Method for producing an engineered wood board and engineered wood board production installation

Abstract

A method for producing an engineered wood board. The method includes production of the substrate and application of a fluid to an application area of the substrate by means of an applicator, where the monitoring of the application occurs by means of an infra-red camera such that an inhomogeneity of the application can be detected.

Claims

1. A method for producing an engineered wood board, comprising: (a) production of a substrate; (b) application of a fluid onto an application area of the substrate by means of an applicator; and (c) monitoring of the application of the fluid onto the application area of the substrate by an infra-red camera such that an inhomogenity of the application of the fluid is recorded, wherein: the production of the substrate comprises a scattering of wood fibres coated in an adhesive that results in a pressed fibre mat; the fluid is applied to the fibre mat after the scattering; the fibre mat is pressed to form an engineered wood board following the application of the fluid; and the infrared camera automatically monitors the application of the fluid in a discharge area behind the application area of the fluid by monitoring a temporal temperature distribution at the application area that is caused by the application of the fluid to determine an inhomogeneity of the temperature in the discharge area.

2. The method according to claim 1, wherein the monitoring of the application occurs with the infra-red camera by recording the inhomogeneity of the application by means of the temperature change effected by the application of the fluid.

3. The method according to claim 1, wherein: (a) the pressed fibre mat is pressed to form an engineered wood board using a hot press following the application of the fluid.

4. The method according to claim 3, wherein the hot press is a heated belt press.

5. The method according to claim 1, wherein: the substrate has a substrate temperature in a material flow direction in front of the applicator; and the fluid has a fluid temperature during application that differs from the substrate temperature by at least 1 Kelvin.

6. The method according to claim 5, wherein the temperature is at least 5 Kelvin.

7. The method according to claim 1, further comprising: continuous automatic recording of an inhomogeneity parameter that describes an inhomogeneity in the application of the fluid; and emission of a signal if the inhomogeneity parameter deviates from a predetermined nominal value by more than a predetermined threshold value, or indication of the inhomogeneity parameter.

8. The method according to claim 7, wherein the inhomogeneity parameter describes an application area temperature difference within the application area.

9. The method according to claim 1, wherein the application involves spraying.

10. The method according to claim 9, wherein the spraying is an atomisation.

11. An engineered wood board production installation that is designed for producing an engineered wood board, comprising: (a) a substrate production installation for producing a substrate; (b) an applicator for applying a fluid to an application area of the substrate; and (c) an infra-red camera that is designed for automatic recording in a discharge area behind at least one part of the application area of the fluid such that an inhomogeneity of the application of the fluid can be recorded and the infrared camera monitors the application of the fluid by means of monitoring a change of temperature that is caused by the application of the fluid in the discharge area.

12. The engineered wood board production installation according to claim 11, wherein the applicator is designed to apply the fluid at a temperature that differs from a substrate temperature, which the substrate exhibits prior to the application, by at least 1 Kelvin.

13. The engineered wood board production installation according to claim 12, wherein the temperature is at least 5 Kelvin.

14. The engineered wood board production installation according to claim 11, wherein the infra-red camera is part of an inhomogeneity monitoring device, which is installed for: continuous automatic recording of an inhomogeneity parameter that describes an inhomogeneity in the application of synthetic resin, and automatic emission of a signal if the inhomogeneity parameter deviates from a nominal value by more than a predetermined threshold value.

15. The engineered wood board production installation according to claim 11, wherein the inhomogeneity of the application of the fluid monitored by the infrared camera is used to determine if the applicator is not working properly or a liquid tank containing the fluid is empty.

16. A method for producing an engineered wood board, comprising: (a) application of a fluid synthetic resin onto an application area of a substrate; (b) monitoring, in an area behind the application area, the application of the fluid synthetic resin by an infra-red camera which monitors a change of temperature that is caused by the application of the fluid synthetic resin; (c) determining an inhomogeneity of the temperature of the fluid synthetic resin in the area behind the application area, based on the monitoring; and (d) pressing the substrate into a fibre mat to form an engineered wood board, prior to the application of the fluid synthetic resin; wherein the application of the fluid synthetic resin is onto a moulding skin of the engineered wood board.

17. The method according to claim 16, wherein the fluid synthetic resin contains a melamine resin and/or a urea resin.

18. The method according to claim 16, wherein the substrate comprises a scattering of wood fibres coated in an adhesive that results in the pressed fibre mat and a fluid is applied to the fibre mat after the scattering.

19. The method according to claim 16, wherein the determining of the inhomogeneity of the application of the fluid synthetic resin is used to determine if an applicator is not working properly or a liquid tank containing the fluid synthetic resin is empty.

20. A method for producing an engineered wood board, comprising: (a) production of a substrate; (b) application of a fluid onto an application area of the substrate by means of an applicator; and (c) monitoring of the application of the fluid onto the application area of the substrate by an infra-red camera such that an inhomogenity of the application of the fluid is recorded, wherein: the application of the fluid is an application onto a moulding skin of the engineered wood board; the fluid is a fluid synthetic resin and contains a melamine resin and/or a urea resin; and the infrared camera automatically monitors the application of the fluid in a discharge area behind the application area of the fluid by monitoring a temporal temperature distribution at the application area that is caused by the application of the fluid to determine an inhomogeneity of the temperature in the discharge area.

21. The method according to claim 20, wherein the moulding skin is an unpolished moulding skin.

22. The method according to claim 20 further comprising: application of at least one paper layer impregnated with a synthetic resin on an upper side and/or a lower side of an engineered wood board, resulting in a paper-coated engineered wood board; and pressing of the paper-coated engineered wood board such that the synthetic resin fuses and the paper layer bonds with the engineered wood board, where the fluid is applied in the form of prior to the application of the paper layer.

23. The method according to claim 22, wherein the least one paper layer, is a decorative paper layer and the fluid is a fluid synthetic resin.

24. The method according to claim 20, wherein the application involves spraying.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In the following, the invention will be explained in more detail in the attached drawings. They show

(2) FIG. 1 a diagram of an engineered wood board production installation according to the invention for conducting a method according to the invention for producing an engineered wood board,

(3) FIG. 2 a detailed schematic view of the engineered wood board production installation according to FIG. 1 and

(4) FIG. 3 an image of the engineered wood board production installation according to FIG. 2 that has been recorded by the infra-red camera of the engineered wood board production installation according to FIG. 1.

DETAILED DESCRIPTION

(5) FIG. 1 schematically depicts an engineered wood board production installation 10 that comprises a substrate production installation 12 and an applicator 14 for applying a fluid 16 to a substrate 18. At this point the substrate 18 is a pressed fibre mat and is produced by the substrate production installation 12 by scattering wood fibres that have been coated in an adhesive onto a conveyor 20.

(6) The engineered wood board production installation 10 comprises an infra-red camera 22 in whose field of vision 23 an application area 24 lies. The application area 24 is the area of the substrate 18 that is moistened with fluid 16. A press 26 is arranged in a material flow direction behind the applicator, which presses the pressed fibre mat 18 to form an engineered wood board 27. The press 26 is a double belt press having two belts made from stainless steel that are

(7) A cutting device may be provided behind the press 26 in the material flow direction M that cuts the resulting engineered wood board 27 and arranges it in a layer. These devices are not depicted in FIG. 1. This results in the production of engineered wood boards with a temporally and spatially consistent quality.

(8) It is possible, but not necessary, for the engineered wood board 27 to be processed further to form a floorboard 29. The corresponding method according to the invention is explained in the following. The substrate 18, now in the form of the engineered wood board 27, is also moistened with a second fluid 16.2 in the form of a fluid synthetic resin by a second applicator 14.2. This application of the fluid 16.2 is recorded by a second infra-red camera 22.2.

(9) A paper-layering device 28 is arranged behind the second applicator 14.2 in the material flow direction, this device placing a paper layer at least on top of the engineered wood board 27. A second press 30, which may be a high-speed press, arranged behind this device presses the paper layer together with the engineered wood board 27. In an optional downstream trimming system 32, a connection profile, such as a slot and/or a key, is inserted into the edge area of the engineered wood board 27, which results in a floorboard.

(10) FIG. 2 shows a detailed schematic view of the engineered wood board production installation 10. It should be recognised that the applicator 14 comprises a fluid container 34, a pump 36 for pumping a mixture of the fluid 16 and air, and a number of nozzles 38.1, 38.2, . . . , 38.8. The nozzles 38.i (i=1, 2, . . . ) generate a vapour 40 that condenses on the substrate 18 and thereby moistens it. The fluid 16 here refers to water that contains surfactants. If the substrate 18 passes through the press 26, the water evaporates.

(11) The fluid 16 is at a fluid temperature T.sub.16 that differs from a substrate temperature T.sub.42 in a preliminary area 42, the preliminary area 42 being situated in front of the application area 24 in the material flow direction M. By applying the fluid 16, the temperature of a surface piece of the substrate 18 decreases, which is recorded by the infra-red camera 22.

(12) FIG. 3 shows an image B that was recorded by the infra-red camera 22. It should be noted that the preliminary area 42 is warmer than the application area 24. The infra-red camera 22 (see FIG. 2) continually records this type of image B, for example five images or more per second. A measurement area A is determined within the application area 24. The infra-red camera 22 is part of an inhomogeneity monitoring device 44, which also comprises an evaluation unit 46. The evaluation unit 46 is designed to automatically determine an inhomogeneity parameter P, which may be calculated in the way defined in the following.

(13) The temperature of every pixel in the image B that lies within the measurement area A is determined. The average temperature in the extreme quantiles in then determined, for example in the first decile (T1:10) and the tenth decile (T10:10). If the temperature difference T=T1:10T10:10 of these two temperatures deviates from a nominal value, for example S=0 Kelvin by more than a predetermined threshold value F, a warning signal is emitted.

(14) This warning signal may be an acoustic and/or visual signal that signalises to an operator of the engineered wood board production installation 10 that there is a possible malfunction. Alternatively or additionally, the engineered wood board production installation 10 may comprise a redundant auxiliary applicator 48 that is depicted by a dotted line in FIG. 2. If the inhomogeneity parameter P deviates too much from the nominal value S, the engineered wood board production installation 10 automatically converts to the auxiliary applicator 48 so that the applicator 14 can be repaired and/or cleaned.

(15) FIG. 1 shows that the engineered wood board production installation 10 may comprise a back-up applicator 15 that may be located in material flow direction M behind or in front of the applicator 14. The applicator 14 and/or the back-up applicator 15 may be mounted in a moveable way in order to be moved from an application position into a maintenance position. In FIG. 1, the back-up applicator 15 is shown in its maintenance position and the applicator 14 is in its application position. For example, the applicator 14 and/or the back-up applicator 15 may be swivel-mounted so that it can be pivoted from its application position into its maintenance position and vice versa.

(16) It is possible to determine with the infra-red camera 22 if one or more of the nozzles 38 (cf. FIG. 2) is not working properly and/or if, for example, a liquid tank containing the fluid 16 is empty. If one of the nozzles 38 of the applicator 14 is not working properly, e.g. because it is blocked, the applicator may be shut off an the back-up applicator 15 used to apply the fluid 16. The applicator is then moved into its maintenance position and is repaired. After repair, it is moved back into its application position. Alternatively or in addition, there may be a back-up applicator for the second applicator 14.2.

(17) It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.