DE202017100935U1 - Control device for metering a binder, a feed device for introducing a binder into a material flow and a system for producing material plates - Google Patents

Abstract

Control device (20) for actuating a metering element (22) of a wetting device (24) for metering a binder in the course of producing material plates from spreadable material (14), comprising:
- a measuring interface (42) for receiving a measured value with information for determining the material density of the spreadable material in a material inlet (16) of a feeding device (12) for a wetting device (24);
a processor (44) for calculating the material density based on the at least one measured value and for determining a dosage value based on the material density; and
- A control interface (46) for transmitting a control signal to the metering element (22) to control the metering element (22) for metering the binder according to the determined metering value.

Description

The present invention relates to a control device for controlling a metering element for metering a binder in the manufacture of material plates from scatterable material, a feed device for introducing a binder into a continuous material stream of spreadable material and a system for producing material plates.

In the manufacture of material slabs from scatterable material, a mixture of particles and / or fibrous matter (eg, wood chips or other lignocellulosic material) and a binder (eg, glue) is scattered to a spreading material mat on a forming or conveyor belt (spreading belt conveyor). This grit mat (also referred to as particle mat) is then fed to a possibly required pretreatment of a continuous or discontinuous pressing, which can be done by means of pressure and / or heat. For example, chipboards, MDF (medium-density fiberboard) or Oriented Strand Board (OSB) boards can be produced in this manner.

Before the material is fed to the compression, it is wetted with a binder (gluing). This gluing can be done, for example, in a chute in which the binder is introduced by spraying when falling loosened material. Alternatively, a so-called compulsory mixer can be used in which the particles are mixed together with the binder and possible other agents in a rotating role. Thereafter, an intermediate storage in a grit storage, which acts as a buffer, take place. From this buffer, the material is then discharged again, scattered by means of a scattering device on the press belt and the compression is supplied.

Prior art, from which the invention proceeds with the EP 2 747 966 B1 , of the WO 2014 079 987 A1 and the WO 2014 079 988 A1 known. An exemplary apparatus for metering binder into a flow of material is with the DE 10 2008 059 877 A1 known.

When introducing the binder, a balanced dosage of the binder is relevant in several respects. Too low a dosage of the binder can lead to a poorer stability and quality of the material plates. Overdosing can also degrade the board quality, but rather the binder and any other additives to be incorporated are a significant factor in material costs and thus directly affect manufacturing costs.

So far, the dosage of the amount of binder to be introduced usually takes place starting from the dry wood pulp (eg in percent solid resin to mass atro wood). Usually, it is noted in a recipe which dosage is to be selected depending on the material and / or depending on the required / desired properties of the material plates. The dosage of the binder is then gravimetric.

The theoretically optimal binder dosage depends on the surface of the individual particles of the raw material used (chips, fibers, etc.). Often, however, this material is inhomogeneous and contains particles of different geometries. Due to the different geometries, it may therefore happen that varies at a constant mass to be acted upon by the binder surface of the particles. This in turn means that the binder dosage chosen based on the wood pulp may be too high or too low. To ensure a sufficient amount of binder, therefore, an increased binder dosage is often used for safety's sake. This results in a fluctuating quality of the produced material plates as well as higher costs for the binder.

It is an object of the present invention, on the basis thereof, to optimize the metering of the binder in order to enable material plates of high quality with the lowest possible use of binder. In particular, a control device and a control method for driving a metering element for metering a binder in the production of material plates from scatterable material to be created.

• Steuervorrichtung zum Ansteuern eines Dosierelements einer Benetzungsvorrichtung zum Dosieren eines Bindemittels im Zuge der Herstellung von Werkstoffplatten aus streufähigem Material, mit:
  • - einer Messschnittstelle zum Empfangen eines Messwerts mit Informationen zur Ermittlung der Materialdichte des streufähigen Materials in einem Materialzulauf einer Einbringvorrichtung für die Benetzungsvorrichtung;
  • - einem Prozessor zum Berechnen der Materialdichte basierend auf dem mindestens einen Messwert und zum Ermitteln eines Dosierwerts basierend auf der Materialdichte; und
  • - einer Steuerschnittstelle zum Übermitteln eines Steuersignals an das Dosierelement, um das Dosierelement zum Dosieren des Bindemittels entsprechend dem ermittelten Dosierwert anzusteuern.

According to one aspect, the present invention relates to a solution to this problem

• Control device for controlling a metering element of a wetting device for metering a binder in the course of the production of material plates from scatterable material, comprising:
  • a measurement interface for receiving a measured value with information for determining the material density of the scatterable material in a material feed of a wetting apparatus feed device;
  • a processor for calculating the material density based on the at least one measured value and for determining a dosage value based on the material density; and
  • - A control interface for transmitting a control signal to the metering element to control the metering element for metering the binder according to the determined metering value.

Advantageously, the processor preferably not only determines the material density based on the measured values, but also considers material constants, characteristic structures and further information for determining the material density / bulk density in accordance with its specifications and options.

• - einem Materialzulauf zum Zuführen des streufähigen Materials, wobei der Materialzulauf bevorzugt ein Förderband umfasst;
• - einem Messelement zum Messen eines Messwerts mit Informationen zur Ermittlung der Materialdichte des streufähigen Materials in dem Materialzulauf, wobei das Messelement bevorzugt einen Wegsensor zum kontinuierlichen Ermitteln einer Materialhöhe des Materials und/oder einen Gewichtssensor zum kontinuierlichen Ermitteln einer Gewichtsinformation umfasst;
• - einer Steuervorrichtung wie zuvor beschrieben; und
• - einem Dosierelement zum Dosieren des Bindemittels in Abhängigkeit des Steuersignals, wobei das Dosierelement bevorzugt als Dosierpumpe ausgebildet ist.

In a further aspect, the invention relates to a delivery device for introducing a binder into a continuous material flow of spreadable material, comprising:

• a material feed for supplying the spreadable material, wherein the material feed preferably comprises a conveyor belt;
• a measuring element for measuring a measured value with information for determining the material density of the scatterable material in the material feed, wherein the measuring element preferably comprises a displacement sensor for continuously determining a material height of the material and / or a weight sensor for continuously determining weight information;
• a control device as described above; and
• - A metering element for metering the binder in response to the control signal, wherein the metering element is preferably designed as a metering pump.

• - Zuführen des streufähigen Materials in einem Materialzulauf; Messen eines Messwerts mit Informationen zur Ermittlung der Materialdichte des streufähigen Materials in dem Materialzulauf;
• - Ausführen eines Steuerverfahrens wie zuvor beschrieben; und
• - Dosieren des Bindemittels entsprechend dem berechneten Dosierwert.

Furthermore, one aspect of the invention relates to a method of introducing a binder into a continuous material flow of spreadable material, comprising the steps of:

• - supplying the spreadable material in a material feed; Measuring a measured value with information for determining the material density of the spreadable material in the material feed;
• - carrying out a control method as described above; and
• - Dosing of the binder according to the calculated dosing value.

• - einer Einbringvorrichtung nach Anspruch wie zuvor beschrieben; und
• - einer Benetzungsvorrichtung zum Benetzen des streufähigen Materials mit dem Bindemittel.

In addition, one aspect of the invention relates to a system for the continuous production of material plates, comprising:

• - An insertion device according to claim as described above; and
• - A wetting device for wetting the spreadable material with the binder.

According to one aspect, the invention relates to a computer program product with a data carrier, on which program code is stored, which is designed to execute a method with the steps as described above, when the program code is executed.

Preferred embodiments of the invention are described in the dependent claims. It is understood that the control device, the control method, the insertion device, the insertion method, the system, and the computer program product may be implemented according to the embodiments described for the control device and the control method in the dependent claims.

The control device according to the invention serves to set the metering agent to be introduced by a metering element into a flow of scatterable material. In the production of material plates glue is usually used as a binder. The binder is continuously sprayed, for example by means of a nozzle in the flow of material.

Within the scope of the invention it has been found that the consideration of the density of the material to be mixed with binder can be used for a more precise metering of the binder. By material density herein is meant a quantity calculated from detected measurements for the continuously supplied mass per volume of the spreadable material.

In the previous system, only the weight of the material supplied was usually considered. The binder to be introduced was metered in accordance with a value specified for a specific weight of the material. This approach is not optimal because the total surface area of the material being fed also depends on the material composition and particle geometry.

According to the invention, however, provided that the dosage of the binder is not determined by the weight, but based on the material density. In contrast to previous approaches, the material density is calculated based on a sensor value (measured value) and from this the dosage (dosage value) of the binder is derived. On the basis of this dosage, the dosage of the binder, so the amount of binder introduced, controlled.

Compared to previous approaches, there is the advantage that the use of the binder takes place directly as a function of the material surface to be wetted with the binder. The use of the binder is optimized. An optimal amount of binder is introduced. This can on the one hand costs of excessive use of binder can be avoided and on the other hand a high quality of the produced material plates are ensured.

The control device according to the invention can in particular be used in a feed device for introducing a binder into a system for producing material plates. In such a system scatterable material is wetted with binder and fed to the compression. Preferably, a continuous belt press is used for this purpose.

The inventive methods are particularly suitable for operation in a system for the production of material plates. The control method can be used to control a metering element in an existing system, which has possibly been extended by sensors.

In a preferred embodiment of the control device, the measuring interface is designed to receive a height value from a, preferably tactile, displacement sensor for continuously determining a material height of the material in the material inlet; and the processor is configured to calculate the material density based on the material height. By means of a displacement sensor, the height of the material conveyed on a conveyor belt can be continuously measured. For this purpose, a tactile sensor (touch sensor) is preferably provided. In previous systems, no comparable sensors are used. By using a displacement sensor, it is possible to continuously obtain information about the volume of material introduced in the material feed. The corresponding height value (measured value) is used in the processor, if necessary in conjunction with other measured values, to calculate the material density. Based on the material height and a given by the system geometry and known width, the material volume can be determined. The measurement of the volume of the introduced material is often directly meaningful with regard to the material density. In comparison to previous approaches, a precise statement about the material density is used to optimize the use of the binder, whereby manufacturing costs can be saved.

In a further refinement, the measurement interface is designed to receive a weight value from a weight sensor, preferably a belt scale, for continuously determining weight information of the material in the material feed; and the processor is configured to calculate the material density based on the weight information. By using a weight sensor, which is preferably designed as a belt weigher, it is possible to continuously measure the weight of the supplied material in the material feed. The measured weight preferably serves only as additional information in the calculation of the material density (mass per volume). By using a weight sensor it is possible to make a precise statement about the current material density and to optimize the dosage of the binder.

Advantageously, the processor is designed to determine the dosing value based on a basic value predefined for a nominal value of the material density. In previous production systems, a value for the amount of binder to be introduced is usually noted in a recipe. According to the invention, this recipe is extended to the effect that, in addition, an expected material density (nominal value) is indicated. By comparing this set point with the currently measured value of the material density, it can be determined whether the binder dosage (compared to the base value) should be increased or decreased. Compared to previous facilities can be made so that an automatic adjustment of the binder dosage. The basic value as well as the associated setpoint value are preferably specified by a system manufacturer or by a skilled person and can optionally be adapted during operation. The additional specification of the target value of the material density allows a precise control of the introduction of the binder and thus a high quality of the produced material plates at lower material costs.

Advantageously, the processor is designed to determine the dosing value based on a variable coefficient, preferably for determining the dosing value as the sum of the basic value and the coefficient; and the coefficient results from a predefined assignment to a deviation of the calculated material density from the desired value. The variable coefficient is determined based on the calculated material density with respect to the setpoint. By using a predefined variable coefficient depending on the deviation of the actual material density from the set point, a simple and efficient control of the binder dosage can be made possible. The introduced amount of the binder is therefore adjusted to whether the material density at the current time is higher or lower than the target value, ie the expected value. The dosage of the binder is optimized. With constant board quality, the amount of binder used can be reduced, resulting in cost savings.

In an advantageous embodiment, the processor is designed to determine the dosing value as a linear function between a minimum value as the lowest possible dosage and a maximum value as the highest possible dosage. By using a linear function becomes a efficient derivation of Dosierwerts allows. The use of a double-sided limit for the amount of binder to be incorporated (minimum value or maximum value) ensures that a minimum quantity is not undercut or a maximum quantity is not exceeded. Outliers are prevented. Reliable information regarding upper and lower limit values, which are necessary, for example, as quality data for material boards, is made possible.

In a preferred embodiment, the control interface for transmitting the control signal to a metering pump is formed; and the control signal comprises a rotational speed information of the metering pump. Preferably, the metering element is designed as a metering pump. In a metering pump, the introduced amount of binder can be varied speed-controlled. Due to a higher speed, a higher amount of binder is introduced. An immediate effect on the amount of binder is made possible.

In an alternative or cumulative embodiment, the control interface for transmitting the control signal to controllable valves for spray nozzles and / or a nozzle arrangement or their supply lines may be formed and the control signal comprise a control information for the valves. Straight direct valves in the nozzles allow a particularly precise control of the binder and the discharge amount.

The accuracy of the discharge amount can be optimized by measuring devices in the supply lines and / or the nozzles for the flow rate.

In a preferred embodiment of the control method according to the invention, the method comprises a step of determining the dosing value based on a basic value predefined for a desired value of the material density. As already described above, an indication of a material density (nominal value) is thus predefined for a specific binder dosage. Based on this setpoint, a control can be made based on deviations of the current material density from this setpoint. Deviations can be corrected to the extent that the amount of binder introduced is adjusted accordingly.

In a further advantageous embodiment, the control method comprises a step of determining the dosing value based on a variable coefficient, preferably determining the dosing value as the sum of the basic value and the coefficient, wherein the coefficient results from a predefined assignment to a deviation of the calculated material density from the desired value , As also previously described, a simple and robust control can be achieved by a variable coefficient, which is determined from a predefined assignment to a deviation of the actual material density from the desired value.

Advantageously, the control method further comprises a step of determining the dosing value as a linear function between a minimum value as the lowest possible dosage and a maximum value as the highest possible dosage. A linear function can be implemented easily and in a memory-efficient manner. An amount that moves between a minimum and a maximum value allows a reliable indication of minimum and maximum dosages, as often required in a manual or a product description.

Herein denotes a measuring or a control interface, in particular a hardware or software implemented connection point for connecting or reading a transmitter (sensor). The interface is designed according to the connected device. A measured value is a value provided by a sensor, or a signal that reflects a physical phenomenon. In most cases, an analog or digital signal is to be understood by it. A control signal is understood as meaning an analog or digital, mostly continuous, signal which can be processed in a correspondingly designed metering element. The term "continuous" is understood here to mean the continuous production of material plates, determination of a measured variable, control of a metering element, etc. However, it is possible that parts of a continuous process also run clocked.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

In particular, an already known metering and / or mixing device for wetting agents, for example adhesives, glues, glue liquors, additives, hardeners or the like, can be controlled as the metering element, which in turn distributes the corresponding application volumes to the one or more nozzles for wetting.

The invention achieves excellent results, in particular, when, instead of a pure material flow from one type of material (wood), particles of another type, for example plastics, fillers, wood or plastic recyclates or other substances, are added. By transporting the material flow, it can then to classifying effects come, which need an adapted wetting. In particular, however, in this context, it is also provided independently for a material flow that is homogeneous in its material type, that the control device, preferably at strongly fluctuating densities (bulk densities), a path-time tracking from the location of the measurement (measuring element) to the place of wetting (nozzle arrangement , Dosierelement) in their control or regulation involves.

In comparison, slowly fluctuating bulk densities result from the fact that optimal chips are produced at the beginning of production in a knife ring chipper (during the production of chips). During production time, a deteriorating condition of the knives (grinding condition) influences the quality of the chips and changes their geometry. For this reason, the blades must be regularly reground, which can lead to periodic changes in the chip geometries. According to the invention, such fluctuations can be responded by adjusting the binder dosage.

• 1 eine schematische Darstellung eines Systems zur kontinuierlichen Herstellung von Werkstoffplatten mit einer Einbringvorrichtung und einer Steuervorrichtung gemäß der vorliegenden Erfindung;
• 2 eine schematische Darstellung einer alternativen Ausführungsform eines Systems zur kontinuierlichen Herstellung von Werkstoffplatten;
• 3 eine schematische Darstellung einer Steuervorrichtung zum Ansteuern eines Dosierelements zum Dosieren eines Bindemittels gemäß einem Aspekt der vorliegenden Erfindung; und
• 4 eine schematische Darstellung einer Zuordnung zwischen einer Materialdichte und einem variablen Beiwert zur Verwendung in der Berechnung des Dosierwerts.

The invention will be described in more detail below with reference to some selected embodiments in conjunction with the accompanying drawings and explained. Show it:

• 1 a schematic representation of a system for the continuous production of material plates with a loading device and a control device according to the present invention;
• 2 a schematic representation of an alternative embodiment of a system for the continuous production of material plates;
• 3 a schematic representation of a control device for driving a metering element for metering a binder according to one aspect of the present invention; and
• 4 a schematic representation of an association between a material density and a variable coefficient for use in the calculation of the dosing.

In the 1 is a part of a system 10 a plant for the continuous production of material plates in a sectional view shown schematically. In a delivery device 12 Binder is transformed into a continuous material flow of spreadable material 14 brought in. In the area of a material feed 16 the introduction device 12 is a measuring element 18 arranged through which a measured value with information for determining the material density of the scatterable material 14 can be won. According to the invention is a control device 20 provided by, based on the measured value, a metering element 22 is controlled. Through the dosing element 22 is in a wetting device 24 Binder in the spreadable material 14 brought in. The binder used is preferably glue, but also the dosage according to the invention of other agents to be introduced is possible.

Such systems are used in particular in the production of material plates in continuous press systems. In the present figure, the actual press is not shown for clarity.

Under streufähigem material 14 In particular, wood shavings (eg cover shavings, middle-layer shavings), coarse shavings or even wood fibers are understood. Also surcharge parts or recycled material may be present in the material flow. The individual material components are called particles.

In particular, the present invention is suitable for use in the manufacture of chipboards and OSB boards from wood chips. Fluctuations in the material density (with the same weight) result from the fact that usually a wood mix is used as the material. For example, solid wood of different types of wood, recycled wood, wood with different dust content, wood shavings, etc. can be used. In addition, in the wood mix used, fluctuations can also occur over the production time, which then lead to variations in the material density. Furthermore, different chip geometries can occur in the material to be used, which cause a different bulk density.

The material is delivered via a material feed 26 in the system 10 brought in. The material feeder 26 is a material bunker in the illustrated embodiment 28 downstream, which serves as a material storage for buffering. The material is removed from the material bunker 28 by means of floor tape 31 and discharge rollers 30 the introduction device 12 supplied for introducing the binder. The introduction device 12 includes in the area of a material feed 16 a subsidy 32 , which is preferably designed as a conveyor belt. The discharged material falls on this conveyor 32 or is scattered on the conveyor belt. While the material in the material feed 16 is located, the material density by means of a measuring element 18 measured. In the case of a conveyor belt on which the material is scattered, the material density can therefore also be referred to as spreading density or bulk density. As a possibility of a measuring element 18 Here, for example, a radiating X-ray unit may be mentioned, wherein the determined Radiation values in the control device, which may also be part of the X-ray unit, have to be converted. The suitable measured value for determining the density is transmitted to the control device via a control line 20 , if necessary, also wirelessly, transmitted and utilized insofar as the control device is a dosing element 22 can control which is arranged for the wetting of the material.

Within the scope of the invention, use is made of the fact that the material density is dependent, inter alia, also on the chip geometry. Therefore, it is possible to conclude on the basis of the material density on the surface to be wetted with the binder of the particles and thus to respond to these variations with an adjustment of the dosage of the binder.

In the introduction of the binder so far only weight information of the dry wood are usually continuously determined and used as a basis for the calculation of the amount of binder to be introduced. Compared to this approach, by taking into account the material density avoided, for example, that although a high weight of material is measured and thus a relatively high amount of binder is introduced, but this is mainly due to the current material composition of predominantly large and thus heavy chips with a relatively smaller surface , According to the invention an excessive binder consumption and thus high costs are avoided without reducing the quality of the material plates.

In the illustrated embodiment, by means of a teeing roll 34 the material 14 in a trained example as a compulsory mixer wetting device 24 transferred. In the wetting device 24 the binder is via a nozzle arrangement 36 introduced, in operative connection with the controlled metering element 22 stands. The trained as a forced mixer wetting device 24 mixes the spreadable material 14 with the incorporated binder and so wets the individual particles evenly. After mixing with the binder leaves the material 14 the compulsory mixer to be fed to the compression. In most cases, this is another bunker (not shown) provided as a buffer memory, in which the material is first stored to compensate for short-term capacity fluctuations can. This bunker is the material shown 38 downstream. The actual compression of the material to material plates then takes place preferably by means of a continuous (belt) press and under pressure / heat.

In the 2 is also a section of a system according to the invention 10 shown schematically in a sectional view. Compared to the previous illustration is the wetting device 24 as a chute with corresponding spray nozzles 40 designed for introducing the binder. The execution of the wetting device 24 has no influence on the application of the control device according to the present invention. The spray nozzles 40 can as part of the dosing 22 Consider the method of quantity distribution of the binder on behalf of the dosing element 22 which is controlled by the control device 20 is controlled to.

As measuring elements 18 for determining the material density in the illustrated preferred embodiment, a displacement sensor 18a and a weight sensor 18b intended. The displacement sensor 18a is designed as a tactile (tactile) sensor, which is the surface of the conveyor 32 Scans scattered material and performs an (indirect) volume measurement (with known spread). The weight sensor 18b is designed as a belt weigher that feeds into the material 16 , respectively belonging to the conveyor belt, integrated and clocked or continuously provides weight information.

It is understood that in other embodiments, other numbers and other types of sensors, such as laser distance sensors, can be used as a measuring element.

In the 3 is a schematic representation of a control device according to the invention 20 shown. The control device 20 includes a measurement interface 42 which is in communication with at least one measuring element (sensor) and receives a measured value from it. The measuring interface can be implemented in hardware and / or in software. For example, the measurement interface can correspond to a plug or a corresponding driver interface. The control device according to the invention 20 can be designed in particular as a microcontroller, but also as software in a system control.

Via the measuring interface 42 is made by at least one measuring element 18 received at least one measured value. The measured value contains information for determining the material density of the spreadable material. Preferably, a continuous measurement signal is obtained, which reflects the current value of a measured variable. Based on the reading is in a processor 44 in the control device 20 calculated the material density. For example, the material density may be determined based on a weight as well as a volume of the material detected by means of a displacement and weight sensor.

Based on this calculated material density, a metering value for the dosage of the binder to be introduced is then determined. A metering value is to be understood in particular as meaning the amount of binder to be introduced per unit time. Based on this dosing value is via a control interface 46 the metering element 22 controlled by a control signal so that a metering value corresponding dosage of the binder comes about. The control signal can be both an analog and a digital signal.

The method according to the invention performs the previously described method steps of the control device 20 out. For example, the method according to the invention can be implemented as a control program in an already existing machine control system of an entire plant for producing material plates or a continuously operating press.

The determination of the dosage amount based on the material density is preferably implemented as a function or as a lookup table. From the input variable (current material density), an output variable (dosing value or dosing agent quantity) is determined according to a predefined specification or specification. In most cases, the dosing value refers to a percentage scale, in which the proportion of the binder is given by the weight of the material plates to be produced.

In the 4 schematically an exemplary determination of the dosing is shown. A basic value of the dosage (preferably also as a percentage) is first taken from a recipe as in a classical regulation. The recipe represents a kind of recommendation, which was determined, for example, on the basis of one's own experience or on the basis of a specification from the plant manufacturer. The base value defines a "normal" amount of binder for a particular type of material and certain desired plate properties. This basic value is then corrected by means of a variable and based on the material density coefficient to compensate for possible variations in the composition of the material and thus in the required amount of binder. The variable coefficient thus represents a type of correction factor for tuning the basic value to the current material to be wetted.

The calculation includes a setpoint that corresponds to an expected material density. The correction of the basic value takes place on the basis of a deviation of the current measured value of the material density from this desired value.

Base value, dosing value, setpoint and variable coefficient are preferably given on a percentage scale. However, it is understood that the indication on an absolute (weight) scale is possible. Also a combination is possible.

In the example shown, the currently determined material density is plotted on the x-axis and the resulting (assigned) coefficient on the y-axis. In the present case, a variable coefficient of y2 is assigned to the desired value at point x2. For example, a material density (bulk density, nominal value) of 215 kg / m ³ (x2), which is to be mixed according to the recipe with 10% binder (basic value), a variable coefficient of 0% (y2) to be assigned. If, in determining the current material density, this deviation is then deviated upwards or downwards from this setpoint, the dosage is corrected via the variable coefficient. For example, a variable material value of 180 kg / m ³ (x1) can be assigned a variable coefficient of -0.4% (y1) and a current material density of 250 kg / m ³ (x3) a variable coefficient of +0.4%. (y3), resulting in a dosage of 9.6% and 10.4%, respectively.

As can be seen in the example shown, a minimum value of the variable coefficient can additionally be provided (for x <x1), which is not undershot even if the material density continues to decrease. The same applies to a maximum value (for x> x3), which must not be exceeded even if a predefined material density is exceeded. This increases the safety of the system.

It is understood that the o.g. Numbers as well as the illustrated partially linear function are merely exemplary understood. Different assignments of the setpoint to the points x1, x2 and x3 are possible. It is also possible for the basic value to represent a one-sided limitation of the dosing value up or down, that is to say it can not be undershot or exceeded (eg basic value corresponds to value at the position y3).

The principle of the present invention is particularly advantageous in chipboard and OSB boards in which the material is applied in the material inlet of the introduction device by scattering and as a material density a scattering density can be measured. It is understood that it is possible and useful to determine the material density even with differently designed material feeds, for example in blow-lines, in the production of MDF boards, in order to regulate the binder dosage based thereon.

The invention has been fully described and explained with reference to the drawings and the description. The description and explanation are to be considered as illustrative and not restrictive. The invention is not disclosed on the Limited embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention and upon a thorough analysis of the drawings, the disclosure, and the following claims.

In the claims, the words "comprise" and "with" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or unit may perform the functions of several of the units recited in the claims. The mere mention of some measures in several different dependent claims is not to be understood that a combination of these measures can not be used equally advantageous.

A computer program can be stored / distributed on a non-volatile medium, for example on an optical memory or on a semiconductor drive (SSD). A computer program may be distributed along with hardware and / or as part of a hardware, for example, via the Internet or via wired or wireless communication systems. Reference signs in the claims are not intended to be limiting.

LIST OF REFERENCE NUMBERS

10

system

12

infuser

14

material

16

material supply

18

measuring element

18a

displacement sensor

18b

weight sensor

20

control device

22

metering

24

Wetting device

26

material supply

28

material hopper

30

discharge rollers

31

floor tape

32

funding

34

tee roll

36

nozzle assembly

38

Material continuation

40

spray nozzle

42

Measuring interface

44

processor

46

Control interface

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2747966 B1 [0004]
• WO 2014079987 A1 [0004]
• WO 2014079988 A1 [0004]
• DE 102008059877 A1 [0004]

Claims (9)

Control device (20) for actuating a metering element (22) of a wetting device (24) for metering a binder in the course of producing material plates from spreadable material (14), comprising: - a measuring interface (42) for receiving a measured value with information for determining the material density of the spreadable material in a material inlet (16) of a feeding device (12) for a wetting device (24); a processor (44) for calculating the material density based on the at least one measured value and for determining a dosage value based on the material density; and - A control interface (46) for transmitting a control signal to the metering element (22) to control the metering element (22) for metering the binder according to the determined metering value. Control device (20) after Claim 1 , characterized in that the measuring interface (42) for receiving a height value from a, preferably tactile, displacement sensor (18a) for continuously determining a material height of the material (14) in the material inlet (16) is formed and that the processor (44) for calculating the material density is formed based on the material height. Control device (20) after Claim 1 or 2 characterized in that the measurement interface (42) is adapted for receiving a weight value from a weight sensor (18b), preferably a belt scale, for continuously determining weight information of the material (14) in the material feed (16) and the processor (44) for calculating the material density is formed based on the weight information. Control device (20) according to one of the preceding claims, characterized in that the processor (44) is designed to determine the dosing value based on a predefined for a desired value of the material density basic value. Control device (20) according to any one of the preceding claims, characterized in that the processor (44) for determining the Dosierwerts based on a variable coefficient, preferably for determining the Dosierwert as the sum of the base value and coefficient, is formed and the coefficient of a predefined Assignment to a deviation of the calculated material density results from the desired value. Control device (20) according to one of the preceding claims, characterized in that the processor (44) is designed to determine the Dosierwertes as a linear function between a minimum value as the lowest possible dosage and a maximum value as the highest possible dosage. Control device (20) according to one of the preceding claims, characterized in that the control interface (46) is designed for transmitting the control signal to a metering pump and the control signal comprises a rotational speed information of the metering pump and / or that the control interface (46) for transmitting the control signal controllable valves for spray nozzles (40) and / or a nozzle assembly (36) respectively the supply lines is formed and the control signal comprises a control information for the valves. Insertion device (12) for introducing a binder into a continuous material flow of spreadable material (14), comprising: - A material inlet (16) for supplying the spreadable material, wherein the material feed preferably comprises a conveyor belt; - A measuring element (18) for measuring a measured value with information for determining the material density of the scatterable material in the material feed, the measuring element preferably a displacement sensor (18a) for continuously determining a material height of the material and / or a weight sensor (18b) for continuously determining a weight information comprises; - A control device (20) according to one of the preceding claims; and - A metering element (22) for metering the binder in response to the control signal, wherein the metering element is preferably designed as a metering pump. System (10) for the continuous production of material plates, with an introduction device (12) according to Claim 8 and a wetting device (24) for wetting the spreadable material (14) with the binder.

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