Device and method for detecting fores in a dispensed blank material

Abstract

The invention relates to a device (21) for detecting foreign matters in a blank mat (5) applied to a conveying device (4) during the production of material panels, the blank mat (5) being at least partially composed of fibres or chips and a binder, which are compacted in the event of an increase in temperature, according to the invention, at least one first sensor device (6) is provided which operates using electromagnetic waves or ultrasonic waves or using a magnetic field or using a radiation measurement method, said first sensor device being aligned with one or more spatial measurement regions (22) of the blank mat in order to detect the foreign matter (10). In order to be able to better estimate when foreign matter is likely to damage the steel strip (18a, 18b) of the continuous press (2) and thereby increase the threshold for triggering the foreign matter discharge device (11), at least one second sensor device (7) is provided, which is likewise aligned with the measurement region (22), and wherein the first sensor device (6) is suitable for material detection of foreign matter (10), and the second sensor device (6) is suitable for material detection of foreign matter (10). And the second sensor device (7) is suitable for determining at least one foreign matter size. The invention also relates to a material panel production device equipped with a device (21) or a method for detecting foreign matters.

Description

Technical Field

[0001] The present invention relates to a device for detecting foreign matter in a blank mat spread onto a conveying device during the manufacture of a material plate, wherein the blank mat is at least partially composed of fibers or debris and an adhesive, which are compacted at an elevated temperature, and is provided with at least one first sensor device operating with electromagnetic waves or ultrasound or with a magnetic field or with a radiation measurement method, the first sensor device being aimed at one or more spatial measurement areas of the blank mat in order to identify foreign matter.

[0002] The present invention also relates to a method for detecting foreign matter in a blank mat spread onto a conveying device during the manufacture of a material board, wherein the blank mat is at least partially composed of fibers or debris and an adhesive, which are compacted under elevated temperature, and wherein at least one first sensor device operating using electromagnetic waves or ultrasound or using a magnetic field or using a radiation measurement method is used, and the first sensor device is aligned with one or more spatial measurement areas of the blank mat in order to identify foreign matter.

[0003] The present invention also relates to a production device for manufacturing material boards, which comprises: a spreading station for spreading a blank mat onto a conveying device, wherein the blank mat is at least partially composed of fibers or debris and an adhesive; and a press for compacting the blank mat, which comprises an apparatus for detecting foreign matter according to the present invention; and a method for manufacturing material boards using a spreading station, wherein the blank mat is spread onto a conveying device in the spreading station, wherein the blank mat is at least partially composed of fibers or debris and an adhesive and is compacted in a press, which applies the method for identifying foreign matter according to the present invention. Background Art

[0004] Material boards are mainly man-made material boards that have been manufactured in a preferred continuous press. For example, particle boards, MDF boards (medium density fiberboards) or OSB boards (oriented strand board) can be considered here, in which the particles contained in the blank mat are basically wood fibers or wood chips to which adhesives have been added. Recently, other lignocellulosic materials, such as fibers of annual plants (such as straw), have also been used to press material boards. However, in the sense of the present invention, material boards can also be insulation boards, gypsum boards, plastic boards or other material boards, the particles of which are pressed by heating the continuous belt in the continuous press. This press is sold on the market by the applicant under the name of ContiRoll. Before entering the continuous press, adhesives are usually added to the particles to give the material board a high degree of stability.

[0005] The fibers or chips are spread in the spreading station onto a conveying device, usually onto a conveyor belt also called a forming belt, and there form a mat that is transported to the press. In a continuous press, hydraulic elements apply high pressure to the upper and / or lower steel press belts via mostly heatable press plates and rollers, between which the mat is compacted at the same feed speed as the press belts. These press belts are usually only 0.5 mm to 4 mm thick and are very sensitive to excessive point pressure. Excessive indentations or damage may result in the production of only scrap on the entire device. It is understandable that replacing the press belt is costly and laborious and is not advisable. If you take into account that the compaction takes place in a continuous press and that the thickness variation (i.e. from the mat to the material plate) is therefore very large, it is clear that even relatively small hard foreign objects inside the mat can puncture the surface and damage the press belt. In kg / m 3 Typical compaction values ​​for units are as follows:

[0006] product Density after spreading Density after compaction MDF board 18-35 600-900 Particle Board 140-150 550-750 OSB Board 60-70 500-700

[0007] Therefore, especially with MDF boards, the thickness of the blank mat for the material board is greatly reduced, so that even smaller contained foreign objects can easily penetrate the surface.

[0008] But nowadays, the chips or fibers are subjected to various processes before spreading, such as crushing, washing or spraying with binders, until they are stored in large silos before or above the spreading station. Many upstream processes often lead to unwanted foreign matter entering the spreading process and remaining in the mat. Depending on the size and hardness of the foreign matter, they can protrude from the surface during compaction in the press and cause damage to the press belt.

[0009] Therefore, the blanks are usually checked before entering the press. For example, metal detectors are usually used for this purpose. However, devices are also known that irradiate the web with X-rays. If foreign matter is found, the relevant part of the blank is removed by a foreign matter removal device, thereby stopping the production process. This can be a discharge chute that is opened when the conveyor belt is pulled back a certain distance. However, devices are also known that suck or brush the relevant contaminated blank part off the conveyor belt.

[0010] For example, DE 10 2004 048 275 B3 describes the possible use of metal detectors. Such metal detectors work inductively with a transmitting coil through which an alternating current flows, thereby generating an alternating magnetic field. If this alternating magnetic field passes through a conductive material located below the detector, eddy currents are generated there, which themselves generate a measurable magnetic field. Metal parts are extremely dangerous due to their density, while metal detectors are relatively inexpensive. The detectors can detect individual metal parts with sufficient accuracy. However, non-ferrous metals such as copper or aluminum are not included.

[0011] But metal parts also become significantly smaller during the production process (chips, dust). Metal detectors include metallic substances in their field and cannot distinguish between a single larger object and many smaller objects. This means that metal detectors also detect non-hazardous surface metal dust as metallic foreign matter, which can interrupt production unnecessarily.

[0012] On the other hand, metal detectors cannot locate larger lumps of glue or, for example, plastic nuts, which are also harmful.

[0013] Other devices for detecting foreign bodies have similar problems. An X-ray-based sensor device with a corresponding surface resolution can also detect the contours of objects with a correspondingly high density. However, the scanner cannot detect the height of the object and therefore also the volume and mass of the object. Therefore, not only metallic foreign bodies are detectable, but also foreign bodies consisting of other materials with a correspondingly high density.

[0014] However, since the foreign object scanner can only detect the surface of the foreign object, correspondingly flat objects that are harmless to the press belt can lead to false triggering of the foreign object ejection device.

[0015] In addition to inductive metal detectors and X-ray scanners, there are many other theoretical sensor devices for detecting foreign matter in blank mats. These include:

[0016] a) Image sensor with visible and invisible light

[0017] b) Ultrasonic emitters and sensors

[0018] c) Sensors based on the magneto-optical Kerr effect

[0019] d) Radioactive sensors or radiation measuring sensors

[0020] e) Magnetic Transducer (MRT)

[0021] All of these possible sensors and measuring methods can be part of the invention and are present in the first sensor device or their mode of operation is shown in the method. However, all of these sensors and measuring methods are characterized by their inability to fully detect foreign bodies and often lead to unnecessary production interruptions in order to protect the press belt. Summary of the invention

[0022] The object of the invention is therefore to be able to better estimate when foreign bodies may damage the steel strip of a continuous press during the production of material panels and thereby to increase the threshold for triggering a foreign body ejection device and thus interrupt production less frequently.

[0023] With respect to the device, this object is achieved by having the features of claim 1 and in particular by having at least one second sensor device being arranged in a multi-mode manner, which second sensor device is also aligned with the measuring area, and the first sensor device is suitable for material recognition of the foreign body and the second sensor device is suitable for determining at least one foreign body size.

[0024] With regard to the method, this object is achieved by having the features of claim 13 and in particular by using at least one second sensor device in a multimodal manner, which second sensor device is also directed at the measuring area, optionally with a time offset, wherein the material of the foreign body is identified using the first sensor device and at least one foreign body size is determined using the second sensor device.

[0025] If a first sensor device which is suitable for at least approximate foreign material detection and a second sensor device which is suitable for determining the size of foreign objects are combined, harmful foreign objects can be detected much better than before.

[0026] In this case, there may be devices in which the first sensor device is used first and only then the second sensor device for detection in the direction of flow of the mat. In other devices, the exact opposite order may be more meaningful. This depends on the material being spread and the thickness or density of the mat. In one case, it may be preferred to first determine the material of the foreign body and then the size of the foreign body; in another case, it may be more meaningful to first determine the size of the foreign body and then the material. Therefore, the term "first" and "second" sensor device simply means that there are two different sensor devices, which can follow one another in any order.

[0027] The concept of measuring area should be understood as plane or spatially limited area, which can be detected by each sensor device. At this, such measuring area can cover whole blank mat width and / or blank mat thickness.

[0028] Preferably, the first sensor device has a sensor in order to determine the metal content of the foreign body. If ferrous metal parts are present in the blank, this can be detected immediately using such a sensor (e.g. by means of an electromagnetic coil, i.e. an inductively supported detector). In combination with a second sensor device, which is also preferably suitable for preferably three-dimensionally detecting the size of the foreign material (a sensor supported, for example, by X-ray radiation or radiometry is suitable here), the dangerousness of the foreign body for the press belt can be determined. For example, the operator of the production plant will immediately know that the production of the material sheet does not have to be interrupted if the metal detector has detected the foreign body, but the second sensor only signals scattered microscopic metal particles.

[0029] Particularly useful sensor arrangements are described in claims 4 to 7. These sensor arrangements have already been used and have proven themselves in other technical fields, for example in medicine or food technology.

[0030] Particularly advantageously, an evaluation device is provided which is able to carry out a sensor fusion of the at least one first sensor device and the at least one second sensor device.

[0031] Sensor fusion algorithmically combines the measurement results of the at least one first sensor device and the at least one second sensor device and thus forms a rigorous and precise state estimate for the foreign body. It is then concluded, for example, with the aid of a predefined harmfulness matrix whether the foreign body is harmful or not harmful to the press belt. For this purpose, the matrix clearly classifies, for example, the foreign body material and foreign body size. Likewise, a dependency algorithm can also be stored by means of a formula that defines the critical state when a foreign body exceeds a calculated limit value.

[0032] Preferably, in the event of an estimated possible damage to the press belt, the foreign body ejection device can be activated as a function of the sensor fusion result in the evaluation device.

[0033] Thus, the device according to the invention for detecting foreign bodies opens the discharge chute or activates the suction device completely automatically. The operator of the production plant can also ensure that production is interrupted only when a foreign body that could damage the press belt is detected or when such damage is at least highly likely. For example, if a large but very flat foreign body is hidden in the blank, which would already cause production to stop in a conventional foreign body scanner, the production plant can continue to operate according to the evaluation device, and if necessary, the area with the foreign body is cut out from the material sheet that is subsequently produced. It is therefore not necessary to stop the production plant for foreign bodies that are known but harmless to the press belt.

[0034] The development trend of material sheets is to be able to produce thinner and lighter material sheets. This is particularly relevant to this problem, and the device according to the invention is particularly suitable for mat thicknesses of less than 8 mm. It is therefore advantageous if, in addition to the at least one first sensor device and the at least one second sensor device, there is also a thickness, density or unit weight measuring device for the mat.

[0035] Such thickness, density or unit area weight measuring instruments are common and well known to those skilled in the art when producing spread mats that are pressed into material plates. However, they are usually only used to measure the uniformity at the spread height and / or in the width and along the conveyor belt.

[0036] However, in the device according to the invention, the determined thickness value or density value or weight per unit area value can also be transmitted to the evaluation unit. These measured values ​​can be incorporated into the evaluation matrix for the material of the foreign body and for the size of the foreign body that is present there. In the case of thin mats, even small foreign bodies can endanger the press belt.

[0037] It is particularly preferably provided that a travel / time detection device is provided for synchronizing the sensor signals of the at least one first sensor device and the at least one second sensor device.

[0038] In particular, when the at least one first sensor device and the at least one second sensor device are arranged at a distance from each other along the conveying path of the blank, it must be ensured that the measured values ​​of the first sensor device and the measured values ​​of the second sensor device at the same measuring position are correlated with each other. Therefore, the measured values ​​of the measuring position arranged downstream in the conveying direction arrive at the evaluation device later, depending on the conveying speed of the blank. This time offset must be taken into account. With the help of a stroke / time detection device, this time difference can be detected and transmitted to the evaluation unit. The spacing of the sensor devices is often determined so that the stroke / time detection device only transmits the speed of the conveying device, that is, for example, the speed of the conveyor belt. The evaluation device can then calculate the time offset of the measurement signal and take it into account when analyzing foreign bodies.

[0039] Alternatively, it can also be arranged that at least one first sensor device and at least one second sensor device detect the identical measuring point on the blank pad or in the blank pad simultaneously. In this case, they can even be contained in a housing.

[0040] With regard to the method, the advantages are similar to those described with regard to the device. The method claim corresponds essentially to the device claim for detecting foreign bodies in a mat spread onto a conveyor.

[0041] Importantly, this method also offers clear advantages over the prior art. If, for example, a metal detector is used as a first sensor device and a second sensor device is used that detects the size of foreign material in three dimensions, the following three examples show how effective sensor fusion can be:

[0042] - An object of corresponding area or size is detected by the second sensor device. A metallic substance matching the surface of the object is detected by the first sensor device. Then a corresponding dangerous metal body must be present and the foreign body ejection device is activated.

[0043] - The second sensor device does not detect a suspicious area or size, but the metal detector reports a corresponding metallic substance. There is then a large area of ​​distributed metal dust, but no dangerous foreign objects. No foreign object removal can be performed.

[0044] - An object of corresponding area or size is detected by the second sensor device. No metal is detected by the first sensor device. Then a non-metallic object (e.g. a lump of rubber) is definitely present, which will be processed accordingly if it exceeds a separate threshold value. From a certain size (the value of which also depends on the thickness of the blank and the height of the extrusion gap), the foreign body ejection device is activated.

[0045] Claims 22 and 23 indicate that the device according to the invention and a similar and corresponding method according to the invention are advantageously used for detecting foreign bodies in a production plant between a spreading station and a continuous press. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The invention is further explained below with the aid of the accompanying drawings showing two exemplary embodiments. In the accompanying drawings:

[0047] Figure 1 A schematic side view of a device for producing a material plate in the sense of the invention is shown, which has a device according to the invention for detecting foreign bodies;

[0048] Figure 2 An alternative arrangement of the sensor device is shown. DETAILED DESCRIPTION

[0049] Figure 1 Schematically, a detail of a device 1 for producing material panels is shown in FIG.

[0050] The left side shows the end of a spreading station 3, by which the chips or fibers soaked with adhesive are spread onto a long conveyor device 4 (in the present embodiment a conveyor belt extending on a support structure 17) to form a mat 5. The mat 5 may include a plurality of different layers of chips or fibers of different sizes, which may also be spread in different directions. Figure 1 Only a short section of the blank pad 5 is schematically shown.

[0051] The entrance to the continuous press 2 is located at the right edge, i.e. at the end of the conveying path. The continuous press has an upper press belt 18a and a lower press belt 18b which are continuously looped around different deflection rollers 16 and can exert pressure on the blank mat 5 from both sides. The press belts 18a, 18b are thin metal belts which can be damaged by sharp or hard foreign bodies under point pressure, so that the damage is transmitted to the pressed blank mat 5 and is visible on the material sheet when discharged from the press 2 (not shown).

[0052] This means that the foreign matter 10 (in the blank pad 5) that harms the pressing belts 18a, 18b Figure 2 18a, 18b) must be removed by a foreign matter discharge device 11 before entering the continuous press 2. In this embodiment, the foreign matter discharge device 11 is a discharge chute that can be opened by pulling back a cover and / or a movable conveyor belt section 12 by an adjusting motor 20. After removing the blank mat section containing foreign matter 10 that may endanger the press belts 18a, 18b, the straight edges of the blank mat 5 no longer exist. Therefore, the device 1 for manufacturing material plates has a bevel saw 9, which can saw a new straight edge in the blank mat 5 perpendicular to the feed direction. This edge can smoothly enter the continuous press 2.

[0053] According to the invention, the novelty of this device consists in the device 21 and the method for detecting foreign bodies in the blank mat 5 spread on the conveying device 4. It is important that a first sensor device 6 and a second sensor device 7 are used. The first sensor device 6 is suitable for material recognition of the foreign bodies, and the second sensor device 7 is suitable for determining the size of the foreign bodies. The sensor device 7 is arranged in front of the sensor device 6 in this embodiment. In other cases, the two sensor devices 6, 7 work in reverse order, as is also shown purely schematically in Figure 2 As indicated in .

[0054] But back to Figure 1 The physical measuring system of the sensor device 7 is equipped in such a way that it can determine the size of the foreign body, if necessary even in three dimensions. In this embodiment, it can be, for example, a sensor device 7 that acts using X-rays. During the further advancement of the blank, the sensor device 6 checks whether a foreign body 10 of larger size has been found therein (see also Figure 2 ) in the same spatial measurement region 22. The sensor device 6 can determine the material of the foreign body 10 or at least its density, so that it can be concluded from the size and material characteristics whether the foreign body 10 is harmful to the press belts 18a, 18b in the continuous press 2. In this case, it is sufficient to determine only the metal content of the foreign body 10, which can be achieved with the help of an inductive metal detector.

[0055] In order to make a judgment more quickly, an evaluation device 15 is provided, which has signal lines S1 to S5. Through the signal line S1, the evaluation device obtains the measurement value of the first sensor device 6. Through the signal line S2, the evaluation device obtains the measurement value of the second sensor device 7. Because the foreign matter limit value stored in the evaluation device 15 is closely related to the thickness or density of the current moving blank mat, the corresponding data is supplemented by the additionally installed thickness, density or unit area weight measuring instrument 8 through the signal line S3. In order to be able to take into account the time interval from the second sensor device 7 to the first sensor device 6 in the measurement area 22, the conveyor belt speed meter 19 also notifies the evaluation device 15 via the displacement / time detection device 13 by means of the signal line S4.

[0056] If the evaluation unit 15 detects foreign matter threatening the press belts 18 a and 18 b of the continuous press 2 , it activates the foreign matter ejection device 11 .

[0057] exist Figure 2 In the embodiment, two sensor devices 6 and 7 are used with Figure 1 However, both sensor devices 6, 7 are accommodated in one housing 14 and are therefore arranged next to each other so that the measuring areas 22 of the sensor devices 6, 7 overlap at least partially and both can perform their measurements simultaneously. The blank mat 5 conveyed on the conveyor belt 4 contains large foreign bodies 10. If the blank mat 5 conveyed on the conveyor belt 4 contains large foreign bodies 10, the blank mat 5 conveyed on the conveyor belt 4 is conveyed in the same manner as the conveyor belt 4. Figure 1 If the sensor device 6 detects the material, for example metal, and the sensor device 7 detects the size three-dimensionally, the connected evaluation device can immediately decide whether the foreign body ejection device must be activated based on the measured values ​​and the stored limit values. However, the invention also includes other measuring methods of the sensor devices 6, 7. These include sensor devices that work with electromagnetic waves or ultrasound or with magnetic fields or with radiometric methods.

[0058] Reference numerals list

[0059] 1 Equipment for manufacturing material boards

[0060] 2Entrance to the continuous press

[0061] 3 spreading station (end)

[0062] 4Conveyor device, conveyor belt

[0063] 5-blank pad (partial only)

[0064] 6. First sensor device

[0065] 7 Second sensor device

[0066] 8. Thickness, density or unit area weight measuring instrument

[0067] 9 Miter Saw

[0068] 10 Foreign matter

[0069] 11 Foreign matter removal device

[0070] 12 Removable covers or conveyor belt sections

[0071] 13. Displacement / time detection device

[0072] 14 Housing of sensor device

[0073] 15 Evaluation Device

[0074] 16 Steering roller

[0075] 17 Support structure of conveying device

[0076] 18a Upper pressure belt

[0077] 18b Compression belt

[0078] 19 With speedometer

[0079] 20 Adjustment motor

[0080] 21 Equipment for detecting foreign matter

[0081] 22 Measuring range

[0082] S1 Signal line of the first sensor device

[0083] S2 Signal line of the second sensor device

[0084] S3 Thickness Gauge Signal Line

[0085] S4 Conveyor belt speed signal line

[0086] S5 is used for the signal line of the foreign body ejection device

Claims

1. A device (21) for detecting foreign matter in a blank mat (5) spread onto a conveying device (4) during the production of a material sheet, in, The mat (5) is at least partially composed of fibers or chips and a binder, which are compacted at elevated temperature. There is at least one first sensor device (6) operating with electromagnetic waves or ultrasound waves or with a magnetic field or with a radiation measurement method, the first sensor device being aimed at one or more spatial measurement areas (22) of the blank mat in order to identify foreign bodies (10). It is characterized in that At least one second sensor device (7) is provided, which is also aligned with the measuring region (22), and the first sensor device (6) is suitable for material identification of the foreign body (10), while the second sensor device (7) is suitable for determining at least one foreign body size.

2. The device according to claim 1, It is characterized in that The at least one first sensor device (6) is suitable for detecting a metallic component of the foreign material.

3. The device according to claim 1, It is characterized in that The at least one second sensor device (7) is suitable for three-dimensionally detecting the size of the foreign material.

4. The device according to any one of claims 1 to 3, It is characterized in that The at least one first sensor device (6) comprises a preferably inductive metal detector.

5. The device according to any one of claims 1 to 4, It is characterized in that The at least one second sensor device (7) comprises an X-ray based sensor.

6. The device according to any one of claims 1 to 5, It is characterized in that The at least one first sensor device (6) or the at least one second sensor device (7) comprises a sensor based on thermal imaging.

7. The device according to any one of claims 1 to 6, It is characterized in that The at least one first sensor device (6) or the at least one second sensor device (7) comprises an ultrasound-based sensor having a sound reflection receiver.

8. The device according to any one of claims 1 to 7, It is characterized in that An evaluation device (15) is provided which is capable of performing a sensor fusion of the at least one first sensor device (6) and the at least one second sensor device (7).

9. The device according to claim 8, It is characterized in that The foreign body ejection device (11) can be activated as a function of the result of the sensor fusion in the evaluation device (15).

10. The device according to any one of claims 1 to 9, It is characterized in that In addition to the at least one first sensor device (6) and the at least one second sensor device (7), a thickness, density or weight per unit area measuring device (8) is also present for the mat (5).

11. The device according to any one of claims 1 to 10, It is characterized in that In order to synchronize the sensor signals of the at least one first sensor device (6) and the at least one second sensor device (7), a displacement / time detection device (13) is provided.

12. The device according to any one of claims 1 to 10, It is characterized in that The at least one first sensor device (6) and the at least one second sensor device (7) are mounted in a housing (14).

13. A method for detecting foreign matter (10) in a blank mat (5) spread onto a conveyor device (4) during the production of a material sheet, in, The mat (5) is at least partially composed of fibers or chips and a binder, which are compacted at elevated temperature in a continuous press (2). In this case, at least one first sensor device (6) is used which operates using electromagnetic waves or ultrasound waves or using a magnetic field or using a radiometric method, and which is directed to one or more spatial measurement areas (22) of the blank mat (5) in order to detect foreign bodies (10). It is characterized in that At least one second sensor device (7) is used, which is also directed at the measuring region (22) optionally with a time offset, wherein the material of the foreign body (10) is detected by means of the first sensor device (6) and at least one foreign body size is determined by means of the second sensor device (7).

14. The method according to claim 13, It is characterized in that The at least one first sensor device (6) detects the metallic content of the foreign material.

15. The method according to claim 13 or 14, It is characterized in that The at least one second sensor device (7) detects the size of the foreign material three-dimensionally.

16. The method according to any one of claims 13 to 15, It is characterized in that A sensor fusion of the signals of the at least one first sensor device (6) and the at least one second sensor device (7) is performed by means of an evaluation device (15).

17. The method according to claim 16, It is characterized in that Whether to activate the foreign body discharge device (11) is determined according to the result of sensor fusion in the evaluation device (15).

18. The method according to claim 16 or 17, It is characterized in that The evaluation unit (15) issues a warning about harmful foreign matter (10) or activates the foreign matter ejection device (11) depending on the mat thickness or mat density.

19. The method according to any one of claims 13 to 18, It is characterized in that The at least one first sensor device (6) and the at least one second sensor device (7) use different physical operating methods.

20. The method according to any one of claims 13 to 19, It is characterized in that A displacement / time detection device (13) is used to synchronize the signals for the same measurement area (22).

21. The method according to any one of claims 13 to 19, It is characterized in that The at least one first sensor device (6) and the at least one second sensor device (7) simultaneously detect the same measurement area (22).

22. A production device for manufacturing a material plate, the production device include: a spreading station (3) for spreading a mat (5) onto a conveyor device (4), wherein the mat (5) at least partially consists of fibers or chips and a binder; and a continuous press (2) for compacting the mat (5), It is characterized in that a device (21) for detecting foreign matter according to one of claims 1 to 12 is present between the spreading station (3) and the continuous press (2).

23. A method for producing a material panel using a spreading station (3) in which a mat (5) is spread onto a conveying device (4), in, The mat (5) is at least partially composed of fibers or chips and a binder and is compacted in a continuous press (2). It is characterized in that a method for detecting foreign bodies according to one of claims 13 to 21 is used between the spreading station (3) and the continuous press (2).

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