Method for producing an oriented strand board, and oriented strand board production device

Abstract

The invention relates to a method for producing an oriented strand board, comprising the steps of: treating or producing a raw oriented strand board (16), which has a first side face (S1), a second side face (S2) which runs parallel to the first side face (S1), and edge faces, which connect the side faces (S1, S2) to one another, applying a liquid (34), which contains paraffin and / or wax, at least to the first side face (S1), with the steps of applying a negative pressure to the second side face (S2) so that the liquid (34) is sucked into an edge zone (50) of the raw oriented strand board (16), and / or applying an overpressure to the first side face (S1) so that the liquid (34) is pressed into an edge zone (50) of the raw oriented strand board (16), and heating the first side face (S1) so that the paraffin and / or the wax melts, so that the oriented strand board (54) is formed.

Description

[0001] Method for producing a coarse chipboard and coarse chipboard manufacturing device

[0002] The invention relates to a method for producing a coarse chipboard according to the preamble of claim 1.

[0003] According to a second aspect, the invention relates to a particle board coating device comprising (a) a liquid application device for applying a liquid to the raw particle board, (b) a liquid source which is connected to the liquid application device and contains the liquid, and (c) a suction device which is designed to apply a negative pressure to a side surface of the raw particle board and to automatically apply the negative pressure for a suction time such that the liquid is sucked into an edge zone of the raw particle board, and / or a pressure application device for applying an overpressure to the first side surface such that the liquid is pressed into an edge zone of the raw particle board. The invention also relates to a particle board.

[0004] Particle boards, also known as OSBs (oriented strand boards), are wood-based panels made of long, slender chips that possess increased mechanical strength compared to other wood-based panels. A disadvantage of particle boards is that they are difficult to coat and / or surface finish. Furthermore, particle boards emit more gas than other wood-based panels because they are made from softwoods with a high resin content. Furthermore, particle boards are generally sensitive to water, as water quickly penetrates the surface of the particle board and can cause chips to swell or detach. US 2007 / 122644 A1 discloses a process for incorporating wax into an OSB board. The wax, dissolved in a solvent, is applied to the fiber cake of oriented strands. The fiber cake is then pressed into the wood-based panel.

[0005] EP 3 127 670 A2 discloses a method by which an impregnating medium in the form of an emulsion is applied to a pressed wood-based panel using several nozzles. The nozzles can be individually controlled, allowing the application rate to be adjusted spatially.

[0006] The invention is based on the object of making it possible to produce the chipboards with improved properties.

[0007] The invention solves the problem by a generic method for producing a coarse chipboard with the steps of (c) applying a negative pressure to the second side surface so that the liquid is sucked into an edge zone of the raw coarse chipboard and / or applying an overpressure to the first side surface so that the liquid is pressed into the raw coarse chipboard, and optionally (d) heating the first side surface so that the paraffin and / or the wax melts and penetrates into the surface of the coarse chipboard.

[0008] According to a second aspect, the invention solves the problem by means of a generic particle board manufacturing device in which the liquid contains paraffin and / or wax. It is advantageous if the particle board manufacturing device has a heating device arranged downstream of the liquid application device in the material flow direction, which heating device is designed and arranged to automatically heat a first side surface, which is opposite the second side surface, to a temperature at which the paraffin and / or wax melts and is not decomposed. Also according to the invention is a particle board manufacturing device which has a press for pressing at least one precursor layer to form a raw particle board and a particle board coating device according to the invention. The liquid application device is suitable, in particular arranged, for applying a liquid to the raw particle board.When the chipboard manufacturing device is mentioned below, the chipboard coating device is also generally meant.

[0009] The advantage of the invention is that a particle board with a higher resistance to water can be produced without the need to use organic solvents and / or post-crosslinking substances.

[0010] In addition, chip detachment can generally be prevented when the chipboard comes into contact with water. This expands the range of applications for chipboard.

[0011] For the purposes of the present invention, paraffin is understood to be a mixture of acyclic alkanes. Paraffin is inert and nontoxic, which is advantageous.

[0012] Wax is a mixture of hydrocarbons that melt without decomposition at temperatures above 40°C, forming a low-viscosity liquid. Waxes include both natural and industrially produced waxes. These include, in particular, animal waxes, vegetable waxes, mineral waxes, petroleum waxes, and synthetic waxes. Waxes are malleable, particularly at 20°C, solid to brittle, coarse to fine crystalline, translucent to opaque, but not glassy. The wax is preferably selected so that it is not brittle at 20°C.

[0013] The feature that the liquid contains paraffin and / or wax is understood in particular to mean that the liquid contains standard paraffin, intermediates, microwaxes, hard paraffin, and / or mixtures thereof. Preferably, the liquid is water-based and contains an emulsifier.

[0014] The feature that the first side surface is heated so that the paraffin and / or wax melts is understood in particular to mean that the temperature of the side surface is heated, for example by infrared radiators or by means of warm air, to such an extent that the paraffin and / or wax melts at least partially and forms a film at least in sections.

[0015] The liquid preferably contains an inorganic solvent. For example, the solvent is hydrophilic, especially water-based. The liquid is preferably a dispersion or an emulsion.

[0016] Preferably, the negative pressure is applied such that the pressure applied to the side surface is at most 300 hPa, in particular at most 200 hPa.

[0017] Preferably, the overpressure is applied such that the pressure applied to the side surface is at least 300 hPa, in particular at most 200 hPa.

[0018] If both negative and positive pressure are applied, the pressure difference between the two side surfaces is preferably at least 1000 hPa.

[0019] The chipboard preferably has a length of 2800 to 5600 mm and / or a width of 2000 ± 100 mm.

[0020] Preferably, the liquid is non-crosslinking. To achieve crosslinking, organic solvents are usually required, which is undesirable and can lead to environmental pollution. Melting the paraffin and / or wax results in the formation of a paraffin and / or wax layer without the need for organic solvents.

[0021] According to a preferred embodiment, the liquid is applied in such a quantity that the particleboard has a water vapor permeability that is at least 30%, in particular at least 40%, lower than the water vapor permeability of the raw particleboard. To meet this requirement, the application quantity and / or the concentration of paraffin and / or wax in the liquid can be successively increased until the specified criterion is met. The water vapor permeability is preferably measured in accordance with DIN 53122-1. Phosphorus pentoxide can be used as a desiccant. A test container filled with desiccant is sealed with a circular sample with a diameter of 9 cm. The sample runs horizontally.A 5 ml drop of water is placed centrally on the particle board, and the increase in water content in the test container due to water permeating through the sample is determined by weighing. The edge of the particle board can be sealed with silicone to prevent moisture penetration. The measurement is performed on three independent samples.

[0022] If the chipboard is coated with paraffin and / or wax on only one side - according to a preferred embodiment - the coated side faces away from the sample container.

[0023] Preferably, the water vapor permeability of the chipboard is no more than 20 grams of water per square meter per day.

[0024] According to a preferred embodiment, the liquid contains solid particles, for example, made of a hard material. The hard material preferably has a hardness of at least 530 HV 10, in particular at least 790 HV 10, in particular at least 1100 HV 10, in particular at least 1400 HV 10, in particular at least 1900 HV 10.

[0025] It is possible, but not necessary, for the chipboard manufacturing device to have a heating device which is designed and arranged to melt the paraffin and / or the wax.

[0026] Preferably the grain size is between F120 and F80 (FEPA standard) and / or grain size, measured as sieve size, of 70-110 pm.

[0027] It is advantageous to apply between 30 grams per square meter and 100 grams per square meter of solid particles. This has been shown to result in a sufficiently high increase in slip resistance. Slip resistance is a measure of the coefficient of static friction. For example, slip resistance is measured as the angle of inclination at which a steel block with a 40 cm x 10 cm bearing surface and a mass of 500 g begins to slip.

[0028] The liquid preferably contains elemental carbon, in particular soot and / or graphite.

[0029] It is then also possible, but not necessary, for the particleboard manufacturing device to have a heating device designed and arranged to melt the paraffin and / or wax. Known particleboards have a comparatively low absorption capacity for infrared radiation. By applying the liquid with elemental carbon, the absorption capacity for infrared radiation is significantly increased in a simple manner.

[0030] Preferably, a concentration of elemental carbon in the liquid and an application quantity of liquid are selected such that a coarse particle board reflectivity of the coarse particle board in the direction of a normal to the side surface of the coarse particle board to which the liquid was applied, at 23°C for light with a wavelength of 350 nm, is at least 0.05, in particular at least 0.075, particularly preferably at least 0.1, in particular at least 0.15, smaller than a raw coarse particle board reflectivity of the raw coarse particle board. The greater the concentration of elemental carbon and the application quantity, the greater the difference between the emissivities of the raw coarse particle board and the coarse particle board. The reflectivity is determined by irradiating light of the specified wavelength, measuring the intensity of the reflected light of the same wavelength and calculating the quotient of the stronger irradiated light and the reflected light intensity.

[0031] Known particle boards also have the disadvantage that they easily become electrostatically charged at low relative humidity. Furthermore, they have a low residual moisture content after production, which further increases this effect. According to a preferred embodiment, the liquid contains a salt. This increases the conductivity of the particle board in its edge zone. Preferably, a concentration of the at least one salt in the liquid and an application rate of the liquid to the raw particle board are selected such that an electrical conductivity of the particle board is at least 50%, in particular at least 100%, greater than an electrical conductivity of the raw particle board. The conductivity increases with the concentration of the salt in the liquid and the application rate.By successively increasing one or both sizes, the concentration and application quantity can be determined that results in coarse particle boards that have the specified properties.

[0032] Preferably, the concentration and application rate are selected so that the conductivity of the chipboard is at least five times, or at least ten times, the raw chipboard conductivity. Conductivity is measured by pressing two copper electrodes with a round contact surface with a diameter of 1 cm onto the side surface to which the liquid was applied with a force of 10 Newtons in the normal direction. Measurements are taken at five different locations on the chipboard, and the arithmetic mean is calculated.

[0033] It's advantageous if the liquid contains a dye, allowing the chipboard to be colored with little effort.

[0034] The liquid is preferably applied by means of nozzles and / or rollers, for example from above or below.

[0035] It is also possible for the liquid to be applied to the side surface from below. During application, the liquid preferably has contact with the side surface with its at least substantially horizontal liquid surface.

[0036] According to a preferred embodiment, the overpressure is built up by means of the liquid. This is particularly advantageous if the liquid is applied to the side surface from below. However, it is often advantageous to apply the liquid from above in order to more easily detect any errors during application of the liquid. The method preferably comprises the steps of (a) pressing an applicator of the pressure application device against the raw chipboard so that an introduction space is formed between the applicator and the raw chipboard, which is sealed by a seal of the applicator, (b) forcing liquid into the introduction space and (c) then reducing an introduction pressure in the introduction space, in particular to ambient pressure. The applicator is pressed against the raw chipboard from below or from above. In this way, liquid can be introduced into the raw chipboard in a process-reliable manner.

[0037] Preferably, the method comprises the steps of (a) after reducing an insertion pressure, moving the applicator relative to the raw chipboard, (b) pressing the applicator again against the raw chipboard, (c) injecting liquid into the insertion space, (d) reducing an insertion pressure (p e ) in the introduction space, in particular to ambient pressure and (e) repeating the above steps until the raw particle board is provided with the liquid.

[0038] The negative pressure is preferably applied to a suction surface by means of a suction hood. It is advantageous if the suction surface corresponds to a pressure surface onto which the liquid is pressed. The suction surface is that part of the corresponding side surface onto which the negative pressure (compared to the ambient pressure) is applied. The pressure surface is correspondingly that surface of the (opposite) side surface onto which the pressure (compared to the ambient pressure) is applied. The feature that the suction surface corresponds to the pressure surface is understood in particular to mean that the projection of the suction surface onto the plane in which the pressure surface extends forms an intersection with the pressure surface whose surface area corresponds to at least 0.75 times, in particular 0.8 times, preferably 0.85 times, particularly preferably 0.95 times the surface area of ​​the pressure surface.

[0039] Preferably, the applicator is moved at least temporarily relative to the raw chipboard when the liquid is being pressed in. Alternatively or additionally, the raw chipboard is moved at least temporarily and the applicator is moved along with it. In this way, the liquid can be applied at a locally increased concentration. Alternatively, a concentration of paraffin and / or wax and the application amount as well as the vacuum and suction time are selected such that an internal concentration of paraffin and / or wax in an inner thickness quintile of a thickness extension from the first side surface to the second side surface is at most 0.8 times, in particular at most 0.6 times, preferably at most 0.4 times, particularly preferably at most 0.1 times, an external concentration in an outermost thickness quintile that extends to the first side surface.In this way, a particularly high water-repellent effect is achieved without the need to add a lot of paraffin and / or wax.

[0040] Preferably, the liquid is applied in such a way that the edge zone of at least 90% of the side surface area of ​​the chipboard contains paraffin and / or wax. As a rule, areas that do not have a sufficiently high paraffin and / or wax content must be removed. By applying the liquid to at least 90% of the corresponding side surface, waste is reduced.

[0041] The application of the liquid includes or is, for example, spraying, applying, pouring and / or flooding.

[0042] According to a preferred embodiment, the application quantity is selected such that at least 75 g / m 2 , in particular at least 85 g / m 2 , particularly preferably at least 90 g / m 2, paraffin and / or wax is applied to the side surface. It has been shown that this significantly reduces water vapor permeability.

[0043] Preferably, the concentration of wax and / or paraffin in the liquid corresponds to at least 25 percent by weight, in particular at least 30 percent by weight, particularly preferably at least 35 percent by weight, in particular at least 40 percent by weight. In this way, little solvent, in particular water, is introduced into the raw particle board, which facilitates any optional subsequent drying.

[0044] The liquid preferably contains a dye. This dye is preferably not elemental carbon. The temperature of the liquid upon application to the side surface is preferably below the melting temperature of the paraffin and / or wax. This prevents premature formation of large paraffin and / or wax particles.

[0045] It is advantageous to heat the first side surface to a temperature of at least 50°C. This ensures that the paraffin melts sufficiently quickly.

[0046] According to a preferred embodiment, the method comprises the steps of (a) rotating the raw coarse chipboard after introducing the liquid into the edge zone of the first side surface, (b) applying the liquid to the second side surface and (c) applying a negative pressure to the first side surface so that the liquid is sucked into an edge zone of the second side surface of the raw coarse chipboard, so that the coarse chipboard is produced.

[0047] According to a preferred embodiment, the suction device is designed to automatically apply the negative pressure for a suction time such that the liquid is not sucked through the raw, coarse chipboard. Alternatively or additionally, the pressure application device is designed to automatically apply the positive pressure for a pressure time such that the liquid is not forced through the raw, coarse chipboard.

[0048] Preferably, the pressure application device is designed to apply the overpressure to a pressure area that corresponds to at least 50%, preferably at least 80%, and particularly preferably at least 90%, of the surface area of ​​the chipboard. In this way, the liquid can be quickly introduced into the raw chipboard.

[0049] According to a preferred embodiment, the coarse particle board manufacturing device has (a) an applicator which is designed to press against the raw coarse particle board so that an introduction space is formed between the applicator and the raw coarse particle board, which introduction space is sealed by a seal of the applicator, and (b) a control unit which is designed to automatically carry out a method with the steps of controlling the applicator (i) so that it presses liquid into the introduction space, and (ii) thereafter reducing an introduction pressure in the introduction space, in particular to ambient pressure.

[0050] Preferably, the applicator has an actuator for pressing the applicator against the raw chipboard.

[0051] The suction device is preferably arranged to apply a negative pressure to a suction surface which corresponds to the pressure surface.

[0052] According to the invention, a coarse particle board is also provided which has an internal concentration of paraffin and / or wax in an inner thickness quintile of a thickness extension from the first side surface to the second side surface which corresponds to at most 0.5 times, in particular at most 0.25 times, particularly preferably at most 0.1 times, an external concentration in a first outermost thickness quintile which extends to the first side surface.

[0053] Alternatively or additionally, a second-decile concentration of paraffin and / or wax in the second thickness decile of the thickness extension, which lies adjacent to the first, outermost thickness decile (D1) in the direction of a center of the thickness extension, is at most 0.5 times, in particular at most 0.25 times, and thus preferably at most 0.1 times, the outer concentration. Such a coarse particle board has low water vapor permeability with a comparatively low paraffin and / or wax content.

[0054] Preferably, elemental carbon, in particular carbon black or graphite, is applied to at least 50% of the side surface.

[0055] Alternatively or additionally, the coarse chipboard preferably has at least 30 g per square meter of hard material particles having a grain size between 70 and 150 pm, wherein the hard material particles are bound to coarse chips by paraffin and / or wax.

[0056] Alternatively or additionally, the area-specific application rate of elemental carbon is at least 10 g / m 2 and / or a maximum of 100 g / m 2 The thickness of the chipboard is preferably between 8 and 35 mm.

[0057] The invention is explained in more detail below with reference to the accompanying drawings.

[0058] Figure 1 shows a coarse particle board coating device according to the invention as part of a coarse particle board manufacturing device according to the invention for carrying out a method according to the invention for a coarse particle board according to the invention,

[0059] Figure 2 shows a detailed view of the chipboard coating device according to Figure 1,

[0060] Figure 3 in part 3a a schematic cross section through a coarse particle board according to the invention, in part 3b the internal concentration of paraffin and / or wax of a coarse particle board according to the invention according to a first embodiment and in part 3c the internal concentration of paraffin and / or wax according to a second embodiment and

[0061] Figure 4 shows a detailed view of a coarse chipboard manufacturing device according to a second embodiment with a suction device and a pressure application device

[0062] Figure 5 is a schematic detailed view of a chipboard manufacturing device having an applicator and

[0063] Figure 6 in part figure 6a a schematic side view of a coarse chipboard manufacturing device according to the invention with a movable applicator and a movable suction hood in part figure 6b the coarse chipboard manufacturing device according to part figure 6a in a view from above and in part figure 6c a schematic side view of a coarse chipboard manufacturing device according to the invention with a movable applicator according to a second embodiment.

[0064] Figure 1 schematically shows a particleboard coating device 8, which comprises a press 12 in the form of a continuous belt press for pressing at least one pre-product layer 14, in this case three pre-product layers 14.1, 14.2, 14.3, into a raw particleboard 16, as well as a particleboard manufacturing device 10. The at least one pre-product layer 14 is produced by a spreading device 18.

[0065] In the present case, the spreading device 18 comprises a first spreader 20.1 for spreading the first precursor layer 14.1 in the form of a first cover chip layer, a second spreader 20.2 for spreading a second precursor layer 14.2 in the form of a middle chip layer and a third spreader 20.3 for spreading a third precursor layer 14.3 in the form of a second cover chip layer.

[0066] After pressing by means of the press 12, the resulting raw particleboard has a first cover layer 22.1, a middle layer 22.2, and a second cover layer 22.3. The press is heated, for example, by means of a thermal fluid 24 flowing in heating pipes 26. j (j = 1, ...)). The heat of the thermal fluid 24 is transferred to a rotating press belt 28, which is pressed onto the pre-product layer 14.1, 14.2, 14.3 by means of pressure rollers 30. k (k = 1, 2, ...). Independently, more or fewer than three pre-product layers can be present.

[0067] A liquid application device 32 is arranged downstream of the press 12 in a material flow direction, by means of which a liquid 34 is applied to a first side surface S1 of the raw particle board 16. The liquid application device 32 comprises a liquid reservoir 38 and a pump 40, by means of which the liquid 34 is directed to at least one nozzle 41 at a liquid pressure p34. The nozzle 41 generates a spray 42 that deposits on the first side surface S1. The nozzle 41 can be part of a nozzle bar 43 (see Figure 2) having two, three, or more nozzles. The liquid application device 32 can have a temperature control device 45 that keeps the liquid 34 at a predetermined temperature T34. The liquid 34 is a suspension or emulsion and contains paraffin and / or wax as well as solid particles. An application quantity Q34 of liquid 34 is Q34 = 300 g / m 2The content of paraffin and / or wax in the liquid 34 is so high that this corresponds to a paraffin / wax application quantity of QPW = 300 g / m 2 The solid particles in this case are made of corundum and have a particle size of F 120 according to the FEPA standard. The content of solid particles in the liquid 34 is so large that a solid particle application rate of QFP = 50 g / m 2 arises.

[0068] A heating device 37, which comprises, for example, at least one infrared radiator 37a, 37b, is arranged downstream of the liquid application device 32 in the material flow direction M. The heating device 37 dries a liquid layer 39 formed by the liquid on the raw particle board 18. Furthermore, the paraffin and / or wax in the liquid layer 38 is heated to such an extent that it begins to melt. In this way, a thin paraffin / wax layer 39' is formed.

[0069] By means of a suction device 36, which has a suction hood 47 and a circumferential seal 44, by means of which the second side surface S2 is sealed against a suction chamber 46, a negative pressure is applied in the suction chamber 46, so that a pressure p46 in the suction chamber 46 is less than p46 = 500 hPa, in particular less than P46 = 200 hPa. Due to the negative pressure, the liquid 34 is sucked into a first edge zone 50.1 of the raw particle board 16.

[0070] The suction device 36 has supports 48. m (m = 1, 2, ...) to reduce or prevent deflection of the raw chipboard 16 due to the negative pressure.

[0071] Figure 2 shows an enlarged view of the suction device 36. The suction chamber 46 is connected to a vacuum pump 52 via a vacuum line 49. The liquid 34 can be applied to the first side surface S1 by means of an application roller 53 or another device, alternatively or in addition to the at least one nozzle 41. Figure 3a schematically shows a cross-section through a coarse particle board 54 according to the invention, which has a first edge surface K1 and a second edge surface K2.

[0072] Figure 3b shows the curve of a concentration CPW of paraffin and / or wax in the particle board 54 as a function of the distance z from the nearest side surface S1, S2. It can be seen that the concentration CPW.QI in the first, i.e. outermost quintile Q1 is significantly greater, in particular by a factor of 10 or more, than in an inner thickness quintile Q3, i.e. the quintile with the greatest distance to both side surfaces S1, S2. It is possible that - as shown in Figure 3b - paraffin and / or wax is applied to only one side of the particle board 54. If, as provided according to a preferred embodiment, the raw particle board 16 is turned over after the application of the liquid 34 and the liquid 34 is applied to the opposite side, the curve of the concentration CFP shown with a dashed line, for example, results.

[0073] Figure 3 c shows a subdivision into deciles. It can be seen that a second-decile concentration CPW,D2 of paraffin and / or wax in the second decile D2, which lies adjacent to the first, outermost thickness decile D1 in the direction of a center of thickness extension, can be less than one-third of a first-decile concentration CPW.DI .

[0074] Figure 4 shows a liquid application device 32 of a particleboard manufacturing device 10 according to the invention, which has a pressure application device 56 that, by means of the pump 40, forces liquid 34 from the liquid reservoir 38 into an introduction chamber 58 at an introduction pressure PE. The introduction chamber 58 is delimited by a seal 60 of the pressure application device 56. The pressure application device 56 can be designed to apply the liquid 34 from below or from above, as shown in Figure 4.

[0075] By means of the vacuum pump 52 of the suction device 36, a pressure of, for example, p46 = 100 hPa is set in the suction chamber 46 via the vacuum line 49.

[0076] Figure 5 schematically shows that the suction device 36 can be designed to apply a local negative pressure. In this case, a suction area Fs is smaller than the area of ​​the raw particle board 16. In the present case, the suction area Fs is smaller than one-tenth of the area of ​​the raw particle board 16. The wood-based panel manufacturing device can also have a second suction device 36', which is preferably structurally identical to the first suction device 36.

[0077] A pressure surface FD, on which the pressure application device 56 is applied to the application pressure p e corresponds essentially to the suction area Fs, for example with a deviation of at most a factor of 2, in particular a factor of at most 1.1, in particular a factor of at most 1.25.

[0078] Figure 6a shows a positioning device 62, for example, a robot, for positioning an applicator 64 and for pressing the applicator 64 against the raw chipboard 16. For this purpose, the positioning device 62 has, for example, an arm 66. The arm 66 can have two or more partial arms 68.1, 68.2, which can be connected to one another in an articulated manner. By means of a drive 70, the applicator 64 can be automatically positioned to a predeterminable position relative to the raw chipboard 16.

[0079] By means of a flexible line 72, the applicator 64 is supplied with pressurized liquid 34, which is sprayed onto the raw chipboard 16 and / or pressed into the raw chipboard 16 under pressure.

[0080] Independently of the features otherwise mentioned for the present embodiment, the wood-based panel manufacturing device 10 can have a suction device 36 having a suction hood 47 that can be positioned at a predeterminable location. The suction device 36 is designed such that the suction hood 47 is always arranged opposite the applicator 64. For this purpose, the drive 70 is controlled by a control unit 76 of the wood-based panel manufacturing device 10. The suction hood 47 is connected to the vacuum pump 52 by means of a flexible vacuum line.

[0081] Figure 6c shows a further embodiment of a pressure application device 56, in which the flame retardant-containing liquid 34 is introduced into the introduction chamber 58 by means of a nozzle 78. By means of a pressure source 80, which is connected to the introduction chamber 58 via a pressure line 82, the introduction pressure p eIt is possible to move the applicator 64 and, if applicable, the suction hood 47 while a positive and / or negative pressure is applied. Alternatively, the pressure in the suction chamber and / or the introduction pressure is brought closer to, in particular completely closer to, the ambient pressure before moving the applicator and / or the suction hood.

[0082] The control unit 76 is used in all embodiments of the particle board manufacturing device 10 to control the suction device 36 and / or the pressure application device 56 such that a predetermined negative pressure for a predetermined suction time tsuction and / or a predetermined positive pressure for a predetermined positive pressure time tpressure is applied to the raw particle board 16.

[0083] Example 1: Surface sealing

[0084] A liquid 34 in the form of a paraffin emulsion / dispersion is applied to an unsanded chipboard with a thickness d of d = 16 mm OSB using an application roller in an application quantity of Q34 = 100 g / m 2 applied. Pressure P46 = 100 hPa is applied to the second side surface S2. The suction time is t suction = 30 sec. The emulsion is then absorbed into the plate to such an extent that no more liquid is visible. The plate is dried using a heating device 37 in the form of an infrared radiator, and the wax is melted so that it spreads over the surface. Depending on the application, soft paraffin, microwax, or hard paraffin can be used.

[0085] After drying and cooling, the particleboard is tested using a water application test. 5 ml of water is applied to the surface and covered with a watch glass. An untreated particleboard is also tested. While the water was absorbed into the untreated particleboard after one hour, the water was recovered from the treated OSB after two days.

[0086] A water vapor permeability test based on DIN 53122-1 was also conducted. The ambient temperature was 90% relative humidity and 23°C. The flask onto which the sample was placed contained phosphorus pentoxide as a desiccant. The values ​​were 16 g / m² xd (paraffin coating) and 29 g / (m² 2 xd) (control sample). The water vapor permeability could thus be almost halved with this coating. The water permeability can be controlled by varying the amount of paraffin applied.

[0087] Example 2: Surface sealing with anti-slip properties

[0088] A mixture of paraffin emulsion dispersion and corundum in two grain sizes, F 120 and F 80 according to FEPA standards, is applied to an unsanded 16 mm chipboard using an applicator roller. The paraffin / wax application rate is Qpw = 100 g, and the solid particle application rate is QFP = 50 g corundum per square meter. The solids content of the emulsion / dispersion is 50 percent by weight. A pressure of p46 = 100 mbar is applied, and the absorption time is tab = 30 seconds. The emulsion / dispersion is then absorbed into the board to such an extent that no more liquid is visible.

[0089] The board is dried using a heating device 37 in the form of an infrared radiator, and the wax is melted, allowing it to spread more evenly over the surface and ensure good integration of the solid particles into the paraffin film. Depending on the application, soft paraffin, microwax, or hard paraffin can be used. A second chipboard is coated with the same quantity of glass beads instead of corundum. Their grain size is between 70 and 110 pm.

[0090] Another chipboard was manufactured without hard material particles and only with paraffin. A chipboard without surface treatment was also tested. The slip resistance of all chipboards was then determined using a small metal block (500 g). The metal block was placed on one end of a 40 cm long and 10 cm wide test specimen and then the chipboard was slowly moved upwards at this end. The angle of inclination at which the piece of metal begins to slip is the measure of the slip resistance. This was tested in both dry and wet conditions. For the wet measurement, 100 g of water per square meter was applied. The following table shows that the chipboards treated with paraffin and corundum have clear advantages in terms of slip resistance compared to the blank sample and the chipboard treated with glass beads.

[0091] Table 1 : Slip test

[0092] List of reference symbols

[0093] 8 Chipboard coating device 50 Edge zone 52 Vacuum pump

[0094] 10 Chipboard manufacturing device 54 Chipboard 56 Pressure application device

[0095] 12 Press 58 Feeding area

[0096] 14 Pre-product layer 60 Seal

[0097] 16 Raw chipboard 62 Positioning device

[0098] 18 Spreader 64 Applicator

[0099] 20 spreaders 66 arms

[0100] 22.1 first cover layer 68 partial arm

[0101] 22.2 Middle class 70 drive

[0102] 22.2 second cover layer 72 line

[0103] 24 Thermofluid 76 Control unit

[0104] 26 heating pipe

[0105] 28 Press belt CFP solid particle concentration

[0106] 30 Pressure roller CPW Paraffin / Wax concentration

[0107] 32 Liquid application device d thickness

[0108] 34 Liquid D Decile

[0109] 36 Suction device Fs suction area

[0110] 37 Heating device FD printing surface

[0111] 37a, 37b Infrared heater PE insertion pressure

[0112] 38 Liquid reservoir P46 Pressure in the suction chamber

[0113] 39 Liquid layer Q Quintile

[0114] 39' Paraffin / wax layer Q1 outermost quintile

[0115] 40 Pump Q3 Inside Quintile

[0116] 41 Nozzle Q34 Application quantity

[0117] 42 Spray QFP Solid Particle Application Rate

[0118] 43 Nozzle bar QPW Paraffin / wax application quantity

[0119] 44 Seal 51 first side surface

[0120] 45 Tempering device 52 second side surface

[0121] 46 Suction chamber t pressure overpressure time

[0122] 47 Suction hood tsaug suction time

[0123] 48 Support

Claims

Patent claims 1 . A method for producing a chipboard, comprising the steps: (a) treating or producing a raw chipboard (16) having a first side surface (S1), a second side surface (S2) running parallel to the first side surface (S1), and edge surfaces which connect the side surfaces (S1, S2) with each other, (b) applying a liquid (34) containing paraffin and / or wax at least to the first side surface (S1), characterized by the steps (c) applying a negative pressure to the second side surface (S2) so that the liquid (34) is sucked into an edge zone (50) of the raw chipboard (16), and / or Applying an overpressure to the first side surface (S1 ) so that the liquid (34) is pressed into an edge zone (50) of the raw chipboard (16), and (d) Heating the first side surface (S1 ) so that the paraffin and / or wax melts to form the chipboard (54).

2. Method according to claim 1, characterized in that the liquid (34) is applied with such an application quantity (Q34) that the coarse chipboard (54) has a coarse chipboard water vapor permeability of the coarse chipboard (54) which is at least 30% smaller than a raw coarse chipboard water vapor permeability of the raw coarse chipboard (16).

3. Method according to one of the preceding claims, characterized in that the liquid (34) contains solid particles.

4. Method according to one of the preceding claims, characterized in that the liquid (34) contains elemental carbon.

5. The method according to claim 4, characterized in that a concentration of elemental carbon in the liquid (34) and an application quantity (Q34) are selected such that a coarse chipboard reflectivity of the coarse chipboard (54) in the direction of a normal to the coarse chipboard (54) at 23°C with IR light having a wavelength of 700 nm is at least 0.05 smaller than a raw coarse chipboard reflectivity of the raw coarse chipboard (16).

6. Method according to one of the preceding claims, characterized in that the liquid (34) contains a salt and a concentration of the at least one salt in the liquid (34) and an application quantity of the liquid (34) to the raw chipboard (16) are selected such that an electrical chipboard conductivity of the chipboard (54) is at least 50% greater than an electrical raw chipboard conductivity of the raw chipboard (16).

7. Method according to one of the preceding claims, characterized in that the liquid (34) contains a dye.

8. Method according to one of the preceding claims, characterized in that (a) the liquid (34) is applied by means of nozzles (41) and / or rollers and / or (b) the liquid (34) is applied from below onto the side surface (S1, S2), wherein the liquid (34) is in contact with the side surface (S1, S2) during application with its at least substantially horizontally extending liquid surface. Method according to one of the preceding claims, characterized in that a vacuum is applied from above, wherein the vacuum is preferably applied by means of a suction hood (47) on a suction surface (Fs) which corresponds to a pressure surface (FD) onto which the liquid is pressed. Method according to one of the preceding claims, characterized in that (a) the applicator (64) is moved relative to the raw chipboard (16) when the liquid (34) is pressed in and / or (b) the raw particle board (16) is moved and the applicator (64) is carried along. Method according to one of the preceding claims, characterized in that a concentration of paraffin and / or wax and the application quantity are selected and the vacuum and the suction time (t suction) are selected such that an internal concentration (CF.QS) of paraffin and / or wax in an inner thickness quintile (Q) of a thickness extension from the first side surface (S1) to the second side surface (S2) is at most 0.8 times an external concentration (CF,QI) in a first outermost thickness quintile (Q1) extending to the first side surface (S1). Chipboard coating device (8) with (a) a liquid application device (32) for applying a liquid (34) to a raw chipboard (16), (b) a liquid source connected to the liquid application device (32) and containing the liquid (34), and (c) a suction device (36) which is designed to apply a negative pressure to a second side surface (S2) of the raw coarse chipboard (16) and to automatically apply the negative pressure for a suction time (tsaug) such that the liquid (34) is sucked into an edge zone (50) of the raw coarse chipboard (16) and / or a pressure application device (56) for applying an overpressure to the first side surface so that the liquid (34) is pressed into an edge zone (50) of the raw coarse chipboard (16), characterized in that (d) the liquid (34) contains paraffin and / or wax and (e) the particleboard manufacturing device (10) comprises a heating device (37) arranged downstream of the liquid application device (32) in the material flow direction, which heating device is designed and arranged to automatically heat a first side surface, which is opposite the second side surface, to a temperature at which the paraffin and / or wax melts and is not decomposed. The particleboard coating device (8) according to claim 12, characterized in that (a) the suction device (36) is designed to automatically apply the negative pressure for such a suction time (tsaug) that the liquid (34) is not sucked through the raw chipboard (16) and / or (b) the pressure application device (56) is designed to automatically apply the overpressure for such an overpressure time (t pressure) that the liquid (34) is not forced through the raw chipboard (16). Chipboard, characterized in that (a) an internal concentration of paraffin and / or wax in an inner thickness quintile (Q) of a thickness extension from the first side surface (S1) to the second side surface (S2) of at most 0.5 times an external concentration in a first outermost thickness quintile (Q1) extending to the first side surface (S1) and / or (b) a second decile concentration (CF,D2) of paraffin and / or wax in the second thickness decile (D2) of the thickness extension, which lies towards a center of the thickness extension next to the first, outermost thickness decile (D), at least 0.1 times a first decile concentration (CF,DI ) in the first outermost thickness decile (D). Chipboard according to claim 14, characterized in that a chipboard surface of the chipboard (a) contains elemental carbon and / or (b) contains at least 30 g per square meter of hard material particles having a grain size between 70 and 150 pm

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