Method and apparatus for the process-optimized production of manufactured wood boards

Abstract

The invention relates to a method and an apparatus for the process-optimized production of manufactured wood boards, in particular oriented strand boards. In order to provide a method and an apparatus for the process-optimized production of manufactured wood products which make it possible to optimize quality while providing continuous quality assurance, which allow the best possible control variables to be determined particularly easily and quickly, and which also guarantee continuous production that results in the lowest possible wastage while maintaining the highest possible level of process stability, the invention provides the following: at least one process parameter, in particular the water content and / or the quantity of adhesive applied to the raw chip material, is measured in the course of the method by means of near-infrared spectroscopy; the measured values of the at least one process parameter are then sent to a control unit for process optimization and / or process-optimized control of the method, wherein the measurement of the at least one process parameter is taken at one or more positions, selected from: a position immediately upstream of the gluing, in particular between a dry raw chip hopper and the gluing station; a position immediately downstream of the gluing, in particular between the gluing station and a chip material distributor and / or a dispersing station; a position in the provision phase immediately downstream of a timber yard, in particular between the timber yard and a subsequent dryer; and / or a position in the provision phase immediately downstream of a dryer, in particular between the dryer and a sieving station and / or a dry raw chip hopper.

Description

[0001] (20149-0)

[0002] Description: METHOD AND DEVICE FOR PROCESS-OPTIMIZED PRODUCTION OF WOOD-BASED PANELS

[0003] The invention relates to a method and a device for the process-optimized production of wood-based panels, in particular oriented strand board (OSB).

[0004] Methods and devices for manufacturing wood-based panels, and in particular oriented strand board (OSB), are already known in various forms from the prior art. Operating such a process requires selecting numerous settings and control parameters, which depend on a multitude of influencing factors, such as the wood species, the moisture content of the wood used, the pH value, the particle size, the type and composition of the adhesive used, the amount of adhesive, the amount of water added, the process and pressing temperature, the pressing pressure, the pressing time, and other parameters.

[0005] In the prior art, regular quality control of the finished wood-based panels is therefore carried out, as well as close monitoring of the quality after any changes are made to the manufacturing process. However, this approach already has the disadvantage that the equipment and processes of the prior art are typically operated continuously, and therefore quality control is typically delayed by about 15 minutes after the gluing of the raw chip material. If suboptimal quality is detected, a significant quantity of wood-based panels will already have been produced by the time the quality control of a finished panel is performed. Thus, before the process parameters can be optimally adjusted, a considerable number of wood-based panels will have been produced, at the very least with reduced quality, and in the worst case, as rejects.Furthermore, changes in influencing factors during ongoing production, such as changes in the quality, wood species composition and / or moisture content of the raw chip material supplied, can also lead to a reduction in product quality, which may only be detected with a considerable time delay.

[0006] Furthermore, the disadvantage of the prior art methods and devices is that only within the framework of a relatively long process of changing control parameters and subsequent quality controls of the finished wood-based panels can a set of control parameters be found that leads to a high-quality product.

[0007] The invention is therefore based on the objective of providing a method and a device for the process-optimized production of wood-based panels, which allow for quality optimization as well as continuous quality assurance, enable a particularly simple and quick determination of the best possible control parameters and also ensure continuous production with the lowest possible waste and the greatest possible process stability.

[0008] The problem is solved according to the invention by a method for the process-optimized production of wood-based panels according to claim 1 and by a device for the process-optimized production of wood-based panels according to claim 11. Advantageous embodiments of the invention are specified in the dependent claims.

[0009] The inventive method for the process-optimized production of wood-based panels, in particular oriented strand board (OSB), comprises as process steps first a provision of raw chip material from a wood yard and / or from a dryer and / or from a dry raw chip bunker, followed by gluing of the raw chip material, in particular within a gluing station, a spreading of the glued chip material to form a forming strand, in particular in a spreading station and / or onto a transport mat, and finally followed by pressing, in particular continuous pressing, of the forming strand to form a wood-based panel.The invention provides that at least one process parameter, in particular the water content and / or the amount of adhesive applied to the raw chip material, is measured by means of near-infrared spectroscopy and the measured values ​​of the at least one process parameter are transmitted to a control unit for process optimization and / or for process-optimized control of the method, in particular for optimized control of the gluing process.the production of the wood-based panel, wherein the measurement of at least one process parameter is carried out at one or more positions, selected from a position immediately before gluing, in particular between a dry raw chip bunker and the gluing station, a position immediately after gluing, in particular between the gluing station and a chip distributor and / or a spreading station, a position during the supply immediately after a wood yard, in particular between the wood yard and a subsequent dryer, and / or a position during the supply immediately after a dryer, in particular between the dryer and a screening station and / or a dry raw chip bunker.

[0010] The device according to the invention for the process-optimized production of wood-based panels and preferably of oriented strand board, in particular by means of the method according to the invention, preferably has a wood storage area and / or a dry raw chip bunker for providing raw chip material, at least one gluing station for gluing the raw chip material, at least one spreading station for spreading the glued chip material to form a forming strand, in particular onto a transport mat, and a press, in particular a continuous press, for pressing the forming strand into a wood-based panel.Furthermore, the device comprises at least one near-infrared measuring device for measuring at least one process parameter, in particular the water content and / or the amount of adhesive applied to the raw chip material, and preferably also at least one control unit to use the measured values ​​of the at least one process parameter for process optimization and / or for process-optimized control of the process or.to be used in the production of the wood-based panel, wherein a near-infrared measuring device or several near-infrared measuring devices are arranged immediately before the gluing station, in particular between a dry raw chip bunker and the gluing station, immediately after the gluing station, in particular between the gluing station and a chip material distributor and / or the spreading station, immediately after the wood yard, in particular between the wood yard and a subsequent dryer, and / or immediately after a dryer, in particular between the dryer and a screening station and / or the dry raw chip bunker.

[0011] The inventive method and device enable a particularly fast and efficient optimization of the manufacturing process for wood-based panels based on process parameters measured by near-infrared spectroscopy. This allows for a simple improvement in quality and subsequent quality assurance. A significantly reduced reaction time to suboptimal settings and control variables can reduce rejects generated during continuous production and also increase process stability, even with varying materials such as the raw wood chips and the adhesive.Furthermore, automatic control is enabled, for example of the amount of water added to the raw chip material to regulate the moisture content of the chip material, especially immediately before and / or during gluing, which means that in the event of fluctuations in process parameters and especially the moisture content of the raw chip material, it is no longer necessary to slow down the production process and / or the amount of defective material produced can be significantly reduced.

[0012] According to the invention, a process-optimized manufacturing of wood-based panels is understood to be a process in which it is possible to optimize at least one control variable of the manufacturing process based on measured values ​​of at least one process parameter, in particular as the primary control variable of the process optimization, such that a wood-based panel of higher quality and / or with consistently high quality can be obtained despite a change in process parameters. The primary or preferred process parameters are the moisture content and / or the amount of adhesive applied to the measured material, in particular the raw chip material, the glued chip material, and / or the molded strand.

[0013] The term "provisioning of raw chip material" refers to a process that ultimately yields a coarse chip material suitable for immediate gluing and / or use in the production of wood-based panels, particularly OSB panels. This provisioning process may include transporting raw chip material from a lumberyard, subsequently drying the raw chip material from the lumberyard, screening the preferably dried raw chip material in a screening station, and / or storing the preferably dried and / or screened raw chip material in a drying chip bunker. Furthermore, a means for reducing the wood or the coarse chip material may be provided at any point in the process, preferably between the lumberyard and the dryer, and / or immediately downstream of the dryer.

[0014] According to the invention, the raw chip material is coated with at least one adhesive, and preferably with exactly one adhesive, preferably in a gluing station, which particularly preferably comprises a gluing drum. Although the gluing can be carried out in any manner, at least one adhesive, and preferably exactly one adhesive, is preferably added to the moving raw chip material, particularly preferably by spraying, especially within a gluing drum. Water can also be added to the raw chip material at the same time, also preferably by spraying, especially within a gluing drum. Preferably, the adhesive used is a phenol formalin aldehyde (PF) or polymeric diphenylmethane diisocyanate (PMDI) and / or any isocyanate-based adhesive.

[0015] From the glued chip material, a shaped strand is subsequently produced by sprinkling the chip material in one or more layers. This strand is then formed into a wood-based panel by pressing and preferably also heating. The pressing is preferably carried out in a continuously operated press or a constant press. Following pressing, the panel is preferably cut to the desired dimensions.

[0016] Measuring at least one process parameter for subsequent process optimization is preferably carried out without contact and / or in such a way that the measured material can subsequently be used for the production of a wood-based panel. Generally, measurement in contact with the measured material and / or by means of a contact sensor is also possible, although this is preferably carried out exclusively with unglued raw chip material to prevent contamination of the contact sensor or the corresponding measuring device. According to the invention, at least some of these measurements, and preferably all measurements, are carried out using near-infrared spectroscopy (NIRS).

[0017] Near-infrared spectroscopy, as defined in the invention, is a spectroscopic investigation that analyzes the material under investigation in the near-infrared range, and preferably exclusively in the near-infrared range. The near-infrared range is preferably defined as the wavelength range between 700 nm and 3000 nm, particularly preferably between 760 nm and 2500 nm, and most preferably between 780 nm and 2500 nm. Near-infrared spectroscopy is primarily used to determine the moisture content of wood, raw chip material, pre-moistened and / or glued chip material, and / or any other material at any process step in the production of a wood-based panel.

[0018] Near-infrared spectroscopy is preferably performed using a near-infrared spectrometer, although measurement using only a near-infrared spectroscope would also be conceivable. Accordingly, the near-infrared measuring device according to the invention is preferably a near-infrared spectroscope or a near-infrared spectrometer and / or preferably an online near-infrared measuring device, which is particularly preferably configured to perform near-infrared measurements continuously or periodically. Additionally, event-driven measurements can also be performed, for example, when a user triggers such a measurement and / or when a deterioration in product quality is detected during automatic or manual quality control.

[0019] According to the invention, a near-infrared measuring device is arranged at at least one, preferably several, and particularly preferably all system- or process-relevant positions of the raw chip production process and / or the manufacturing process of the wood-based panel. A process-relevant position is generally understood to be any position at which the properties and measurable process parameters of the measured material have changed compared to a previous measurement position. Particularly relevant positions include the position after the raw chip material has been provided, before and / or after gluing, before and / or after the application of the glued chip material, and / or immediately before and / or after pressing the glued and applied chip material. Furthermore, a near-infrared measuring device for measuring immediately after gluing is preferably arranged between the gluing station and a chip material distributor and / or a spreading station.Accordingly, it is preferred that the near-infrared measuring device is located downstream of and / or not within the gluing station and / or that the measurement using the near-infrared measuring device is carried out after completion of the gluing process.

[0020] Preferably, a near-infrared measuring device is arranged at at least two system- or process-relevant positions in the raw chip production process and / or the manufacturing process of the wood-based panel. It is particularly preferred that these two positions are selected from a position for measuring the raw chip material immediately before gluing, in particular between a dry raw chip hopper and the gluing station, and / or a position immediately after gluing between the gluing station and a chip material distributor and / or a spreading station, and / or a position during the supply of chip material immediately after a wood storage area, in particular between the wood storage area and a subsequent dryer, and / or a position during the supply immediately after a dryer, in particular between the dryer and a screening station and / or a dry raw chip hopper.

[0021] The optimization of the manufacturing process ultimately takes place within a control unit, which can be located directly on the device or separately. Preferably, the control unit is a programmable logic controller (PLC), but it can also be any other computing unit, a computer, or even a data center. The process optimization is based on at least some of the measured values ​​of at least some of the process parameters. Preferably, the optimization is based on all measurable or measured process parameters and / or takes into account all measured values ​​of the respective process parameter. Particularly preferably, the process optimization is based on numerous and especially all measurable or measured process parameters, for which purpose the respective measured values ​​are stored in a database and / or kept retrievable.

[0022] In a preferred embodiment of the process according to the invention, in addition to the water content and / or the pH value, the amount of adhesive applied to the raw chip material and / or the wood species and / or the amount of additives are also measured as process parameters using near-infrared spectroscopy. Preferably, the measurement is not limited to the adhesive, particularly before the adhesive is added to the raw chip material and / or before gluing. Accordingly, it is preferred that at least one measurement, preferably several measurements, particularly preferably the majority of the measurements, and most preferably all measurements, particularly using near-infrared spectroscopy and / or a single near-infrared measuring device, are carried out on the glued chip material, after the raw chip material has been glued, and / or directly on the chip material or the raw chip material.Particularly preferably, two measurements are taken, especially by means of near-infrared spectroscopy and / or by means of a single near-infrared measuring device, before pressing the extrusion into a wood-based panel and / or before finishing a wood-based panel. Furthermore, preferably not one measurement, and in particular not exclusively one measurement, is carried out to measure one or more components of the adhesive, especially the synthetic resin content of such an adhesive.

[0023] In principle, each process parameter can be measured using near-infrared spectroscopy and / or a single near-infrared measuring device. Furthermore, several, and in particular all, process parameters can be measured simultaneously or using a single near-infrared measuring device. Preferably, each near-infrared measuring device is used to record all process parameters that can be meaningfully recorded at the respective stage of the process. For example, measuring the amount of adhesive is only meaningful after the raw chip material has been glued. The same applies to all process parameters. A preferred embodiment of the invention provides that the moisture content, or...The water content is measured at at least two positions, particularly preferably at three positions, and most preferably at each individual position. This is advantageous because this process parameter can change continuously during the process due to the process parameters, especially due to water addition and / or drying caused by heat input. Initially, determining the wood species multiple times only seems sensible at a single position, as the composition should not change during the process. However, when using different wood species, information about uniform distribution and successful mixing or segregation can also be obtained during the process. Accordingly, the wood species can be measured only once, multiple times, or even using any near-infrared measuring device.

[0024] An advantageous further development of the method according to the invention provides that a measurement using near-infrared spectroscopy is carried out at least immediately after the gluing of the raw chip material in order to obtain information about the amount of adhesive applied to the raw chip material and / or about the current moisture content of the glued chip material. The information about the amount of adhesive applied to the raw chip material is preferably also obtained by determining the moisture content, whereby, if the moisture content before gluing is known and, optionally, the amount of additional water added in the gluing station is known, the amount of adhesive in the glued chip material can be determined. Using the process parameters measured at this stage of the method, the amount of adhesive added and / or additional water supplied can then be controlled almost in real time.Furthermore, the absolutely dry (atro) wood mass can be determined based on the values ​​measured by means of near-infrared spectroscopy, whereby preferably the amount of water to be added before and / or during gluing and / or the amount of adhesive to be used is then determined on the basis of the atro wood mass.

[0025] Although measurements of at least one process parameter can be carried out at any point in the process using near-infrared spectroscopy, it is preferred that at least one further measurement of the at least one process parameter be carried out using near-infrared spectroscopy after the application of the glued chip material, in particular onto a transport mat, or after the application station and before pressing into a wood-based panel. Measuring immediately before the press enables complete optimization of the manufacturing process, since the material properties of the finished wood-based panel result directly from the properties of the glued chip material before pressing.Furthermore, it is preferred to control the amount of water to be added before and / or during gluing and / or the amount of adhesive to be used based on the process parameters measured before pressing, and in particular on the water content measured there and / or the amount of adhesive applied. This can be done solely on the basis of the process parameters measured there or additionally to process parameters measured at another measuring position.

[0026] In order to advantageously minimize the amount of rejects or produced wood-based panels with suboptimal product properties or not of the highest product quality, a process optimization is carried out in an advantageous embodiment of the inventive method based on the process parameters measured by means of near-infrared spectroscopy, in particular by means of the control unit, so that an adjustment of the method for producing wood-based panels is made possible within a period of less than 20 minutes, preferably less than 15 minutes, particularly preferably less than 10 minutes and most preferably less than 5 minutes.

[0027] According to a preferred embodiment of the inventive method, the individual process parameters are correlated with their respective control variables for process optimization. Preferably, the measured values ​​of the process parameters from all near-infrared measuring devices are used within the control unit to calculate the control variables, and the calculated control variables are used for the controlled operation of the method for producing wood-based panels and / or a device for producing wood-based panels. Accordingly, a retrograde correlation of the measured values ​​of the process parameters within the manufacturing process is preferred.

[0028] In principle, it is still conceivable that each process parameter is assigned exactly one control variable, or that one or more control variables are calculated using several or all process parameters. A direct correlation exists, for example, between a measured wood species and the control of the addition and / or mixing of the supplied raw chip material. In contrast, the amount of adhesive added and / or the adhesive composition and / or the amount of water to be added during gluing can be determined depending on several process parameters. In particular, the water content at various points in the process, but also the wood species used, the pH value, and / or the amount of adhesive remaining on the chip material after gluing can be crucial here. Depending on the pH value, the amount of adhesive, the adhesive composition, and / or the type of adhesive can also be adjusted.

[0029] Furthermore, based on the measured values ​​of the process parameters, adjustments can be made to other control variables, such as the pressing time, the pressing pressure, the pressing temperature, the amount of glued chip material to be spread and / or the transport speed.

[0030] An advantageous embodiment of the inventive method for the process-optimized production of wood-based panels provides that, within the framework of process optimization, at least one water addition to the raw chip material before and / or during gluing is controlled as a variable based on the process parameter of the moisture content of the raw chip material before gluing and / or the amount of adhesive applied to and remaining on the raw chip material. Particularly preferably, the water addition is regulated depending on the measured initial moisture content of the raw chip material and / or the moisture content immediately before the press. Additionally or alternatively, the amount of adhesive added and / or the emulsion with water and / or the amount of additives to be added can also be controlled based on the measured process parameters.

[0031] In a multi-layered wood-based panel, the moisture content can be controlled for all layers simultaneously. However, it is preferred that at least one layer, particularly preferably an outer face layer, and most preferably all outer face layers, is controlled or process-optimized independently of the other layers. This advantageously eliminates the need for manual adjustments to the water content of the raw chip material for the face layers, which are common in the prior art. Furthermore, the present invention achieves a significant time saving compared to quality control after production and subsequent adjustments.

[0032] Process optimization, particularly in the control unit, is preferably implemented as a self-learning process, an automatically controlled process, and / or using artificial intelligence, preferably allowing user intervention, especially in the form of configurable offset values ​​and / or limit values. Process optimization as an automatically controlled process preferably involves controlling the process to defined target values, such as a target moisture content and / or a target sizing quantity, at a defined point in the process. The limit values ​​defined by the user can be minimum and / or maximum values ​​for a target variable, particularly to keep the process within desired and / or technically feasible limits.

[0033] To optimize the process, a data model is preferably created in the control unit, the programmable logic controller (PLC), and / or any other computer. Additionally or alternatively, a database can be created containing the recorded measurements, other recorded process variables, and / or the control variables of the process flow, as well as, if applicable, data from subsequent quality inspections of the wood-based panels. Such a database then makes it particularly easy to subsequently perform optimization using self-learning processes or artificial intelligence, whereby the models developed and / or the correlations identified can be fed back into the real-time control of the manufacturing process.

[0034] An advantageous embodiment of the method according to the invention further provides that, immediately before at least one, preferably several, and particularly preferably all measurements using near-infrared spectroscopy, the material to be measured, in particular the raw chip material, the glued chip material, and / or the forming strand, is leveled. The leveling is preferably carried out using a stripping plate or a leveling plate, which particularly preferably extends at least over the area to be measured and most preferably over the entire width of the material to be measured. The stripping or leveling plate extends over the material to be measured in such a way that a uniform layer thickness, a flat surface, a uniformly compacted packing, and / or a uniform surface is achieved.Accordingly, equalization increases the quality and reliability of the measured values, whereby a constant distance between the measured material and the near-infrared measuring device is particularly important.

[0035] Finally, a preferred embodiment of the inventive method is one in which, for the production of a wood-based panel with at least one face layer and at least one middle layer, the supply of raw chip material and the gluing of the raw chip material for the face layer and the middle layer are carried out separately, and for the production of multi-layered wood-based panels, the material for the individual layers is then applied successively. Preferably, the wood-based panel has a middle layer and a face layer on each side of the middle layer, wherein the face layers can be identical and / or different in composition. If the two face layers have an identical composition and / or gluing, it is preferred that the supply and gluing of all face layers, or all layers with identical composition, are carried out together.Preferably, the process steps, including measurements using near-infrared spectroscopy, are carried out separately for each composition of the chip material and / or for the at least one surface layer and the at least one middle layer, in accordance with the invention. Particularly preferably, the moisture control, and especially the control of the water content of the chip material for the surface layers, is carried out taking into account the water content of the chip material of the middle layers and / or the moisture input from the middle layer(s) into the surface layer(s). Additionally or alternatively, a reduction of the moisture input can also be provided by recycling the mat edging into the middle layers.

[0036] Preferably, the glued chip material for the individual layers is joined immediately before pressing and / or in a respective spreading station. Particularly preferred is the provision of a spreading station for a bottom cover layer along a transport direction, followed by at least one spreading station for the middle layer, and finally another spreading station for a top cover layer, wherein the two spreading stations for the two cover layers can be supplied together with identical glued chip material and / or from a single distributor and / or a single gluing station.

[0037] Particularly preferably, the application of the glued chip material for the middle layer is carried out by means of a first spreading station for the chip material of the lower half of the middle layer, followed by a second spreading station for the chip material of the upper half of the middle layer. It is again preferred that the two spreading stations for the two middle layer halves are supplied together with identical, glued chip material and / or from a single distributor and / or a single gluing station.

[0038] An advantageous embodiment of the device according to the invention provides that, in addition to the near-infrared measuring device(s) according to the invention, a further near-infrared measuring device is arranged after the spreading station and before the press, and / or a device for measuring the moisture content of the raw chip material is provided at the lumberyard and / or after a dryer for the raw chip material and / or before a screening station for the raw chip material. The device for measuring the moisture content of the raw chip material can determine the moisture or water content of the raw chip material in any desired manner, although this is preferably not done by means of near-infrared spectroscopy.Furthermore, it is preferred that the measurement of the raw chip material using near-infrared spectroscopy and / or a single near-infrared measuring device in the area of ​​the lumberyard and / or during delivery immediately after a lumberyard is not carried out as part of a check of recycled material and / or the recycling of wood material. Accordingly, it is preferred that this measurement is carried out after the lumberyard on the complete raw chip material transported from the lumberyard and / or intended for gluing.

[0039] Regarding the measurement of materials using near-infrared spectroscopy, there are fundamentally two different possibilities. Firstly, the measurement can be carried out during the ongoing manufacturing process, particularly without disrupting the process and / or on the material directly used in the manufacturing process. Secondly, material to be measured can be removed or separated from the manufacturing process, and in this case, it is also conceivable to return the previously measured material to the manufacturing process.

[0040] Accordingly, a design of the device according to the invention is preferred in which at least one measurement by means of near-infrared spectroscopy is carried out directly on the material in the manufacturing process and / or without prior separation or diversion of the material to be measured, wherein the material flow to be measured is preferably not slowed down and / or equalized before, in particular immediately before, the measurement.

[0041] Alternatively or additionally, for at least some of the measurements to be performed, a conveying device for the material to be measured by near-infrared spectroscopy can be provided, and / or the material to be measured can be removed from the rest of the material, in particular the rest of the raw chip material or the rest of the glued chip material, before measurement. In this configuration of the device and the method, the material to be measured is thus first separated and preferably fed into a bypass section and measured there, with the measured material being particularly preferably subsequently returned to the manufacturing process. The conveying device is preferably a conveyor belt and / or has ribs extending transversely to the direction of transport.

[0042] Separating or diverting the material to be measured allows for a particularly simple process of leveling and / or smoothing the material and / or bringing it to a predetermined strand thickness or density, which may differ from that of the forming strand. Furthermore, slowing down or even temporarily stopping the material to be measured, especially for measurement purposes, is conceivable, although measurement without slowing down is generally preferred. It is also generally conceivable that some measurements using near-infrared spectroscopy are performed with separated material, and some measurements using near-infrared spectroscopy are performed directly within the process. Separating material is particularly preferred for the chip material that has just been glued, immediately following the gluing process or immediately after the gluing station.

[0043] Finally, an advantageous embodiment of the device according to the invention provides that at least one near-infrared measuring device, preferably some of the near-infrared measuring devices, and particularly preferably all near-infrared measuring devices, are arranged in a height-adjustable manner and / or traversing on a rail, in particular being displaceable at right angles to the transport direction of the material to be measured. The height adjustment and / or traversing can be carried out manually, although it is preferred that this is additionally or exclusively motorized, in particular to enable precise positioning at one or more measuring positions.The height setting is preferably configured such that the surface of the material to be measured, in particular regardless of the layer thickness of the material to be measured, can generally be measured from a height between 50 mm and 750 mm, particularly preferably between 100 mm and 500 mm, most preferably between 200 mm and 300 mm and particularly from a height of 250 mm.

[0044] In the case of using a contact sensor and / or measuring in direct contact with the material to be measured, particularly using a near-infrared measuring device, a height-adjustable and / or traversing arrangement is not strictly necessary, and a fixed and / or non-adjustable arrangement of the contact sensor or near-infrared measuring device is also possible. It is particularly preferred that the near-infrared measuring device(s) measuring in direct contact with the unglued chip material is fixed in place, and that the near-infrared measuring device(s) arranged at a distance from the material to be measured are height-adjustable and / or traversable.

[0045] An exemplary embodiment is described in more detail below with reference to the drawing. Figure 1 shows a schematic diagram of the arrangement of the individual components and the sequence of the manufacturing process, including the positions of the respective near-infrared spectroscopy measurements.

[0046] In a schematically and simplified system for producing oriented strand board (OSB), as shown in Fig. 1, raw wood chips are first transported from a wood storage area 1 towards a dryer 2. During transport on a conveyor mat, the raw wood chips are leveled by means of a scraper plate and then measured during transport using a first near-infrared measuring device 9a from a distance of approximately 25 cm. From the measurement data, at least the wood moisture content, and preferably also the wood species and, if necessary, the pH value, are determined as process parameters.

[0047] In dryer 2, the raw chip material is dried, and subsequently, another measurement is taken using a near-infrared measuring device 9b, determining the same process parameters as before drying. The difference at this stage is that the raw chip material to be measured is separated from the rest of the material stream before measurement with the near-infrared measuring device 9b and transported to the device via a ribbed conveyor belt. During this process, the raw chip material is at least slowed down and, if necessary, temporarily stopped, for example, to allow the dried raw chip material to cool completely and / or evaporate before measurement. Furthermore, the material is leveled again before measurement. After measurement, the measured raw chip material is returned to the rest of the raw chip material.

[0048] After drying in dryer 2, the dried raw chip material is screened in a screening station 7 and then fed to a raw chip bunker 3a for the surface layer material and a raw chip bunker 3b for the core layer material. To form a multi-layer OSB board and / or an OSB board with a core layer that differs from the two outer surface layers, it is advantageous to process the material for the two surface layers and the at least one core layer separately after screening. The core layer may have a different particle size distribution and / or average particle size, a different quality of the raw chip material, and / or a different wood composition.

[0049] Upon exiting the respective raw chip bunker 3a, b, the dried and sieved raw chip material is measured again using a near-infrared measuring device 9c, e, whereby the wood moisture content and / or the pH value are preferably determined again as process parameters. The raw chip material is then fed to a gluing station 4a, b and mixed there in a gluing drum with a defined quantity of adhesive and, if necessary, with the addition of a small quantity of water. Upon exiting the gluing station 4a, b, a further measurement is then carried out using a near-infrared measuring device 9d, f, in particular to determine the quantity of adhesive applied and remaining on the chip material as a process parameter. Preferably, the moisture content of the glued chip material and, if necessary, the pH value are also determined again.

[0050] The surface layer material and the core layer material are then fed to four spreading stations 5a, b via a respective chip material distributor 6a, b, where a strand is spread layer by layer to form a particleboard. Between the spreading of the chip material for a portion or all individual layers and / or after spreading and thus the completion of the strand's formation, a further measurement is taken using a near-infrared measuring device 9g. Finally, the strand is pressed, in particular in a continuous press 8, to form a particleboard.

[0051] To minimize production downtime during production changes, which can occur three times a day, and to ensure consistently high-quality production of OSB boards even with changing raw materials, such as slight variations in wood composition, wood species, or wood moisture content, and / or changing environmental parameters, such as ambient temperature or humidity, it is planned that all measured values ​​of the process parameters, in particular the wood species, moisture content, pH value, and applied adhesive quantity, recorded by the near-infrared measuring devices 9a-g, will be transmitted to a control device. From there, automatic process optimization and control of the individual process steps will take place in real time, using the measured process parameters as control variables.Of course, measured values ​​and data from the system and other sensors can also be taken into account.

[0052] It is advantageous to create a data model of the process flow using data that has been measured over a longer period and stored in a database, taking into account the variations of all process parameters, and this can also be done using artificial intelligence.

[0053] Contrary to the design described above, some or all of the near-infrared measuring devices 9a-g, but in particular the near-infrared measuring devices 9a, b, c, e, may also be arranged in direct contact with the material to be measured and / or be stationary and / or not height-adjustable and / or not traversing, since at these positions the material to be measured is not yet glued and therefore corresponding contamination of the respective near-infrared measuring device 9a, b, c, e is excluded.

[0054] (20149-0)

[0055] Reference symbol list

[0056] 1 lumberyard

[0057] 2 dryers

[0058] 3a Raw chip bunker for top layer material

[0059] 3b Raw chip bunker for middle layer material

[0060] 4a Gluing station for top layer material

[0061] 4b Gluing station for middle layer material

[0062] 5a Spreading station for surface course material

[0063] 5b Spreading station for middle layer material

[0064] 6a Chip material distributor for top layer material

[0065] 6b Chip material distributor for middle layer material

[0066] 7 Sieving station

[0067] 8 Press

[0068] 9a - g Near-infrared measuring device

Claims

(20149-0) Claims 1. Method for the process-optimized production of wood-based panels, in particular oriented strand board, comprising the following steps: Providing raw chip material from a wood yard (1) and / or from a dryer (2) and / or from a dry raw chip bunker (3a, b), gluing the raw chip material, in particular within a gluing station (4a, b), Spreading the glued chip material to form a shaped strand in a spreading station (5a, b) and / or onto a transport mat, Pressing the forming strand into a wood-based panel, characterized in that at least one process parameter, in particular the water content and / or the amount of adhesive applied to the raw chip material, is measured by means of near-infrared spectroscopy and the measured values ​​of the at least one process parameter are sent to a control unit for process optimization and / or for process-optimized control of the method, in particular for optimized control of the gluing, wherein the measurement of the at least one process parameter takes place at one or more positions selected from a) immediately before gluing, in particular between a dry raw chip bunker (3a, b) and the gluing station (4a, b), b) immediately after gluing, in particular between the gluing station (4a, b) and a chip material distributor (6a, b) and / or a spreading station (5a, b), c) during the supply immediately after a wood storage area (1),in particular between the timber yard (1) and a subsequent dryer (2), and / or d) when making the timber available immediately after a dryer (2), in particular between the dryer (2) and a screening station (7) and / or a dry raw chip bunker (3a, b).

2. Method for the process-optimized production of wood-based panels according to claim 1, characterized in that, in addition to the water content and / or the amount of adhesive applied to the raw chip material, the pH value and / or the wood species are also measured as process parameters using near-infrared spectroscopy.

3. Method for the process-optimized production of wood-based panels according to claim 1 or 2, characterized in that a measurement using near-infrared spectroscopy is carried out at least immediately after the gluing of the raw chip material in order to obtain information about the amount of adhesive applied to the raw chip material and / or about the current moisture content of the glued chip material.

4. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that at least one further measurement of the at least one process parameter is carried out by means of near-infrared spectroscopy after the sprinkling of the glued chip material, in particular onto a transport mat, and before pressing to form a wood-based panel.

5. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that, based on the process parameters measured by means of near-infrared spectroscopy, a process optimization is carried out by means of the control unit, so that an adaptation of the method for the production of wood-based panels is made possible within a period of less than 20 minutes.

6. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that a correlation of the individual process parameters is used for process optimization. The control variables are adjusted accordingly, preferably using all process parameter values ​​measured by means of near-infrared spectroscopy within the control unit to calculate the control variables and using the calculated control variables for the controlled operation of the process.

7. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that, within the framework of process optimization, at least one addition of water to the raw chip material before and / or during gluing is controlled as a control variable based on the process parameter of the water content of the raw chip material before gluing and / or the amount of adhesive applied to and remaining on the raw chip material.

8. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that the process optimization in the control unit is carried out as a self-learning process, as an automatically controlled process and / or using artificial intelligence, preferably enabling user intervention, in particular in the form of storable offset values ​​and / or limit values.

9. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that the material to be measured is equalized immediately before at least one measurement by means of near-infrared spectroscopy.

10. Method for the process-optimized production of wood-based panels according to at least one of the preceding claims, characterized in that, for the production of a wood-based panel with at least one top layer and at least one middle layer, the provision of raw chip material and the gluing of the raw chip material for the top layer and the middle layer are carried out separately, and for the production of multi-layer wood-based panels, the material is then sprinkled onto the individual layers. Layers are applied one after the other.

11. Device for the process-optimized production of wood-based panels, in particular oriented strand board (OSB), comprising a means for feeding raw chip material from a wood storage area (i) and / or from a dry raw chip bunker (3a, 3b), at least one gluing station (4a, b) for applying glue to the raw chip material, at least one spreading station (5a, b) for spreading the glued chip material to form a molded strand, a press (8) for pressing the molded strand into a wood-based panel, characterized by at least one near-infrared measuring device (9a - f) for measuring at least one process parameter, in particular the moisture content and / or the amount of adhesive applied to the raw chip material, wherein one or more near-infrared measuring devices (9a - f) are located a) immediately before the gluing station (4a, b), in particular between a dry raw chip bunker (3a, b) and the gluing station (4a, b), b) immediately after the gluing station (4a, b), especially between the gluing station (4a,b) and a chip material distributor (6a, b) and / or the spreading station (5a, b), c) immediately after the wood yard (1), in particular between the wood yard (1) and a subsequent dryer (2), and / or d) immediately after a dryer (2), in particular between the dryer (2) and a screening station (7) and / or the dry raw chip bunker (3a, b).

12. Device for the process-optimized production of wood-based panels according to claim 11, characterized in that a near-infrared measuring device (9g) is additionally arranged after the spreading station (5a, b) and before the press (8) and / or a device for measuring the moisture content of the raw chip material at the wood storage area (1) and / or after a dryer (2) for the raw chip material and / or is provided in front of a screening station (7) for the raw chip material.

13. Device for the process-optimized production of wood-based panels according to claim 11 or 12, characterized in that a conveying device is provided for the material to be measured by means of near-infrared spectroscopy and / or the material to be measured is removed from the remaining material, in particular the remaining raw chip material or the remaining glued chip material, before the measurement.

14. Device for the process-optimized production of wood-based panels according to at least one of claims 11 - 13, characterized in that at least one measurement by means of near-infrared spectroscopy is carried out directly on the material in the manufacturing process and / or without prior separation of the material to be measured, wherein the material flow to be measured is preferably equalized and / or not slowed down before the measurement.

15. Device for the process-optimized production of wood-based panels according to at least one of claims 11 - 14, characterized in that at least a part of the near-infrared measuring devices (9a - g) and preferably all near-infrared measuring devices (9a - g) are arranged to be height-adjustable and / or traversing on a rail.

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