Corrugated board system

Abstract

A corrugated board system comprises a corrugated board production device (1) for producing a single-faced laminated corrugated board web (2) comprising a face paper (7) and a corrugated paper web (10) adhered thereto. Furthermore, the corrugated board system comprises an adhesion detection device for detecting the adhesion between the face paper (7) and the corrugated paper web (10). The adhesion detection device comprises a detection device (41) for detecting the adhesion between the face paper (7) and the corrugated paper web (10) in the single-faced laminated corrugated board web (2, 26) at a detection device detection frequency. The detection device detection frequency is selected depending on the configuration of the single-faced laminated corrugated board web (2). Furthermore, the adhesion detection device comprises an adhesion evaluation device (42) in signal communication with the detection device (41) and receiving a detection signal from the detection device representative of the adhesion between the face paper (7) and the corrugated paper web (10) in the single-faced laminated corrugated board web (2).

Description

Technical Field

[0001] This invention relates to a corrugated board system. It also relates to a method for producing corrugated board. Background Technology

[0002] In the production process of corrugated board, a corrugated roll is typically formed and bonded to a linerboard to create a single-faced corrugated board roll. The bond between the corrugated roll and the linerboard is a key factor determining the quality of the finished corrugated board. Various methods for detecting the bond quality between the linerboard and the corrugated roll are known. For example, sampling is employed; however, this involves a significant time lag before obtaining results regarding the bond quality. Prior-disclosed online inspection methods are also known, based, for example, on imaging assessment of the corrugated profile of the single-faced corrugated board roll, or on empirical inspection methods using detection waves such as ultrasound. Imaging assessments often cannot reliably detect defective internal bonds between the linerboard and the corrugated roll, defects caused, for example, by external deformation of the corrugated board or the single-faced corrugated board roll. Inspection methods using detection waves typically only allow for random checks. Calibrating or adjusting the inspection system is often difficult or complex. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art. Specifically, it aims to provide a corrugated cardboard system with a particularly reliable and user-friendly adhesive detection device. Furthermore, it also aims to provide a corresponding method.

[0004] According to the present invention, this objective is achieved by the features disclosed in independent claims 1 and 15. The core of the invention lies in a detection device that operates at a detection frequency during operation. The detection frequency depends on the geometry, structure, cross-section, and / or material configuration of the single-faced corrugated cardboard roll to be detected. During operation, the detection device is selected or set as appropriate. During operation, the detection frequency to be used or selected is preferably within a detection frequency range.

[0005] For example, the configuration of the single-faced corrugated board roll to be inspected is determined by a sensor device in order to select / set the inspection frequency of the inspection device. Alternatively, the configuration of the corrugated board system can also be communicated manually, for example, by the system operator. Or, more preferably, the corrugated board system uses, for example, information related to the production of the single-faced corrugated board roll, which relates to its configuration and is information known to the system for the production process. The corrugated board system knows which type of (single-faced) corrugated board roll or what type of corrugation is currently being produced.

[0006] Advantageously, the testing device operates without physical contact during operation. It can detect adhesion directly or indirectly. For example, it can measure adhesion strength directly or indirectly. For example, it can measure at least one value characterizing adhesion strength. The testing device is preferably operated during the conveying of single-faced corrugated board rolls. It is advantageously operated continuously or periodically. Advantageously, during operation, the main plane of the testing device or its testing field is oriented perpendicular to the face paper or its adjacent area. Preferably, it is not necessary to adjust the angle of the testing device relative to the face paper. However, alternatively, other angles may be used between the testing device and the face paper during operation.

[0007] The detection device preferably includes at least one sensor unit associated with the single-faced corrugated cardboard roll to be detected, and is preferably configured as a transmission sensor unit or a transmission measurement unit. Advantageously, the at least one sensor unit includes at least one transmitter and at least one associated receiver, the receiver being spaced apart from the transmitter, particularly opposite to the transmitter, wherein the single-faced corrugated cardboard roll to be detected is located between the at least one transmitter and the receiver.

[0008] Advantageously, the at least one sensor unit of the detection device is designed as an ultrasonic or microwave sensor unit. For example, it is capable of moving across the width of the single-faced corrugated board roll to be tested, so as to detect the bond strength over the entire width of the single-faced corrugated board roll. Alternatively, for example, multiple sensor units may be arranged adjacent to each other in the width direction of the single-faced corrugated board roll to detect the bond strength over the entire width of the single-faced corrugated board roll.

[0009] Advantageously, an excitation signal is sent to the at least one transmitter at each detection point; the excitation signal is preferably selected as a transient signal or a burst signal, such as a double sinusoidal burst signal, preferably having at least two periods, more preferably having multiple periods. Advantageously, a high-pass filter is used to suppress or filter out low-frequency interference components in the detection signal or in the signal recorded by the receiver.

[0010] The bonding assessment device can be positioned adjacent to or spaced apart from the detection device. It can be, for example, a component of a corrugated board system control unit (such as a corrugated board system control / regulation unit), or at least intermittently communicate with that control unit. The bonding assessment device can be, for example, electrical or electronic. It communicates with the detection device, for example, in signal communication, either permanently or only when transmitting signals. The signal communication between the bonding assessment device and the detection device can be wireless or wired. Based on the received detection signals, the bonding assessment device determines, for example, the bond strength or its bond quality. For example, the bonding assessment device can be used to detect deviations from the desired bond quality in the single-faced corrugated board roll. In particular, it can reliably and easily distinguish between good and bad bonds.

[0011] The detection signal is preferably an electrical signal. It depends on the adhesion between the face paper and the corrugated paper roll in the single-faced corrugated paper roll to be detected, and particularly on the quality of the adhesion.

[0012] The adhesion detection device preferably operates automatically during operation. It preferably utilizes a data processing algorithm. This data processing algorithm is advantageously capable of predicting the quality of the adhesion. The prediction of adhesion quality can be achieved using only a single sensor unit.

[0013] When inspecting the bonding of the single-faced corrugated board roll, the roll is preferably conveyed in the main conveying direction, advantageously in a continuous manner. Advantageously, the corrugations of the corrugated board roll extend perpendicular to the main conveying direction of the single-faced corrugated board roll.

[0014] Advantageously, in the desired state of the single-faced corrugated board roll, the corrugated board roll is bonded to the face paper via the corrugated troughs adjacent to the face paper. Therein exist corresponding internal glued or bonded areas. Preferably, in the desired state, the bond between the face paper and a corrugated trough is linear in each case. According to this desired state, the bond lines are equidistant from each other in the single-faced corrugated board roll, have equal and uniform widths, extend parallel to each other, and / or are continuous in the width direction of the single-faced corrugated board roll. Bonding is preferably performed using adhesives or glues (e.g., starch glue).

[0015] Advantageously, the single-faced corrugated board roll is continuous. It is preferably (substantially) made of paperboard, paper, or similar materials. Both the linerboard and the corrugated roll are composed of paperboard, paper, or similar materials. The linerboard is advantageously a smooth sheet. Air (particularly ambient air) is present in the single-faced corrugated board roll. This is primarily due to the three-dimensional corrugated roll structure.

[0016] Advantageously, the defective areas of the detected single-face laminated corrugated paper roll can be individually removed or discarded from the corrugated paper system.

[0017] The corrugated board production apparatus preferably includes a corrugating device for corrugating the material sheet to form the corrugated paper roll or corrugated paper roll. It also advantageously includes a gluing device for applying adhesive to the corrugated paper roll. Advantageously, the corrugated board production apparatus further includes a pressure device for pressing the face paper against the adhesive-coated corrugated paper roll to form the single-faced corrugated board roll. In the single-faced corrugated board roll, the face paper and the corrugated paper roll are advantageously glued or bonded together in layers.

[0018] The single-faced corrugated board roll is preferably used to produce double-faced corrugated board roll, such as three-, five-, or seven-layered rolls. Therefore, for producing five- or seven-layered corrugated board rolls, the corrugated board system has more than one corrugated board production unit.

[0019] Advantageously, the corrugated board system includes an unwinding device for unwinding the face paper. Advantageously, it also includes an unwinding device for unwinding the corrugated paper roll or the material roll used to form the corrugated paper roll. Preferably, the corrugated board system further includes a laminate unwinding device for unwinding the laminated roll.

[0020] In addition, the corrugated board system preferably includes an adhesive coating unit for applying adhesive to the corrugated paper roll of the single-face laminated corrugated board roll.

[0021] Advantageously, the corrugated board system also includes a joining device for joining the glue-coated single-faced corrugated board roll to the laminated sheet to form a double-faced corrugated board roll.

[0022] Preferably, the corrugated board system further includes a longitudinal cutting / cripping device for longitudinally cutting and creasing the double-sided laminated corrugated board roll.

[0023] Advantageously, the corrugated board system also includes a cross-cutting device for cross-cutting the double-sided laminated corrugated board roll or a portion thereof to form a corrugated board sheet.

[0024] Advantageously, the corrugated cardboard sheets can be stacked in the stacking device of the corrugated cardboard system.

[0025] Other advantageous embodiments of the invention are disclosed in the dependent claims.

[0026] According to the configuration described in dependent claim 2, a functionally reliable adhesion detection device is obtained. The detection wave is preferably an acoustic wave (especially ultrasonic) or an electromagnetic wave (e.g., microwave). The phase velocity or propagation speed of the detection wave depends on the wavelength and the detection frequency of the detection device.

[0027] According to dependent claim 3, the detection frequency of the detection device is selected based on the configuration of the corrugated paper roll of the single-faced corrugated cardboard roll to be detected (e.g., its geometry, shape, cross-section, corrugation configuration / type (e.g., flute pitch, flute height) and / or material). According to the invention, it has been recognized that the configuration of the corrugated paper roll has a (significant) influence on the detection frequency of the detection device. Corrugated sheets differ from each other, for example, in their flute types. The corrugated paper roll of the single-faced corrugated cardboard roll to be detected has, for example, K-flute, A-flute (coarse flute), C-flute (medium flute), B-flute (fine flute), D-flute (fine flute), E-flute (extra-fine or micro flute), F-flute (micro-fine flute), G-flute (micro-fine flute), or N-flute (micro-fine flute).

[0028] According to dependent claim 5, the detection frequency of the detection device is selected based on the flute height of the single-faced corrugated paper roll to be detected. The term "flute height" is preferably understood to represent the vertical distance between the corrugated crests / ridges (particularly the upper / outer regions) and the corrugated troughs (particularly the lower / outer regions) in the corrugated paper roll.

[0029] According to dependent claim 6, the lower limit detection frequency preferably depends on the single-faced corrugated board roll to be tested, particularly on its corrugated paper roll, particularly its corrugated configuration, and particularly its flute height. If the detection frequency of the detection device is lower than the lower limit detection frequency, problems will arise when detecting the adhesion (e.g., when testing the single-faced corrugated board roll to be tested). In particular, problems will subsequently arise when detecting the adhesion between the face paper and the corrugated paper roll in the single-faced corrugated board roll to be tested.

[0030] According to dependent claim 7, the upper limit detection frequency advantageously depends on the single-faced corrugated paper roll to be tested, particularly on its corrugated roll, especially the corrugation configuration, and especially the flute height. If the detection frequency of the detection device is above the upper limit detection frequency, anomalies will occur during the detection of the bonding (e.g., anomalies will appear in the obtained images showing the bonding).

[0031] If the detection frequency of the selected detection device is too high, signals from the material of the single-faced corrugated board roll being tested will dominate. For example, the wavelength is refracted in each individual layer of the single-faced corrugated board roll. Detection frequencies above the upper limit should be avoided, as refraction will dominate there. The resulting bonding image will become irregular.

[0032] The detection frequency of the detection device must not be set too low. It is, for example, selected such that refraction can be detected in at least one cavity of the single-faced corrugated board roll to be tested. Preferably, the detection frequency should also be selected such that the detection device can completely penetrate or pass through the single-faced corrugated board roll to be tested. It is advantageously selected such that refraction occurs in the single-faced corrugated board roll (particularly in its corrugated sections, especially in the corrugated ridges).

[0033] The obtained spectrum is preferably sharp or well-defined.

[0034] The detection device operating according to dependent claim 8 is particularly reliable during operation. It can reliably and easily detect bonding defects. The material of the single-faced corrugated cardboard roll to be tested is, in particular, cardboard, paper, or similar materials.

[0035] The statement relating to dependent claim 8 applies substantially in a similar manner to dependent claim 9. Air is particularly located within the single-faced corrugated paper roll, especially adjacent to it.

[0036] According to dependent claim 10, when there are no bonding defects in the single-faced laminated corrugated cardboard roll to be inspected, the detection signal is preferably always the same. The detection signal is identical, particularly in terms of signal amplitude, signal shape, and / or signal propagation delay. Advantageously, the detection field of the detection device can detect more than one corrugated ridge at a time during inspection.

[0037] The configuration according to dependent claim 11 is user-friendly and prevents operational errors. Preferably, no calibration of the detection device is required.

[0038] The design according to dependent claim 12 enables reliable detection of bonding defects. The set includes, for example, between 2 and 10, preferably between 3 and 8, previous detection values. In particular, defects caused by outlier detection values ​​can be detected easily or reliably.

[0039] The configuration according to dependent claim 13 is highly reliable in function.

[0040] The corrugated board system according to dependent claim 14 is highly efficient. It preferably forms a control section. For example, the amount of adhesive applied for bonding between the face paper and the corrugated roll can be adjusted accordingly. This allows for the avoidance or reduction of corrugated board waste. Advantageously, the bonding detection device is arranged (closely) adjacent to the corrugated board production apparatus (e.g., its corrugating device) to react as quickly as possible to detected bonding defects.

[0041] Dependent claims 2 to 14 also relate to advantageous embodiments of the method according to independent claim 15.

[0042] The terms “upstream,” “downstream,” “in the upstream,” and “in the downstream,” or similar terms, as used herein, are particularly relevant to the main transport direction of the face paper, the corrugated paper roll, or the single-faced laminated corrugated board roll.

[0043] The indefinite articles used in the claims should not be construed as limiting in number. For example, the corrugated board system may include more than one corrugated board production device and / or adhesion detection device. Attached Figure Description

[0044] Preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings. In the drawings: Figure 1 A partial view of the corrugated cardboard system according to the present invention is shown. Figure 2 Basically showed Figure 1 The diagram shows a schematic enlarged portion of the corrugated board system, specifically illustrating the corrugated board production apparatus for producing single-faced corrugated board rolls and the bonding detection device. Figure 3 A simplified view showing the structure of the single-faced laminated corrugated cardboard roll to be tested is shown. Figure 4 It shows Figure 2 A simplified magnified view of the detection device shown. Figure 5 It shows the corresponding Figure 4 A view of an alternative detection device, and Figure 6 A simplified view of another alternative detection device is shown. Detailed Implementation

[0045] First refer to Figure 1 The corrugated board system shown only partially here includes a first corrugated board production apparatus 1 for producing single-face laminated, continuous first corrugated board rolls 2.

[0046] The first paper splicing device 3 and the first material sheet splicing device 4 are arranged upstream of the first corrugated cardboard production device 1.

[0047] The first face paper splicing device 3 includes a first unwinding unit 5 for unwinding a continuous first face paper from a first face paper roll; and a second unwinding unit 6 for unwinding a continuous second face paper from a second face paper roll. The continuous first face paper and the continuous second face paper are joined together by a joining and cutting unit (not shown) of the first face paper splicing device 3 to provide a continuous first face paper 7.

[0048] The design of the first material sheet splicing device 4 corresponds to the first face paper splicing device 3. It includes a third unwinding unit 8 for unwinding a continuous first material sheet from the first material sheet; and a fourth unwinding unit 9 for unwinding a continuous second material sheet from the second material sheet. The continuous first material sheet and the continuous second material sheet are joined together by a joining and cutting unit (not shown) of the first material sheet splicing device 4 to provide a continuous first material sheet 10.

[0049] The continuous first face paper 7 is fed into the first corrugated board production device 1 via a first heating roller 11, while the continuous first material sheet 10 is fed into the first corrugated board production device 1 via a first deflection roller 12.

[0050] In order to produce a continuous first corrugated paper roll containing corrugations from the continuous first material sheet 10, the first corrugated board production apparatus 1 includes a corrugating roll device with a first corrugating roll 13 and a second corrugating roll 14 (see also...) Figure 2 The embossing rollers 13 and 14 form an embossing gap for threading and embossing the continuous first material sheet 10. The rotation axes of the embossing rollers 13 and 14 are parallel to each other and extend horizontally.

[0051] To bond a continuous first cover paper 7 to a continuous corrugated first material sheet or corrugated paper roll 10 to form a single-sided laminated, continuous first corrugated board roll 2, the first corrugated board production apparatus 1 includes a glue applicator 15, which preferably includes a glue metering roller 16, a glue tank 17, and a glue applicator roller 18. A glue applicator gap 19 is formed between the glue applicator roller 18 and the first corrugating roller 13 to guide the continuous first corrugated paper roll 10 and apply glue to it. Glue contained in the glue tank 17 is applied via the glue applicator roller 18 to adjacent corrugated crests or ridges of the corrugations of the continuous first corrugated paper roll 10. The glue metering roller 16 is arranged adjacent to the glue applicator roller 18 and is used to form a uniform glue layer on the glue applicator roller 18.

[0052] Subsequently, the continuous first face paper 7 is joined in the first corrugated board production apparatus 1 to the continuous first corrugated paper roll 10 coated with glue from the glue storage tank 17 to produce the single-sided laminated, continuous first corrugated board roll 2.

[0053] The first corrugated board production apparatus 1 includes a pressure device 20 for pressing the continuous first face paper 7 against the continuous first corrugated paper roll 10 coated with adhesive, the first corrugated paper roll 10 being segmentally abutted against the first pressure roller 13. The pressure device 20 is advantageously designed as a pressure belt device. The pressure device is arranged above the first pressure roller 13. The pressure device 20 includes at least two deflecting rollers and a continuous pressure belt guided around the deflecting rollers. Alternatively, the pressure device 20 may include, for example, at least one pressure roller.

[0054] The first pressure roller 13 extends segmentally from below into the space between the outermost lateral deflection rollers of the pressure application device 20, thereby deflecting the pressure band by the first pressure roller 13. The pressure band presses against the continuous first face paper 7, which in turn is pressed against the continuous first corrugated paper roll 10 coated with adhesive, and the first corrugated paper roll 10 is attached to the first pressure roller 13.

[0055] In order to temporarily store and buffer the single-sided laminated, continuous first corrugated cardboard roll 2, the first corrugated cardboard roll is fed into the first storage device 22 of the corrugated cardboard system via a first vertical conveyor 21, and forms a loop in the storage device.

[0056] Furthermore, the corrugated board system includes a second corrugated board production unit 23, which is designed to correspond to the first corrugated board production unit 1. The second corrugated board production unit 23 is capable of producing single-faced, continuous second corrugated board rolls 26 from a continuous second face paper and a continuous second material sheet. The continuous second material sheet is corrugated.

[0057] Therefore, a second face paper splicing device 24 for providing the continuous second face paper and a second material sheet splicing device 25 for providing the continuous second material sheet are arranged upstream of the second corrugated cardboard production device 23. The second face paper splicing device is designed to correspond to the first face paper splicing device 3 and the first material sheet splicing device 4, respectively.

[0058] The single-sided laminated, continuous second corrugated board roll 26 is fed into the second storage device 27 of the corrugated board system, where it forms a loop. Alternatively, as described above, a configuration without the second corrugated board production device 23 is also possible.

[0059] The corrugated cardboard system also includes a sheet splicing device 28, which comprises a fifth unwinding unit 29 for unwinding a continuous first sheet from the first sheet; and a sixth unwinding unit 30 for unwinding a continuous second sheet from the second sheet. The continuous first sheet and the continuous second sheet are joined together by a joining and cutting unit (not shown) of the sheet splicing device 28 to provide a continuous sheet 31.

[0060] Downstream of the storage devices 22 and 27 and the laminated sheet bonding device 28, the corrugated board system includes a preheating device 32 comprising three preheating rollers 33, 34, and 35 arranged vertically. The single-sided laminated, continuous corrugated board rolls 2 and 26 and the continuous laminated sheet 31 are fed into the preheating device 32, where they are wound around the corresponding preheating rollers 33, 34, and 35 and thereby heated.

[0061] Downstream of the preheating device 32, the corrugated board system includes a coating unit (not shown) with coating rollers, a portion of which is partially immersed in a corresponding glue bath. The single-faced, continuous first corrugated board roll 2 contacts the first coating rollers through its corrugated roll 10, thereby coating the corrugations of the corrugated roll 10 with glue from the associated first glue bath. The single-faced, continuous second material sheet 26 contacts the second coating rollers through its corrugated roll, thereby coating the corrugations of the corrugated roll with glue from the associated second glue bath.

[0062] Downstream of the coating unit, the corrugated board system has a joining device (not shown) designed as a heating and pressure device and comprising a horizontally extending heating platform. Adjacent to the heating platform is a continuous pressure belt guided around guide rollers. A pressure gap is formed between the pressure belt and the heating platform, through which the single-faced, continuous corrugated board rolls 2, 26 and the continuous laminated sheet 31 are guided to form a continuous double-faced corrugated board roll (not shown). The continuous double-faced corrugated board roll here has a total of five layers.

[0063] Downstream of the joining device, the corrugated board system includes a longitudinal cutting / crimping device (not shown) for longitudinally cutting and creasing the continuous double-sided laminated corrugated board roll. The longitudinal cutting / crimping device comprises creasing stations and longitudinal cutting stations arranged sequentially. Each creasing station includes a pair of creasing tools stacked vertically, between which the double-sided laminated, continuous corrugated board roll is threaded. Each of the longitudinal cutting stations is equipped with rotatable cutters capable of contacting the double-sided laminated, continuous corrugated board roll for longitudinal cutting. In the longitudinal cutting / crimping device, the double-sided laminated, continuous corrugated board roll can produce initially parallel continuous sheets.

[0064] Downstream of the longitudinal cutting / crimping device, the corrugated board system has a distributor (not shown) for conveying the individual sheets of the double-sided laminated, continuous corrugated board roll to different planes.

[0065] Downstream of the distributor, the corrugated board system includes a cross-cutting device with cross-cutting units arranged vertically. Each cross-cutting unit includes two pairs of blade rollers with radially projecting blades. The blades of each blade roller in a cross-cutting unit work together to cross-cut the slit sheet. Thus, corrugated board sheet is produced from the slit sheet.

[0066] A conveyor belt device (not shown) is arranged downstream of each cross-cutting unit for forward conveying the corrugated cardboard sheets produced from the slitting sheets.

[0067] A stacking device (not shown) is arranged downstream of each conveyor belt device. In the stacking device, the corrugated cardboard sheets can be stacked one by one.

[0068] In corrugated board production, the single-sided laminated, continuous first corrugated board roll 2, the single-sided laminated, continuous second corrugated board roll 26, and the continuous laminated sheet 31 are all conveyed along the main conveying direction 36.

[0069] The configuration of the single-faced, continuous first corrugated board roll 2 is described in more detail below with examples. The single-faced, continuous second corrugated board roll 26 is constructed in a similar manner.

[0070] As described above, the single-sided laminated, continuous first corrugated paper roll 2 comprises the continuous first face paper 7 and the continuous first corrugated paper roll 10, which are bonded or adhered together (see also...). Figure 3 ).

[0071] The continuous first corrugated paper roll 10 has regular corrugations and extends perpendicular to the main transport direction 36 as it is conveyed through the corrugated board system. The continuous first corrugated paper roll 10 has alternating corrugated ridges or crests 37 and corrugated troughs 38. A corrugated flank 39 extends between a corrugated ridge 37 and an adjacent corrugated trough 38. Each corrugated ridge 37 extends parallel to each other. Each corrugated ridge also extends parallel to each corrugated trough 38. In the corrugated board system, each corrugated ridge 37 and corrugated trough 38 extends perpendicular to the main transport direction 36 and perpendicular to the longitudinal direction of the single-faced, continuous first corrugated paper roll 2. The corrugated ridges and corrugated troughs extend along the width or transverse direction of the single-faced, continuous first corrugated paper roll 2. The single-faced, continuous first corrugated paper roll 2 bends at the corrugated ridges 37 and corrugated troughs 38. The corrugated wing 39 extends, for example, at an angle relative to the continuous first sheet 7.

[0072] In the single-face laminated, continuous first corrugated board roll 2, the continuous first corrugated paper roll 10 is bonded to the continuous first face paper 7 via its corrugated troughs 38. In the single-face laminated, continuous first corrugated board roll 2, the corrugated troughs 38 are arranged adjacent to the continuous first face paper 7. On the other hand, the corrugated ridges 37 are arranged spaced apart from the continuous first face paper 7. In the single-face laminated, continuous first corrugated board roll 2, the corrugated ridges are exposed.

[0073] In the desired state of the single-faced, continuous first corrugated paper roll 2, each corrugated trough 38 is bonded to the continuous first face sheet 7 via a linear or strip-shaped bonding area 40, which is composed of adhesive or glue and extends across the entire width of the single-faced, continuous first corrugated paper roll 2 between the continuous first face sheet 7 and the corresponding corrugated trough 38 of the continuous first corrugated paper roll 10. The bonding areas 40 extend parallel to each other and spaced apart in the width or transverse direction of the single-faced, continuous first corrugated paper roll 2. They extend continuously along adjacent corrugated troughs 38 and have a uniform width and thickness. The bonding areas 40 are located on the inside of the single-faced, continuous first corrugated paper roll 2.

[0074] The single-sided laminated, continuous first corrugated paper roll 2 or continuous first corrugated paper roll 10 has a uniform flute height WH, which is measured between a corrugated ridge 37 and a corrugated trough 38. It has a uniform flute pitch T.

[0075] The first detection device 41 of the first adhesion detection device is arranged downstream of the first corrugated cardboard production device 1. Figure 2 The first detection device 41 is associated with the single-sided laminated, continuous first corrugated paperboard roll 2 and is arranged adjacent to the first corrugated paperboard production device 1.

[0076] The first adhesion detection device further includes a first adhesion evaluation device 42 ( Figure 2 ).

[0077] The first detection device 41 includes at least one first sensor unit, which further includes a first transmitter 43 and an associated first receiver 44. The first transmitter 43 and the first receiver 44 of each sensor unit are each spaced apart from the single-faced, continuous first corrugated cardboard roll 2 to be detected, and are arranged (substantially) opposite to each other. The first transmitter and the first receiver are oriented opposite to each other and arranged in pairs. The single-faced, continuous first corrugated cardboard roll 2 is guided between the first transmitter 43 and the first receiver 44 of each sensor unit. The first transmitter 43 and the first receiver 44 are oriented perpendicular to the continuous first face 7. Figure 2 , Figure 4 Specifically, during operation, the first transmitter 43 generates a first detection field, the principal plane H of which extends perpendicularly to the continuous first face sheet 7. Each sensor unit is preferably oriented perpendicularly to the principal plane of the single-sided laminated, continuous first corrugated cardboard roll 2. The principal plane of the single-sided laminated, continuous first corrugated cardboard roll 2 extends parallel to the continuous first face sheet 7.

[0078] The first transmitter 43 is directed toward or associated with the continuous first face 7 of the single-sided laminated, continuous first corrugated paper roll 2. Conversely, the first receiver 44 is directed toward or associated with the continuous first corrugated paper roll 10.

[0079] The first detection device 41 is designed as an ultrasonic detection device, particularly an air-coupled ultrasonic detection device.

[0080] Accordingly, the first transmitter 43 of each sensor unit is an ultrasonic transmitter, and the first receiver 44 of each sensor unit is an ultrasonic receiver.

[0081] During operation, the first transmitter 43 preferably emits ultrasonic waves repeatedly or periodically. These ultrasonic waves pass through the conveyed single-faced, continuous first corrugated cardboard roll 2, particularly through the continuous first face 7 and the continuous first corrugated roll 10, and reach the corresponding first receiver 44 of the respective sensor unit, where they are received. The sound waves thus completely penetrate the single-faced, continuous first corrugated cardboard roll 2 along its thickness direction. During this process, the internal adhesive region 40 of the single-faced, continuous first corrugated cardboard roll 2 is also detected. The first detection device 41 operates based on the principle of single-pass ultrasonic waves.

[0082] During operation, a power supply voltage is applied to the first detection device 41. During operation, the first detection device 41 operates at a first detection frequency, which is preferably selected or set to a value between 90 kHz and 390 kHz according to the specific configuration of the single-faced, continuous first corrugated board roll 2, particularly the flute height WH. To cover the entire range of corrugated board production specifications, each first sensor unit preferably comprises multiple, advantageously two different test head pairs. Single-faced, continuous first corrugated board roll 2 with coarse flutes preferably uses a test head between 90 kHz and 150 kHz or is detected at this frequency. Single-faced, continuous first corrugated board roll 2 with fine flutes, for example, uses a test head between 280 kHz and 390 kHz or is detected at this frequency.

[0083] The first adhesion evaluation device 42 communicates with the first receiver 44 of the corresponding sensor unit at least intermittently. For example, the first adhesion evaluation device 42 is arranged on or forms part of the associated first receiver 44. Alternatively, the first receiver 44 and the first adhesion evaluation device 42 are arranged separately from each other.

[0084] The detection of the adhesion of the single-sided laminated, continuous first corrugated cardboard roll 2 is based, for example, on the measurement of the ultrasonic amplitude penetrating the single-sided laminated, continuous first corrugated cardboard roll 2.

[0085] In principle, the thicker or denser the single-sided laminated, continuous first corrugated cardboard roll 2, the lower the proportion of transmitted ultrasonic waves. In cases of poor bonding of the single-sided continuous first corrugated cardboard roll 2, the propagation of ultrasonic waves within it is disrupted, and the signal amplitude decreases. The shorter the wavelength, the more severe the signal disruption caused by the internal structure of the single-sided continuous first corrugated cardboard roll 2. For example, uneven adhesive application results in a lower signal amplitude. Ultrasonic signals must pass through layers with different stiffnesses within the single-sided laminated, continuous first corrugated cardboard roll 2. These different impedances disrupt the propagation of ultrasonic waves within the single-sided laminated, continuous first corrugated cardboard roll 2.

[0086] The corresponding detection signal of the first receiver 44 of the corresponding sensor unit with respect to the single-sided laminated, continuous corrugated cardboard roll 2 is fed into the associated first adhesion evaluation device 42. The first adhesion evaluation device 42 is capable of processing the received detection signal characterizing the single-sided laminated, continuous first corrugated cardboard roll 2.

[0087] To detect adhesion, the single-sided laminated, continuous first corrugated cardboard roll 2 can be described as an anisotropic layered medium. For example, Floquet wave theory can be used to describe wave propagation. Accordingly, the layered medium acts as a mechanical filter. If the wavelength of the signal becomes less than twice the layer thickness, the medium can no longer be assumed to be homogeneous. Refraction occurs within the microstructure of the medium. Therefore, the detection frequency is selected such that it is below an upper detection frequency, allowing sound waves to effectively penetrate the medium.

[0088] Advantageously, information about transmission energy, signal propagation delay, and / or signal entropy can be extracted or determined from the detection signal in the first adhesion evaluation device 42.

[0089] Advantageously, the transmitted energy, signal propagation delay, and / or signal entropy are combined to obtain conclusions regarding the bonding or adhesion quality in the single-sided laminated, continuous first corrugated paperboard roll 2. In particular, the relative relationships between them are considered. The excitation signal used to determine the signal entropy preferably has a narrow spectrum. For example, if the signal undergoes multiple refraction processes during detection, it will broaden. Its frequency range becomes wider.

[0090] For example, uneven gluing of the single-faced, continuous first corrugated board roll 2 results in a lower signal amplitude. This is because the signal must pass through layers with different stiffnesses. These different impedances disrupt the propagation of ultrasonic waves within the single-faced, continuous first corrugated board roll 2. Delamination in the single-faced, continuous first corrugated board roll 2 can be reliably detected.

[0091] The bonding detection device detects the bonding lines, corrugated ridges 37, and corrugated troughs 38 of the single-sided laminated, continuous first corrugated cardboard roll 2. It can distinguish between the corrugated ridges and the corrugated troughs. The data processing algorithm used can differentiate between the bonding and the corrugated ridges 37. To ensure this, a refraction process must occur in the corrugated ridges 37 during detection. Therefore, during operation, the detection frequency of the detection device is selected to be sufficiently high to allow this to occur.

[0092] Generally speaking, the lower the detection frequency of the detection device, the better the signal-to-noise ratio. The shorter the wavelength, the more susceptible the signal is to interference.

[0093] When the single-sided laminated, continuous first corrugated cardboard roll 2 is conveyed along the main conveying direction 36 through the stationary first detection device 41, all the bonded areas 40 are detected sequentially.

[0094] The second detection device 47 is designed and arranged in a similar manner. The second bonding detection device 47 is located downstream of the second corrugated board production unit 23. The second detection device 47 is associated with and arranged adjacent to the single-face-laminated, continuous second corrugated board roll 26. It operates similarly and is capable of detecting the bonding of the single-face-laminated, continuous second corrugated board roll 26. The second bonding detection device is capable of detecting the bonding of the single-face-laminated, continuous second corrugated board roll 26. The second bonding detection device includes a second sizing evaluation device.

[0095] exist Figure 5 In the alternative configuration shown, the positions of the first transmitter 43 and the first receiver 44 within a sensor unit are interchanged. Here, the first transmitter 43 faces or is associated with the continuous first corrugated paper roll 10 of the single-faced, continuous first corrugated paper roll 2. The first receiver 44 faces or is associated with the continuous first face sheet 7 of the single-faced, continuous first corrugated paper roll 2. Its function and specific configuration are the same as in the prior embodiment.

[0096] exist Figure 6 In the preferred embodiment shown, the detection field generated by the first transmitter 43 consistently detects two corrugated troughs 38 arranged side-by-side along the main conveying direction 36. Specifically, the detection field has a range X along the main conveying direction 36 on the single-sided laminated, continuous first corrugated cardboard roll 2, which is larger than the flute pitch T. Here, the first transmitter 43 generates a near-field detection area 45 and a far-field detection area 46.

[0097] Combinations of different embodiments are possible.

Claims

1. Corrugated cardboard system a) A corrugated board production apparatus (1, 23) for producing single-faced corrugated board rolls (2, 26), the single-faced corrugated board rolls comprising a face liner (7) and a corrugated roll (10) bonded to the face liner; and b) Includes an adhesion detection device for detecting the adhesion between the face paper (7) and the corrugated paper roll (10) in the single-faced laminated corrugated paper roll (2, 26), wherein, The adhesion detection device includes: i) A detection device (41, 47), arranged downstream of the corrugated board production apparatus (1, 23), is used to detect the adhesion between the face paper (7) and the corrugated board roll (10) of the single-faced corrugated board roll (2, 26) to be tested at a detection frequency of the detection device, wherein the detection frequency of the detection device is selected according to the configuration of the single-faced corrugated board roll (2, 26) to be tested; and ii) Adhesion evaluation device (42) communicates with the detection device (41, 47) at least intermittently and receives from the detection device a detection signal representing the adhesion between the face paper (7) and the corrugated paper roll (10) of the single-faced corrugated paper roll (2, 26) to be tested.

2. The corrugated cardboard system according to claim 1, characterized in that, The detection frequency of the detection device is selected based on the phase velocity of the detection wave of the detection device (41, 47) in the single-faced laminated corrugated cardboard roll (2, 26) to be detected.

3. The corrugated cardboard system according to claim 1 or 2, characterized in that, The detection frequency of the detection device is selected according to the configuration of the corrugated paper roll (10) of the single-sided laminated corrugated paper roll (2, 26) to be detected.

4. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The detection frequency of the detection device is selected according to the corrugated configuration of the single-sided laminated corrugated paper roll (10) of the paper roll (2, 26) to be detected.

5. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The detection frequency of the detection device is selected based on the flute height (WH) of the corrugated paper roll (10) of the single-sided laminated corrugated paper roll (2, 26) to be detected.

6. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The detection frequency of the detection device is selected such that it is greater than a lower limit detection frequency, and a refraction process occurs in the corrugated paper roll (10) of the single-sided laminated corrugated paper roll (2, 26) to be detected, particularly in at least one corrugated ridge (37) of the corrugated paper roll (10) to be detected.

7. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The detection frequency of the detection device is selected such that it is less than an upper limit detection frequency, and the detection wave penetrates the single-faced laminated corrugated cardboard roll (2, 26) to be detected.

8. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The detection frequency of the detection device is selected such that it is less than the quotient of the phase velocity of the detection wave of the detection device (41, 47) in the material of the single-faced corrugated paper roll (2, 26) to be detected and twice the flute height (WH) of the corrugated paper roll (10) of the single-faced corrugated paper roll (2, 26) to be detected.

9. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The detection frequency of the detection device is selected such that it is greater than the quotient of the phase velocity of the detection wave of the detection device (41, 47) in air and twice the flute height (WH) of the corrugated paper roll (10) of the single-face laminated corrugated paper roll (2, 26) to be detected.

10. The corrugated cardboard system according to any one of the preceding claims, characterized in that, During operation, the detection device (41, 47) is able to generate a detection field that together detects at least two adjacent corrugated ridges (37) of the corrugated paper roll (10) of the single-face laminated corrugated paper roll (2, 26) to be tested.

11. The corrugated cardboard system according to any one of the preceding claims, characterized in that, No need to manually set upper and / or lower defect thresholds.

12. The corrugated cardboard system according to any one of the preceding claims, characterized in that, The bonding assessment device (42) compares the current detection value with a set of prior detection values ​​to detect bonding defects.

13. The corrugated cardboard system according to any one of the preceding claims, characterized in that, In order to detect the adhesion between the face paper (7) and the corrugated paper roll (10) in the single-faced corrugated paper roll (2, 26) to be tested, the adhesion evaluation device (42) evaluates the signal amplitude, signal propagation delay and / or signal shape of the detection signal.

14. The corrugated cardboard system according to any one of the preceding claims, characterized in that... A closed-loop control loop is provided for controlling the corrugated cardboard production apparatus (1, 23) based on the detection signal.

15. A method for producing corrugated cardboard, comprising the following steps: - Single-faced corrugated board rolls (2, 26) are produced by corrugated board production apparatus (1, 23), the single-faced corrugated board rolls comprising a face liner (7) and a corrugated roll (10) bonded to the face liner; and - The adhesion between the face paper (7) and the corrugated paper roll (10) in the single-faced laminated corrugated paper roll (2, 26) is detected by an adhesion detection device in the following manner: -- Select a testing device and its testing frequency based on the configuration of the single-faced laminated corrugated cardboard roll (2, 26) to be tested. -- The bonding detection device is arranged downstream of the corrugated board production unit (1, 23) and the detection device (41, 47) detects the bonding between the face paper (7) and the corrugated board roll (10) of the single-faced corrugated board roll (2, 26) under the detection frequency of the detection device. -- The bonding evaluation device (42) of the bonding detection device receives a detection signal representing the bonding between the face paper (7) and the corrugated paper roll (10) of the single-faced laminated corrugated paper roll (2, 26) to be tested, and the bonding evaluation device communicates with the detection device (41, 47) at least intermittently.

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