Production method of formaldehyde-free routed fiberboard for electrostatic powder spraying

Abstract

The present application belongs to the technical field of fiberboard production, and particularly relates to a production method of formaldehyde-free milling fiberboard for electrostatic powder spraying, which comprises the steps of wood selection, wood treatment to obtain wood fibers, wax and glue application, and hot pressing. In the wood selection step, 10-20% of eucalyptus wood and 80-90% of miscellaneous wood are selected. In the wood treatment to obtain wood fibers step, the length of eucalyptus wood fibers is 202-318 μm, and the length of miscellaneous wood fibers is 221-404 μm. In the wax and glue application step, the applied adhesive is isocyanate glue, and the application amount is 4.5-5% of the weight percentage of the dry fibers. In the hot pressing step, the process parameters of hot pressing are as follows: the temperature of the high-pressure section is 190-200℃, the pressure is 1.0-4.0 N / mm 2 ; the temperature of the pressure maintaining section is 190-195℃, the pressure is 0.2-0.8 N / mm 2 ; and the temperature of the thickness setting section is 185-190℃, the pressure is 1.0-1.9 N / mm 2 . The formaldehyde-free fiberboard prepared by the production method has a smooth surface and high internal bonding strength when applied to milling processing, and is not prone to cracking when applied to electrostatic powder spraying processing, thereby improving the utilization rate of formaldehyde-free milling fiberboard.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fiberboard production, and particularly relates to a production method of formaldehyde-free milling fiberboard for electrostatic powder spraying. BACKGROUND

[0002] In recent years, electrostatic powder spraying method has been applied to the deep processing of fiberboard. The electrostatic powder spraying method is different from the general electrostatic spraying method of liquid coating in that the medium of powder spraying is dispersed, not atomized. The coating sprayed by the electrostatic powder spraying gun is dispersed while making the powder particles negatively charged. The charged powder particles are attached to the grounded coated object under the action of air flow (or centrifugal force and other forces) and electrostatic force, and then are heated, melted and solidified into a film. The electrostatic powder spraying process technology is increasingly widely used in the surface treatment of fiberboard furniture due to its low cost, better hardness, wear resistance, aging resistance and other advantages. However, the internal material properties and surface quality of the fiberboard will directly affect the milling effect and spraying quality.

[0003] The formaldehyde-free milling fiberboard is called formaldehyde-free board because no adhesive containing formaldehyde or other additives containing formaldehyde is added, and the formaldehyde emission reaches the limit value ≤0.025mg / m³ (climate chamber detection method) standard. Some enterprises can also achieve higher standards, so the formaldehyde-free milling fiberboard has stronger advantages in environmental safety than E1 / E0 grade board, and also has excellent moisture resistance. In terms of nail holding force, elastic modulus, static bending strength, heat resistance, boiling resistance and other aspects, it meets the national standards, so the formaldehyde-free milling fiberboard is attracting more and more attention. The development of medium-density formaldehyde-free MDI fiberboard has been relatively rapid in recent years, and the production capacity of MDI fiberboard is continuously expanding. Although MDI fiberboard does not add formaldehyde, its environmental protection is beyond doubt, but as its application range gradually increases, the limitations in processing performance are becoming more and more prominent, especially in milling processing. The milling performance of MDI fiberboard is poorer than that of urea-formaldehyde resin board, which is manifested in that the milling surface smoothness is not enough, the internal bonding strength is low, and the application in electrostatic powder spraying processing is prone to cracking, thereby causing low utilization rate of formaldehyde-free milling fiberboard.

[0004] At present, there are many studies on improving the milling performance of MDI fiberboard by improving isocyanate glue, such as patent CN110272707A discloses an isocyanate adhesive composition and a milling fiberboard manufactured thereby, the inventor uses double-crown layer silica composite material and lignin material to form a secondary skeleton in a synergistic coating manner, which improves the defects of pure isocyanate, and realizes the goals of no hair on the milling section and good dimensional stability; patent CN113601660A discloses a water glass homogeneous isocyanate and a formaldehyde-free milling fiberboard prepared thereby, which uses water glass homogeneous isocyanate to improve the milling performance of the formaldehyde-free milling fiberboard. However, the formaldehyde-free milling fiberboard prepared by the above patents still needs to be studied in improving the coating film performance of electrostatic powder spraying. SUMMARY

[0005] The purpose of the present application is to provide a production method of formaldehyde-free milling fiberboard for electrostatic powder spraying, which overcomes the defects of insufficient smoothness of the milling surface of the fiberboard, low internal bonding strength, insufficient paint film adhesion in spraying decoration, uneven adsorption, and easy blistering and cracking of the paint film.

[0006] To achieve the above-mentioned purpose, the present application provides a production method of formaldehyde-free milling fiberboard for electrostatic powder spraying, which comprises the steps of wood selection, wood treatment to obtain wood fibers, wax and glue application, and hot pressing.

[0007] In the wood selection step, eucalyptus wood and miscellaneous wood are used as raw materials, and the weight ratio of each component is 10-20% of eucalyptus wood and 80-90% of miscellaneous wood; further, the miscellaneous wood is one or more of broad-leaved materials such as Quercus macrophylla, Dendrobium and Schisandra.

[0008] In the wood treatment step to obtain wood fibers, the length of eucalyptus wood fibers is 202-318pm, and the length of miscellaneous wood fibers is 221-404pm.

[0009] In the wax and glue application step, the applied adhesive is isocyanate glue, and the application amount of the isocyanate glue is 4.5-5% based on the weight percentage of dry fibers; further, the isocyanate glue is first mixed with water at a ratio of 1:1.5-2 and then applied to the wood fibers.

[0010] In the hot pressing step, the process parameters of hot pressing are as follows: the temperature of the high-pressure section is 190-200℃, the pressure is 1.0-4.0N / mm 2 ; the temperature of the pressure maintaining section is 190-195℃, the pressure is 0.2-0.8N / mm 2 ; the temperature of the thickness setting section is 185-190℃, the pressure is 1.0-1.9N / mm 2 ; further, the hot pressing plate time is 250-350S.

[0011] The broad-leaved wood such as Quercus leucotricha, Syzygium Zeylanicum and Lithocarpus polystachyus is selected as one or more kinds of mixed wood with eucalyptus wood, the fiber size of which is similar to that of eucalyptus wood, and the mixed wood with eucalyptus wood can achieve the tightness of the milling board and maintain the interweaving of the fibers, thereby saving the cost of material selection and effectively preventing the cracking in the electrostatic powder spraying process; the viscosity of the isocyanate adhesive is about 26S at 25 DEG C by using a No. 4 cup test, and the viscosity of the MDI adhesive is reduced to below 20S after being diluted by mixing with water at a ratio of 1:1.5-2, so as to ensure the dispersibility and uniformity of the adhesive in the process of applying the adhesive to the board, thereby ensuring that the internal bonding strength of the board is above 1.6 MPa; the press is fixed with 6 heating cycles, the first and second cycles correspond to the high-pressure section of the process, the third to fifth cycles correspond to the pressure maintaining section, and the sixth cycle corresponds to the thickness setting section. The temperature before and after the heating cycle process has no obvious difference, and the hot pressing temperature is 185-200 DEG C, which effectively prevents the problems of bubbling and strength degradation of the board due to overheating;

[0012] Further, in the production method of the above-mentioned electrostatic powder spraying formaldehyde-free milling fiber board, in the wax application and adhesive application step, the adhesive components applied are as follows: multifunctional POSS 0.1-0.5%, isocyanate adhesive 4.5-5%, catalyst organic tin 0.05-0.1%, and hydrated lithium chloride 0.5-0.8%, based on the percentage of the weight of the dry fiber; further, the structural formula of the multifunctional POSS is wherein R is a hydroxyl group; the isocyanate adhesive is first mixed with water at a ratio of 1:1.5-2 and then applied to the wood fibers.

[0013] The multifunctional POSS has special nano structure, nano size effect, cross-linking effect, effective modification of polymers, and good and controllable miscibility, and also contains eight hydroxyl reaction functional groups, which can be chemically bonded with the isocyanate groups in the isocyanate adhesive under the action of the catalyst organic tin, so as to quickly bond the adhesive with the wood fiber and further improve the comprehensive performance of the board. The addition of the lava hydrate lithium chloride can reduce the crystallinity of cellulose and make the two kinds of wood cellulose better cross-linked, so that the comprehensive performance of the board is significantly improved by optimizing the adhesive.

[0014] Further, in the wax and glue applying step of the above production method of the electrostatic powder spraying formaldehyde-free milling fiberboard, the wax applied is paraffin wax and paraffin wax dispersion, and further, the paraffin wax is 58# full refined or semi-refined paraffin wax, and the application amount is 0.2-0.25% of the weight of the absolutely dry fiber; further, the main components of the paraffin wax dispersion include 40% paraffin wax and 5% lignin, and the rest is water; and the application amount is 0.17-0.22% of the weight of the absolutely dry fiber. In order to ensure moisture resistance and consider the economy of cost, the combination of 58# full refined or semi-refined paraffin wax and paraffin wax dispersion is used, and in the process of applying wax, the diameter of the 58# full refined or semi-refined paraffin wax is about 5-10 microns, and the diameter of the paraffin wax dispersion can reach 0.2-0.5 microns, and when spreading on the surface of the wood fiber, it can be quickly absorbed and fully combined to achieve good coverage effect, further reducing the amount of paraffin wax while not reducing the waterproof effect of the board.

[0015] Further, in the production method of the electrostatic powder spraying formaldehyde-free milling fiberboard, the thickness of the electrostatic powder spraying formaldehyde-free milling fiberboard is 18-22 mm; and the average density is 800-820 kg / m 3 The average density of the board affects the electrostatic powder spraying effect, and if the average density of the board is low, the strength is not enough, so that the board is easy to crack in the process of electrostatic powder spraying; if the average density of the board is high, the production cost is increased, and the production efficiency is affected. The thickness of the formaldehyde-free milling fiberboard produced by the present application is 18-22 mm; and the average density is 800-820 kg / m 3 The structure of the board ensures a reasonable core-to-surface layer density ratio, and the density distribution is smooth without depression, and the core layer density ratio is more than 90%, which meets the milling requirements and can be processed by electrostatic powder spraying.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1. The production method of formaldehyde-free milling fiberboard for electrostatic powder spraying provided by the present application selects broadleaf materials such as Quercus infectoria, Dendrobium and Schima superba as mixed wood, and eucalyptus 10-20%, mixed wood 90-80% when selecting materials, which saves cost and maintains fiber interweaving; the application amount of wax and isocyanate glue is controlled in wax and glue application, and the isocyanate glue is mixed and diluted with water in a certain proportion, which can increase the dispersion and uniformity of the glue when applied; the combination of paraffin and paraffin dispersion liquid can quickly and fully combine with the fiber, achieving good covering effect; the optimization of hot pressing process effectively prevents the problems of bubble and strength degradation of the board due to overheating; the improvement of these processes makes the internal bonding strength of the produced formaldehyde-free milling fiberboard reach more than 1.6 MPa, the milling surface of the board is smooth, the paint film has strong adhesion in the electrostatic powder spraying process, the adsorption is uniform, the paint film does not bubble and crack, so that the utilization rate of the board is increased from 60% to 90%, greatly improving the production effect and reducing the production cost.

[0018] 2. The production method of formaldehyde-free milling fiberboard for electrostatic powder spraying provided by the present application, through the improvement of the adhesive, a multifunctional POSS containing eight hydroxyl functional groups is used to chemically bond with the isocyanate group in the isocyanate glue under the action of the catalyst organic tin, so that the adhesive is quickly and adsorbed with the wood fiber, and lithium chloride hydrate is added to reduce the crystallinity of cellulose, increase the density and strength of the board, and further improve the comprehensive performance of the formaldehyde-free milling fiberboard, so that the produced formaldehyde-free milling fiberboard is more suitable for milling process and electrostatic powder spraying process. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The eucalyptus wood fiber used in the present application.

[0020] Figure 2 The mixed wood fiber used in the present application.

[0021] Figure 3 The cross-sectional density distribution diagram of the formaldehyde-free fiberboard prepared in Example 1 of the present application.

[0022] Figure 4 The cross-sectional density distribution diagram of the formaldehyde-free fiberboard prepared in Comparative Example 1.

[0023] Figure 5 The formaldehyde-free fiberboard prepared in Example 1 of the present application does not crack in the electrostatic spraying process.

[0024] Figure 6 The formaldehyde-free fiberboard of Comparative Example 1 cracks in the electrostatic spraying process.

[0025] Figure 7The static spraying effect diagram of the formaldehyde-free fiberboard prepared in Example 1 of the present application. Embodiments

[0026] The specific embodiments of the present application are described in detail below, but it should be understood that the protection scope of the present application is not limited by the specific embodiments. Example 1

[0027] The present embodiment provides a production method of formaldehyde-free milling fiberboard for electrostatic powder spraying, which comprises the following steps: Figures 1-7 , including the following steps:

[0028] (1) Wood selection: wood is used as raw material, 20% of which is eucalyptus wood and 80% of which is miscellaneous wood, the age of the eucalyptus wood and the miscellaneous wood is 3-6 years, and the felled wood is stacked for no more than 4 months;

[0029] (2) Wood treatment to obtain wood fibers: the selected wood is flaked by a flaker to obtain wood chips, and then the wood chips are cooked in a cooking cylinder at a temperature of 170-180℃ and a pressure of 8.8-9.2 bar for 3.8-4.0 min, and then sent to a hot mill for fiber separation to obtain qualified fibers, wherein the length of eucalyptus wood fibers is 202-318μm and the length of miscellaneous wood fibers is 221-404μm;

[0030] (3) Wax and glue application: paraffin wax and paraffin wax dispersion liquid are sprayed on the wood fibers, and then adhesive is sprayed, and finally the wood fibers are sent to a drying machine for drying to reduce the moisture content of the fibers to 8-9%; wherein the applied paraffin wax is 58# full refined paraffin wax, and the application amount is 0.2% of the weight of the dry fibers; the composition of the paraffin wax dispersion liquid is 40% of 58# full refined paraffin wax, 5% of lignin, and the balance is water; the application amount is 0.17% of the weight of the dry fibers; the composition of the adhesive is isocyanate glue, and the application amount is 4.5% of the weight of the dry fibers, wherein the isocyanate glue is first mixed with water at a ratio of 1:2 and then applied to the wood fibers;

[0031] (4) Forming and pre-pressing: the dried fibers are formed into a mat, and then the mat is pre-pressed, and then the pre-pressed mat is heated by steam spraying, and the temperature of the mat is 50-60℃;

[0032] (5) Hot pressing: the pre-pressed mat is sent to a hot press for hot pressing to obtain a semi-finished product; the process parameters of hot pressing are: the temperature of the high-pressure section is 200℃, the pressure is 4N / mm 2 , the temperature of the pressure maintaining section is 195℃, the pressure is 0.8N / mm 2 , the temperature of the thickness setting section is 190℃, the pressure is 1.9N / mm 2 , and the pressing time of the high-pressure section, the pressure maintaining section and the thickness setting section is 350S; the density curve in the hot pressing process is adjusted so that the peak density is about 1050 kg / m 3 ;

[0033] (6) Cooling, after hot pressing to get into semi-finished, cooling and stacking 48 hours curing, and then sanding can get electrostatic powder spraying without formaldehyde milling fiberboard.

[0034] Comparative Example 1

[0035] The difference between this comparative example and Example 1 is that the component of the adhesive is isocyanate glue, the application amount is 4.5% of the weight of the dry fiber (not mixed with water at 1:2 for dilution and application); the process parameters of hot pressing are: high pressure section, temperature 220℃, pressure 2.7N / mm 2 ; pressure maintaining section, temperature 208℃, pressure 0.35N / mm 2 ; thickness setting section, temperature 200℃, pressure 1.7N / mm 2 , high pressure section, pressure maintaining section, thickness setting section plate time is 285 seconds, and the remaining steps are the same as Example 1.

[0036] The profile density distribution diagram of the electrostatic powder spraying without formaldehyde milling fiberboard prepared in Example 1 is shown in Figure 3 , Figure 3 The curve is smooth without depression, the density distribution is good, the core layer density can be controlled above 90%, the strength is relatively high, and it is not easy to crack. The profile density distribution of the formaldehyde-free fiberboard prepared in Comparative Example 1 is shown in Figure 4 , Figure 4 There are obvious depressions, the density distribution is poor, the core layer depression rebounds, and the core layer density ratio is low, only about 88%, the internal bonding strength is about 0.2MPa lower than that of the electrostatic powder spraying without formaldehyde milling fiberboard of this example, and it is easy to crack.

[0037] The electrostatic powder spraying is carried out on the electrostatic powder spraying without formaldehyde milling fiberboard prepared in Example 1 and Comparative Example 1, and the results are shown in Figure 5 , Figure 6 The final effect diagram of electrostatic powder spraying of the formaldehyde-free milling fiberboard of Example 1 is shown in Figure 7 .The utilization rate of the board is only 60% when the formaldehyde-free fiberboard prepared in Comparative Example 1 is processed by electrostatic spraying due to cracking, while the coating of the formaldehyde-free milling fiberboard prepared in Example 1 is smooth and flat, the coating adhesion is high, so there is no cracking, bulging and other phenomena, so that the utilization rate of the board reaches 90%, greatly improving the production effect and reducing the production cost. Example 2

[0038] The difference between this example and Example 1 is that 10% eucalyptus wood and 90% miscellaneous wood are used as raw materials for wood, and the remaining steps are the same as Example 1. Example 3

[0039] The difference between this example and Example 1 is that the adhesive components applied by the adhesive applicator are, as a percentage of the weight of the dry fibers, 0.1% multifunctional ridge-shaped POSS, 4.5% isocyanate glue, 0.05% catalyst organic tin, and 0.5% hydrated lithium chloride; the isocyanate glue is first mixed with water at a ratio of 1:1.5, and then multifunctional ridge-shaped POSS, catalyst organic tin, and hydrated lithium chloride are applied to the wood fibers, and the remaining steps are the same as in Example 1. Example 4

[0040] The difference between this example and Example 1 is that the adhesive components applied by the adhesive applicator are, as a percentage of the weight of the dry fibers, 0.5% multifunctional ridge-shaped POSS, 5% isocyanate glue, 0.1% catalyst organic tin, and 0.8% hydrated lithium chloride; the isocyanate glue is first mixed with water at a ratio of 1:2, and then multifunctional ridge-shaped POSS, catalyst organic tin, and hydrated lithium chloride are applied to the wood fibers, and the remaining steps are the same as in Example 1. Example 5

[0041] The difference between this example and Example 1 is that the wax applied is 58# semi-refined paraffin wax and a paraffin wax dispersion liquid, and the amount of 58# semi-refined paraffin wax applied is 0.25% of the weight of the dry fibers; the paraffin wax dispersion liquid has a mass percentage of 40% 58# semi-refined paraffin wax and 5% lignin, with the balance being water; the amount of paraffin wax dispersion liquid applied is 0.2% of the weight of the dry fibers, and the remaining steps are the same as in Example 1. Example 6

[0042] The difference between this example and Example 1 is that the process parameters for hot pressing are: the temperature in the high-pressure section is 190°C, the pressure is 2.2 N / mm 2 ; the temperature in the pressure-maintaining section is 190°C, the pressure is 0.2 N / mm 2 ; the temperature in the thickness-setting section is 185°C, the pressure is 1.6 N / mm 2 ; and the hot-pressing platen time is 250 s, and the remaining steps are the same as in Example 1.

[0043] Comparative Example 2

[0044] The difference between this example and Example 1 is that the wax is 58# fully refined paraffin wax, and the amount applied is 0.37% of the weight of the dry fibers, and the remaining steps are the same as in Example 1.

[0045] Comparative Example 3

[0046] The difference between this example and Example 1 is that the process parameters for hot pressing are: the temperature in the high-pressure section is 220°C, the pressure is 2.5 N / mm 2 ; the temperature in the pressure-maintaining section is 180°C, the pressure is 0.15 N / mm 2 ; the temperature in the thickness-setting section is 170°C, the pressure is 1.3 N / mm 2The hot press platen time is 350 seconds, and the remaining steps are the same as in Example 1.

[0047] Comparative Example 4

[0048] The difference between this comparative example and Example 1 is that the adhesive applied is multifunctional POSS 0.6%, isocyanate glue 4.5%, and catalyst organic tin 1%. The isocyanate glue is first mixed with water at a ratio of 1:1.5, and then multifunctional POSS and catalyst organic tin are applied to the wood fibers. The remaining steps are the same as in Example 1.

[0049] Comparative Example 5

[0050] The difference between this comparative example and Example 1 is that the adhesive applied is isocyanate glue 5% and hydrated lithium chloride 1.3%. The isocyanate glue is first mixed with water at a ratio of 1:1.5, and then hydrated lithium chloride is applied to the wood fibers. The remaining steps are the same as in Example 1.

[0051] The properties of the formaldehyde-free fiberboard produced in Examples 1-6 and Comparative Examples 1-5 are shown in Table 1.

[0052] Table 1 is the properties of the formaldehyde-free fiberboard produced in Examples 1-6 and Comparative Examples 1-5

[0053] As can be seen from the above table, in Comparative Example 1, the adhesive applied is isocyanate glue, the viscosity of the glue increases, and it is difficult to penetrate into the fibers, resulting in the fibers clumping together; in Comparative Example 2, only 58# refined paraffin wax is added, and the paraffin wax particles cannot quickly absorb the fibers for bonding; in Comparative Examples 1 and 3, the hot pressing process parameters are changed, there is a large temperature difference, the board blank is not evenly heated, the heat transfer is not equal, and the internal stress of the board blank is different; the above comparative examples have changed the adhesive, the wax applied, or the hot pressing process, which directly affects the density performance of the fiberboard, reduces the comprehensive performance of the fiberboard, and does not meet the standard requirements, making the produced fiberboard prone to delamination, cracking, and bubbling during the electrostatic powder spraying process, and greatly reducing the milling performance and electrostatic spraying performance of the fiberboard. In Examples 1-2 and Examples 5-6, by controlling the viscosity of the glue, combining paraffin wax and paraffin wax dispersion liquid, strictly controlling the amount of glue and paraffin wax, and optimizing and adjusting the press process, the density and strength of the board can be increased, and the produced formaldehyde-free fiberboard has a density of 800-820 kg / m 3, the internal bonding strength reaches 1.6 MPa or more, the maximum water absorption expansion rate is only 3.4%, the static bending strength reaches 43.25 MPa or more, which can meet the requirements of milling and effectively prevent cracking in the electrostatic powder spraying process. Examples 3-4 improve the adhesive, add multifunctional POSS and lithium chloride hydrate, and compared with Example 1, the comprehensive performance of the produced formaldehyde-free milling fiber board is significantly improved. From Comparative Examples 4-5, it can be seen that only the formaldehyde-free milling fiber board produced by the combination of multifunctional POSS and lithium chloride hydrate can achieve ideal comprehensive performance.

[0054] In summary, the production method of the formaldehyde-free milling fiber board for electrostatic powder spraying provided by the present application optimizes the selection of wood raw materials, the structure of the board and the press process, and the formaldehyde-free milling fiber board produced has low water absorption expansion rate, high internal bonding strength and high static bending strength, and the comprehensive performance is significantly improved. When applied to milling processing, the surface is smooth and not hairy, and the texture is uniform and dense; when applied to electrostatic powder spraying processing, the paint film is uniformly adsorbed, and there is no blistering or cracking, so that the utilization rate of the formaldehyde-free fiber board in electrostatic powder spraying is increased from 60% to 90%, and through the improvement of the adhesive, the comprehensive performance of the formaldehyde-free milling fiber board is significantly improved, and it is more suitable for milling process and electrostatic powder spraying process.

[0055] The foregoing description of specific exemplary embodiments of the application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the application. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application and to allow others skilled in the art to understand the application for various exemplary embodiments with various modifications being suited to the particular use contemplated. The scope of the application is intended to be defined by the claims and their equivalents.

Claims

1. A method for producing a formaldehyde-free routed fiberboard for electrostatic powder spraying, characterized by, The wood selection, wood treatment to obtain wood fiber, wax and glue application, and hot pressing step are included. In the wood selection step, eucalyptus wood and miscellaneous wood are used as raw materials, and the weight ratio of each component is 10-20% of eucalyptus wood and 80-90% of miscellaneous wood. In the wood treatment to obtain wood fiber step, the eucalyptus wood fiber length is 202-318 μm, and the miscellaneous wood fiber length is 221-404 μm. In the wax and glue application step, the applied adhesive is isocyanate glue, and the application amount of the isocyanate glue is 4.5-5% of the weight of the dry fiber. The process parameters of hot pressing in the hot pressing step are: high pressure section temperature 190-200℃, pressure 1.0-4.0N / mm 2 ; holding pressure section temperature 190-195℃, pressure 0.2-0.8N / mm 2 ; constant thickness section temperature 185-190℃, pressure 1.0-1.9N / mm 2 ; In the wax and glue application step, the components of the applied adhesive are as follows: 0.1-0.5% of multifunctional POSS, 4.5-5% of isocyanate glue, 0.05-0.1% of catalyst organic tin, and 0.5-0.8% of hydrated lithium chloride, based on the weight of the dry fiber. The multifunctional ridge-type POSS has a structural formula wherein R is a hydroxyl group; In the hot pressing step, the pressing time of the high-pressure section, the pressure maintaining section, and the thickness setting section is 250-350 S. In the wax and glue application step, the applied wax is paraffin wax and paraffin wax dispersion liquid. The paraffin wax is 58# full or semi-refined paraffin wax, and the application amount is 0.2-0.25% of the weight of the dry fiber.

2. The production method of the formaldehyde-free routed fiberboard for electrostatic powder spraying according to claim 1, characterized in that, The miscellaneous wood is one or more of Quercus infectoria, Cornus controversa, and Schima superba.

3. The production method of the formaldehyde-free routed fiberboard for electrostatic powder spraying according to claim 1, characterized in that, The paraffin wax dispersion liquid contains 40% paraffin wax and 5% lignin, and the rest is water. The application amount of the paraffin wax dispersion liquid is 0.17-0.22% of the weight of the dry fiber.

4. The production method of the formaldehyde-free routed fiberboard for electrostatic powder spraying according to claim 1, characterized in that, The thickness of the non-formaldehyde milling fiberboard for electrostatic powder spraying is 18-22 mm, and the average density is 800-820 kg / m 3 .

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