Manufacturing wooden composite panels comprising soybeans

Abstract

The present invention relates to a method of manufacturing a wood composite panel, in particular an MDF panel, comprising the steps of: a. Providing and mixing soybean flour and water in a weight ratio of about 10% to 45% to form a soybean solution; b, introducing the soybean solution into a high-pressure blowing pipeline containing wood fibers; c. Introducing the resin into a high pressure blow line to form a soybean solution wood fiber resin mixture; d. Pre-drying the soybean solution wood fiber resin mixture to form a pre-dried soybean meal wood fiber resin mixture; and e, the pre-dried soybean meal wood fiber resin mixture is subjected to hot pressing to form the wood composite panel.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a wood composite panel containing soybeans, a wood composite panel containing soybeans, and a corresponding system for manufacturing a wood composite panel containing soybeans. Background Art

[0002] In the prior art, many different wood composite boards or panels are known, in particular so-called medium density fiberboard (MDF panels) or high density fiberboard (HDF boards). To manufacture such panels, wood particles or fibers are typically mixed with a suitable binder, such as resin, and pressed to form the resulting wood composite panel. For example, such panels are used as basic elements or carrier boards for the production of furniture or floor coverings. Since resins can be very expensive and are typically made from non-environmentally friendly chemicals, many attempts have been made in the art to use different alternative materials that at least to some extent allow the replacement of resin in wood composite panels. A promising approach that has been achieved is to use soybeans as a substitute for resin, which is an inexpensive and rapidly renewable material. However, when using soybeans as an alternative material, difficulties still exist with respect to the quality and durability of the resulting panels, such as physical resistance and chemical resistance, compared to panels made only from resin.

[0003] Accordingly, it is an object of the present invention to provide an inexpensive and environmentally friendly alternative for manufacturing wood composite panels while achieving high quality of the panels produced. Summary of the Invention

[0004] The noted problems are solved at least in part by a method for manufacturing a wood composite panel according to claim 1, a corresponding wood composite panel according to claim 11, and a corresponding system for manufacturing a wood composite panel according to claim 15.

[0005] In particular, the present invention relates to a method for manufacturing a wood composite panel, in particular an MDF panel, comprising the steps of: a. providing and mixing soybean flour and water in a weight ratio of about 10% to 45% to form a soybean solution; b. introducing the soybean solution into a high-pressure blowing pipeline containing wood fibers; and c. introducing resin into the high-pressure blowing pipeline to form a soybean solution wood fiber resin mixture; d. pre-drying the soybean solution wood fiber resin mixture to form a pre-dried soybean flour wood fiber resin mixture; e. hot pressing the pre-dried soybean flour wood fiber resin mixture into a wood composite panel.

[0006] Therefore, a durable and inexpensive wood composite panel can be obtained; on the one hand, a large amount of resin is replaced by soybean powder in the wood composite panel; on the other hand, the wood composite panel provides high quality, such as good physical resistance, etc. The method of the present invention provides a very uniform mixture of soybean and water and a very uniform mixture of soybean solution, wood fiber and resin, which cannot be achieved by the methods of the prior art. The above steps a to e can be carried out in a different order or preferably in a given order. Preferably, the introduction of the resin into the high-pressure blowing pipeline can be carried out downstream of the introduction of the soybean solution into the high-pressure blowing pipeline, that is, the resin is added after the soybean solution is added to the wood fiber. Water can be supplied to the soybean solution via a corresponding water regulating valve, and the water regulating valve can be adjusted according to the amount of water required to prepare the desired amount of soybean solution to start or stop the water supply. After providing a sufficient amount of water, the water regulating valve can be closed accordingly.

[0007] Soybeans can be added to water based on the amount of resin added in subsequent steps and can have an addition rate with a weight ratio of about 5% to 20% between the total amount of soybean solids and resin. For example, if it is desired to add at a solid soybean addition rate of 10% with a 20% concentration of soybean solution (equivalent to adding 20 kg of soybeans to 80 kg of water), and the resin addition flow rate is set to 1000 kg per hour, then the solid soybean addition amount can be 100 kg per hour. This is equivalent to 500 kg of 20% concentration soybean solution.

[0008] In a preferred embodiment, in step a, soybean powder and water are mixed at a weight ratio of about 12.5% to 35%, preferably at a weight ratio of about 15% to 30%, to form a soybean solution.

[0009] Therefore, a mixture with a suitable viscosity can be obtained, which contains a sufficient amount of soybeans and can also achieve suitable processability. The mixing of soybean powder and water can be adjusted according to the needs of the panel to be manufactured. The term "weight ratio" should be understood that if, for example, a mixture with a 20% weight ratio should be obtained, then, for example, 200 g of soybeans are added to 1000 g of water.

[0010] Preferably, the soybean powder can be unmodified soybean powder. Thus, an inexpensive and easily accessible soybean source can be used to manufacture the wood composite panel according to the present invention.

[0011] The temperature of the water supplied for mixing with the soybean powder can be in the range of about 4°C to 40°C, preferably about 7°C to 35°C, and most preferably about 10°C to 25°C. Within this temperature range, the mixing of soybean powder and water can be promoted. Below the said temperature, more time and energy may be required to dissolve the soybean powder in water. Above the said temperature, due to the start of soybean fermentation, the shelf life of the soybean-water mixture will be shorter (less than 2 hours). Thus, the viscosity of the mixture may increase.

[0012] In a preferred embodiment, between step d and step e, an additional step of forming a mat from the pre-dried soy flour lignocellulosic resin mixture is provided, where the mat is then hot pressed in the next step.

[0013] Taking into account the subsequent pressing step, the thickness or height of the mat can be adjusted to obtain the final suitable thickness of the resulting panel, thus allowing for rapid and proper pressing. The mat can be formed to have a thickness of about 25 mm to 500 mm, preferably about 50 mm to 350 mm. Additionally, the mat can also be sized and shaped in terms of length and / or width to obtain the suitable dimensions of the resulting panel after pressing. Alternatively, the mat can be provided as a continuous mat that forms an "infinite" panel after pressing, which can then be cut into the desired dimensions accordingly.

[0014] In a preferred embodiment, the mixing in step a includes a recycling step, where the soy solution is recycled for about 2 minutes to 180 minutes, preferably about 5 minutes to 120 minutes, and most preferably about 10 minutes to 60 minutes to obtain a homogeneous soy solution.

[0015] Thus, a specific homogeneous mixture can be obtained. The recycling can be set such that soy is continuously added during the recycling process. Thereby, enrichment of the soy solution with soy to the desired soy concentration can be achieved. Alternatively, soy can also be added to the soy solution at the start of the recycling process. The recycling flow can be regulated via a corresponding valve or gate provided in the recycling path. During the recycling process, soy can be added continuously or discontinuously.

[0016] Before the recycling step, a pre-recycling step can be performed, where pure water is recycled without adding soy. This can prevent clogging of components such as any pipelines, valves, batches, and / or mixers that the soy solution may flow through during the recycling process. The pre-recycling step can be performed for about 0.1 minute to 10 minutes, preferably about 0.5 minute to 5 minutes, and most preferably about 1 minute to 2 minutes.

[0017] In a preferred embodiment, the high-pressure blowing pipeline provides a pressure of about 0.2 MPa to 0.8 MPa, preferably about 0.3 MPa to 0.7 MPa, and most preferably about 0.4 MPa to 0.6 MPa, and / or the high-pressure blowing pipeline provides a temperature of about 100 °C to 200 °C, preferably about 130 °C to 180 °C, and most preferably about 150 °C to 165 °C.

[0018] Thus, the mixture contained in the high-pressure blowing pipeline can be pressurized and / or can have a specific elevated temperature, thereby achieving a particularly good mixing of the different composites contained in the high-pressure blowing pipeline. The high-pressure blowing pipeline can include an outlet, and the prepared mixture can then be further conveyed from the outlet towards downstream system components such as a dryer or a press.

[0019] In a preferred embodiment, the resin is a synthetic resin, preferably a PMDI resin.

[0020] Thus, a proper binding of the wood fibers can be obtained. However, the present invention is not limited to the resins mentioned above. Thus, any other suitable type of resin commonly used in the art, such as urea-formaldehyde resin or phenolic resin, etc., can also be used.

[0021] The resin and / or the soybean solution can be introduced into the high-pressure blowing pipeline at a pressure of 0.2 MPa to 0.8 MPa, preferably at a pressure of 0.3 MPa to 0.7 MPa, and most preferably at a pressure of 0.4 MPa to 0.6 MPa. Thus, a particularly good mixing of the pressurized-introduced resin and / or soybean solution with the wood fibers contained in the high-pressure blowing pipeline can be achieved. The soybean solution and the resin can be introduced or injected into the high-pressure blowing pipeline through corresponding suitable pumps and valves, which allow the establishment of the corresponding pressures for introducing or injecting the composites into the high-pressure blowing pipeline. The flow rate of the resin can be adjusted according to the thickness of the panel to be produced and can vary in the range of about 400 L to 1600 L per hour, preferably in the range of about 600 L to 1400 L per hour, and more preferably in the range of about 800 L to 1200 L per hour.

[0022] In a preferred embodiment, the water content of the soybean solution wood resin mixture obtained in step c is about 40% to 90%, preferably about 50% to 80%, and most preferably about 70%.

[0023] Therefore, the soybean solution wood resin mixture can have a low enough viscosity for further processing steps. For example, the mixture can be easily pumped to a remote location before further processing.

[0024] In a preferred embodiment, the water content of the pre-dried soybean flour wood fiber resin mixture obtained in step d is about 5% to 30%, preferably about 7% to 20%, and most preferably about 10%.

[0025] Accordingly, the excess moisture that may damage the subsequent pressing process can be reduced. The degree of pre-drying can be adjusted according to the parameters of the downstream press, for example, based on the temperature used in the pressing process. The pre-drying process can be carried out for about 1 second to 60 seconds, preferably about 3 seconds to 30 seconds, more preferably about 4 seconds to 20 seconds, and most preferably about 5 seconds to 6 seconds. The pre-drying time can depend on the moisture content of the soy solution lignocellulose resin mixture and can be adjusted accordingly. In addition, the drying process parameters can also be adjusted considering the thickness of the panel or the amount of the mixture to be dried, and the drying process parameters can also include a suitable pre-drying temperature.

[0026] In a preferred embodiment, the recycling step and the injection step of the soy solution are carried out simultaneously.

[0027] This can reduce the panel manufacturing processing time because the soy solution preparation step and the step of injecting the soy solution into the high-pressure blowing pipeline and mixing the soy solution with the lignocellulose are carried out in parallel. The respective steps can be controlled in such a way that when the injection into the high-pressure blowing pipeline is completed, a new batch of soy solution has been prepared. Accordingly, the new batch of solution can be immediately conveyed.

[0028] The present invention also relates to a wood composite panel obtainable by the method according to any one of the preceding claims, wherein the panel comprises: at least about 0.1% to 3.0% by weight of soybeans, preferably about 0.2% to 1.2% by weight of soybeans, and most preferably about 0.4% to 0.8% by weight of soybeans.

[0029] Accordingly, a durable and inexpensive wood-based composite panel comprising soybeans is obtained. The panel according to the present invention may of course also comprise any other suitable materials common in the field of manufacturing composite panels, such as additives, fillers, and / or colorants.

[0030] According to an embodiment of the present invention, the wood composite panel of the present invention has the following physical properties:

[0031] Table 1: Physical properties of the soybean panel samples according to the present invention and the corresponding comparative control panels without soybeans

[0032]

[0033] The above panel samples were obtained using a continuous press with a press speed of 10.82 m per second. In the above table, "density" is the average density of each sample, "surface density" is the highest density of the panel sample near the surface of each sample, and "core density" is the lowest density of the panel sample near the center of the panel. The density at each sample thickness was measured using an x-ray density measuring machine. "IB" is "Internal bond strength", which can be obtained by measuring the force required to break a 25 cm 2 sample in the thickness direction using a dynamometer machine. "MOR" is "Modulus of rupture", which can be obtained by measuring the force required to bend a 250 cm 2 sample to the breaking point using a dynamometer machine. "TS" is "Thickness swell", which can be obtained by measuring the initial thickness of the 250 cm 2 panel sample before soaking in water and the final thickness after soaking in water for 24 hours. "MC" is "Moisture content", which can be obtained by measuring the initial weight of the 225 cm 2 panel sample and the final weight after drying in an oven for 24 hours. As can be seen from Table 1 above, the wood-based composite panel containing soybeans can obtain the same or even improved physical properties as the comparative wood-based composite panel without soybeans.

[0034] The present invention also relates to a system for manufacturing a wood composite panel, particularly an MDF panel, wherein the system comprises: a mixing device for mixing water with soybean powder to form a soybean solution; a high-pressure blowing pipeline connected to the mixing device, the high-pressure blowing pipeline comprising: a wood fiber port for introducing wood fibers into the high-pressure blowing pipeline; a soybean solution port for introducing the soybean solution into the high-pressure blowing pipeline; and a resin port for introducing resin into the high-pressure blowing pipeline to form a soybean solution wood fiber resin mixture; wherein the system further comprises: a dryer provided downstream of the high-pressure blowing pipeline and for pre-drying the soybean solution wood resin mixture to obtain a pre-dried soybean powder wood fiber resin mixture; and a press for hot-pressing the pre-dried soybean powder wood fiber resin mixture to form a wood composite panel.

[0035] Accordingly, a system is provided that allows for the manufacture of inexpensive and durable wood composite panels. Preferably, the resin port can be arranged downstream of the soy solution port such that the resin is added after the soy solution has been added to the wood fibers in the high-pressure blowing line. The blowing line can include other ports for introducing other compounds, such as additives, fillers, and / or colorants, etc., to mix and obtain the wood composite panel. The dryer can be any type of dryer that allows for proper drying of the mixture, such as a hot air dryer or a pneumatic flash dryer including a dryer fan that provides hot air to dry the mixture. The press can be a continuous press, such as a belt press, but is not limited to this type of press. Thus, any other suitable type of press for pressing the soy flour wood fiber resin mixture into a panel can also be used, such as a flat press, etc. If a continuous press is employed, the press can operate at a speed of about 100 mm to 5000 mm per second, preferably about 270 mm to 2700 mm per second. A pressing time of about 0.1 minute to 30 minutes, preferably 0.5 minute to 15 minutes, and most preferably about 1 minute to 7 minutes can be used. The suitable pressure applied by the press can be up to about 1500 N / mm 2 , preferably up to about 1000 N / mm 2 , more preferably up to about 500 N / mm 2 . The temperature used in the press can be about 80°C to 400°C, preferably about 120°C to 300°C, and more preferably about 170°C to 230°C.

[0036] In a preferred embodiment, the system further includes a mat forming device for forming the pre-dried soy solution wood resin mixture into a mat before pressing.

[0037] Accordingly, before pressing, the pre-dried soy solution wood resin mixture can be made into a suitable predetermined shape and size. The mat forming device can include means for providing a suitable shape, including, for example, means for setting the suitable height, length, and width of the mat according to the desired dimensions of the panel. The mixture can also be placed on a continuous conveyor belt to form mats of different sizes and heights. Thus, the mat forming device and the conveyor belt can be controlled relative to each other accordingly such that a predetermined amount of the pre-dried soy solution wood resin mixture can be placed on the conveyor belt moving at different speeds each time. In addition, the processing times of the mat forming device, the conveyor belt, and the press can be controlled relative to each other accordingly to allow one or more mats to be continuously fed into the press.

[0038] In a preferred embodiment, the mixing device comprises: a soybean solution preparation tank having an inlet and an outlet; and a mixer, preferably a high-shear mixer, having an inlet and an outlet; wherein the inlet of the mixer is connected to the outlet of the soybean solution preparation tank to receive water or a soybean solution from the soybean solution preparation tank; and wherein the outlet of the mixer is connected via a recirculation path to the inlet of the soybean solution preparation tank to allow recirculation of the water or the soybean solution.

[0039] Thus, proper recirculation of the soybean solution to be prepared can be obtained to allow a constant mixture of soybeans and water to be obtained. The mixing device can be a single element or can comprise a plurality of elements interconnected and working together to effect proper mixing. In particular, the use of a high-shear mixer can improve mixing, thereby reducing the effective time required to obtain a uniformly mixed soybean solution. The preparation tank can be of appropriate size to allow storage of an appropriate amount of soybean solution. Of course, the present invention is not limited to providing only one soybean solution preparation tank or one mixer, and can also include a plurality of corresponding soybean solution preparation tanks or a plurality of mixers.

[0040] In addition, the system can include a three-way valve that can be disposed between the soybean solution preparation tank and the soybean solution feed tank for allowing flow to the soybean solution feed tank or allowing recirculation back to the soybean solution preparation tank. The three-way valve can be set to the following states: allowing flow from the soybean solution preparation tank to the soybean solution feed tank and blocking recirculation back to the soybean solution preparation tank. Alternatively, the three-way valve can be set to a different state: blocking flow from the soybean solution preparation tank and allowing recirculation back to the soybean solution preparation tank. Thus, during the manufacturing process of the wood composite panel according to the present invention, proper control of the fluid flow can be obtained. Of course, if desired, the system of the present invention can also be equipped with other or different fluid flow control devices, such as different or other valves.

[0041] The system may further include a wood refiner, which can be supplied with any type of suitable wood chips, such as softwood or hardwood. The wood chips can be supplied to the refiner via a wood chip supply path. In addition, hot press steam can be supplied to the refiner via a steam supply path. The supplied hot steam can provide an increased pressure, for example, in the range of about 0.3 MPa to 1.5 MPa, preferably in the range of about 0.6 MPa to 1.0 MPa, and most preferably about 0.8 MPa, to decompose the wood chips into wood fibers. To decompose the wood chips into wood fibers of a suitable size, an appropriate amount of electricity can be used, such as in the range of about 25 kW to 250 kW per ton of wood chips, preferably in the range of about 50 kW to 200 kW, more preferably in the range of about 75 kW to 150 kW, and most preferably about 100 kW, to power the refiner. Decomposing the wood chips into fibers may take about 0.5 minutes to 20 minutes, preferably about 2 minutes to 10 minutes, more preferably about 3 minutes to 5 minutes, and can be carried out at a temperature of about 80 °C to 300 °C, preferably about 130 °C to 250 °C, most preferably about 160 °C, and / or at a pressure of about 0.2 MPa to 1.5 MPa, preferably about 0.4 MPa to 1 MPa, most preferably about 0.6 MPa.

[0042] The system may further include a device for separating coarse particles, such as a cyclone separator, etc., which can be used to separate, for example, the solid components of a pre-dried soybean flour wood fiber resin mixture (i.e., wood fibers, resin, soybean flour, and any other solids) from the hot air stream provided by a dryer located upstream of the separator. The separation may take about 5 seconds to 120 seconds, preferably about 10 seconds to 60 seconds, and most preferably about 15 seconds to 20 seconds.

[0043] In a preferred embodiment, the system further includes a soybean solution feed tank, which is adapted to receive the soybean solution from the soybean solution preparation tank and is also adapted to convey the soybean solution to a high-pressure blowing pipeline, preferably, adapted to convey the soybean solution to the high-pressure blowing pipeline via a pump disposed between the soybean solution feed tank and the high-pressure blowing pipeline.

[0044] The soybean solution preparation tank can be filled with water to a predetermined level to ensure a uniform soybean concentration can also be obtained in different batches of soybean solution, such as one or more consecutive batches. The preparation of the soybean solution in the soybean solution preparation tank can be carried out while the soybean solution feed tank feeds the soybean solution into the high-pressure blowing pipeline. This allows for time savings and increased productivity of the claimed system. Thus, this can reduce or even completely prevent downtime before a newly prepared batch of soybean solution can be injected into the high-pressure blowing pipeline.

[0045] The soybean solution prepared in the soybean solution preparation tank can be transferred to the soybean solution feed tank before the soybean solution feed tank is completely emptied. Thus, the transfer to the high-pressure blowing pipeline can be stopped, and the soybean solution feed tank can be refilled with a newly prepared batch of soybean solution from the soybean solution preparation tank. The minimum liquid level of the soybean solution in the soybean solution feed tank at which the supply of the newly prepared soybean solution starts can be set to prevent the soybean solution feed tank from being completely emptied. Thus, sufficient time can be provided to pump the soybean solution from the soybean solution preparation tank to the soybean solution feed tank without the risk of interruption of panel production due to the exhaustion of the soybean solution. The minimum soybean solution level in the soybean solution feed tank can depend on the required flow rate and the tank capacity used, and can be about 5% to 40%, preferably about 10% to 30%, more preferably about 20% of the total storage volume of the tank. The present invention is of course not limited to providing only one soybean solution feed tank, and may also include a plurality of corresponding soybean solution feed tanks. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Hereinafter, specific embodiments of the present invention will be briefly described with reference to the drawings. It should be noted that the drawings only depict exemplary embodiments of the present invention and are only for illustrative purposes to enhance the understanding of the present invention, and thus do not limit the present invention to the described configurations.

[0047] Figure 1 A schematic diagram of a panel manufacturing system according to an embodiment of the present invention is shown, and

[0048] Figure 2 A schematic working flowchart of a panel manufacturing method according to an embodiment of the present invention is shown.

[0049] Figure 1FIG. 0 shows a schematic diagram of a panel manufacturing system 100 according to an embodiment of the present invention. The panel manufacturing system includes: a water supply device 1 that supplies water to a soybean solution preparation tank 5 via a water regulating valve 3. Water is filled into the soybean solution preparation tank 5 until a predetermined water level is reached. Then, the water regulating valve 3 is closed, and the water is recirculated for 1 to 2 minutes (also referred to as pre-recirculation). Pre-recirculation can prevent the mixer 9 from being blocked. During pre-recirculation, water is guided from the soybean solution preparation tank 5 through the soybean solution preparation tank outlet 15 towards the mixer inlet 8. Then, the water is guided through the mixer 9 and further towards the three-way valve 11 from the mixer outlet 10. Therefore, the three-way valve 11 is controlled to be in a state of opening towards the recirculation path 13 and closing towards the soybean solution feed tank supply path 17. Thus, the water is recirculated back to the soybean solution preparation tank inlet 16 via the recirculation path 13. After the pre-recirculation is completed, while the water is circulating, a predetermined amount of soybean powder is supplied to the mixer 9 via the soybean powder supply path 7. Thus, the soybean powder is mixed with the circulating water to form a soybean solution. The soybean solution is continuously recirculated for about 10 to 60 minutes to obtain a uniform and consistent mixture. During the recirculation process, additional soybean powder is added and mixed. Thus, a predetermined amount of soybean powder is continuously supplied to the recirculating soybean solution until an appropriate amount of soybean solution with a sufficiently high soybean concentration is prepared. The soybean solution can be temporarily stored in the soybean solution preparation tank 5. After obtaining the required amount and concentration of the soybean solution, the three-way valve 11 is controlled to close towards the recirculation path 13 and open towards the soybean solution feed tank supply path 17. Thus, the soybean solution is supplied to the soybean solution feed tank 19 via the soybean solution feed tank inlet 18.

[0050] After the soybean solution is transported to the soybean solution feed tank 19, the three-way valve 11 closes again towards the soybean solution feed tank supply path 17 and opens again towards the recirculation path 13, so that a new batch of soybean solution can be prepared and stored in the soybean solution preparation tank 5. The soybean solution is continuously transported from the soybean solution feed tank 19 via the soybean solution feed tank outlet 20, the soybean solution pump 21, and through the blowline soybean solution supply path 23 to the soybean solution port 24 of the high-pressure blowline 31. Then the soybean solution is injected into the high-pressure blowline 31 at a pressure of 0.4 MPa to 0.6 MPa.

[0051] Once the soybean solution feed tank 19 reaches a predetermined minimum liquid level, the supply of the soybean solution to the high-pressure blowline 31 is stopped, and the soybean solution feed tank 19 can be refilled with a new batch of soybean solution from the soybean solution preparation tank 5. The soybean solution feed tank 19 is provided with an internal stirrer that keeps the soybean solution uniform when the soybean solution is transported to the high-pressure blowline 31.

[0052] The panel manufacturing system 100 further includes a wood refiner 25, which is supplied with wood chips via a wood chip supply path 27 and hot pressing steam at 0.8 MPa via a steam supply path 29. The wood refiner 25 is supplied with 100 kW of electricity per ton of wood chips and decomposes the wood chips into wood fibers at a temperature of 160 °C and a pressure of 0.6 MPa within approximately 3 to 5 minutes. The resulting wood fibers are supplied to a high-pressure blowing pipeline 31 via a wood fiber port 26 upstream of a soybean solution port 24. PMDI resin is transported to the high-pressure blowing pipeline 31 through a blowing pipeline resin supply path 37 via a resin supply path 33 and a resin pump 35. The resin is injected into the high-pressure blowing pipeline 31 downstream of the soybean solution port 24 at a pressure of 0.4 MPa to 0.6 MPa at a resin port 38.

[0053] The high-pressure blowing pipeline 31 operates at a pressure of 0.4 MPa to 0.6 MPa and a temperature of 150 °C to 165 °C. The hot-pressed soybean powder wood fiber resin mixture finally exits the high-pressure blowing pipeline 31 and heads towards a dryer 39, where the mixture is pre-dried from a water content of approximately 70% to a water content of approximately 10% within about 5 to 6 seconds. Then, the pre-dried soybean powder wood fiber resin mixture is transported from the dryer 39 to a cyclone separator 41 to separate the solid components of the pre-dried soybean powder wood fiber resin mixture from the hot air stream within about 15 to 20 seconds. Thus, the pre-dried soybean powder wood fiber resin mixture separated in this way is supplied to a mat forming device 43, where the pre-dried soybean powder wood fiber resin mixture is placed on a continuous conveyor belt 45 to form a mat 47 with a predetermined thickness between 50 mm and 350 mm. Then, the mat 47 is transported via the conveyor belt 45 to a continuous press 49, which appropriately presses the mat into a wood composite panel 51.

[0054] Figure 2 A schematic working flowchart of a panel manufacturing method 200 according to an embodiment of the present invention is shown, and the panel manufacturing method includes different manufacturing steps. In a first step 210, soybean powder and water with a weight ratio of approximately 10% to 45% are provided to form a corresponding soybean solution. Subsequently, in a second step 220, the soybean solution is introduced into a high-pressure blowing pipeline 31 containing wood fibers. Subsequently, in a third step 230, resin is introduced into the high-pressure blowing pipeline 31. The resin is introduced downstream of the soybean solution introduction position. Thus, a soybean solution wood fiber resin mixture is formed. Subsequently, in a fourth step 240, the soybean solution wood fiber resin mixture is pre-dried, thereby forming a pre-dried soybean powder wood fiber resin mixture. Finally, in a fifth step 250, the pre-dried soybean powder wood fiber resin mixture is hot-pressed into a wood composite panel 51.

[0055] List of reference signs

[0056] 1: Water supply device

[0057] 3: Water regulating valve

[0058] 5: Soybean solution preparation tank

[0059] 7: Soybean powder supply path

[0060] 8: Mixer inlet

[0061] 9: Mixer

[0062] 10: Mixer outlet

[0063] 11: Three-way valve

[0064] 13: Recirculation path

[0065] 15: Soybean solution preparation tank outlet

[0066] 16: Soybean solution preparation tank inlet

[0067] 17: Soybean solution feed tank supply path

[0068] 18: Soybean solution feed tank inlet

[0069] 19: Soybean solution feed tank

[0070] 20: Soybean solution feed tank outlet

[0071] 21: Soybean solution pump

[0072] 23: Blowing pipeline soybean solution supply path

[0073] 24: Soybean solution port

[0074] 25: Wood refiner

[0075] 26: Wood fiber port

[0076] 27: Wood chip supply path

[0077] 29: Steam supply path

[0078] 31: High-pressure blowing pipeline

[0079] 33: Resin supply path

[0080] 35: Resin pump

[0081] 37: Blowing pipeline resin supply path

[0082] 38: Resin port

[0083] 39: Dryer

[0084] 41: Cyclone separator

[0085] 43: Pad forming device

[0086] 45: Conveyor belt

[0087] 47: Pad

[0088] 49: Press

[0089] 51: Panel

[0090] 100: Panel manufacturing system

[0091] 200: Panel manufacturing method

[0092] 210: First manufacturing step

[0093] 220: Second manufacturing step

[0094] 230: Third manufacturing step

[0095] 240: Fourth manufacturing step

[0096] 250: Fifth manufacturing step

Claims

1. A method (200) for manufacturing a wood composite panel (51), particularly an MDF panel, comprising the following steps: a. Providing and mixing (210) soybean flour and water in a weight ratio of about 10% to 45% to form a soybean solution; b. Introducing (220) the soybean solution into a high-pressure blowing pipeline (31) containing wood fibers; c. Introducing (230) resin into the high-pressure blowing pipeline (31) to form a soybean solution wood fiber resin mixture; And d. Pre-drying (240) the soybean solution wood fiber resin mixture to form a pre-dried soybean flour wood fiber resin mixture; e. Hot-pressing (250) the pre-dried soybean flour wood fiber resin mixture into the wood composite panel (51).

2. The method according to the preceding claim, wherein, In step a, the soybean flour and water are mixed in a weight ratio of about 12.5% to 35%, preferably in a weight ratio of about 15% to 30% to form the soybean solution.

3. The method according to any one of the preceding claims, wherein, Between steps d and e, an additional step of forming a mat (47) from the pre-dried soybean flour wood fiber resin mixture is provided, where the mat (47) is then hot-pressed in the next step.

4. The method according to any one of the preceding claims, wherein, The mixing in step a includes a recycling step, where the soybean solution is recycled for about 2 minutes to 180 minutes, preferably about 5 minutes to 120 minutes, most preferably about 10 minutes to 60 minutes, to obtain a uniform soybean solution.

5. The method according to any one of the preceding claims, wherein, The high-pressure blowing pipeline (31) provides a pressure of about 0.2 MPa to 0.8 MPa, preferably about 0.3 MPa to 0.7 MPa, most preferably about 0.4 MPa to 0.6 MPa.

6. The method according to any one of the preceding claims, wherein, The high-pressure blowing pipeline (31) provides a temperature of about 100 °C to 200 °C, preferably about 130 °C to 180 °C, most preferably about 150 °C to 165 °C.

7. The method according to any one of the preceding claims, wherein, The resin is a synthetic resin, preferably a PMDI resin.

8. The method according to any one of the preceding claims, wherein, The water content of the soybean solution wood resin mixture obtained in step c is about 40% to 90%, preferably about 50% to 80%, most preferably about 70%.

9. The method according to any one of the preceding claims, wherein The water content of the pre-dried soybean flour wood fiber resin mixture obtained in step d is about 5% to 30%, preferably about 7% to 20%, most preferably about 10%.

10. The method according to any one of the preceding claims 4 to 9, wherein, The recycling step and the injection step of the soybean solution are carried out simultaneously.

11. A wood composite panel (51), obtainable by the method according to any one of the preceding claims, wherein, The panel (51) comprises: at least about 0.1% to 3.0% by weight of soybean, preferably about 0.2% to 1.2% by weight of soybean, most preferably about 0.4% to 0.8% by weight of soybean.

12. A system (100) for manufacturing a wood composite panel (51), in particular an MDF panel, wherein, The system (100) comprises: A mixing device for mixing water with soybean flour to form a soybean solution; A high-pressure blowing pipeline (31) connected to the mixing device, the high-pressure blowing pipeline comprising: A wood fiber port (26) for introducing wood fibers into the high-pressure blowing pipeline (31), A soybean solution port (24) for introducing the soybean solution into the high-pressure blowing pipeline (31), and A resin port (38) for introducing resin into the high-pressure blowing pipeline (31) to form a soybean solution wood fiber resin mixture; wherein, the system (100) further comprises: a dryer (39) disposed downstream of the high-pressure blowing pipeline (31) and configured to pre-dry the soybean solution wood resin mixture to obtain a pre-dried soybean powder wood fiber resin mixture; and a press (49) configured to hot-press the pre-dried soybean powder wood fiber resin mixture to form the wood composite panel (51).

13. The system (100) according to the preceding claim, wherein, The system (100) further comprises: a mat forming device (43) configured to form the pre-dried soybean solution wood resin mixture into a mat (47) before pressing.

14. The system (100) according to any one of the preceding claims, wherein, The mixing device comprises: a soybean solution preparation tank (5) having an inlet (16) and an outlet (15); and a mixer (9), preferably a high-shear mixer, having an inlet (8) and an outlet (10), wherein the inlet (8) of the mixer is connected to the outlet (15) of the soybean solution preparation tank to receive water or soybean solution from the soybean solution preparation tank (5); and wherein the outlet (10) of the mixer is connected to the inlet (16) of the soybean solution preparation tank via a recirculation path (13) to allow recirculation of the water or the soybean solution.

15. The system (100) according to any one of the preceding claims, wherein, The system (100) further comprises: a soybean solution feed tank (19) adapted to receive the soybean solution from the soybean solution preparation tank (5) and further adapted to transport the soybean solution to the high-pressure blowing pipeline (31), preferably adapted to transport the soybean solution to the high-pressure blowing pipeline (31) via a pump (21) disposed between the soybean solution feed tank (19) and the high-pressure blowing pipeline (31).

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