Preparation method of anti-corrosion high-strength OSB (oriented strand board)-based laminated wood

Abstract

The invention discloses a preparation method of anti-corrosion type high-strength OSB (oriented strand board)-based laminated wood, which comprises the following steps of: dipping an OSB base material in a copper azole anti-corrosion solution, sequentially performing vacuum dipping and pressurizing treatment, and forming gradient distribution of the drug loading capacity of a preservative from the surface layer to the core layer of the OSB base material; performing double-sided slicing on the OSB base material subjected to preservative treatment, removing a high-concentration anticorrosive layer on the surface layer, and processing an inverted-cone-shaped micropore array through nanosecond laser; adding nano-zinc oxide into the resorcinol-formaldehyde resin glue solution, and performing ultrasonic dispersion to form a nano-modified adhesive with a three-dimensional network structure; uniformly coating the surface of the activated OSB base material with a nano modified adhesive, and carrying out directional assembly; and a high-frequency hot press is adopted for synchronously applying an electromagnetic field and conducting hot pressing treatment on the assembled OSB base material, curing is conducted, and the anti-corrosion type high-strength OSB-based laminated wood is obtained. The bonding strength is improved while the excellent corrosion resistance is maintained, and collaborative optimization of the corrosion resistance and the structural strength is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of glued laminated timber, and particularly to a preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. Background Art

[0002] Currently, OSB-based glued laminated timber is an engineered wood product formed by laminating and bonding with other woods or composite materials through a gluing process using oriented strand board (OSB) as the base material. OSB-based glued laminated timber uses oriented strand board (OSB) as the base material and is laminated and bonded with veneer, sawn timber or other composite materials through a gluing process to form a structural material with oriented mechanical properties; the raw materials of the OSB base material mostly come from fast-growing forests or wood processing residues, such as small-diameter logs and branch wood, which are sliced, dried, adhesively applied, oriented paved and hot-pressed into a criss-cross mechanical reinforcement structure; however, in outdoor or high-humidity environments, traditional OSB-based glued laminated timber is vulnerable to fungal, pest and moisture erosion, resulting in problems such as strength attenuation and interlayer cracking. To improve durability, the existing technology usually adopts a strategy of combining anti-corrosion treatment with high-strength gluing technology.

[0003] The mainstream preparation technologies of OSB-based glued laminated timber in the existing technology mainly focus on the optimization of adhesive systems, anti-corrosion treatment processes and lamination parameters; in terms of adhesives, phenolic resin (PF) and isocyanate (MDI) are widely used due to their high water resistance and bonding strength, and the gluing efficiency is improved by adjusting the curing temperature and pressure of PF resin; anti-corrosion treatment is divided into two categories: one is the post-treatment impregnation method, in which the formed glued laminated timber is impregnated in an anti-corrosion liquid such as copper azole (CA-B) or ammoniacal copper quat (ACQ), and the preservative is penetrated into the material interior through a vacuum-pressure process; the other is the pre-treatment modification method, in which zinc borate or nano-copper particles are added to the wood chips during the OSB preparation stage to achieve in-situ loading of anti-corrosion functions; although the existing technology takes into account the anti-corrosion and strength requirements to a certain extent, its core contradiction has not been effectively solved, and the curing reaction of the adhesive is easily interfered by the preservative; and the anti-corrosion treatment process often sacrifices mechanical properties.

[0004] Therefore, it is necessary to improve a preparation method of an anti-corrosion high-strength OSB-based glued laminated timber in the existing technology to solve the above problems. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the existing technology and provides a preparation method of an anti-corrosion high-strength OSB-based glued laminated timber, aiming to solve the problems that the curing of the adhesive is interfered by the preservative and the anti-corrosion treatment process is likely to reduce the mechanical properties in the existing technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a preparation method of an anti-corrosion high-strength OSB-based glued laminated timber, comprising:

[0007] S1. Immersing the OSB substrate in a copper azole anticorrosive solution, sequentially performing vacuum impregnation and pressure treatment, to form a gradient distribution of the anticorrosive loading from the surface layer to the core layer of the OSB substrate;

[0008] S2, double-sided planing of the anti-corrosion treated OSB substrate to remove the high-concentration anti-corrosion layer on the surface, and nanosecond laser processing of an inverted tapered micropore array;

[0009] S3, adding nano zinc oxide to the resorcinol-formaldehyde resin glue solution, and forming a nano-modified adhesive with a three-dimensional network structure through ultrasonic dispersion;

[0010] S4, evenly coating the nano-modified adhesive on the surface of the activated OSB substrate and performing oriented assembly;

[0011] S5. A high-frequency hot press is used to simultaneously apply an electromagnetic field and hot press to the assembled OSB substrate, and solidify the OSB substrate to obtain anti-corrosion high-strength OSB-based glued laminated wood.

[0012] In a preferred embodiment of the present invention, the OSB substrate is an oriented strand of fast-growing coniferous or broadleaved wood, the strand size is 50-80 mm long, 10-20 mm wide, and 2-4 mm thick, and the number of layers is three-layer structure, with the surface layer arranged longitudinally and the core layer arranged transversely, and the density is 600-680 kg / m 3 .

[0013] In a preferred embodiment of the present invention, the copper azole antiseptic solution is formed by chelating a copper salt with an azole compound, the copper salt is alkaline copper carbonate or copper sulfate, the azole compound is tebuconazole or propiconazole, the molar ratio of copper to azole is 1:1.5-2.0, the active ingredient concentration is 0.3-0.8%, and the pH value is 8.5-9.5.

[0014] In a preferred embodiment of the present invention, the vacuum impregnation pressure is -0.08 to -0.10 MPa, maintained for 30-40 minutes; the pressure treatment pressure is 1.0-1.5 MPa, maintained for 1.5-2.5 hours, the temperature is 25-40 ° C, and the surface drug loading after treatment is 1.5-2.0 kg / m 3 , core layer drug loading 1.0-1.3kg / m 3 .

[0015] In a preferred embodiment of the present invention, double-sided planing uses carbide tools, the cutting thickness is 0.5-0.7mm / side, the total removal amount is 1.0-1.4mm, the feed speed is 15-25m / min, and the surface Cu after planing is 2+ Content ≤800ppm.

[0016] In a preferred embodiment of the present invention, the parameters of nanosecond laser processing are as follows: pulse width is 100 - 200 ns, spot diameter is 50 - 100 μm, pulse energy is 40 - 60 mJ, energy density is 3 - 5 J / cm 2 , the depth of the micro - hole is 200 - 300 μm, the opening diameter is 500 - 800 μm, the taper angle is 60° - 70°, and the array density is 15 - 20 pieces / cm 2 , and hexagonal close - packed arrangement is adopted.

[0017] In a preferred embodiment of the present invention, the resorcinol - formaldehyde resin adhesive solution is obtained by polycondensing resorcinol and formaldehyde at a molar ratio of 1:1.8 - 2.2, with a solid content of 40 - 44%, a nano - zinc oxide addition amount of 3 - 5 wt%, a particle size of 20 - 50 nm, an ultrasonic dispersion frequency of 30 - 40 kHz, a power density of 300 - 350 W / L, and a duration of 25 - 35 min.

[0018] In a preferred embodiment of the present invention, in step S4, the sizing amount is 250 - 280 g / m 2 , the coating angle is 45° - 60°, the coating temperature is 25 - 30 °C, the number of layers of the oriented lay - up is an odd number and the structure is symmetric, and the fiber directions of adjacent veneers are orthogonally arranged.

[0019] In a preferred embodiment of the present invention, in step S5, pre - heating stabilizes the initial temperature at 50 - 60 °C, the electromagnetic field frequency is 2.4 - 2.5 GHz, the power density is 0.8 - 1.2 W / cm 3 , the hot - pressing pressure is 1.0 - 1.5 MPa, the temperature is 85 - 90 °C, and the time is 30 - 45 min.

[0020] In a preferred embodiment of the present invention, in step S5, after curing, the pressure is released in a gradient manner, the pressure - reducing speed is 0.2 - 0.3 MPa / min, the temperature - reducing speed is 2 - 3 °C / min, and the board is cooled to below 40 °C for discharging.

[0021] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0022] (1) The present invention discloses a preparation method of anti - corrosion high - strength OSB - based glued - laminated wood. Through gradient anti - corrosion penetration and double - sided planing technology, an anti - corrosion system with high protection on the surface layer and low interference in the core layer is constructed inside the OSB substrate. Combining nanosecond laser micro - hole processing and nano - zinc oxide - modified adhesive, a three - dimensional mechanical interlock and chemical enhancement dual - interface bonding mechanism is formed. Then, through high - frequency electromagnetic hot - pressing technology, rapid directional cross - linking of the adhesive is realized, breaking through the technical bottleneck that it is difficult to balance traditional anti - corrosion treatment and bonding performance. While maintaining excellent anti - corrosion performance, the bonding strength is improved, the curing efficiency is increased, and the internal stress of the board is significantly reduced, realizing the synergistic optimization of anti - corrosion performance and structural strength.

[0023] (2) The present invention realizes multi-scale enhancement of the bonding interface through the synergistic effect of nanosecond laser micropore processing and nano-modified adhesive. The inverted cone micropores formed by laser processing construct a mechanical anchoring structure through the wedge effect, and nano zinc oxide is embedded in the resin under ultrasonic dispersion to form a three-dimensional network. The dual effect increases the filling rate of the micropores with the adhesive; while constructing the inverted cone mechanical interlocking structure on the OSB surface, the three-dimensional network enhancement effect of nano zinc oxide is utilized to increase the penetration depth of the adhesive layer and improve the interface shear strength; compared with traditional planar bonding, this method solves the problem of decreased interface bonding force caused by anti-corrosion treatment through the dual mechanism of wedge effect and nano enhancement.

[0024] (3) The present invention achieves rapid curing and deep crosslinking of the adhesive by combining a resorcinol-formaldehyde resin system with a high-frequency electromagnetic hot pressing process. Selective electromagnetic field heating allows the adhesive layer to quickly reach the gel point, shortening the curing time compared to traditional hot compression. Simultaneously, the catalytic effect of nano-zinc oxide promotes the formation of a denser crosslinked network in the resin, increasing bonding strength and improving water resistance.

[0025] (4) The present invention combines gradient anti-corrosion penetration with double-sided planing technology, forms a surface high-drug-loading barrier through vacuum-pressure gradient impregnation, and accurately removes the surface high copper area by S2 precision planing, which not only retains the moderate anti-corrosion ability of the core layer, but also eliminates the inhibition of metal ions on the curing of the adhesive; forms an anti-corrosion system with high surface protection and low core interference inside the OSB substrate, which not only retains the surface anti-biological erosion ability, but also avoids the high concentration of preservatives inhibiting the adhesive curing reaction; compared with the existing technology, it breaks through the contradiction between anti-corrosion treatment and bonding performance, and achieves the reduction of the core layer drug loading while improving the strength of the surface anti-corrosion barrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0027] Figure 1 is a flow chart of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0030] Summary of the Application:

[0031] In the existing technology, the curing reaction of the adhesive phenolic resin is easily interfered by preservatives. The moisture in the preservatives will delay the cross-linking process of the resin, resulting in a decrease in the curing degree of the adhesive layer. In addition, the metal ions in the preservatives may react with the free formaldehyde in the adhesive to generate insoluble precipitates, further weakening the interfacial bonding force. Existing anti-corrosion treatment processes often come at the cost of mechanical properties. Taking the vacuum-pressure impregnation method as an example, the high drug loading of the preservatives will cause the swelling of wood fibers, damage the oriented structure of OSB, and thus reduce the material stiffness.

[0032] The present application provides a method for preparing anti-corrosion high-strength OSB-based glued laminated timber, aiming to solve the above problems. By optimizing the distribution of the preservative drug loading, planing and removing the high-concentration anti-corrosion layer, processing micro-hole arrays by nanosecond laser, preparing nano-modified adhesives, and adopting high-frequency hot pressing technology, it effectively overcomes the problems that the curing of the adhesive is interfered by preservatives and the anti-corrosion treatment process is likely to reduce the mechanical properties in the existing technology, significantly improves the anti-corrosion performance and mechanical strength of OSB-based glued laminated timber, and realizes the coordinated improvement of anti-corrosion and strength.

[0033] Exemplary Method:

[0034] As Figure 1 shown, a method for preparing anti-corrosion high-strength OSB-based glued laminated timber includes the steps of:

[0035] S1. Immerse the OSB substrate in a copper azole anti-corrosion solution, and successively perform vacuum impregnation and pressure treatment to form a gradient distribution of the preservative drug loading from the surface layer to the core layer of the OSB substrate;

[0036] S2. Perform double-sided planing on the anti-corrosion treated OSB substrate to remove the high-concentration anti-corrosion layer on the surface layer, and process an inverted conical micro-hole array by nanosecond laser;

[0037] S3. Add nano-zinc oxide to the resorcinol-formaldehyde resin glue solution, and form a nano-modified adhesive with a three-dimensional network structure through ultrasonic dispersion;

[0038] S4. Uniformly coat the nano-modified adhesive on the surface of the activated OSB substrate, and perform oriented layup;

[0039] S5. Use a high-frequency hot press to synchronously apply electromagnetic fields and hot press the OSB substrate for forming blanks, and then cure it to obtain an anti-corrosion high-strength OSB-based glued wood.

[0040] The OSB substrate is made of oriented particle flakes of fast-growing coniferous woods including southern pine and radiata pine, or broad-leaved woods including poplar and eucalyptus. The fibers of these woods are long and have stable mechanical properties, which are suitable for oriented paving to improve mechanical properties.

[0041] The size of the particle flakes for the oriented particle flakes is 50 - 80 mm in length, 10 - 20 mm in width, and 2 - 4 mm in thickness; it has a three-layer structure, uses phenolic resin as the adhesive, with the surface layer arranged longitudinally and the core layer arranged transversely; density: 600 - 680 kg / m 3 .

[0042] The composition of the copper azole anti-corrosion solution: the chelate of copper salt and azole compound, the copper salt is basic copper carbonate or copper sulfate, and the azole compound is tebuconazole or propiconazole; the molar ratio of copper to azole is 1:1.5 - 2.0;

[0043] The effective ingredient concentration of the copper azole anti-corrosion solution is 0.3 - 0.8%, and the pH value is adjusted to 8.5 - 9.5 to ensure the stability of the copper azole chelate and prevent the precipitation of copper ions; preferably, the effective ingredient concentration is 0.5%, which can balance the anti-corrosion performance and the drug absorption amount of the wood. Too high a concentration is likely to cause swelling of the wood fibers, and too low a concentration will result in insufficient anti-corrosion effect;

[0044] The preparation of the copper azole anti-corrosion solution:

[0045] Dissolve the copper salt in water, stir until completely dissolved, with a rotation speed of 300 - 500 rpm and a temperature of 25 - 30°C;

[0046] Add the azole compound and continuously stir for 30 - 40 minutes to form a stable chelate;

[0047] Adjust the pH with ammonia water, let it stand to defoam and then set aside for use. [[ID=?]] [[ID=?]]

[0048] In step S1, during the vacuum stage, immerse the OSB in the copper azole solution, evacuate to -0.08 ~ -0.10 MPa, and maintain for 30 - 40 minutes to discharge the gas in the wood cell cavity. At the same time, avoid over-compressing the cell wall structure, and use negative pressure to quickly infiltrate the preservative into the surface pores; during the pressurization stage, pressurize to 1.0 - 1.5 MPa, maintain for 1.5 - 2.5 hours, keep the temperature at 25 - 40°C, and use high pressure to drive the preservative to diffuse into the core layer, break through the wood penetration resistance, ensure effective drug loading in the core layer, and form a gradient drug loading amount from the surface layer to the core layer. The drug loading amount of the surface layer is 1.5 - 2.0 kg / m 3 , and the core layer is 1.0 - 1.3 kg / m 3; The high drug loading in the surface layer provides a strong anti-corrosion barrier, while the lower drug loading in the core layer reduces the impact on gluing. Finally, drain the excess solution and air-dry it naturally until the moisture content ≤ 12%.

[0049] In step S1, the OSB substrate is impregnated in the copper azole anti-corrosion solution, and vacuum impregnation and pressure treatment are carried out in sequence, so that the preservative forms a gradient distribution from the surface layer to the core layer of the OSB substrate. This gradient penetration method can not only ensure the formation of an efficient anti-corrosion barrier on the surface layer to resist the invasion of external fungi and pests, but also reduce the drug loading in the core layer and reduce the interference of the preservative on the subsequent gluing process.

[0050] However, although step S1 realizes the gradient penetration of the preservative, due to the existence of a certain concentration of preservative in the surface layer, this may affect the bonding effect of the adhesive on the surface layer.

[0051] Since the drug loading of the preservative in the surface layer is much higher than that in the core layer, metal ions will inhibit the curing of the adhesive during direct gluing; by simultaneously performing equal-thickness cutting on the upper and lower surfaces of the OSB substrate with a precision planer, that is, double-sided planing, the high-concentration anti-corrosion layer on the surface layer is removed to solve the problem of glue interface pollution caused by the enrichment of the preservative; the oxide layer on the surface layer after preservative impregnation is removed to release the natural pore structure of the wood fibers, enhance the penetration of the glue solution, and also eliminate the surface unevenness caused by the anti-corrosion treatment, providing a reference plane for subsequent laser micro-hole processing.

[0052] In step S2, the tool material of the high-precision double-sided planer is cemented carbide, and the edge sharpness Ra ≤ 0.2μm; the planing parameters: the cutting thickness is 0.5 - 0.7mm / surface, and the total removal amount is 1.0 - 1.4mm; the feed speed is 15 - 25m / min to avoid tearing of wood fibers caused by high-speed cutting; the tool angle is the rake angle of 15° - 20° and the clearance angle of 8° - 10° to optimize the surface roughness of the planed sheet; after planing, the Cu content in the surface layer 2+ ≤ 800ppm;

[0053] Use a nanosecond pulsed laser to process inverted conical micro-holes on the surface of the planed OSB substrate to form a mechanical interlocking structure, which increases the specific surface area of the OSB substrate, exposes more fiber channels on the inner wall of the micro-holes, improves the wettability of the glue solution, and the inverted conical structure is narrow at the top and wide at the bottom, enhancing the mechanical bonding force between the glue layer and the substrate through the "wedging effect".

[0054] In step S2, the pulse width of the nanosecond pulsed laser is 100 - 200ns, the focused spot diameter is 50 - 100μm, the pulse energy is 40 - 60mJ, and the single-pulse energy density is 3 - 5J / cm 2 ; The processing cycle for each hole is the superposition of 3 - 5 pulses, and the pulse repetition frequency is 20 - 30kHz;

[0055] Micropore parameters: the depth is 200 - 300 μm, penetrating the fiber activation layer after surface shaving, the opening diameter is 500 - 800 μm, the taper angle is 60° - 70°, forming an inverted cone with a major axis ratio of 1:1.2 - 1.5; the array distribution density is 15 - 20 per cm 2 ; Adopt hexagonal close packing to avoid excessive hole spacing resulting in loss of substrate strength.

[0056] In step S2, through the collaborative process of double-sided shaving and nanosecond laser micro-texturing, while eliminating the interference of surface preservatives, a mechanical interlocking interface is constructed, solving the compatibility problem between the gradient anti-corrosion substrate and the adhesive. Double-sided shaving not only removes the metal ion contamination layer that inhibits the curing of the adhesive but also exposes the natural pore channels of wood fibers, activating the surface of the OSB substrate; the inverted conical micropore array processed by nanosecond laser forms a three-dimensional anchoring structure through the wedging effect. After being treated by S2, the surface of the OSB substrate has both a clean and active interface with low copper residue and a micro-nano scale mechanical interlocking topological structure; however, conventional adhesives are difficult to fully fill the inverted conical micropores and form a strong and tough bond. Therefore, in step S3, a three-dimensional network enhanced adhesive is constructed by introducing nano-zinc oxide, and the high specific surface area and interface effect of the nanoparticles are used to strengthen the penetration and anchoring ability of the adhesive layer to the micropore structure.

[0057] Resorcinol-formaldehyde resin is a high-performance thermosetting resin, which is formed by the polycondensation of resorcinol and formaldehyde under alkaline conditions. It has the characteristics of high reaction activity and excellent weather resistance. It can be pre-polymerized within 5 - 40 °C, and forms a highly cross-linked network after high-temperature curing, with resistance to water, heat and humidity, and biodegradation. Moreover, the polar hydroxyl groups form hydrogen bonds with wood cellulose, and it has high permeability, resulting in strong interfacial bonding ability.

[0058] In step S3, dissolve resorcinol in water at 40 - 50 °C, stir until completely dissolved, with a rotation speed of 200 - 300 rpm, slowly add the formaldehyde solution, control the dropping speed at 1 - 2 mL / min, the molar ratio of resorcinol to formaldehyde is 1:1.8 - 2.2, add sodium hydroxide to adjust the pH to 8.5 - 9.0, raise the temperature to 65 - 70 °C, and react for 2 - 3 hours until the viscosity reaches 300 - 400 mPa·s; cool down to 25 - 30 °C, add 5 - 8% ethanol to terminate the polycondensation, and obtain a resorcinol-formaldehyde resin adhesive solution with a solid content of 40 - 44%.

[0059] Mix 3-5 wt% of nano-zinc oxide into the resorcinol-formaldehyde resin solution, and conduct preliminary dispersion by mechanical stirring at a rotation speed of 400-500 rpm for 10-15 minutes; then perform ultrasonic dispersion. The ultrasonic dispersion parameters are: ultrasonic frequency of 30-40 kHz, power density of 300-350 W / L, and duration of 25-35 minutes, which is used to generate and rupture microbubbles in the adhesive, generating local high temperature and high pressure to break the agglomeration of nanoparticles; the high-frequency vibration enables the nano-zinc oxide to be evenly embedded in the resin prepolymer chain segments to form a resin-nanoparticle interpenetrating network;

[0060] The particle size of the nano-zinc oxide is 20-50 nm, and the specific surface area is 50-100 m 2 / g, and the nano-zinc oxide forms physical entanglement with the resorcinol-formaldehyde resin matrix to enhance the rigidity of the adhesive layer; and the nano-zinc oxide releases Zn 2+ , which synergistically inhibits fungi with copper ions Cu 2+ . The nanoparticles fill the micropores in the adhesive layer, reducing the porosity and blocking the penetration of water vapor.

[0061] In step S3, through the nano-zinc oxide modified adhesive technology, the synergistic effect of the mechanical properties and anti-corrosion function of the adhesive layer is realized, and the problems of efficient filling and long-term durability of the inverted conical microporous structure are solved. Under the action of ultrasonic dispersion, the zinc oxide particles are evenly embedded in the resorcinol-formaldehyde resin matrix. At the same time, the high specific surface area of the nanoparticles enhances the wettability of the adhesive solution to the inner wall of the micropores, forming nano-level anchoring nodes in the inverted conical channels.

[0062] In step S4, coat the surface of the OSB substrate, with the sizing amount of 250-280 g / m 2 , the coating angle is 45°-60°, and the coating temperature is 25-30 °C. The adhesive penetrates into the inverted conical micropores under capillary action. The hydroxyl groups (-OH) of the adhesive form an initial hydrogen bond network with the wood cellulose to enhance the adhesion. The coated OSB veneer is left standing for 5-10 minutes to allow the adhesive solution to initially penetrate the micropores; the number of layers of the oriented layup is an odd number and the structure is symmetrical. Specifically, it is 5 layers or 7 layers, and the fiber directions of adjacent veneers are orthogonally arranged.

[0063] In step S5, send the OSB substrate coated with the nano-modified adhesive and oriented layup into a high-frequency hot press, ensure that the laminates are aligned and the pressure is evenly distributed, and pre-heat the board through the hot press plate to make the initial temperature stable in the range of 50-60 °C to ensure the uniformity of the adhesive layer heating;

[0064] Start the electromagnetic field, with a frequency of 2.4-2.5 GHz and a power density of 0.8-1.2 W / cm 3, selectively activate polar molecules in the adhesive layer through dielectric heating, synchronously apply mechanical pressure to 1.0 - 1.5 MPa, the hot pressing temperature is 85 - 90 °C, and the hot pressing time is 30 - 45 min; through the coupling action of electromagnetic-thermal-force three fields, realize the directional cross-linking driven by the temperature gradient of the adhesive layer; continuously apply the electromagnetic field until curing is completed to ensure that the resin is fully cross-linked by the temperature gradient inside the adhesive layer;

[0065] After curing is completed, depressurize in a gradient manner, and the pressure reduction speed is 0.2 - 0.3 MPa / min to avoid internal stress concentration, and then cool down, with a cooling speed of 2 - 3 °C / min. Cool the board to below 40 °C before discharging, and finally obtain the anti-corrosion high-strength OSB-based glued laminated timber.

[0066] Example 1:

[0067] A method for preparing anti-corrosion high-strength OSB-based glued laminated timber, comprising the steps:

[0068] S1. Select southern pine oriented strand wafers as the OSB substrate. The wafer size is 60 mm in length, 15 mm in width, and 3 mm in thickness. Lay them in a three-layer structure, with the surface layer arranged longitudinally and the core layer arranged transversely, and the density is 650 kg / m 3 ; Immerse the OSB substrate in a copper azole anti-corrosion solution. The solution composition is a chelate of basic copper carbonate and tebuconazole, with a copper to azole molar ratio of 1:1.8, an active ingredient concentration of 0.5%, and a pH value of 9.0; During the vacuum impregnation stage, evacuate to -0.09 MPa and maintain for 35 minutes; During the pressurization stage, pressurize to 1.2 MPa and maintain for 2 hours, with a temperature of 30 °C; After treatment, the drug loading amount on the surface layer is 1.8 kg / m 3 , and the core layer is 1.2 kg / m 3 , and air dry naturally to a moisture content of 10%.

[0069] S2. Use cemented carbide tools to perform double-sided planing on the OSB substrate, with a cutting thickness of 0.6 mm per side, a total removal amount of 1.2 mm, a feed speed of 20 m / min, a tool rake angle of 18°, and a tool clearance angle of 9°; Use a nanosecond pulsed laser to process inverted conical micropores, with a pulse width of 150 ns, a spot diameter of 80 μm, a pulse energy of 50 mJ, and an energy density of 4 J / cm 2 , stack 4 pulses for each hole, with a repetition frequency of 25 kHz; The micropore depth is 250 μm, the opening diameter is 600 μm, the taper angle is 65°, and the array density is 18 per cm 2 , and distribute in a hexagonal close-packed pattern.

[0070] S3. Dissolve resorcinol in water at 45 °C with a stirring speed of 250 rpm. Dropwise add formaldehyde solution until the molar ratio of resorcinol to formaldehyde is 1:2.0. Add sodium hydroxide to adjust the pH to 8.8. Raise the temperature to 68 °C and react for 2.5 hours. After the viscosity reaches 350 mPa·s, cool down to 28 °C. Add 6% ethanol to terminate the polycondensation to obtain a resorcinol-formaldehyde resin adhesive solution with a solid content of 42%. Add 4 wt% of nano-zinc oxide with a particle size of 30 nm and a specific surface area of 80 m 2 / g. First, mechanically stir at 450 rpm for 12 min, and then ultrasonically disperse at 35 kHz for 30 min with a power density of 320 W / L to form a three-dimensional network structure adhesive.

[0071] S4. Apply the nano-modified adhesive to the surface of the activated OSB substrate at a sizing amount of 260 g / m 2 . The coating angle is 50°, the temperature is 28 °C, and let it stand for 8 minutes to allow the adhesive solution to penetrate initially. The oriented layup is a 5-layer structure, and the fiber directions of adjacent veneers are orthogonally arranged to ensure structural symmetry.

[0072] S5. Feed the laid-up OSB substrate into a high-frequency hot press, preheat to 55 °C, start a 2.45 GHz electromagnetic field with a power density of 1.0 W / cm 3 , simultaneously apply a pressure of 1.2 MPa, the hot pressing temperature is 88 °C, and maintain for 40 minutes. After curing is completed, release the pressure at a rate of 0.25 MPa / min, and cool down to 35 °C at a rate of 2.5 °C / min and then discharge to obtain an anti-corrosion high-strength OSB-based glued laminated timber.

[0073] Example 2:

[0074] A method for preparing an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as in Example 1 will not be described in detail. The differences between this example and Example 1 are as follows: the concentration of the active ingredient of copper azole is 0.3%.

[0075] Example 3:

[0076] A method for preparing an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as in Example 1 will not be described in detail. The differences between this example and Example 1 are as follows: the concentration of the active ingredient of copper azole is 0.8%.

[0077] Example 4:

[0078] A method for preparing an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as in Example 1 will not be described in detail. The differences between this example and Example 1 are as follows: the cutting thickness is 0.5 mm per side.

[0079] Example 5:

[0080] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 1 will not be described again. The differences between this example and Example 1 are as follows: The cutting thickness is 0.7 mm per surface.

[0081] Example 6:

[0082] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 2 will not be described again. The differences between this example and Example 2 are as follows: The cutting thickness is 0.5 mm per surface.

[0083] Example 7:

[0084] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 2 will not be described again. The differences between this example and Example 2 are as follows: The cutting thickness is 0.7 mm per surface.

[0085] Example 8:

[0086] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 3 will not be described again. The differences between this example and Example 3 are as follows: The cutting thickness is 0.5 mm per surface.

[0087] Example 9:

[0088] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 3 will not be described again. The differences between this example and Example 3 are as follows: The cutting thickness is 0.7 mm per surface.

[0089] Example 10:

[0090] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 1 will not be described again. The differences between this example and Example 1 are as follows: The taper angle of the inverted conical micropores is 60°.

[0091] Example 11:

[0092] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 1 will not be described again. The differences between this example and Example 1 are as follows: The taper angle of the inverted conical micropores is 70°.

[0093] Example 12:

[0094] A preparation method of an anti-corrosion high-strength OSB-based glued laminated timber. The same parts as those in Example 1 will not be described again. The differences between this example and Example 1 are as follows: 3 wt% of nano-zinc oxide is added to the adhesive.

[0095] Example 13:

[0096] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 1 will not be described again. The differences between this example and Example 1 are as follows: 5 wt% of nano-zinc oxide is added to the glue solution.

[0097] Example 14:

[0098] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 10 will not be described again. The differences between this example and Example 10 are as follows: 3 wt% of nano-zinc oxide is added to the glue solution.

[0099] Example 15:

[0100] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 10 will not be described again. The differences between this example and Example 10 are as follows: 5 wt% of nano-zinc oxide is added to the glue solution.

[0101] Example 16:

[0102] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 11 will not be described again. The differences between this example and Example 11 are as follows: 3 wt% of nano-zinc oxide is added to the glue solution.

[0103] Example 17:

[0104] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 11 will not be described again. The differences between this example and Example 11 are as follows: 5 wt% of nano-zinc oxide is added to the glue solution.

[0105] Comparative Example 1:

[0106] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 1 will not be described again. The differences between this comparative example and Example 1 are as follows: No planing is carried out.

[0107] Comparative Example 2:

[0108] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 1 will not be described again. The differences between this comparative example and Example 1 are as follows: There are no inverted conical micropores.

[0109] Comparative Example 3:

[0110] A preparation method of anti-corrosion high-strength OSB-based glued laminated wood. The same parts as in Example 1 will not be described again. The differences between this comparative example and Example 1 are as follows: Nano-zinc oxide is not added.

[0111] Experimental Example 1:

[0112] In this experimental example, Examples 1-9 and Comparative Example 1 were selected to conduct physical and chemical property tests on glued laminated timber;

[0113] The penetration depth of the preservative was detected to confirm whether the vacuum-pressure process in Step S1 achieved a gradient distribution of high drug loading in the surface layer and low drug loading in the core layer, and to avoid excessive preservative in the core layer interfering with gluing; the copper ion mobility reflects the migration stability of the preservative in wood, and a low mobility indicates that the gradient distribution is effectively fixed.

[0114] Table 1 Test results of Experimental Example 1

[0115]

[0116] Example 1 had the best effect, mainly because the selection of the concentration of the active ingredient of copper azole and the cutting thickness was relatively reasonable. When the copper azole concentration was 0.5%, it was in an effective balance state, which could not only ensure that there was enough preservative in the surface layer to form a strong anti-corrosion barrier, but also would not cause excessive drug loading in the core layer and affect subsequent gluing. At the same time, the cutting thickness was 0.6 mm / surface, which could effectively remove the high-concentration anti-corrosion layer on the surface, avoid the inhibition of the curing of the adhesive by metal ions, and could also fully expose the natural pores of the wood fibers, enhancing the penetration of the adhesive. This comprehensive parameter combination made the shear strength of the glue layer of the glued laminated timber reach 12.3 MPa, and the penetration depth of the preservative and the copper ion mobility were also at a good level, effectively preventing the adverse effects of excessive penetration and migration of the preservative on the wood properties, thus achieving a good balance in terms of anti-corrosion performance and gluing strength.

[0117] Experimental Example 2:

[0118] In this experimental example, Examples 1, 10-17 and Comparative Examples 2-3 were selected to conduct physical and chemical property tests on glued laminated timber; the micro-hole taper angle affects the penetration depth of the adhesive and the mechanical interlocking effect, and the content of nano-zinc oxide directly affects the cross-linking density and anti-corrosion performance of the glue layer; the retention rate of the water-resistant peel strength reflects the durability of the glue layer in a humid and hot environment, verifying whether the S3 nano-modified adhesive solves the problem that traditional adhesives are prone to water absorption and failure, and the micro-hole filling rate is used to confirm whether the S2 laser micro-holes are fully filled to form a three-dimensional anchoring structure.

[0119] Table 2 Test results of Experimental Example 2

[0120]

[0121] Example 1 is also in a relatively optimal state in terms of parameters such as the micropore taper angle and the content of nano-zinc oxide. The micropore taper angle is 65°, which is beneficial for the adhesive to fully penetrate the micropores and can enhance the mechanical interlocking effect through the appropriate "wedging effect" to form a stable three-dimensional anchoring structure. The content of nano-zinc oxide is 4wt%, which can effectively enhance the crosslinking density and anti-corrosion performance of the adhesive layer. On the one hand, the physical entanglement formed by nano-zinc oxide and resorcinol-formaldehyde resin improves the rigidity of the adhesive layer. On the other hand, the released Zn 2+ synergistically inhibits fungi with copper ions. The synergistic effect of this microporous structure and the nano-modified adhesive makes the shear strength of the adhesive layer reach 13.1 MPa, the retention rate of the water-resistant peel strength is 91.2%, and the micropore filling rate is 92.5%. While ensuring the bonding strength, the durability of the adhesive layer and the micropore filling effect are improved, so that the glued wood of Example 1 shows the best overall performance.

[0122] Based on the ideal embodiments of the present invention as inspiration, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A preparation method of an anti-corrosion high-strength OSB-based glued laminated wood, characterized in that, Including: S1. Immerse the OSB substrate in the copper azole antiseptic solution, and successively carry out vacuum impregnation and pressure treatment to form a gradient distribution of the drug loading of the preservative from the surface layer to the core layer of the OSB substrate; S2. Double-sided planing is carried out on the antiseptically treated OSB substrate to remove the high-concentration antiseptic layer on the surface layer, and an inverted conical micropore array is processed by nanosecond laser; S3. Add nano-zinc oxide to the resorcinol-formaldehyde resin adhesive solution, and form a nano-modified adhesive with a three-dimensional network structure through ultrasonic dispersion; S4. Uniformly coat the nano-modified adhesive on the surface of the activated OSB substrate, and carry out directional lay-up; S5. Use a high-frequency hot press to synchronously apply electromagnetic field and hot press treatment to the lay-up OSB substrate, and carry out curing to obtain an antiseptic and high-strength OSB-based glued laminated timber.

2. The preparation method of an anti-corrosion high-strength OSB-based glued laminated timber according to claim 1, characterized in that: The OSB substrate is oriented shaving slices of fast-growing softwood or hardwood. The shaving size is 50-80 mm in length, 10-20 mm in width, and 2-4 mm in thickness. It has a three-layer structure with the surface layer arranged longitudinally and the core layer arranged transversely, and the density is 600-680 kg / m 3 .

3. The preparation method of an anti-corrosion high-strength OSB-based glued laminated timber according to claim 1, wherein: The copper azole antiseptic solution is chelated by a copper salt and a azole compound. The copper salt is basic copper carbonate or copper sulfate, the azole compound is tebuconazole or propiconazole, the molar ratio of copper to azole is 1:1.5 - 2.0, the effective ingredient concentration is 0.3 - 0.8%, and the pH value is 8.5 - 9.

5.

4. A method for preparing an anti-corrosion high-strength OSB-based glued laminated wood according to claim 1, characterized in that: The vacuum impregnation pressure is -0.08 to -0.10 MPa and is maintained for 30 - 40 minutes; the pressure treatment pressure is 1.0 - 1.5 MPa, is maintained for 1.5 - 2.5 hours, the temperature is 25 - 40 °C, and the drug loading amount on the surface layer after treatment is 1.5 - 2.0 kg / m 3 , and the drug loading amount in the core layer is 1.0 - 1.3 kg / m 3 .

5. The preparation method of an anti-corrosion high-strength OSB-based glued laminated timber according to claim 1, characterized in that: Double-sided planing uses cemented carbide tools, with a cutting thickness of 0.5 - 0.7 mm per side, a total removal amount of 1.0 - 1.4 mm, a feed speed of 15 - 25 m / min, and the surface Cu 2+ content ≤ 800 ppm.

6. A method for preparing an anti-corrosion high-strength OSB-based glued laminated timber according to claim 1, characterized in that: The nanosecond laser processing parameters are as follows: pulse width 100 - 200 ns, spot diameter 50 - 100 μm, pulse energy 40 - 60 mJ, energy density 3 - 5 J / cm 2 , micro-hole depth 200 - 300 μm, opening diameter 500 - 800 μm, taper angle 60° - 70°, array density 15 - 20 pieces / cm 2 , and hexagonal close packing is adopted.

7. A method for preparing an anti-corrosion high-strength OSB-based glued laminated wood according to claim 1, characterized in that: The resorcinol-formaldehyde resin adhesive solution is polycondensed from resorcinol and formaldehyde at a molar ratio of 1:1.8 - 2.2, the solid content is 40 - 44%, the addition amount of nano-zinc oxide is 3 - 5wt%, the particle size is 20 - 50nm, the ultrasonic dispersion frequency is 30 - 40kHz, the power density is 300 - 350W / L, and the duration is 25 - 35min.

8. A method for preparing an anti-corrosion high-strength OSB-based glued laminated timber according to claim 1, characterized in that: In step S4, the sizing amount is 250-280 g / m 2 , the coating angle is 45°-60°, the coating temperature is 25-30 °C, the number of layers of the oriented lay-up is an odd number and the structure is symmetrical, and the fiber directions of adjacent veneers are orthogonally arranged.

9. A method for preparing an anti-corrosion high-strength OSB-based glued laminated timber according to claim 1, characterized in that: In step S5, preheating stabilizes the initial temperature at 50 - 60 °C, the electromagnetic field frequency is 2.4 - 2.5 GHz, and the power density is 0.8 - 1.2 W / cm 3 , the hot pressing pressure is 1.0 - 1.5 MPa, the temperature is 85 - 90 °C, and the time is 30 - 45 min.

10. A method for preparing an anti-corrosion high-strength OSB-based glued laminated wood according to claim 1, characterized in that: In step S5, after curing is completed, the pressure is gradually released, the pressure reduction speed is 0.2 - 0.3MPa / min, the temperature reduction speed is 2 - 3°C / min, and the board is cooled to below 40°C for discharging.

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