 16 is a dynamic paper parameter 16, the value of which is a function of the width and / or length of the paper web of the paper rolls 10, 12. In contrast, a static paper parameter has the same value along the entire paper web. Papermaking process parameters, i.e., process parameters used in producing the paper itself of the respective paper rolls 10, 12, are also suitable as paper parameters 16.

[0064] The corrugator 2 has a data interface 28, through which the values ​​of the paper parameters 16 of the paper of each paper roll 10, 12 are communicated to the corrugator 2. For example, all values ​​are communicated together as a single aggregated data set through the data interface 18, and then immediately available, i.e., the paper data can be accessed by the corrugator 2 while the paper rolls 10, 12 are, for example, still stored in the roll storage 14, or even earlier. In the exemplary embodiment shown here, the corrugator 2 is connected to the roll storage 14 via the data interface 28.

[0065] Here, each paper roll 10, 12 is assigned a data carrier 30 on which individual values ​​of the paper parameters 16 of the respective paper rolls 10, 12 are stored (offline solution). For the method described herein, the data carrier 30 is read by the corrugator 2. For this purpose, the corrugator 2 has a suitable reader, for example as part of the data interface 28. Here, the data carrier 30 is attached to each paper roll 10, 12 and is read by the reader, for example upon entry into the roll store 14. Alternatively or in addition to the above-mentioned offline solution, online solutions, such as cloud solutions, are also possible. For this purpose, for example, each paper roll 10, 12 has an individual ID (which is, for example, attached to the paper roll 10, 12 instead of the data carrier 30), which is stored in the database 26 together with the paper data 16 of the respective paper roll 10, 12. In that case, the ID is used to assign a specific paper roll 10, 12 to its paper data 16, in which case the paper data is detected and / or stored independently of the paper roll 10, 12. The paper parameters 16 can also reach the database 26, for example, via a data interface 28, which is then not necessarily connected to the roll storehouse 14 but is therefore connected to a suitable network. Alternatively, the database 26 can be designed separately from the corrugator 2 and connected to the corrugator for data transmission, for example via the Internet or another network. In FIG. 1, the database 26 is part of the corrugator 2.

[0066] In principle, the paper rolls 10, 12 are considered to be used several times, i.e., they are not necessarily completely used up after being fed to the corrugator 2, but are only partially used, and then removed from the corrugator 2 and stored again. This is indicated in FIG. 1 by the arrow from the corrugator 2 to the roll storage 14, which further indicates that the partially used paper rolls 10, 12 are shown in the roll storage 14 and are therefore thinner than the other paper rolls 10, 12. If necessary, these partially used paper rolls 10, 12 are then fed again to the corrugator 2 at a later time. Therefore, in this case, the data carrier 30 is designed to be reliably connected to the paper rolls 10, 12 even if the paper rolls 10, 12 are fed to or removed from the corrugator 2 several times. For example, the data carrier 30 is detachable for this purpose, being detached when the paper rolls 10, 12 are fed and reattached to the paper rolls 10, 12 when they are removed and then stored again. In the partially used paper rolls 10, 12 shown here, the data carrier 30 is attached to the paper rolls 10, 12 in such a way that it does not have to be removed, i.e. it remains on the paper rolls 10, 12 when the paper rolls 10, 12 are processed in the corrugator 2. For this purpose, the data carrier 30 is attached centrally to the sleeve of the paper rolls 10, 12 in Figure 1. The comments regarding the data carrier 30 apply equally to the ID already mentioned.

[0067] The corrugator 2 here further comprises a control unit 32 designed to carry out the above-described method. The control unit 32 is designed to carry out one or more of the above-described steps of the method and for this purpose comprises a database 26. Furthermore, the control unit 32 of Figure 1 also comprises allocation rules 18.

[0068] Individual aspects that are explicitly indicated and described or illustrated only in connection with an exemplary embodiment can also be applied to other exemplary embodiments essentially independently of the remaining concepts contained in the exemplary embodiment. [Explanation of symbols]

[0069] 2 Corrugator 4. Corrugated cardboard web 6 Processing Unit 8 Unwinder 10 First Paper Roll 12 Second Paper Roll 14 Roll Storage 16 Paper parameters 18 Allocation Rules 20 Quality Parameters 24 sensors 26 databases 28 Data Interface 30 Data Carrier 32 Control Unit

Claims

1. A method for producing a corrugated fiberboard web (4) by means of a corrugator (2), comprising the steps of: - a plurality of paper rolls (10, 12) are provided, each having a paper web made of paper, - said paper rolls (10, 12) are each characterized by a number of paper parameters (16) having individual values ​​for each of said paper rolls (10, 12), whereby each of said paper rolls (10, 12) is individually characterized based on said values ​​of said paper parameters (16); - allocation rules (18) are provided that link the paper parameters (16) of two paper rolls (10, 12) with quality parameters (20) that are obtained when combining the two paper rolls (10, 12) for the production of the corrugated board web (4); - selecting a first paper roll (10) and a second paper roll (12) from said paper rolls (10, 12) using said allocation rule (18) so that said quality parameter (20) is optimized; - the corrugated board web (4) is produced by feeding the first paper roll and the second paper roll (10, 12) to the corrugator (2), which then splices the paper webs of the first paper roll and the second paper roll (10, 12) together.

2. the quality parameters (20) are or depend on cardboard parameters characteristic of the cardboard web (4); The method of claim 1.

3. the quality parameter (20) being or depending on a change in an operating parameter of the corrugator (2) during the production of the corrugated board web (4); 3. The method according to claim 1 or 2.

4. the allocation rules (18) are designed and the quality parameters (20) are selected so that the paper parameters (16) are optimized by a combination of mutually compensating paper rolls (10, 12); The method according to any one of claims 1 to 3.

5. one of said paper parameters (16) of each paper roll (10, 12) is moisture and said quality parameter (20) is a measure of the moisture difference; The method according to any one of claims 1 to 4.

6. During or after the production of the corrugated board web (4), quality parameters (20) of each combination of the two paper rolls (10, 12) are repeatedly measured, and the paper parameters (16) of the two paper rolls (10, 12) are stored together with the quality parameters (20) as historical data in a database (26); The allocation rules (18) are based on the historical data. The method according to any one of claims 1 to 5.

7. the paper webs of the first paper roll and the second paper roll (10, 12) form different layers of the corrugated board web (4); The method according to any one of claims 1 to 6.

8. the number of paper parameters (16) for each paper roll (10, 12) is at least 10, preferably at least 100; The method according to any one of claims 1 to 7.

9. The one or more of the paper parameters (16) are selected from the following paper parameters (16): fiber orientation of the paper of the paper roll (10, 12), breaking stress of the paper of the paper roll (10, 12), The method according to any one of claims 1 to 8.

10. at least one of said paper parameters (16) is a dynamic paper parameter (16), the value of said dynamic paper parameter being a function of the width and / or length of the paper web of said paper roll (10, 12); The method according to any one of claims 1 to 9.

11. The paper parameters (16) include a number of papermaking process parameters used in producing the paper of each paper roll (10, 12); The method according to any one of claims 1 to 10.

12. the values ​​of the paper parameters (16) of the paper of each paper roll (10, 12) are detected before the paper roll (10, 12) is fed to the corrugator (2); The method according to any one of claims 1 to 11.

13. at least some of the paper rolls (10, 12), in particular all of the paper rolls (10, 12), have an ID, which is stored in a database (26) together with the value of the paper parameter (16) of each of the paper rolls (10, 12); The corrugator (2) requests the values ​​of the paper parameters (16) of each paper roll (10, 12) from the database (26) based on the ID. The method according to any one of claims 1 to 12.

14. A corrugator (2) having a control unit (32) designed to carry out the method according to any one of claims 1 to 13.

15. 14. A computer program product comprising commands which, when executed by a corrugator (2), cause the corrugator to select a second paper roll (12) from a plurality of paper rolls (10, 12) for a first paper roll (10) using allocation rules (18) such that a quality parameter (20) is optimized in the method of any one of claims 1 to 13.

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