Wood composite board production method and wood composite board production equipment

Abstract

This invention relates to a method for producing wood composite panels, the method comprising the following steps: producing a raw wood composite panel having a first side surface, a second side surface extending parallel to the first side surface, and an edge surface connecting the side surfaces to each other; applying a liquid containing a flame retardant to at least the first side surface; applying a negative pressure to the second side surface to draw the liquid containing the flame retardant into the edge region of the raw wood composite panel; and / or applying a positive pressure to the first side surface to force the liquid containing the flame retardant into the edge region of the raw wood composite panel, thereby producing the wood composite panel.

Description

Technical Field

[0001] The present invention relates to a method for producing wood-based panels. According to a second aspect, the present invention relates to a wood-based panel production apparatus comprising: (a) a press, particularly a strip press, for pressing at least one primary product layer to produce raw wood-based panels; (b) a liquid application device for applying liquid to the raw wood-based panels; and (c) a suction device designed to apply negative pressure to the side surface of the wood-based panels. Background Technology

[0002] This method and the apparatus for producing wood-based panels are known and used to produce wood-based panels. In order to use renewable raw materials such as wood as building materials, they are typically required to be flame-retardant.

[0003] The production of flame-retardant wood panels has been known for decades. In this process, the primary product, such as sawdust, wood fibers, or coarse chips, is treated with a liquid containing a flame retardant before the production of a primary product layer made from the primary product itself. This is achieved by spraying the primary product into a mixer, coil, or blowpipe. The primary product is then dispersed onto a belt, thus forming at least one primary product layer. The primary product layer is subsequently pressed to form the wood panel.

[0004] The disadvantage of this method is that it produces a relatively large amount of waste because the flame retardant content of the wood panels is usually not high enough, especially at the beginning of production.

[0005] EP3388213A2 describes a method for producing flame-retardant and / or cured wood fiber panels. First, cut wood fiber panels are arranged on a processing apparatus. Then, a flame retardant and / or curing agent is applied to the upper side of the wood fiber panel. The applied agents are drawn into or forced into the wood fiber panel by applying negative pressure downwards and / or by applying overpressure upwards.

[0006] EP3127670A2 discloses a method for impregnating wood fiber panels, wherein the material board is placed as annular wood chips on a transport device. The wood chips are continuously guided through an impregnation station for introducing an impregnating agent into the wood fiber panel from above. The impregnating agent is applied by means of a plurality of application devices arranged in at least one row across the entire width of a single material panel or a continuous series of material panel wood chips, and can be individually controlled in a time-controlled manner during the continuous transport of the individual or continuous material panel wood chips. The impregnated material panel exhibits impregnation only at the desired points to obtain the desired useful properties.

[0007] EP2168738A1 describes a method for producing wood fiber panels, the method comprising the steps of: pressing fiber fluff to produce raw wood fiber panels, applying an aqueous liquid to at least an upper portion of the raw wood fiber panels, and applying negative pressure to at least a lower portion by means of a suction table, such that the aqueous liquid is drawn in and / or passes through the raw wood fiber panels. Summary of the Invention

[0008] The purpose of this invention is to improve the production of flame-retardant wood-based panels.

[0009] The present invention solves the aforementioned problem by a method for producing wood-based panels, the method comprising the steps of: (a) producing raw wood-based panels, particularly by pressing a primary product containing wood, the raw wood-based panels comprising a first side surface and a second side surface extending parallel to the first side surface; (b) applying a liquid containing a flame retardant to at least the first side surface; and (c) applying a negative pressure to the second side surface such that the liquid containing the flame retardant is drawn into the raw wood fiber panel, particularly into the peripheral region, and / or applying a negative pressure to the first side surface such that the liquid containing the flame retardant is forced into the peripheral region of the raw wood-based panel, thereby producing the wood-based panel.

[0010] The present invention also solves the aforementioned problem by means of a wood panel production apparatus according to the foregoing, wherein the liquid contains a flame retardant, and wherein the suction device is designed to automatically apply negative pressure and maintain such suction time that the liquid containing the flame retardant is drawn into the peripheral area of ​​the original wood panel but does not penetrate the original wood panel, and / or has a pressure application device for applying overpressure to a first side surface so that the liquid containing the flame retardant is forced into the peripheral area of ​​the original wood panel.

[0011] According to a third aspect, the present invention solves the aforementioned problem by using wood paneling with a concentration gradient of flame retardant, particularly a continuous gradient, wherein the flame retardant concentration decreases with increasing distance from the surface to the center of the wood paneling. It is advantageous if the wood paneling is flame retardant according to specification standard DIN EN 13501-1:2010 and testing standard DIN EN 13823:2015. It is also advantageous if the wood paneling is Class B (particularly B-s1 or B-s1 d0) or Class C (particularly C-s1, C-s1 d0) or Class B... fl Class (especially B) fl -s1 or B fl -s1 d0) or C fl Classes (especially C) fl -s1、C fl-s1 D0) or B1, B2 or B3 type wood panels are particularly beneficial.

[0012] By introducing flame retardants into wood-based panels after pressing using a liquid containing the flame retardant, the amount of flame retardant in the panel can typically be controlled with high process reliability. This reduces waste compared to existing methods.

[0013] Another advantage of this invention is that it generally reduces the consumption of flame retardants. In known methods of manufacturing flame-retardant wood panels, flame retardants are lost when the primary product is sprayed and during subsequent transportation of the sprayed primary product. Flame retardant losses exceeding 20% ​​frequently occur.

[0014] This is especially true in cases where the wood panels are not made from defined surface and intermediate layers, and are also manufactured separately. In such cases, all the wood used to manufacture the panels must be treated with flame retardants. Given that the surface layer typically accounts for 30% to 40% of the wood panel, 60% to 70% of the flame retardant is wasted. This is particularly true for MDF and HDF panels.

[0015] Another advantage is that the introduction of flame retardants typically does not lead to an increase in the moisture content of the pulverized primary product. Increased moisture content can cause so-called steam cracking in the press, which is undesirable. Steam cracking is the area in which wood panels crack due to moisture evaporation.

[0016] Furthermore, when flame retardants are introduced, it is generally not necessary to increase the proportion of adhesive, i.e., the proportion of bonding agent and / or binder on the primary product layer. Many adhesives, such as polymethylene diphenyl diisocyanate, react with certain flame retardants. Therefore, in the methods according to the prior art, when using flame retardants, more adhesive is required compared to manufacturing wood panels without flame retardants. This disadvantage is generally eliminated in the production process according to the invention.

[0017] Furthermore, it is advantageous that, unlike methods according to the prior art, it is generally not necessary to reduce the pressing speed. In the prior art, the moisture content of the primary product layer often increases due to the introduction of the flame retardant into the liquid before pressing. To prevent vapor cracking, it is usually necessary to reduce the pressing speed and / or the pressing temperature. This can be eliminated in the method according to the invention.

[0018] Furthermore, the method according to the invention can be carried out at least substantially unrestricted by the production time and location of the raw wood panels. Therefore, previously produced non-flame-retardant raw wood panels can be made flame-retardant at a later point in time. Specifically, a flame retardant is applied to the previously pressed raw wood panels. Thus, according to a preferred embodiment of the invention, it is possible and provided to store and / or move the raw wood panels after pressing for a considerable period, particularly at least one minute, and particularly at least 10 minutes, before applying the flame-retardant liquid. For example, the raw wood panels can be stored in a star cooler. This allows for flexible production of flame-retardant wood panels, especially in small batches. However, the liquid application device can also be arranged close to the press and is included in the invention. Preferably, the distance between the liquid application device and the press is at most 100 m or at most 50 m, particularly at most 30 m.

[0019] Within the scope of this specification, virgin wood panel specifically refers to a panel made of wood material, which can be processed to produce a wood panel by introducing flame retardants.

[0020] The application of liquid is specifically understood to mean bringing the liquid into contact with the first side surface. Preferably, a liquid film is formed on the side surface during this process.

[0021] The peripheral region refers to the area of ​​the original wood panel that is confined on one side by the side surface and does not extend to the center of the wood panel on the other side. The characteristic of liquid being drawn into the peripheral region is specifically understood to mean that liquid can, but is not required to, be exclusively drawn into the peripheral region.

[0022] Applying liquid to a raw wood panel is specifically understood to mean that the liquid comes into contact with the top of the raw wood panel. The liquid can come into contact with the raw wood panel from above or below.

[0023] According to a preferred embodiment, the liquid application device is designed and / or arranged to apply liquid from below to the original wood material panel.

[0024] In this case, it is beneficial if the suction device is arranged to automatically apply negative pressure from above.

[0025] Raw wood-based panels include, for example, medium-density fiberboard (MDF panels), high-density fiberboard (HDF panels), oriented strand board (OSB panels), wood chip laminate, plywood, soft fiberboard, hard fiberboard, bent plywood, multi-layer board, core board, laminated plywood, low-density fiberboard (LDF panels), or partition boards.

[0026] The thickness of the wood panel is preferably at least 6 mm, particularly at least 10 mm, especially preferably at least 15 mm, and particularly preferably at least 20 mm. Alternatively or additionally, the thickness of the wood panel is preferably at most 50 mm, particularly at most 30 mm, particularly preferably at most 28 mm, and preferably at most 25 mm.

[0027] The liquid containing the flame retardant contains the flame retardant. The liquid is preferably an aqueous liquid. It is advantageous if the flame retardant contains phosphorus. The flame retardant may contain organic and / or inorganic phosphorus compounds, such as phosphates, polyphosphates, phosphonates, and / or guanidine salts. The flame retardant may have a base of melamine or melamine derivatives, aluminum hydroxide, or basic sulfates. However, it is preferred if the boron content of the flame retardant is at most 1% by weight. The flame retardant preferably contains ammonia.

[0028] The produced wood-based panels are preferably flame-retardant according to DIN EN 13501-1:2010. In particular, the produced wood-based panels have the characteristics of wood-based panels according to the present invention.

[0029] If the original density of the raw wood panel and / or the raw density of the wood panel is at least 550 kg / cm³ 3 Especially at least 600 kg / cm 3 This is beneficial. The original density of the raw wood panel and / or wood panel is preferably at most 1000 kg / cm³. 3 Especially up to 800 kg / cm 3 However, if the original density of the raw wood panel is less than 350 kg / cm³... 3 For example, below 300 kg / cm 3 This can also be beneficial. This is especially true when the original wood panel is an insulated panel.

[0030] The application of liquids containing flame retardants and / or the application of negative pressure can be performed on both moving and stationary raw wood panels.

[0031] Preferably, overpressure is applied locally and a liquid containing a flame retardant is introduced into the overpressured area. Local application of overpressure is understood to mean that the overpressure is not applied to the entire surface of the wood panel. For example, the surface to which overpressure is applied is less than half the entire surface of the wood panel.

[0032] Preferably, the applicator is pressed against the original wood panel, forming an inlet chamber between the applicator and the original wood panel, the inlet chamber being sealed by the applicator's seal. In this way, leakage of the pressurized fluid is reduced, by means of which pressure accumulates in the inlet chamber.

[0033] The applicator is preferably part of a liquid application device.

[0034] To maintain a seal, the applicator is pressed against the original wood panel. This is preferably done from below. Alternatively, the applicator is pressed against the original wood panel from above.

[0035] Preferably, a liquid containing a flame retardant is pressurized or introduced into the inlet chamber. It is advantageous if, during pressing, the liquid containing the flame retardant fills at least half, but preferably at least 75%, of the volume of the inlet chamber. This keeps the gas volume in the inlet chamber relatively small, and allows for rapid increase and decrease of the inlet pressure used for the pressing process. Once the liquid containing the flame retardant has been pressurized into the inlet chamber and thus into the original wood panel, the inlet pressure is reduced, particularly to ambient pressure.

[0036] Preferably, after the inlet pressure has been reduced, the applicator is moved relative to the original wood panel. The applicator is then pressed back against the original wood panel, and more liquid containing the flame retardant is forced into the inlet chamber. The inlet pressure is then reduced and the steps are repeated until the original wood panel has flame retardant on all designated surfaces.

[0037] To facilitate the introduction of the flame-retardant-containing liquid into the raw wood panel, negative pressure is preferably applied to the raw wood panel from above, but alternatively from below. This is preferably done in an area where overpressure is applied from the other side of the raw wood panel. In other words, negative pressure is applied to the side surface, which corresponds to the pressure surface where the flame-retardant-containing liquid is forced in. The application of negative pressure is achieved by a suction device.

[0038] While the liquid containing the flame retardant is being injected, the applicator can move relative to the original wood panel, but this is not necessary. Alternatively, the original wood panel and the applicator can move simultaneously, so that the applicator remains stationary relative to the original wood panel but moves in space.

[0039] The suction device preferably has a suction cup that can be automatically positioned at a preset point. The suction device is preferably designed such that the suction cup is always arranged opposite the applicator. For this purpose, the suction cup's actuator (which may be called a positioning actuator) is controlled by the control unit of the wood panel production apparatus.

[0040] A suction cup is a component that forms a sealed cavity when placed on a raw wood panel, through which a negative pressure can be applied. The walls of the suction cup may, but are not required to, be elastic, especially entropically elastic; however, they may also be rigid. The suction cup preferably has a seal by which it abuts against the wood panel.

[0041] Preferably, a negative pressure is applied such that the internal concentration of the flame retardant at the inner fifth of the thickness in the thickness direction from the first side surface to the second side surface of the wood material panel is at most 0.8 times the external concentration at the first outermost fifth of the thickness extending to the first side surface. It is advantageous if the internal concentration is at most 0.7 times, particularly at most 0.6 times, preferably at most 0.5 times, especially preferably at most 0.4 times, especially at most 0.3 times, especially preferably at most 0.2 times, for example at most 0.1 times, of the external concentration.

[0042] To determine the internal concentration of the flame retardant, a 5cm × 5cm cube was cut from the wood panel, with the base region extending parallel to the first side surface. Subsequently, slices were cut from both sides parallel to the side surfaces, each slice being 0.2 times the thickness of the wood panel. The mass of the flame retardant in the sample obtained in this manner was determined and divided by the total mass of the sample. This provides the internal concentration.

[0043] The external concentration was obtained by analyzing the material of a slice with a thickness 0.2 times that of the wood panel, with the side of the slice being the first side surface.

[0044] If the wood-based panel is oriented strand board (OSB), the concentration of flame retardant in at least one surface layer is at least 65%, preferably at least 50%, and particularly at least 100% higher than the concentration of flame retardant in the intermediate layer. The intermediate layer is disposed between the two surface layers. The surface layer is formed from a primary product layer that is separately distributed from another layer, and the intermediate layer is generated from said other layer during the pressing process.

[0045] It is advantageous if the liquid is applied in such a manner that at least 80%, particularly at least 90%, of the peripheral area of ​​the side surface of the wood panel contains the flame retardant. In other words, at most 10% of the peripheral area of ​​the wood panel is free of flame retardant. This reduces the number of panels that must be discarded due to insufficient flame retardant.

[0046] Specifically, flame retardants are also introduced into the outer perimeter of the wood panel. The outer perimeter includes all points within the wood panel that are at most 10 cm from the edge of the wood panel.

[0047] Liquids can be applied by spraying, rinsing, brushing, rolling, pouring, or other methods. Spraying can be accomplished, for example, by means of overpressure, in which the liquid is forced through a nozzle. Alternatively, spraying can be accomplished by atomization. Specifically, the liquid can be applied to a moving, particularly rotating or vibrating, body to form droplets.

[0048] It is advantageous if the concentration of the flame retardant in the liquid corresponds to at least half, particularly at least 65%, of the flame retardant's solubility. At the temperature at which the liquid impacts the virgin wood panel, the flame retardant has a solubility that can be measured, for example, in grams per liter. This solubility is the maximum mass of the flame retardant per unit volume of liquid solution. The concentration of the flame retardant in the liquid is at least half of this solubility. Therefore, only a small amount of liquid needs to be applied to the virgin wood panel. In other words, the quotient of the actual concentration of the flame retardant according to DIN 1310 to its solubility is at least 0.5, particularly at least 0.65, and preferably at least 0.75.

[0049] Preferably, the concentration of the flame retardant in the liquid is at least 30% by weight, particularly at least 40% by weight, and preferably at least 50% by weight.

[0050] The liquid is preferably a solution, especially an aqueous solution, or a suspension, especially an aqueous solution.

[0051] The liquid preferably contains at least one colorant. The colorant is preferably selected such that the flame retardant content can be determined by the color of the cross-section of the wood panel, particularly in a time-resolved manner.

[0052] For example, the colorant is a fluorescent colorant, so the amount of flame retardant can be determined by irradiating a cross-section of a wood panel with excitation light and measuring the intensity of the resulting fluorescent radiation at a time resolution. This makes quality control particularly easy.

[0053] Preferably, the liquid temperature when applied to the side surface is at least 40°C, particularly at least 50°C, and especially preferably at least 60°C. The solubility of flame retardants generally increases at higher temperatures. Therefore, higher temperatures mean less liquid is required to apply a given amount of flame retardant. Temperatures below 100°C, particularly below 90°C, are advantageous.

[0054] According to a preferred embodiment, during the application of the liquid, the surface temperature of the first side surface is at least 30°C, particularly at least 40°C. Alternatively or additionally, the surface temperature is preferably at most 65°C, particularly at most 50°C. It is advantageous if the surface temperature is at most 20°C, particularly 10°C, lower than the liquid temperature. The surface temperature is preferably at least as high as the liquid temperature. In this case, the flame retardant will not precipitate from the liquid and the flame retardant can be absorbed into the peripheral area.

[0055] At the point where the liquid containing the flame retardant is applied, the surface temperature of the first side surface is preferably lower than the liquid temperature. For example, the difference between the surface temperature and the liquid temperature is preferably at least 5 Kelvin, and particularly at least 10 Kelvin. Flame retardants are generally not very soluble in solvents, especially in water. However, solubility increases with increasing temperature. To introduce as little water as possible into the virgin wood panel, the temperature of the liquid containing the flame retardant is chosen to be higher than the surface temperature. After penetrating into the virgin wood panel...

[0056] Introducing a flame retardant into the original wood panel is particularly effective when the concentration of the flame retardant in the liquid is higher than the saturation concentration of the flame retardant in the liquid at the surface temperature of the first side surface where the liquid containing the flame retardant is applied. In this case, shortly after the liquid containing the flame retardant comes into contact with the original wood panel, the flame retardant precipitates out of the solution, resulting in a particularly high concentration of the flame retardant in the outer area of ​​the original wood panel.

[0057] The application rate of the liquid over a specific area is preferably at least 0.3 kg / cm². 2 and / or up to 5 kg / cm 2 .

[0058] It is advantageous if the amount of liquid applied, measured in liters per square meter, over a specific area is chosen such that, after the liquid has been absorbed into the peripheral areas, the surface moisture content of the wood panel deviates from the core moisture content by at most 30%. When at least one primary product is pressed to form the virgin wood panel, the virgin wood panel loses moisture in the peripheral areas due to evaporation. This results in an undesirable moisture gradient within the virgin wood panel. By applying a liquid containing a flame retardant, the moisture loss in the peripheral areas can be at least partially offset. Therefore, post-treatments that would otherwise be necessary, such as those in a climate chamber, can often be omitted.

[0059] The negative pressure is preferably at least 100 hPa, particularly at least 150 hPa, preferably at least 200 hPa, and especially preferably at least 300 hPa. This should be understood to mean that the pressure deviates from the ambient pressure by at least 300 hPa. If the negative pressure is at least 400 hPa, it is advantageous. For example, the pressure is at least 50 hPa and / or at most 700 hPa.

[0060] According to a preferred embodiment, the method includes the following steps: (a) rotating the original wood panel after the liquid has been drawn into the peripheral area of ​​the first side surface; (b) applying the liquid to the second side surface; and (c) applying negative pressure to the first side surface such that the liquid is drawn into the peripheral area of ​​the second side surface of the original wood panel, thereby obtaining the wood panel. In other words, the treatment with a solution containing a flame retardant is performed from both sides.

[0061] It is advantageous if the method includes the steps of (a) spreading a first surface debris layer, (b) spreading at least one intermediate debris layer on top of the first surface debris layer, (c) spreading a second surface debris layer on the intermediate debris layer, and (d) pressing the layers to form a raw wood panel, the raw wood panel comprising a first surface layer produced by the first surface debris layer, an intermediate layer produced by the intermediate debris layer, and a second surface layer produced by the second surface debris layer.

[0062] The method preferably includes step (d1) applying a liquid containing a flame retardant at a specific area application amount corresponding to at least 10% by weight of a specific area mass of the first surface layer.

[0063] Alternatively or additionally, the method preferably includes step (d2) applying a liquid containing a flame retardant at a specific area application amount corresponding to at least 10% by weight of a specific area mass of the surface layer. This has been shown to typically produce flame-retardant wood panels.

[0064] It is advantageous if the first and / or second surface debris layers are made of coarse debris. Alternatively or additionally, at least one surface debris layer may be made of fine debris.

[0065] Alternatively or additionally, the intermediate cinder layer is made of coarse cinders. However, the first and / or second surface cinder layers do not need to be made of coarse cinders; they can be made of other primary products containing wood. The same applies to the intermediate cinder layer.

[0066] Preferably, the coarse chips do not contain flame retardants or contain such a low concentration of flame retardants that the proportion of flame retardants introduced into the wood panel via the coarse chips corresponds to at most 50% by weight, particularly at most 30% by weight, and preferably at most 10% by weight of the total flame retardants contained in the wood panel.

[0067] The wood panel production apparatus according to the invention preferably includes a pressure application device for applying overpressure to a pressure surface. The pressure surface is a surface capable of withstanding overpressure by means of the pressure application device. The pressure surface preferably, but not necessarily, constitutes at most 50% of the surface of the wood panel.

[0068] The wood panel production apparatus preferably includes a control unit configured to control components of the wood panel production apparatus to automatically execute the method described above.

[0069] The wood panel production apparatus preferably has an applicator with a seal. The applicator is designed to press against the raw wood panel, thereby forming an inlet chamber between the applicator and the raw wood panel, the chamber being sealed by the seal.

[0070] Preferably, the applicator has an actuator, such as a hydraulic cylinder, pneumatic cylinder, or electric actuator, for pressing the applicator against the raw wood panel. The wood panel production apparatus may have a positioning device, such as a robot, for positioning the applicator.

[0071] In the case of the wood-based panel according to the invention, the internal concentration of the flame retardant in the inner thickness quintile of the thickness extension from the first side surface to the second side surface is at most 0.8 times, particularly at most 0.6 times, particularly preferably at most half, particularly at most 0.4 times, preferably at most 0.3 times, and particularly preferably at most 0.1 times, the external concentration in the first outer thickness quintile extending to the first side surface. In other words, the internal concentration of the flame retardant is significantly lower than the concentration of the flame retardant in the peripheral region adjacent to the side surface. The flame retardant has proven to be particularly effective in this respect.

[0072] It is advantageous if the concentration of the flame retardant in the second decimal place of the thickness extension is at least 0.1 times that in the first decimal place of the outermost thickness. In other words, flame retardant is introduced not only in the outermost decimal place but also further into the interior of the original wood panel.

[0073] If the wood-based panel is a coarse wood chip laminate, as contemplated according to the preferred embodiment, it is preferably a fire-resistant building panel. In particular, this coarse wood chip laminate (i.e., oriented strand board, OSB) is designed for installation within buildings. If the wood-based material according to the invention is an HDF panel, it can be used, for example, as flooring, wall, or ceiling cladding.

[0074] The wood-based panels in the form of MDF panels according to the present invention are suitable for use as, for example, door panels or furniture panels.

[0075] The invention also includes an isolation element, such as an exterior wall isolation element, having at least one layer composed of a wooden panel according to the invention. Attached Figure Description

[0076] The invention will be explained in more detail below with the aid of the accompanying drawings. The drawings show:

[0077] Figure 1 A schematic diagram of a wood panel production apparatus according to the present invention, the apparatus being used to perform a method according to the present invention for producing a wood panel according to the present invention;

[0078] Figure 2 according to Figure 1 A schematic cross-sectional view of the suction device in a wood panel production apparatus;

[0079] Figure 3 In local Figure 3 a, Figure 3 b and Figure 3 Each of c depicts a schematic cross-section through a wooden panel produced according to the invention;

[0080] Figure 4 A cross-section of the wood panel production apparatus according to the present invention, based on the second embodiment;

[0081] Figure 5 according to Figure 4 A schematic diagram of two applicators in a wood panel production apparatus; and

[0082] Figure 6 in detail Figure 6a and Figure 6b The image depicts two views of a portion of a wood material production apparatus according to a third embodiment, and in detail... Figure 6c The image depicts a portion of a wood material production apparatus according to a third embodiment. Detailed Implementation

[0083] Figure 1 A wood panel production apparatus 10 is schematically depicted, comprising a press 12 in the form of a continuous tape press for pressing at least one primary product layer 14 (in this case, three primary product layers 14i) to form a raw wood panel 16. The at least one primary product layer 14 is produced by a distributing device 18.

[0084] In the present case, the dispensing device 18 includes a first dispenser 20.1 for dispensing a first primary product layer 14.1 in the form of a first surface debris layer, a second dispenser 20.2 for dispensing a second primary product layer 14.2 in the form of an intermediate debris layer, and a third dispenser 20.3 for dispensing a third primary product layer 14.3 in the form of a second surface debris layer.

[0085] After being pressed by the press 12, the resulting wood material panel 16 has a first surface layer 22.1, an intermediate layer 22.2, and a second surface layer 22.3.

[0086] The press 12 is heated, for example, by means of a hot fluid 24 flowing in heating tubes 26.1, 26.2, ... The heat of the hot fluid 24 is transferred to a circulating pressing belt 28, which is pressed onto the primary product layer 14.i by means of pressure rollers 30.1, 30.2, ...

[0087] The liquid application device 32 is arranged downstream of the press 12 in the direction of the material flow M, by means of which the flame retardant liquid 34 can be applied to the first side surface S1 of the original wood material panel 16.

[0088] In addition, the suction device 36 is arranged downstream of the press 12 in the direction of the material flow M, and the liquid 34 that has been applied to the first side surface S1 is sucked into the original wood material panel 16 by means of the suction device.

[0089] The liquid application device 32 includes a reservoir 38 and a pump 40, by means of which liquid 34 is applied at a liquid pressure p. 34 It is directed to at least one nozzle 41. Nozzle 41 produces a spray 42 that falls onto the first side surface S1. Nozzle 41 may be part of a nozzle rod 43 comprising three or more nozzles.

[0090] The liquid application device 32 may include a temperature control device 43 that maintains the liquid 34 at a given temperature T. 34 .

[0091] Figure 2 An enlarged view of the suction device 36 is shown, which includes a vacuum stage 37 with a circumferential seal 44, by means of which the second side surface S2 is sealed onto the suction chamber 46. The suction device 36 has supports 48.j (j = 1, 2, ...) that support the original wooden panel 16.

[0092] The suction chamber 46 is connected to the vacuum pump 52 via a vacuum line 49. Preferably, an energy level less than p is applied to the suction chamber. 46 =500 hPa pressure p 46 Therefore, liquid 34 is drawn into the first peripheral region 50.1 of the original wood panel. During a given suction time t... saug Afterwards, the suction chamber is ventilated, the original wooden panel 16 rotates, and the pressure is p. 46 It is reapplied to the suction chamber, and liquid 34 is applied to the second side surface. During a given suction time t... saug Afterwards, the suction chamber was ventilated again.

[0093] Alternatively, or in addition to nozzle 41, liquid application device 32 may include application roller 53 or another device for applying liquid 34 to first side surface S1.

[0094] Figure 3 a schematic diagram shows a cross section through a wooden panel 54 according to the invention, having a first edge surface K1 and a second edge surface K2.

[0095] Figure 3 b shows the concentration of flame retardant in wood panel 54. c F,54 The concentration varies with the distance z from the nearest side surface. Notably, the concentration is highest on the surface. As the distance z from the first side surface S1 of the wood panel 54 increases, the concentration decreases until the center of the wood panel 54.

[0096] Within the internal thickness quintile Q3, the wood panel 54 has an internal concentration c of flame retardant. F,Q3 In the first outermost thickness quintile Q1, the wood panel 54 has a first external concentration c of flame retardant. F,Q1 In the second outermost thickness quintile Q5, the wood material panel 54 has a second outer concentration c. F,Q5 .

[0097] It should be noted that the external concentration is significantly higher than the internal concentration. In this case, the following applies: c F,Q3 =0.25 . c F,Q1 .

[0098] Figure 3 c describes the division into tenths. It should be noted that c represents the second tenths concentration of the flame retardant in the second tenths of thickness extension (which is immediately adjacent to the first outermost tenths in the central direction of thickness extension). F,D2 The concentration c of the first decimal place of the first outermost layer thickness F,D1 At least 0.1 times.

[0099] Figure 4 A liquid application device 32 of a wood panel production apparatus 10 according to the present invention is shown. The liquid application device includes a pressure application device 56, which, by means of a pump 40, introduces a liquid 34 containing a flame retardant from a reservoir 38 to an introduction pressure p. e The liquid 34 containing the flame retardant is introduced into the lower inlet chamber 58. The inlet chamber 58 is limited by the seal 60 of the pressure application device. The pressure application device 56 can be designed to apply the liquid 34 containing the flame retardant from below or above.

[0100] Negative pressure can be applied to the original wooden panel 16 via vacuum line 49 using vacuum pump 52 of suction device 36. For example, the pressure p inside suction chamber 46 46 For at most p 46 = 700 hPa. This corresponds to a negative pressure of at least 300 hPa.

[0101] Figure 5 The illustration schematically shows that the suction device 36 can be configured to apply a localized negative pressure. In this case, the suction surface F sThe surface is smaller than the original wood panel by 16. In this case, the suction surface F s It is less than one-tenth the size of the original wood panel 16.

[0102] The wood panel production apparatus may also include a second suction device 36', which is preferably structurally identical to the first suction device 36.

[0103] The pressure applying device 56 applies an introduction pressure p to it. e Pressure surface F D To a large extent, it corresponds to the suction surface F S That is, having, for example, a deviation of up to 2 times, particularly a deviation of up to 1.1 times, particularly a deviation of up to 1.25.

[0104] Figure 6a A positioning device 62, such as a robot, is shown for positioning the applicator 64 and for pressing the applicator 64 against the original wood panel 16. For this purpose, the positioning device 62 has, for example, an arm 66. The arm 66 may include two or more sub-arms 68.1, 68.2, which may be hinged together. With the aid of a actuator 70, the applicator 64 can be automatically positioned relative to the original wood panel 16, wherein the position can be preset.

[0105] The applicator 64 supplies pressurized liquid 34 via flexible conduit 72, which is sprayed onto the original wood panel 16 and / or pressed into the original wood panel 16 under pressure.

[0106] Without regard to other features specified in this embodiment, the wood material production apparatus 10 may include a suction device 36 having a suction cup 74 that can be positioned at a given point. The suction device 36 is designed such that the suction cup 74 is always positioned opposite the applicator 64. For this purpose, the actuator 70 is controlled by the control unit 76 of the wood material panel production apparatus. The suction cup 74 is connected to the vacuum pump 52 by means of a flexible vacuum line.

[0107] Figure 6c Another embodiment of the pressure application device 56 is depicted, wherein a liquid 34 containing a flame retardant is introduced into an inlet chamber 58 through a nozzle 78. The inlet pressure p e The pressure source 80 can be used to set the pressure, which is connected to the inlet chamber 58 via a pressure line 82.

[0108] When overpressure and / or negative pressure is applied, the applicator 64 can be moved, and the suction cup 74 can be moved if necessary. Alternatively, before moving the applicator and / or suction cup, the pressure in the suction chamber and / or the introduced pressure is close to, and particularly very close to, ambient pressure.

[0109] Example 1:

[0110] An unsanded raw wood panel 16, in the form of an OSB panel with a thickness d = 20 mm, is placed on a vacuum stage 37. The raw wood panel 16, produced by using 1% more PMDI binder (PMDI: polymeric methylene diphenyl diisocyanate) in surface layers 22.1 and 22.3 compared to a non-flame-retardant wood panel, is produced using a nozzle bar at 0.49 kg / m². 2 The amount was treated with a solution of Ecoaphos MK 68 flame retardant from Ecoatech (60% by weight).

[0111] This corresponds to 15% by weight of the specific area weight relative to the top layers 22.1 and 22.3. The top layer thickness is d. 22.1 =d 22.3 =3mm ± 1mm. Apply a negative pressure of 300 mbar from below. At t saug Within 120s ± 15s, liquid 34, i.e., the flame retardant solution, has completely penetrated into the original wood panel 16.

[0112] Rotate the original wood panel 16 and repeat the above method. The sample (base area: DIN A4, Sample 1) is then cut from the original wood panel 16 and tested together with a conventionally produced flame-retardant OSB panel. The conventionally produced flame-retardant OSB panel has a considerable amount of the aforementioned flame retardant in the surface layer and has been air-conditioned (moisture content: approximately 9%) prior to testing. During this process, the sample is flame-treated for different durations using a gas burner positioned at a defined distance from the surface. Once the flame-treatment cycle is complete, whether combustion / further combustion can be observed is recorded, and the duration of further combustion is determined.

[0113] Example 2 of the implementation plan:

[0114] It will have a thickness of d = 20 mm (original density approximately 650 kg / m³). 3 An unsanded raw wood panel 16 in OSB panel form is placed on a vacuum stage 37 equipped with a circumferential seal 44. The raw wood panel 16, produced using a more than one percent bonding agent (PMDI) in the surface layer, is applied using a nozzle rod 43 at a speed of 0.49 kg / m². 2 The amount was treated using a flame retardant solution (Ecoaphos MK 68, 60% by weight) from Ecoatech. The flame retardant solution had been preheated to approximately T. 34 =60℃ to promote penetration.

[0115] The amount of liquid corresponds to 15% by weight of the surface layer wood chips (approximately 3 mm thick on each side). A vacuum of 150 mbar is applied from below. saug =After a 90-second suction time, the flame retardant solution has completely penetrated into the original wood panel 16. Rotate the original wood panel 16 and repeat the method.

[0116] Subsequently, 16 samples (DIN A4, Sample 2) were cut from the original wood panel 16 and their flammability was tested together with conventionally produced flame-retardant OSB panels in accordance with DIN EN 13823:2015.

[0117] The OSB panels produced in a conventional manner contain a significant amount of the aforementioned flame retardant in the surface layer and have been air-conditioned (moisture content: approximately 9%) prior to testing.

[0118] When testing flammability, the samples were flame-treated for different durations using a gas burner positioned at a defined distance from the surface, according to the left column of the table below. Once the flame-treatment cycle was complete, the observability of combustion / further combustion and the duration of further combustion were recorded.

[0119] Table 1: Observation results after flame treatment

[0120]

[0121]

[0122] Flame treatment tests showed that the wood panels produced using the method according to the invention performed as well as the reference panel. Even after 15 minutes of flame treatment, none of the samples exhibited further burning after the burner was turned off. Subsequent testing showed that the wood panels produced according to the invention exhibited even higher strength after testing. In the case of the reference panel, individual charred wood chips could be easily and mechanically removed from the structure, which was only possible with greater effort in the case of the two wood panels produced according to the invention.

[0123] Example 3:

[0124] It will have a thickness d = 8mm (original density approximately 850 kg / m³). 3 An unsanded raw wood panel 16 in HDF (High-density Fiber) form is placed on a vacuum stage 37 equipped with a circumferential seal 44. The raw wood panel 16, produced using a urea-formaldehyde adhesive with a bonding agent of more than one percent, is applied using a nozzle rod 43 at a speed of 0.31 kg / m². 2The amount was treated using a flame retardant solution from Ecoatech (Ecoaphos MK 68, 50% by weight). The proportion of binder in the panel was also increased (2% more than the standard). The flame retardant solution was preheated to approximately T. 34 =60℃ to promote penetration.

[0125] A certain amount of flame retardant is introduced into the wood panel via the liquid, constituting 15% by weight relative to the surface layer (the surface layer thickness is approximately 1.2 mm on each side). A vacuum of 150 mbar is applied from below. saug =After a suction time of 120 seconds, the flame retardant solution has completely penetrated into the original wood panel 16. Rotate the original wood panel 16 and repeat the method.

[0126] Sixteen samples (DIN A4, Sample 2) were then cut from the wood panel 16 and their flammability was tested according to DIN EN13823:2015 together with conventionally produced flame-retardant HDF panels.

[0127] Conventionally produced wood panels contain a significant amount of the aforementioned flame retardant and have been air-conditioned prior to testing (moisture content: approximately 9%).

[0128] When testing flammability, the samples were tested in exactly the same manner as with the OSB test. The results regarding flammability and strength after the fire resistance test were comparable to those of the OSB test.

[0129] Example 4:

[0130] For materials with a thickness d = 8 mm (original density approximately 750 kg / m³) 3 The steps performed in Example 3 are performed on the unsanded raw wood material panel 16 in the form of an MDF panel.

[0131] When testing flammability, the samples were tested in exactly the same manner as conventionally produced MDF panels. When compared with conventionally produced MDF panels, the MDF panels produced according to the present invention meet or exceed the results in terms of flammability and strength.

[0132] Example 5 of the implementation plan:

[0133] For materials with a thickness d = 8 mm (original density approximately 650 kg / m³) 3 The unsanded raw wood material panel 16 in the form of wood chip laminate is subjected to the steps performed in Example 3.

[0134] When testing flammability, samples were tested in the exact same manner as conventionally produced wood chip laminates. When compared to conventionally produced wood chip laminates, the wood chip laminate produced according to the present invention meets or exceeds the results in terms of flammability and strength.

[0135] Example 6 of the implementation plan:

[0136] For materials with a thickness d = 20 mm (original density approximately 250 kg / m³) 3 The unsanded raw wood panel 16 in the form of a partition board is used to perform the steps performed in Example 3.

[0137] When testing flammability, samples were tested in exactly the same manner as conventionally produced isolation panels. When compared with conventionally produced isolation panels, the isolation panels produced according to the present invention meet or exceed the results in terms of flammability and strength.

[0138] List of reference numerals

[0139] 10 Wood-based panel production equipment

[0140] 12 Press

[0141] 14. Primary Product Layer

[0142] s14.1 First surface debris layer

[0143] 14.2 Intermediate Clastic Layer

[0144] 14.3 Second Surface Debris Layer

[0145] 16 Raw wood panel

[0146] 18. Distribution device

[0147] 20 Distributors

[0148] 22.1 First Surface Layer

[0149] 22.2 Intermediate Layer

[0150] 22.3 Second Surface Layer

[0151] 24. Thermal fluid

[0152] 26 heating elements

[0153] 28 Pressure belt

[0154] 30 pressure rollers

[0155] 32 Liquid application device

[0156] 34 Liquid

[0157] 36. Suction device

[0158] 37 Vacuum Stage

[0159] 38. Liquid reservoir

[0160] 40 pumps

[0161] 41 Nozzle

[0162] 42 sprays

[0163] 43 Nozzle rod

[0164] 44 Seals

[0165] 46 Suction Chamber

[0166] 48 Support components

[0167] 49 Vacuum lines

[0168] 50 Outer Area

[0169] 52 Vacuum Pump

[0170] 53 Applying roller

[0171] 54 Wood-based panels

[0172] 56 Pressure application device

[0173] 58. Introduction Room

[0174] 60 Seals

[0175] 62 Positioning device

[0176] 64 Applicator

[0177] 66 arms

[0178] 68-point arm

[0179] 70 drives

[0180] 72 pipelines

[0181] 74 Suction Cups

[0182] 76 Control Unit

[0183] 78 nozzles

[0184] c F Flame retardant content

[0185] c F,D1 First tenths concentration

[0186] c F,D2 Second tenths concentration

[0187] cF,Q1 First external concentration

[0188] c F,Q3 Internal concentration

[0189] c F,Q2 Second external concentration

[0190] d Thickness

[0191] D Thickness tenths

[0192] D1 First outermost thickness tenths

[0193] D10 Second outermost thickness tenth place

[0194] F s Suction surface

[0195] F D pressure surface

[0196] i. Operating index of the primary product layer

[0197] j Support component operating index

[0198] K edge surface

[0199] M. Direction of material flow

[0200] p 46 suction chamber pressure

[0201] p e Introducing pressure

[0202] S1 First side surface

[0203] S2 Second Side Surface

[0204] Q Thickness quintile

[0205] Q1 First outermost thickness quintile

[0206] Q3 Internal thickness quintile

[0207] Q5 Second outermost thickness quintile

[0208] t saug Aspiration time

[0209] T temperature

[0210] z is the distance from the surface of the wood panel.

Claims

1. A method for producing wood-based panels (54), comprising the following steps: (a) Producing raw wood panel (16), the raw wood panel comprising: First side surface (S1). The second side surface (S2) extends parallel to the first side surface (S1), and Edge surfaces that connect the side surfaces (S1, S2) to each other. (b) Applying a liquid (34) containing a flame retardant to at least the first side surface (S1), and (c) Apply negative pressure to the second side surface (S2) so that the flame retardant-containing liquid (34) is drawn into the peripheral area (50) of the original wood material panel (16), and / or Overpressure is applied to the first side surface (S1) so that the flame retardant-containing liquid (34) is forced into the peripheral area (50) of the original wood material panel (16). This produces the wood panel (54). Its features are, (d) At the surface temperature of the location on the first side surface (S1) where the liquid (34) containing the flame retardant is applied, the concentration of the flame retardant in the liquid (34) is higher than the saturation concentration of the flame retardant in the liquid (34).

2. The method according to claim 1, characterized by the following steps: (a) Press the applicator (64) against the original wood panel, such that an inlet chamber (58) is formed between the applicator (64) and the original wood panel, the inlet chamber being sealed by a seal (60) of the applicator (64). (b) Pressuring a liquid (34) containing a flame retardant into the inlet chamber (58), and (c) The inlet pressure (p) in the inlet chamber (58) is then reduced. e ).

3. The method according to claim 2, characterized in that, The applicator (64) presses against the original wood panel from below.

4. The method according to claim 2, characterized by the following steps: (d) Reducing the introduced pressure (p) e After that, the applicator (64) is moved relative to the original wood material panel. (e) Press the applicator (64) back onto the original wood panel. (f) The liquid (34) containing the flame retardant is injected into the inlet chamber (58). (g) Reduce the inlet pressure (p) in the inlet chamber (58). e ),as well as (h) Repeat the above steps until the original wood panel is equipped with flame retardant.

5. The method according to claim 1, characterized in that... The negative pressure is applied in the following manner: The internal concentration (c) of the flame retardant in the internal thickness quintile (Q3) of the thickness extension from the first side surface (S1) to the second side surface (S2) is increased. F,Q3 The external concentration (c) in the first outermost thickness quintile (D1) extending to the first side surface (S1) is the concentration of the outermost layer of the outermost layer (c). F,Q1 (at most 0.8 times) 6. The method according to claim 1, characterized in that, The liquid (34) contains at least one colorant, which is selected in such a way that the flame retardant content can be determined based on the color of the cross section of the wood panel (54).

7. The method according to claim 1, characterized in that, (a) During application to the first side surface, the liquid temperature of the liquid (34) is at least 40°C, and / or (b) During the application of the liquid (34), the surface temperature of the first side surface (S1) is at most 50°C.

8. The method according to claim 1, characterized in that, (a) The amount of liquid (34) applied to a specific area is at least 0.3 kg / m² and / or at most 5 kg / m², and / or (b) Select the specific area application amount of liquid (34) such that the surface moisture content of the surface layer of the wood panel (54) deviates from the core moisture content by up to 30%.

9. The method according to claim 1, characterized by the following steps: (a) After the liquid (34) has been introduced into the peripheral area (50) of the first side surface (S1), the original wood panel (16) is rotated. (b) Applying the liquid (34) to the second side surface (S2), and (c) Apply negative pressure to the first side surface (S1) so that the liquid (34) is drawn into the peripheral area (50) of the second side surface (S2) of the original wood material panel (16) to produce the wood material panel (54).

10. The method according to claim 1, characterized by the following steps: (a) Dispersed first surface debris layer (14.1). (b) At least one intermediate debris layer (14.2) dispersed on the first surface debris layer, and (c) A second surface debris layer (14.3) dispersed on the intermediate debris layer. (d) Pressing the layer to form the original wood material panel (16), the original wood material panel comprising: - A first surface layer (22.1), which is formed by the first surface debris layer (14.1). - Intermediate layer (22.2), which is generated by the intermediate debris layer (14.2), and - A second surface layer (22.3), which is formed by the second surface debris layer (14.3). (e) The flame retardant-containing liquid (34) is applied at a specific area application amount corresponding to at least 10% of the specific area mass of the first surface layer (22.1).

11. A wood-based panel production apparatus (10), the wood-based panel production apparatus comprising: (a) A press (12) for pressing at least one primary product layer (14) to form a raw wood material panel (16). (b) A liquid application device (32) for applying liquid (34) to the original wood panel (16), and (c) A suction device (36) designed to apply negative pressure to the side surface (S) of the original wood panel (16), (d) wherein the liquid (34) contains a flame retardant, and (e) wherein the suction device (36) is designed to automatically apply the negative pressure and continue suction for a duration (t). saug ), such that the liquid (34) containing the flame retardant is drawn into the peripheral area (50) of the original wood panel (16) but does not penetrate the original wood panel (16), and / or The wood panel production apparatus (10) has a pressure application device (56) for applying overpressure to a first side surface of the original wood panel (16), such that the liquid containing the flame retardant is forced into the peripheral area of ​​the original wood panel. Its features are, (f) The liquid application device (32) includes a temperature control device (43) configured to maintain the liquid (34) at a predetermined temperature (T34), the predetermined temperature being selected such that at the surface temperature of the location on the first side surface (S1) where the liquid (34) containing the flame retardant is applied, the concentration of the flame retardant in the liquid (34) is higher than the saturation concentration of the flame retardant in the liquid (34).

12. The wood panel production apparatus according to claim 11, characterized in that, (a) The applicator (64) is designed to press against the original wood panel, such that an inlet chamber (58) is formed between the applicator (64) and the original wood panel, the inlet chamber being sealed by a seal (60) of the applicator (64), and (b) A control unit (76) configured to automatically perform a method including steps of controlling the applicator (64). (i) The liquid (34) containing the flame retardant is forced into the inlet chamber (58), and (ii) Reduce the inlet pressure (p) in the inlet chamber (58). e ).

13. The wood panel production apparatus according to claim 12, characterized in that, The applicator (64) includes an actuator for pressing the applicator (64) against the original wood panel.

14. The wood panel production apparatus according to claim 11, characterized in that, The suction device (36) is arranged to direct the suction towards the pressure surface (F). D The suction surface (F) S Apply negative pressure.

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