A method for preparing a preservative type high-strength OSB-based glued wood

Abstract

This invention discloses a method for preparing corrosion-resistant, high-strength OSB-based glued laminated timber, comprising: impregnating an OSB substrate in a copper azole preservative solution, followed by vacuum impregnation and pressure treatment to form a gradient distribution of preservative loading from the surface to the core of the OSB substrate; double-sided planing the preservative-treated OSB substrate to remove the high-concentration preservative layer on the surface, and processing an inverted conical micropore array using a nanosecond laser; adding nano-zinc oxide to a resorcinol-formaldehyde resin adhesive, and ultrasonically dispersing it to form a three-dimensional network structure of nano-modified adhesive; uniformly coating the nano-modified adhesive onto the surface of the activated OSB substrate and oriented it for preformation; simultaneously applying an electromagnetic field and hot-pressing the preformed OSB substrate using a high-frequency hot press, and then curing it to obtain corrosion-resistant, high-strength OSB-based glued laminated timber. This invention maintains excellent corrosion resistance while improving bonding strength, achieving synergistic optimization of corrosion resistance and structural strength.

Description

Technical Field

[0001] This invention relates to the field of glued laminated timber technology, and more particularly to a method for preparing corrosion-resistant, high-strength OSB-based glued laminated timber. Background Technology

[0002] Currently, OSB-based glulam is an engineered wood product made by laminating oriented strand board (OSB) with other wood or composite materials using a gluing process. OSB-based glulam uses OSB as its base material and is laminated with veneers, sawn timber, or other composite materials through a gluing process to form a structural material with directional mechanical properties. The raw materials for OSB base material are mostly derived from fast-growing forests or wood processing residues, such as small-diameter timber and branches. These are planed, dried, glued, oriented, and hot-pressed to ultimately form a cross-laminated, mechanically reinforced structure. However, in outdoor or high-humidity environments, traditional OSB-based glulam is susceptible to fungal, insect, and moisture damage, leading to problems such as strength loss and interlayer cracking. To improve durability, existing technologies typically employ a strategy combining preservative treatments with high-strength gluing processes.

[0003] Current mainstream OSB-based glued laminated timber (glulam) preparation technologies mainly revolve around adhesive systems, preservative treatment processes, and lamination parameter optimization. Regarding adhesives, phenolic resins (PF) and isocyanates (MDI) are widely used due to their high water resistance and bonding strength. Gluing efficiency is improved by adjusting the curing temperature and pressure of PF resin. Preservative treatments fall into two categories: one is the post-treatment impregnation method, where the formed glulam is impregnated in preservative solutions such as copper azole (CA-B) or quaternary ammonium copper (ACQ), and the preservative penetrates into the material through a vacuum-pressurization process; the other is the pre-treatment modification method, where zinc borate or nano-copper particles are added to the wood shavings during OSB preparation to achieve in-situ loading of preservative function. Although current technologies have to some extent balanced the requirements of preservation and strength, their core contradiction remains unresolved: the curing reaction of the adhesive is easily interfered with by the preservative; and the preservative treatment process often comes at the cost of sacrificing mechanical properties.

[0004] Therefore, it is necessary to improve the existing method for preparing corrosion-resistant, high-strength OSB-based glued laminated timber in order to solve the above problems. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a method for preparing corrosion-resistant high-strength OSB-based glued laminated timber, aiming to solve the problems in the prior art where the curing of adhesives is interfered with by preservatives and the corrosion treatment process easily reduces mechanical properties.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a method for preparing corrosion-resistant high-strength OSB-based glued laminated timber, comprising:

[0007] S1. The OSB substrate is immersed in copper azole anti-corrosion solution, and vacuum impregnation and pressure treatment are performed in sequence to form a gradient distribution of anti-corrosion loading from the surface layer to the core layer of the OSB substrate.

[0008] S2. Double-sided planing is performed on the OSB substrate after anti-corrosion treatment to remove the high-concentration anti-corrosion layer on the surface, and an inverted conical micropore array is processed by nanosecond laser.

[0009] S3. Nano-zinc oxide is added to resorcinol-formaldehyde resin adhesive and ultrasonically dispersed to form a three-dimensional network structure of nano-modified adhesive.

[0010] S4. The nano-modified adhesive is uniformly coated on the surface of the activated OSB substrate and then oriented and assembled.

[0011] S5. The OSB substrate is assembled by simultaneously applying an electromagnetic field and hot pressing with a high-frequency hot press, and then cured to obtain corrosion-resistant, high-strength OSB-based glued laminated wood.

[0012] In a preferred embodiment of the present invention, the OSB substrate is oriented strands of fast-growing coniferous or broadleaf wood, with strand dimensions of 50-80 mm in length, 10-20 mm in width, and 2-4 mm in thickness, having a three-layer structure, with the surface layer arranged longitudinally and the core layer arranged transversely, and a density of 600-680 kg / m³. 3 .

[0013] In a preferred embodiment of the present invention, the copper azole preservative solution is formed by chelating a copper salt with an azole compound. The copper salt is alkaline 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, the concentration of the active ingredient 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, and the temperature is 25-40°C, resulting in a surface drug loading of 1.5-2.0 kg / m² after treatment. 3 The core layer drug loading is 1.0-1.3 kg / m³. 3 .

[0015] In a preferred embodiment of the present invention, double-sided planing is performed using a carbide tool, with a cutting thickness of 0.5-0.7 mm / sided, a total material removal of 1.0-1.4 mm, and a feed rate of 15-25 m / min. The resulting surface layer is Cu. 2+ Content ≤800ppm.

[0016] In a preferred embodiment of the present invention, the nanosecond laser processing parameters are: pulse width 100-200 ns, spot diameter 50-100 μm, pulse energy 40-60 mJ, and energy density 3-5 J / cm². 2 Micropore depth 200-300μm, opening diameter 500-800μm, taper angle 60°-70°, array density 15-20 pores / cm 2 It adopts a hexagonal close-packed arrangement.

[0017] In a preferred embodiment of the present invention, the resorcinol-formaldehyde resin adhesive is formed by the condensation polymerization of resorcinol and formaldehyde in a molar ratio of 1:1.8-2.2, with a solid content of 40-44%, an addition of 3-5 wt% of nano zinc oxide, 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 amount of adhesive applied is 250-280 g / m³. 2 The coating angle is 45°-60°, the coating temperature is 25-30℃, the number of oriented preform layers is odd and the structure is symmetrical, and the fiber directions of adjacent veneers are orthogonally arranged.

[0019] In a preferred embodiment of the present invention, in step S5, preheating is performed to stabilize 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 / cm². 3 The hot pressing pressure is 1.0-1.5MPa, the temperature is 85-90℃, and the time is 30-45min.

[0020] In a preferred embodiment of the present invention, in step S5, after curing is completed, the pressure is gradually released at a rate of 0.2-0.3 MPa / min and a cooling rate of 2-3 °C / min, so that the board is cooled to below 40 °C before being discharged.

[0021] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0022] (1) This invention discloses a method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. Through gradient corrosion-resistant penetration and double-sided slicing technology, a corrosion-resistant system with high surface protection and low core interference is constructed inside the OSB substrate. Combined with nanosecond laser micropore processing and nano zinc oxide modified adhesive, a three-dimensional mechanical interlocking and chemically reinforced dual interface bonding mechanism is formed. Then, the adhesive is rapidly cross-linked in a directional manner through a high-frequency electromagnetic hot pressing process. This method breaks through the technical bottleneck that traditional corrosion-resistant treatment and bonding performance are difficult to balance. While maintaining excellent corrosion resistance, it improves bonding strength, increases curing efficiency, and significantly reduces internal stress of the board, achieving synergistic optimization of corrosion resistance and structural strength.

[0023] (2) This invention achieves multi-scale enhancement of the bonding interface through the synergistic effect of nanosecond laser micropore processing and nano-modified adhesive. The inverted conical micropores formed by laser processing construct a mechanical anchoring structure through the wedge effect. 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 adhesive to the micropores. While constructing an inverted conical mechanical interlocking structure on the OSB surface, the three-dimensional network enhancement effect of nano zinc oxide increases the penetration depth of the adhesive layer and improves the interfacial shear strength. Compared with traditional planar bonding, this invention solves the problem of decreased interfacial bonding caused by anti-corrosion treatment through the dual mechanism of wedge effect and nano-reinforcement.

[0024] (3) This invention achieves rapid curing and deep cross-linking of adhesives by linking the resorcinol-formaldehyde resin system with a high-frequency electromagnetic hot pressing process. The selective heating of the electromagnetic field enables the adhesive layer to quickly reach the gel point, resulting in a shorter curing time compared to traditional hot compression. At the same time, the catalytic effect of nano zinc oxide promotes the formation of a denser cross-linked network in the resin, thereby improving the bonding strength and water resistance.

[0025] (4) This invention combines gradient anti-corrosion penetration with double-sided slicing process. Vacuum-pressure gradient impregnation forms a high drug-load barrier on the surface, while S2 precision slicing accurately removes the high copper area on the surface. This retains the core layer's moderate anti-corrosion capability and eliminates the inhibition of adhesive curing by metal ions. A high-protection surface and low-interference core anti-corrosion system is formed inside the OSB substrate. This retains the surface's resistance to biological erosion and avoids the inhibition of adhesive curing reaction by high-concentration preservatives. Compared with the prior art, this invention overcomes the contradiction between anti-corrosion treatment and bonding performance, achieving a reduction in the drug load on the core layer while increasing the strength of the surface anti-corrosion barrier. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart of a preferred embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

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

[0030] Application Overview:

[0031] The curing reaction of phenolic resin adhesives in existing technologies is easily interfered with by preservatives. The moisture in the preservatives can delay the cross-linking process of the resin, resulting in a decrease in the curing degree of the adhesive layer. In addition, metal ions in the preservatives may react with free formaldehyde in the adhesive to form insoluble precipitates, which further weakens the interfacial bonding force. Existing preservative treatment processes often sacrifice mechanical properties. For example, in the vacuum pressure impregnation method, the high amount of preservative can cause wood fibers to swell, destroy the oriented structure of OSB, and thus reduce the stiffness of the material.

[0032] This application provides a method for preparing high-strength OSB-based glued laminated timber with corrosion resistance, aiming to solve the above-mentioned problems. By optimizing the distribution of preservative loading, removing the high-concentration preservative layer by planing, processing the microporous array with nanosecond laser, preparing nano-modified adhesive, and using a high-frequency hot-pressing process, the method effectively overcomes the problems in the prior art where adhesive curing is interfered with by the preservative and the preservative treatment process easily reduces mechanical properties. This significantly improves the corrosion resistance and mechanical strength of OSB-based glued laminated timber, achieving a synergistic improvement in corrosion resistance and strength.

[0033] Exemplary method:

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

[0035] S1. The OSB substrate is immersed in copper azole anti-corrosion solution, and vacuum impregnation and pressure treatment are performed in sequence to form a gradient distribution of anti-corrosion loading from the surface layer to the core layer of the OSB substrate.

[0036] S2. Double-sided planing is performed on the OSB substrate after anti-corrosion treatment to remove the high-concentration anti-corrosion layer on the surface, and an inverted conical micropore array is processed by nanosecond laser.

[0037] S3. Nano-zinc oxide is added to resorcinol-formaldehyde resin adhesive and ultrasonically dispersed to form a three-dimensional network structure of nano-modified adhesive.

[0038] S4. The nano-modified adhesive is uniformly coated on the surface of the activated OSB substrate and then oriented and assembled.

[0039] S5. The OSB substrate is assembled by simultaneously applying an electromagnetic field and hot pressing with a high-frequency hot press, and then cured to obtain corrosion-resistant, high-strength OSB-based glued laminated wood.

[0040] OSB substrates are made from fast-growing coniferous woods, including southern pine and radiata pine, or broad-leaved woods, including poplar and eucalyptus, using oriented strand chips. These woods have long fibers and stable mechanical properties, making them suitable for oriented paving to improve mechanical properties.

[0041] Oriented wood shavings have a blade size of 50-80mm in length, 10-20mm in width, and 2-4mm in thickness; they have a three-layer structure, using phenolic resin as an adhesive, with the surface layer arranged longitudinally and the core layer arranged transversely; density: 600-680kg / m³. 3 .

[0042] The composition of copper azole preservative solution: a chelate of copper salt and azole compound, wherein 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 concentration of the effective component of copper azole in the copper azole preservative 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 copper ion precipitation. Preferably, the concentration of the effective component is 0.5%, which can balance the preservative performance and the amount of drug absorbed by the wood. Too high a concentration can easily cause the wood fibers to swell, while too low a concentration will result in insufficient preservative effect.

[0044] Preparation of copper azole preservative solution:

[0045] Dissolve the copper salt in water, stirring until completely dissolved at 300-500 rpm and 25-30℃.

[0046] Add azole compounds and stir continuously for 30-40 minutes to form stable chelates;

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

[0048] In step S1, during the vacuum stage, OSB is immersed in a copper azole solution, and a vacuum is drawn to -0.08 to -0.10 MPa and maintained for 30-40 minutes to expel gas from the wood cell cavities. Excessive compression of the cell wall structure is avoided, and the negative pressure allows the preservative to quickly penetrate the surface pores. In the pressurization stage, the pressure is increased to 1.0-1.5 MPa and maintained for 1.5-2.5 hours, with the temperature kept at 25-40℃. The high pressure drives the preservative to diffuse into the core layer, overcoming the wood's permeability resistance and ensuring effective drug loading in the core layer, forming a gradient drug loading from the surface to the core layer. The surface drug loading is 1.5-2.0 kg / m³. 3 Core layer 1.0-1.3 kg / m 3The high drug loading on the surface layer provides a strong anti-corrosion barrier, while the lower drug loading in the core layer reduces the impact on bonding. Finally, drain off the excess solution and air dry until the moisture content is ≤12%.

[0049] Step S1 involves immersing the OSB substrate in a copper azole preservative solution, followed by vacuum impregnation and pressure treatment, to create a gradient distribution of the preservative from the surface to the core layer of the OSB substrate. This gradient penetration method ensures the formation of an efficient anti-corrosion barrier on the surface layer to resist external fungal and insect infestations, while also reducing the amount of preservative loaded in the core layer and minimizing interference from the preservative in subsequent bonding processes.

[0050] However, although step S1 achieves gradient penetration of the preservative, the presence of a certain concentration of preservative on the surface may affect the adhesion of the adhesive on the surface.

[0051] Because the surface preservative loading is much higher than that of the core layer, metal ions will inhibit the curing of the adhesive during direct bonding. By using a precision planer to simultaneously cut the upper and lower surfaces of the OSB substrate to the same thickness (i.e., double-sided planing), the high-concentration surface preservative layer is removed, solving the problem of interface contamination caused by preservative accumulation. Removing the surface oxide layer after preservative impregnation releases the natural porous structure of the wood fibers, enhances adhesive penetration, and eliminates surface unevenness caused by preservative treatment, providing a reference plane for subsequent laser micro-hole processing.

[0052] In step S2, the high-precision double-sided planer tool is made of cemented carbide with a cutting edge sharpness Ra≤0.2μm; the planing parameters are: cutting thickness 0.5-0.7mm / face, total removal 1.0-1.4mm; feed speed 15-25m / min to avoid tearing of wood fibers due to high-speed cutting; tool angles are rake angle 15°-20° and clearance angle 8°-10° to optimize the surface roughness of the planer blade; the surface layer after planing is Cu. 2+ Content ≤800ppm;

[0053] Nanosecond pulsed lasers are used to process inverted conical micropores on the surface of sliced ​​OSB substrates, forming a mechanically interlocking structure. This increases the specific surface area of ​​the OSB substrate, exposes more fiber channels on the inner walls of the micropores, and improves the wettability of the adhesive. The inverted conical structure is narrower at the top and wider at the bottom, which enhances the mechanical bonding force between the adhesive layer and the substrate through the "wedge effect".

[0054] In step S2, the nanosecond pulsed laser has a pulse width of 100-200 ns, a focused spot diameter of 50-100 μm, a pulse energy of 40-60 mJ, and a single pulse energy density of 3-5 J / cm². 2 The processing cycle for each hole consists of 3-5 pulse superpositions, with a pulse repetition frequency of 20-30kHz.

[0055] Micropore parameters: depth 200-300μm, penetrating the surface slicing fiber activation layer; opening diameter 500-800μm; taper angle 60°-70°, forming an inverted cone shape with a length-to-diameter ratio of 1:1.2-1.5; array distribution density 15-20 pores / cm². 2 The hexagonal close-packed arrangement avoids the loss of substrate strength caused by excessively dense hole spacing.

[0056] Step S2 utilizes a combined process of double-sided planing and nanosecond laser microtexturing to eliminate interference from surface preservatives while constructing a mechanically interlocking interface. This solves the compatibility problem between the gradient preservative substrate and the adhesive. The double-sided planing not only removes the metal ion contamination layer that inhibits adhesive curing but also exposes the natural pore channels of the wood fibers, thus activating the OSB substrate surface. The inverted conical micropore array processed by nanosecond lasers forms a three-dimensional anchoring structure through a wedge effect. After treatment in S2, the OSB substrate surface possesses both a clean, active interface with low copper residue and a micro / nano-scale mechanically interlocking topology. However, conventional adhesives are difficult to fully fill the inverted conical micropores and form a strong bond. Therefore, in step S3, nano-zinc oxide is introduced to construct a three-dimensional network to enhance the adhesive. The high specific surface area and interface effect of nanoparticles are used to strengthen the adhesive layer's penetration and anchoring ability to the microporous structure.

[0057] Resorcinol-formaldehyde resin is a high-performance thermosetting resin formed by the condensation polymerization of resorcinol and formaldehyde under alkaline conditions. It has the characteristics of high reactivity and excellent weather resistance. It can be prepolymerized within the range of 5-40℃ and forms a highly cross-linked network after high-temperature curing. It is resistant to water, damp heat and biodegradation. In addition, the polar hydroxyl groups form hydrogen bonds with wood cellulose, resulting in high permeability and strong interfacial bonding ability.

[0058] In step S3, resorcinol is dissolved in water at 40-50℃ and stirred until completely dissolved. Formaldehyde solution is slowly added at a speed of 200-300 rpm, with the dropping rate controlled at 1-2 mL / min. The molar ratio of resorcinol to formaldehyde is 1:1.8-2.2. Sodium hydroxide is added to adjust the pH to 8.5-9.0. The temperature is raised to 65-70℃, and the reaction is carried out for 2-3 hours until the viscosity reaches 300-400 mPa·s. The temperature is then lowered to 25-30℃, and 5-8% ethanol is added to terminate the polycondensation, resulting in a resorcinol-formaldehyde resin solution with a solid content of 40-44%.

[0059] 3-5 wt% nano zinc oxide is mixed into resorcinol-formaldehyde resin solution and initially dispersed by mechanical stirring at 400-500 rpm for 10-15 min. Then, ultrasonic dispersion is performed with the following parameters: ultrasonic frequency 30-40 kHz, power density 300-350 W / L, and duration 25-35 min. This is used to generate and rupture microbubbles in the adhesive, producing local high temperature and pressure to break up nanoparticle agglomeration. High-frequency vibration causes nano zinc oxide to be uniformly embedded in the resin prepolymer chain segments, forming a resin-nanoparticle interpenetrating network.

[0060] Nano zinc oxide particles have a diameter of 20-50 nm and a specific surface area of ​​50-100 m². 2 / g, nano-zinc oxide forms physical entanglement with the resorcinol-formaldehyde resin matrix, improving the rigidity of the adhesive layer; and nano-zinc oxide releases Zn 2+ With copper ions Cu 2+ It synergistically inhibits fungi, and nanoparticles fill the micropores of the adhesive layer, reducing porosity and blocking water vapor penetration.

[0061] Step S3 utilizes nano-zinc oxide modified adhesive technology to achieve synergistic enhancement of the adhesive layer's mechanical properties and anti-corrosion function, solving the problems of efficient filling and long-term durability of the inverted conical microporous structure. Under ultrasonic dispersion, zinc oxide particles are uniformly 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 to the inner wall of the micropores, forming nanoscale anchoring nodes in the inverted conical channels.

[0062] In step S4, the OSB substrate surface is coated with adhesive at a rate of 250-280 g / m². 2 The coating angle is 45°-60° and the coating temperature is 25-30℃. 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, which enhances the adhesion. After the OSB veneer is coated, it is left to stand for 5-10 minutes to allow the adhesive to initially penetrate the micropores. The number of layers in the oriented veneer is odd and the structure is symmetrical, specifically 5 or 7 layers, with the fiber directions of adjacent veneers arranged orthogonally.

[0063] In step S5, the OSB substrate coated with nano-modified adhesive and oriented into a high-frequency hot press is sent to ensure that the layers are aligned and the pressure is evenly distributed. The substrate is preheated by passing it through a hot press plate to stabilize the initial temperature in the range of 50-60℃, ensuring that the adhesive layer is heated evenly.

[0064] The electromagnetic field is activated at a frequency of 2.4-2.5 GHz and a power density of 0.8-1.2 W / cm². 3The polar molecules in the adhesive layer are selectively activated by dielectric heating, while mechanical pressure of 1.0-1.5 MPa is applied simultaneously. The hot-pressing temperature is 85-90℃ and the hot-pressing time is 30-45 min. The temperature gradient of the adhesive layer drives directional cross-linking through the coupling of electromagnetic, thermal and mechanical fields. The electromagnetic field is continuously applied until curing is complete to ensure that the temperature gradient inside the adhesive layer drives the resin to fully cross-link.

[0065] After curing, the pressure is gradually released at a rate of 0.2-0.3 MPa / min to avoid stress concentration. The material is then cooled at a rate of 2-3℃ / min until it reaches below 40℃ before being discharged, thus obtaining corrosion-resistant, high-strength OSB-based glued laminated timber.

[0066] Example 1:

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

[0068] S1. Southern pine oriented strands are selected as the OSB substrate. The strand dimensions are 60mm in length, 15mm in width, and 3mm in thickness. They are laid in a three-layer structure, with the surface layer arranged longitudinally and the core layer arranged transversely. The density is 650kg / m³. 3 The OSB substrate was impregnated in a copper azole preservative solution, which consisted of a chelate of alkaline 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 of 9.0. During the vacuum impregnation stage, the pressure was increased to -0.09 MPa and maintained for 35 minutes. During the pressurization stage, the pressure was increased to 1.2 MPa and maintained for 2 hours at 30°C. The resulting surface drug loading was 1.8 kg / m². 3 Core layer 1.2kg / m 3 Air dry naturally until the moisture content reaches 10%.

[0069] S2. Double-sided planing of the OSB substrate was performed using a carbide cutting tool, with a cutting thickness of 0.6 mm / side, a total material removal of 1.2 mm, a feed rate of 20 m / min, a tool rake angle of 18°, and a clearance angle of 9°. Inverted conical micro-holes were machined using a nanosecond pulsed laser 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 / cm³. 2 Four pulses are superimposed on each well, with a repetition frequency of 25 kHz; the microwell depth is 250 μm, the opening diameter is 600 μm, the taper angle is 65°, and the array density is 18 wells / cm². 2 They are arranged in a hexagonal close-packed pattern.

[0070] S3. Dissolve resorcinol in water at 45℃, stir at 250 rpm, add formaldehyde solution dropwise until the molar ratio of resorcinol to formaldehyde is 1:2.0, add sodium hydroxide to adjust the pH to 8.8, heat to 68℃ and react for 2.5 hours. When the viscosity reaches 350 mPa·s, cool to 28℃ and add 6% ethanol to terminate the polycondensation, obtaining a resorcinol-formaldehyde resin solution with a solid content of 42%. Add 4 wt% nano zinc oxide with a particle size of 30 nm and a specific surface area of ​​80 m² to the solution. 2 / g, first mechanically stir at 450rpm for 12min, then ultrasonically disperse at 35kHz for 30min, with a power density of 320W / L, to form a three-dimensional network structure adhesive.

[0071] S4. Apply the nano-modified adhesive at 260g / m 2 The adhesive is applied to the activated OSB substrate surface at a 50° angle and a temperature of 28°C, and allowed to stand for 8 minutes to allow initial penetration. The oriented strand board has a 5-layer structure, with adjacent veneer fibers arranged orthogonally to ensure structural symmetry.

[0072] S5. The assembled OSB substrate is fed into a high-frequency hot press, preheated to 55°C, and a 2.45GHz electromagnetic field is activated with a power density of 1.0W / cm². 3 Simultaneously apply a pressure of 1.2 MPa, hot-press at 88℃, and maintain for 40 minutes; after curing, depressurize at a rate of 0.25 MPa / min, and cool to 35℃ at a rate of 2.5℃ / min before discharging to obtain corrosion-resistant high-strength OSB-based glued laminated timber.

[0073] Example 2:

[0074] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Example 1 will not be repeated. The difference between this embodiment and Example 1 is that the concentration of copper azole active ingredient is 0.3%.

[0075] Example 3:

[0076] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Example 1 will not be repeated. The difference between this embodiment and Example 1 is that the concentration of copper azole active ingredient is 0.8%.

[0077] Example 4:

[0078] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Embodiment 1 will not be repeated. The difference between this embodiment and Embodiment 1 is that the cutting thickness is 0.5 mm / side.

[0079] Example 5:

[0080] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Embodiment 1 will not be repeated. The difference between this embodiment and Embodiment 1 is that the cutting thickness is 0.7 mm / side.

[0081] Example 6:

[0082] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Embodiment 2 will not be repeated. The difference between this embodiment and Embodiment 2 is that the cutting thickness is 0.5 mm / side.

[0083] Example 7:

[0084] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Embodiment 2 will not be repeated. The difference between this embodiment and Embodiment 2 is that the cutting thickness is 0.7 mm / face.

[0085] Example 8:

[0086] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Embodiment 3 will not be repeated. The difference between this embodiment and Embodiment 3 is that the cutting thickness is 0.5 mm / side.

[0087] Example 9:

[0088] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Example 3 will not be repeated. The difference between this embodiment and Example 3 is that the cutting thickness is 0.7 mm / side.

[0089] Example 10:

[0090] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Example 1 will not be repeated. The difference between this embodiment and Example 1 is that the taper angle of the inverted conical micropore is 60°.

[0091] Example 11:

[0092] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this embodiment and Example 1 will not be repeated. The difference between this embodiment and Example 1 is that the taper angle of the inverted conical micropore is 70°.

[0093] Example 12:

[0094] A method for preparing corrosion-resistant high-strength OSB-based glued laminated wood. The similarities between this embodiment and Example 1 will not be repeated. The difference between this embodiment and Example 1 is that 3wt% nano zinc oxide is added to the glue solution.

[0095] Example 13:

[0096] A method for preparing corrosion-resistant high-strength OSB-based glued laminated wood. The similarities between this embodiment and Example 1 will not be repeated. The difference between this embodiment and Example 1 is that 5 wt% nano zinc oxide is added to the glue solution.

[0097] Example 14:

[0098] A method for preparing corrosion-resistant high-strength OSB-based glued laminated wood. The similarities between this embodiment and Example 10 will not be repeated here. The difference between this embodiment and Example 10 is that 3 wt% nano zinc oxide is added to the glue solution.

[0099] Example 15:

[0100] A method for preparing corrosion-resistant high-strength OSB-based glued laminated wood. The similarities between this embodiment and Example 10 will not be repeated here. The difference between this embodiment and Example 10 is that 5 wt% nano zinc oxide is added to the glue solution.

[0101] Example 16:

[0102] A method for preparing corrosion-resistant high-strength OSB-based glued laminated wood. The similarities between this embodiment and Example 11 will not be repeated. The difference between this embodiment and Example 11 is that 3 wt% nano zinc oxide is added to the glue solution.

[0103] Example 17:

[0104] A method for preparing corrosion-resistant high-strength OSB-based glued laminated wood. The similarities between this embodiment and Example 11 will not be repeated. The difference between this embodiment and Example 11 is that 5 wt% nano zinc oxide is added to the glue solution.

[0105] Comparative Example 1:

[0106] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this comparative example and Example 1 will not be repeated. The difference between this comparative example and Example 1 is that no planing is performed.

[0107] Comparative Example 2:

[0108] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this comparative example and Example 1 will not be repeated. The difference between this comparative example and Example 1 is that it does not have inverted conical micropores.

[0109] Comparative Example 3:

[0110] A method for preparing corrosion-resistant high-strength OSB-based glued laminated timber. The similarities between this comparative example and Example 1 will not be repeated. The difference between this comparative example and Example 1 is that nano zinc oxide is not added.

[0111] Experimental Example 1:

[0112] This experiment selected Examples 1-9 and Comparative Example 1 to test the physical and chemical properties of glued laminated wood.

[0113] The penetration depth of the preservative was tested to confirm whether the vacuum-pressurization process in step S1 achieved a gradient distribution of high preservative loading on the surface and low preservative loading in the core layer, thus avoiding excessive preservative in the core layer from interfering with bonding. The copper ion migration rate reflects the migration stability of the preservative in the wood, and a low migration rate indicates that the gradient distribution has been effectively fixed.

[0114] Table 1. Detection results of Experiment Example 1

[0115]

[0116] Example 1 showed the best results, mainly due to the optimal selection of the effective concentration of copper azole and the cutting thickness. A copper azole concentration of 0.5% achieved an effective balance, ensuring sufficient preservative to form a strong protective barrier on the surface without causing excessive preservative loading in the core layer, which could negatively impact subsequent gluing. Simultaneously, a cutting thickness of 0.6 mm / face effectively removed the high-concentration preservative layer from the surface, preventing metal ions from inhibiting adhesive curing, while also fully exposing the natural pores of the wood fibers, enhancing adhesive penetration. This comprehensive parameter combination resulted in a glue shear strength of 12.3 MPa for the glued laminate, with good preservative penetration depth and copper ion migration, effectively preventing the adverse effects of excessive preservative penetration and migration on wood properties, thus achieving a good balance between preservative performance and gluing strength.

[0117] Experimental Example 2:

[0118] This experiment selected Examples 1, 10-17, and Comparative Examples 2-3 to test the physicochemical properties of glued laminated timber. The micropore taper angle affects the penetration depth of the adhesive and the mechanical interlocking effect, while the content of nano zinc oxide directly affects the crosslinking density and anti-corrosion performance of the adhesive layer. The water-resistant peel strength retention rate reflects the durability of the adhesive layer in a humid and hot environment, verifying whether the S3 nano-modified adhesive solves the problem of traditional adhesives easily absorbing water and failing. The micropore filling rate is used to confirm whether the S2 laser micropores are fully filled to form a three-dimensional anchoring structure.

[0119] Table 2 Detection results of Experiment Example 2

[0120]

[0121] Example 1 also exhibits superior performance in parameters such as micropore taper angle and nano zinc oxide content. The micropore taper angle is 65°, which facilitates the full penetration of the adhesive into the micropores and enhances the mechanical interlocking effect through a suitable "wedge effect," forming a stable three-dimensional anchoring structure. The nano zinc oxide content is 4wt%, effectively enhancing the crosslinking density and corrosion resistance of the adhesive layer. On one hand, the physical entanglement formed between nano zinc oxide and resorcinol-formaldehyde resin improves the rigidity of the adhesive layer; on the other hand, the released Zn... 2+ It synergistically inhibits fungi with copper ions. The synergistic effect of this microporous structure and nano-modified adhesive results in a shear strength of 13.1 MPa, a water-resistant peel strength retention rate of 91.2%, and a micropore filling rate of 92.5%. While ensuring the bonding strength, it improves the durability of the adhesive layer and the micropore filling effect, thus making the glued laminated wood of Example 1 the best in terms of overall performance.

[0122] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing corrosion-resistant, high-strength OSB-based glued laminated timber, characterized in that, include: S1. The OSB substrate is immersed in copper azole anti-corrosion solution, and vacuum impregnation and pressure treatment are performed in sequence to form a gradient distribution of anti-corrosion agent loading from the surface layer to the core layer of the OSB substrate. S2. The OSB substrate after anti-corrosion treatment is double-sided planed to remove the high-concentration anti-corrosion layer on the surface, and an inverted conical micropore array is processed by nanosecond laser to activate the surface of the OSB substrate. S3. Nano-zinc oxide is added to resorcinol-formaldehyde resin adhesive and ultrasonically dispersed to form a three-dimensional network structure of nano-modified adhesive. S4. The nano-modified adhesive is uniformly coated on the surface of the activated OSB substrate and then oriented and assembled. S5. The OSB substrate is assembled by simultaneously applying an electromagnetic field and hot pressing with a high-frequency hot press, and then cured to obtain corrosion-resistant, high-strength OSB-based glued laminated wood.

2. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: OSB substrate uses oriented strands of fast-growing coniferous or broadleaf timber. The strands are 50-80mm long, 10-20mm wide, and 2-4mm thick. The OSB substrate has a three-layer structure, with the surface layer arranged longitudinally and the core layer arranged transversely, with a density of 600-680kg / m³. 3 .

3. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: The copper azole preservative solution is formed by chelating copper salt and azole compound. The copper salt is alkaline 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, the concentration of active ingredient is 0.3-0.8%, and the pH value is 8.5-9.

5.

4. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: Vacuum impregnation pressure is -0.08~-0.10 MPa, maintained for 30-40 minutes; pressurization treatment pressure is 1.0-1.5 MPa, maintained for 1.5-2.5 hours, temperature is 25-40℃, and the surface drug loading after treatment is 1.5-2.0 kg / m². 3 The core layer drug loading is 1.0-1.3 kg / m³. 3 .

5. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: Double-sided planing uses carbide tools, with a cutting thickness of 0.5-0.7 mm / sided, a total material removal of 1.0-1.4 mm, and a feed rate of 15-25 m / min. The resulting surface layer is Cu. 2+ Content ≤800ppm.

6. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: The parameters for nanosecond laser processing are: pulse width 100-200 ns, spot diameter 50-100 μm, pulse energy 40-60 mJ, and energy density 3-5 J / cm². 2 Micropore depth 200-300μm, opening diameter 500-800μm, taper angle 60°-70°, array density 15-20 pores / cm 2 It adopts a hexagonal close-packed arrangement.

7. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: The resorcinol-formaldehyde resin solution is formed by the condensation polymerization of 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 of 3-5wt%, a particle size of 20-50nm, an ultrasonic dispersion frequency of 30-40kHz, a power density of 300-350W / L, and a duration of 25-35min.

8. The method for preparing a corrosion-resistant high-strength OSB-based glued laminated timber according to claim 1, characterized in that: In step S4, the amount of adhesive applied is 250-280 g / m². 2 The coating angle is 45°-60°, the coating temperature is 25-30℃, the number of oriented preform layers is odd and the structure is symmetrical, and the surface oriented shavings of adjacent OSB substrates are arranged orthogonally to each other.

9. A method for preparing a corrosion-resistant, high-strength OSB-based glued laminated timber according to claim 1, characterized in that: In step S5, preheating is performed to stabilize the initial temperature at 50-60℃, the electromagnetic field frequency is 2.4-2.5GHz, and the power density is 0.8-1.2W / cm². 3 The hot pressing pressure is 1.0-1.5MPa, the temperature is 85-90℃, and the time is 30-45min.

10. A method for preparing a corrosion-resistant, high-strength OSB-based glued laminated timber according to claim 1, characterized in that: In step S5, after curing is completed, the pressure is gradually released at a rate of 0.2-0.3 MPa / min and a cooling rate of 2-3 °C / min, and the board is cooled to below 40 °C before being discharged.

Images