Moistureproof and antibacterial straw mixed artificial board and preparation method thereof

Abstract

The invention provides a moistureproof antibacterial straw mixed artificial board and a preparation method thereof, and relates to the technical field of straw artificial boards, the moistureproof antibacterial straw mixed artificial board comprises a core layer, a surface layer and a functional layer, the core layer comprises the following components by weight: 7-8 parts of wheat straw crude fiber, 1-2 parts of fir sawdust, 0.5-1 part of an adhesive, and 0.2-0.4 part of a zeolite compound; the surface layer is prepared from 2-3 parts of wheat straw fine fibers, 6-7 parts of eucalyptus sawdust, 1-2 parts of an adhesive and 0.1-0.3 part of nano silicon dioxide; the functional layer is prepared from the following components in parts by weight: 1 to 3 parts of plant extract, 0.5 to 1.5 parts of nano silver, 2 to 4 parts of titanium dioxide, 0.2 to 0.5 part of KH-550, 0.1 to 0.3 part of dodecafluoroheptyl propyl trimethoxy silane and 5 to 8 parts of polyurethane. A bio-based material system is used, the obtained straw and wood chip mixed artificial board is free of formaldehyde release, and damage to the human body is reduced; a gradient structure design is adopted, so that the mechanical property and moisture resistance of the plate are enhanced; plant extracts are adopted to construct a natural-inorganic antibacterial system, so that the plate has high antibacterial property.

Description

Technical Field

[0001] The present invention belongs to the technical field of straw-based artificial boards, and particularly relates to a moisture-proof and antibacterial straw composite artificial board and a preparation method thereof. Background Art

[0002] With the upgrading of global demands for green buildings and healthy homes, traditional artificial boards face multiple technical bottlenecks: formaldehyde-based adhesives continuously release volatile organic compounds due to chemical irreversibility, forming periodic pollution sources, seriously restricting the application of boards in sensitive scenarios; straw-based artificial boards are affected by the hydrophilicity of cellulose and porous structures, resulting in moisture absorption, swelling and microbial growth during humidity fluctuations, while existing physical moisture-proof layers have defects such as easy wear and interface weakening; the natural silica wax layer on the straw surface hinders the effective bonding of adhesives, and although traditional acid-base modification improves the bonding strength, it destroys the fiber crystallinity and generates pollution; the antibacterial system faces the problems of performance fragmentation between organic / inorganic materials, poor environmental tolerance and heavy metal pollution risks, and it is difficult to meet the long-term antibacterial requirements. Invention Publication No. CN104290151B discloses a method for making a straw board. This solution uses urea-formaldehyde resin as an adhesive, which will continuously release formaldehyde and other volatile organic compounds during long-term use, threatening human health; moreover, its moisture-proof and antibacterial properties are insufficient and cannot meet the long-term use requirements in humid environments such as kitchens and bathrooms. Summary of the Invention

[0003] The purpose of the present invention is to provide a moisture-proof and antibacterial straw composite artificial board and a preparation method thereof. By adopting a bio-based adhesive system, gradient structure design and natural antibacterial materials acting synergistically, the technical defects of formaldehyde release, poor moisture-proof performance, low interface strength and inability to provide long-term antibacterial properties in traditional artificial boards are solved.

[0004] To achieve the above purpose, the present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer and a functional layer, and contains the following components in parts by weight:

[0005] The core layer includes: 7-8 parts of wheat straw coarse fiber, 1-2 parts of Chinese fir sawdust, 0.5-1 part of adhesive, and 0.2-0.4 part of zeolite composite;

[0006] The surface layer includes: 2-3 parts of wheat straw fine fiber, 6-7 parts of eucalyptus sawdust, 1-2 parts of adhesive, and 0.1-0.3 part of nano-silica;

[0007] The functional layer includes: 1-3 parts of plant extract, 0.5-1.5 parts of nano-silver, 2-4 parts of titanium dioxide, 0.2-0.5 part of silane coupling agent, 0.1-0.3 part of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, and 5-8 parts of polyurethane.

[0008] Preferably, the particle size of the wheat straw coarse fiber in the core layer is 0.3 - 2.0 mm, and the aspect ratio is 2 - 3:1; the particle size of the wheat straw fine fiber in the surface layer is ≤0.3 mm, and the aspect ratio is 5 - 8:1.

[0009] Preferably, the zeolite composite is a composite composed of zeolite powder and nano - tourmaline powder, and the weight ratio of zeolite powder to tourmaline powder is 6 - 9:1.

[0010] Preferably, the plant extract is Solanum nigrum extract.

[0011] Preferably, the adhesive is a bio - based adhesive composed of soy protein, lignin, peroxidase and nanocellulose.

[0012] Preferably, the silane coupling agent in the functional layer is KH - 550, and the mass ratio of KH - 550 to dodecafluoroheptylpropyltrimethoxysilane is (2 - 3):1.

[0013] The present invention also provides a preparation method of a moisture - proof and antibacterial straw - mixed artificial board, which comprises the following steps:

[0014] (1) Crush and screen the wheat straw pretreated by steam explosion to obtain wheat straw coarse fiber and wheat straw fine fiber;

[0015] (2) Mix the wheat straw coarse fiber with sawdust, add the remaining raw materials in the surface layer and dry to obtain the surface layer material; mix the wheat straw fine fiber with Chinese fir sawdust, add the remaining raw materials in the core layer and dry to obtain the core layer material;

[0016] (3) Lay the core layer material and the surface layer material in the order of surface layer - core layer - surface layer, and perform segmented hot pressing to obtain the artificial board;

[0017] (4) Dissolve the functional layer raw materials in deionized water, spray them onto the artificial board by ultrasonic atomization, and cure by microwave.

[0018] Preferably, in step (1), the steam explosion parameters are a pressure of 0.9 - 1.1 MPa, a saturated steam temperature of 170 - 190 °C, and a pressure - holding time of 0.5 - 1.5 min.

[0019] Preferably, in step (2), the moisture content of the surface layer material is 8 - 10%; the moisture content of the core layer material is 12 - 14%.

[0020] Preferably, in step (3), the paving density of the surface layer is 0.75 - 0.85 g / cm 3 ; the paving density of the core layer is 0.6 - 0.7 g / cm 3; In the segmented hot pressing process, the temperature in the first stage is 110 - 120°C, the pressure is 3 - 5 MPa, and the time is 10 - 15 min; the pressure in the second stage is 8 - 10 MPa, the temperature is 140 - 150°C, and the time is 20 - 25 min.

[0021] Preferably, the ultrasonic atomization spraying amount of the functional layer raw material in step (4) is 8 - 12 g / m 2 ,; Microwave curing treatment, the microwave power is 2 - 3 kw, the frequency is 2450 MHz, and the treatment time is 3 - 5 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are: (1) Using renewable biomass such as straw and wood chips as the base material, reducing wood consumption and realizing the clean conversion of agricultural waste, meeting the development needs of green building materials; (2) Replacing traditional formaldehyde resins with bio-based composite adhesives to achieve formaldehyde-free for all components and completely eliminate the hidden danger of indoor formaldehyde pollution; (3) Combining physical pretreatment to break the hydrophobic barrier of straw and chemical coupling and directional bonding technology to significantly improve the interfacial bonding strength between fibers and the adhesive layer; (4) Based on the composite structure design of surface layer barrier and core layer moisture absorption and slow release, effectively inhibiting moisture absorption and swelling and maintaining dimensional stability in a humid and hot environment; (5) Integrating the synergistic system of plant extracts and inorganic antibacterial factors to avoid the risk of heavy metal pollution while ensuring long-term and broad-spectrum antibacterial performance. Specific embodiments

[0023] The present invention will be further described below in conjunction with embodiments:

[0024] General embodiment

[0025] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer and a functional layer, and specifically includes the following components in parts by weight:

[0026] The core layer includes: 7 - 8 parts of wheat straw coarse fiber, 1 - 2 parts of Chinese fir wood chips, 0.5 - 1 part of adhesive, and 0.2 - 0.4 part of zeolite composite;

[0027] The surface layer includes: 2 - 3 parts of wheat straw fine fiber, 6 - 7 parts of eucalyptus wood chips, 1 - 2 parts of adhesive, and 0.1 - 0.3 part of nano-silica;

[0028] The functional layer comprises: 1-3 parts of plant extract, 0.5-1.5 parts of nano silver, 2-4 parts of titanium dioxide, 0.2-0.5 parts of KH-550, 0.1-0.3 parts of dodecafluoroheptylpropyltrimethoxysilane, and 5-8 parts of polyurethane. Its technical effect lies in: adopting a layered structure design of the core layer, surface layer and functional layer, combining environmentally friendly materials with functional components to achieve multiple performance optimizations. The core layer uses wheat straw coarse fiber and Chinese fir sawdust as the matrix, and the structure stability and moisture absorption capacity are enhanced through the formaldehyde-free adhesive and zeolite composite; the surface layer uses wheat straw fine fiber, eucalyptus sawdust and nano silica to form a dense anti-permeable surface, improving wear resistance and moisture resistance; the functional layer endows the board with broad-spectrum antibacterial properties through the synergistic effect of plant extract, nano silver and titanium dioxide, and at the same time realizes hydrophobic protection by means of fluorosilane and polyurethane.

[0029] In some preferred cases, the particle size of the wheat straw coarse fiber in the core layer is 0.3-2.0 mm, and the aspect ratio is (2-3):1; the particle size of the wheat straw fine fiber in the surface layer is 0.1-0.3 mm, and the aspect ratio is (5-8):1. Its technical effect lies in: the core layer uses thick and short fibers, combined with Chinese fir sawdust to form a three-dimensional network structure, improving the compressive strength, bending strength and dimensional stability of the artificial board; the surface layer uses long and thin fibers to form a densified structure on the surface layer, significantly improving the surface hardness, wear resistance and anti-permeability, and providing a good attachment surface for the functional layer. In addition, the gradient transition of the micron-level pores and the coarse fibers in the core layer effectively blocks the capillary water migration path, and together with the natural hydrophobic characteristics of eucalyptus sawdust, further strengthens the moisture-proof barrier.

[0030] In some preferred cases, the zeolite composite is a composite composed of zeolite powder and nano tourmaline powder, and the weight ratio of zeolite powder to tourmaline powder is 6-9:1. Its technical effect lies in: the zeolite powder quickly captures environmental moisture and volatile harmful substances through its physical adsorption characteristics, while the negative ions released by the nano tourmaline powder can destroy the cell membrane structure of microorganisms, playing an internal antibacterial role; when the ratio of the two is controlled at 6-9:1, it not only maintains the full filling of the zeolite framework in the gaps of the core layer coarse fibers to maintain mechanical stability, but also forms a local electric field at the fiber-zeolite interface through a small amount of highly active nano tourmaline powder, promoting the directional arrangement of the polar groups of lignin in the adhesive and enhancing the interface bonding strength.

[0031] In some preferred cases, the plant extract is Solanum nigrum extract. Its technical effects are as follows: As the active component of the functional layer, Solanum nigrum extract utilizes its broad-spectrum antibacterial properties to form an organic-inorganic composite antibacterial system with silver nanoparticles and titanium dioxide. At the same time, the polyphenolic hydroxyl structure in Solanum nigrum extract can chelate free metal ions, reduce the aggregation of silver nanoparticles, maintain its high specific surface activity, and improve the flexibility and adhesion of the functional layer film. In addition, the natural hydrophobic components in Solanum nigrum extract and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane synergistically reduce the surface energy, construct a superhydrophobic interface, block the water adsorption path, and achieve the triple integration of antibacterial synergism, nano-dispersion stability, and moisture-proof function.

[0032] In some preferred cases, the adhesive is a bio-based adhesive composed of soy protein, lignin, peroxidase, and nanocellulose. Its technical effects are as follows: Using soy protein as a flexible matrix, its active groups form a stable covalent cross-linking network with lignin under the catalysis of peroxidase. The hydrophobic structure of lignin is embedded in the protein network, combined with the strengthening effect of the nanocellulose skeleton, to construct a three-dimensional interpenetrating system, significantly improving the bonding strength and maintaining excellent wet stability. Nanocellulose endows the colloid with adjustable rheological properties to adapt to different density paving requirements. At the same time, the low-temperature catalytic properties of peroxidase greatly reduce the processing energy consumption.

[0033] The present invention also provides a method for preparing a moisture-proof and antibacterial straw composite artificial board, which specifically includes the following steps:

[0034] (1) Crush and screen the wheat straw pretreated by steam explosion to obtain wheat straw coarse fibers and wheat straw fine fibers;

[0035] (2) Mix the wheat straw coarse fibers with wood chips, and add the remaining raw materials of the surface layer and dry to obtain the surface layer material; mix the wheat straw fine fibers with Chinese fir chips, and add the remaining raw materials of the core layer and dry to obtain the core layer material;

[0036] (3) Lay the core layer material and the surface layer material in the order of surface layer - core layer - surface layer, and perform segmented hot pressing to obtain the artificial board;

[0037] (4) The raw materials of the functional layer are dissolved in deionized water, atomized by ultrasonic spraying onto the wood-based panel, and cured by microwave. Its technical effect lies in: synergistically optimizing the comprehensive performance of the wood-based panel through multi-stage processes. Steam explosion pretreatment effectively breaks the natural barrier structure of wheat straw, improves fiber separation and reaction activity, and provides a homogenized raw material basis for subsequent crushing and screening; the layered batching system is designed differently according to the functional requirements of the core layer and the surface layer. The core layer balances mechanical support and weight control through coarse fibers and light fillers, and the surface layer uses fine fibers and nano-enhancing agents to achieve surface densification and improved wear resistance; the segmented hot pressing process regulates through temperature-pressure gradients to achieve full curing of the adhesive and orderly construction of the fiber three-dimensional network; the functional layer uses ultrasonic atomization spraying combined with microwave curing technology to ensure nano-level uniform loading and rapid cross-linking film formation of antibacterial and moisture-proof components on the substrate surface, forming a stable and lasting functional interface.

[0038] In some preferred cases, the moisture content of the surface layer material in step (2) is 8-10%; the moisture content of the core layer material is 12-14%. Its technical effect lies in: the lower moisture content of the surface layer material ensures that fine fibers and nano-silica quickly form a dense network at the initial stage of hot pressing, avoiding micropore defects caused by water evaporation, and at the same time providing a low-interference environment for the construction of the surface waterproof film layer; moderately increasing the moisture content of the core layer maintains sufficient wetting and diffusion of the active components of the adhesive, promotes the penetration and cross-linking of the adhesive at the straw-wood chip interface, and uses the steam pressure generated by the phase change of water when heated to enhance the entanglement strength between fibers.

[0039] In some preferred cases, the paving density of the surface layer in step (3) is 0.75-0.85 g / cm 3 ; the paving density of the core layer is 0.6-0.7 g / cm 3 ; for the segmented hot pressing process, the temperature in the first stage is 110-120 °C, the pressure is 3-5 MPa, and the time is 10-15 min; the pressure in the second stage is 8-10 MPa, the temperature is 140-150 °C, and the time is 20-25 min. Its technical effect lies in: the higher paving density of the surface layer combined with mild hot pressing in the first stage promotes the directional arrangement of fine fibers and nano-silica, forming a dense and wear-resistant surface layer; the low-density paving of the core layer combined with high-pressure and high-temperature in the second stage triggers the deep cross-linking reaction of the bio-based adhesive, forming a high-strength interpenetrating network at the wood chip-straw interface. The segmented pressure loading strategy guides the fibers to be gradually compacted, eliminating the interlayer voids while retaining the porous structure of the core layer to maintain the lightweight advantage; the temperature gradient activates different reaction groups of the adhesive in stages, ensuring the synchronous improvement of the integrity of the surface waterproof film and the bonding strength of the core layer, and finally forming a "rigid surface and tough core" composite structure, taking into account the bearing capacity and impact resistance of the board.

[0040] In some preferred cases, the ultrasonic atomization spraying amount of the raw materials of the functional layer in step (4) is 8-12 g / m2 ,; Microwave curing treatment is carried out with a microwave power of 2 - 3 kW, a frequency of 2450 MHz, and a treatment time of 3 - 5 min. Its technical effect lies in: by precisely controlling the spraying amount and the input of curing energy, efficient loading and stable fixation of functional components are achieved. Ultrasonic atomization spraying uniformly covers the surface of the substrate with micron-sized droplets, ensuring the controllable deposition of active components such as silver nanoparticles and titanium dioxide per unit area, and avoiding the component aggregation or excessive penetration caused by the traditional dipping method; microwave curing with a specific power and frequency triggers the rapid cross-linking reaction of silane coupling agent and polyurethane through molecular polar selective heating, forming a dense three-dimensional network within 3 - 5 min, and anchoring the antibacterial and moisture-proof components at the fiber pores and surface protrusions; the non-thermal effect of microwaves synchronously activates the surface energy of nanoparticles and enhances the interfacial bonding strength between them and the substrate.

[0042] Example 1

[0043] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer and a functional layer, and specifically contains the following components in parts by weight:

[0044] The core layer includes: 7.5 parts of wheat straw coarse fiber, 1.5 parts of Chinese fir sawdust, 0.8 part of bio-based adhesive, and 0.3 part of zeolite composite;

[0045] The surface layer includes: 2.5 parts of wheat straw fine fiber, 6.5 parts of eucalyptus sawdust, 1.5 parts of bio-based adhesive, and 0.2 part of nano-silica;

[0046] The functional layer includes: 2 parts of Solanum nigrum extract, 1.0 part of silver nanoparticles, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane.

[0047] The present invention also provides a preparation method of the moisture-proof and antibacterial straw composite artificial board, which includes the following steps:

[0048] (1) Pretreatment of raw materials and fiber classification:

[0049] Put the wheat straw into the steam explosion equipment, and treat it under the conditions of 1.0 MPa pressure and 180 °C saturated steam for 1 minute. Use the instantaneous pressure relief to break the surface silica wax layer of the straw and improve the fiber separation activity. After explosion, the wheat straw is crushed by a hammer mill and classified through a vibrating screen to obtain two types of fibers: wheat straw coarse fiber (particle size 0.3 - 2.0 mm, length-diameter ratio 2 - 3:1) and wheat straw fine fiber (particle size 0.1 - 0.3 mm, length-diameter ratio 5 - 8:1). After screening, the fibers are stored separately for later use.

[0050] (2) Preparation of core layer and surface layer materials:

[0051] Mix 7.5 parts of core layer coarse fibers with 1.5 parts of Chinese fir sawdust, add 0.8 parts of bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase, and 2 parts of nanocellulose) and 0.3 parts of zeolite complex (weight ratio of zeolite powder to tourmaline powder is 8:1), stir in a mixer for 15 minutes, and control the moisture content of the material to 13% by spray humidification during this period; mix 2.5 parts of surface layer fine fibers with 6.5 parts of eucalyptus sawdust, add 1.5 parts of adhesive and 0.2 parts of nano-silica, mix for 20 minutes and synchronously dry with hot air until the moisture content reaches 9%.

[0052] (3) Gradient paving and segmented hot pressing:

[0053] Use a continuous paving machine to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is precisely controlled to be 0.8 g / cm 3 , and the core layer density is 0.65 g / cm 3 . After paving, send it into a multi-layer hot press. First, pre-press at a temperature of 115 °C and a pressure of 4 MPa for 12 minutes; then raise the temperature to 145 °C and increase the pressure to 9 MPa and hold for 22 minutes.

[0054] (4) Functional layer spraying and curing:

[0055] Disperse 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomizing spray gun to spray evenly at a distance of 30 cm from the board surface, and control the spraying amount per unit area to be 10 g / m 2 , and immediately send it into a microwave tunnel after forming a uniform liquid film, and irradiate it at a power of 2.5 kW and a frequency of 2450 MHz for 4 minutes to obtain a moisture-proof and antibacterial straw composite artificial board.

[0056] Example 2

[0057] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer, and a functional layer, and specifically contains the following components in parts by weight:

[0058] The core layer includes: 8 parts of wheat straw coarse fibers, 2 parts of Chinese fir sawdust, 1 part of bio-based adhesive, and 0.4 parts of zeolite complex;

[0059] The surface layer includes: 3 parts of wheat straw fine fibers, 7 parts of eucalyptus sawdust, 2 parts of bio-based adhesive, and 0.3 parts of nano-silica;

[0060] The functional layer includes: 3 parts of Solanum nigrum extract, 1.5 parts of nano-silver, 4 parts of titanium dioxide, 0.5 part of KH-550, 0.25 part of dodecafluoroheptylpropyltrimethoxysilane, and 8 parts of polyurethane.

[0061] The present invention also provides a method for preparing a moisture-proof and antibacterial straw composite artificial board, comprising the following steps:

[0062] (1) Raw material pretreatment and fiber classification:

[0063] Put wheat straw into a steam explosion device and treat it for 1.5 minutes under the conditions of 1.1 MPa pressure and 190 °C saturated steam. After explosion, the material is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fibers (particle size 0.3 - 2.0 mm, aspect ratio 2 - 3:1) and wheat straw fine fibers (particle size 0.1 - 0.3 mm, aspect ratio 5 - 8:1). The screened fibers are stored separately for later use.

[0064] (2) Preparation of core layer and surface layer materials:

[0065] Mix 8 parts of wheat straw coarse fibers with 2 parts of Chinese fir sawdust, add 1 part of a bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase, and 2 parts of nanocellulose) and 0.4 part of a zeolite composite (weight ratio of zeolite powder to tourmaline powder is 8:1), and stir for 15 minutes. During this period, spray humidification is used to control the moisture content of the material to 14%; mix 3 parts of wheat straw fine fibers with 7 parts of eucalyptus sawdust, add 2 parts of an adhesive and 0.3 part of nano-silica, mix for 20 minutes and simultaneously hot air dry to a moisture content of 10%.

[0066] (3) Gradient paving and segmented hot pressing:

[0067] Use a continuous paver to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is precisely controlled to be 0.85 g / cm 3 , and the core layer density is 0.7 g / cm 3 . After paving, it is sent to a multi-layer hot press. First, pre-press at a temperature of 120 °C and a pressure of 5 MPa for 15 minutes to preliminarily crosslink the surface layer fibers and the adhesive and form a densified surface; then raise the temperature to 150 °C, increase the pressure to 10 MPa, and maintain for 25 minutes to promote the deep crosslinking of the core layer fibers and the adhesive.

[0068] (4) Functional layer spraying and curing:

[0069] Disperse 3 parts of Solanum nigrum extract, 1.5 parts of nano-silver, 4 parts of titanium dioxide, 0.5 part of KH-550, 0.25 part of dodecafluoroheptylpropyltrimethoxysilane, and 8 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomizing spray gun to spray evenly at a distance of 30 cm from the board surface, control the spraying amount per unit area to be 12 g / m 2 , and immediately send it into a microwave tunnel after forming a uniform liquid film. Radiate at a power of 3 kW and a frequency of 2450 MHz for 5 minutes to obtain a moisture-proof and antibacterial straw composite artificial board.

[0070] Example 3

[0071] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer and a functional layer, and specifically contains the following components in parts by weight:

[0072] The core layer includes: 7 parts of wheat straw coarse fiber, 1 part of Chinese fir sawdust, 0.5 part of bio-based adhesive, and 0.2 part of zeolite composite;

[0073] The surface layer includes: 3 parts of wheat straw fine fiber, 7 parts of eucalyptus sawdust, 2 parts of bio-based adhesive, and 0.3 part of nano-silica;

[0074] The functional layer includes: 1 part of Solanum nigrum extract, 0.5 part of nano-silver, 2 parts of titanium dioxide, 0.2 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 5 parts of polyurethane.

[0075] The present invention also provides a preparation method of the moisture-proof and antibacterial straw composite artificial board, which includes the following steps:

[0076] (1) Raw material pretreatment and fiber classification:

[0077] Put the wheat straw into the steam explosion equipment and treat it for 1 minute under the conditions of 0.9 MPa pressure and 170 °C saturated steam. After explosion, the material is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fiber (particle size 0.3 - 2.0 mm, aspect ratio 2 - 3:1) and wheat straw fine fiber (particle size 0.1 - 0.3 mm, aspect ratio 5 - 8:1). After screening, the fibers are stored separately for later use.

[0078] (2) Preparation of core layer and surface layer materials:

[0079] Mix 7 parts of wheat straw coarse fiber with 1 part of Chinese fir sawdust, add 0.5 part of bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase and 2 parts of nano-cellulose) and 0.2 part of zeolite composite (weight ratio of zeolite powder to tourmaline powder is 8:1), and stir in a mixer for 15 minutes. During this period, spray humidification is used to control the moisture content of the material to 12%. At the same time, mix 3 parts of wheat straw fine fiber with 7 parts of eucalyptus sawdust, add 2 parts of bio-based adhesive and 0.3 part of nano-silica, mix for 20 minutes and synchronously dry with hot air to a moisture content of 8%.

[0080] (3) Gradient paving and segmented hot pressing:

[0081] Use a continuous paving machine to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is precisely controlled to be 0.75 g / cm 3 , and the density of the core layer is 0.6 g / cm 3After paving, it is sent to a multi-layer hot press, first pre-pressed at a temperature of 110°C and a pressure of 3 MPa for 10 minutes; then the temperature is raised to 140°C and the pressure is increased to 8 MPa and maintained for 20 minutes.

[0082] (4) Functional layer spraying and curing:

[0083] Disperse 1 part of Solanum nigrum extract, 0.5 part of nano silver, 2 parts of titanium dioxide, 0.2 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane and 5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 15%. Use an ultrasonic atomizing spray gun to spray evenly at a distance of 25 cm from the board surface, and control the spraying amount per unit area to be 8 g / m 2 , and after forming a uniform liquid film, it is sent into a microwave tunnel and irradiated at a power of 3 kW and a frequency of 2450 MHz for 5 minutes to obtain a moisture-proof and antibacterial straw composite artificial board.

[0084] Comparative Example 1

[0085] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which consists of a core layer, a surface layer and a functional layer, and specifically contains the following components in parts by weight:

[0086] The core layer includes: 7.5 parts of wheat straw coarse fiber, 1.5 parts of Chinese fir sawdust, 1 part of urea-formaldehyde resin adhesive, and 0.3 part of zeolite composite;

[0087] The surface layer includes: 2.5 parts of wheat straw fine fiber, 6.5 parts of eucalyptus sawdust, 2 parts of urea-formaldehyde resin adhesive, and 0.2 part of nano-silica;

[0088] The functional layer includes: 2 parts of Solanum nigrum extract, 1.0 part of nano silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane.

[0089] The present invention also provides a preparation method of a moisture-proof and antibacterial straw composite artificial board, which includes the following steps:

[0090] (1) Raw material pretreatment and fiber classification:

[0091] Put wheat straw into a steam explosion device and process it under the conditions of 1.0 MPa pressure and 180°C saturated steam for 1 minute. After explosion, the material is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fiber (particle size 0.3 - 2.0 mm, aspect ratio 2 - 3:1) and wheat straw fine fiber (particle size 0.1 - 0.3 mm, aspect ratio 5 - 8:1). After screening, the fibers are stored separately for later use.

[0092] (2) Preparation of core layer and surface layer materials:

[0093] Mix 7.5 parts of wheat straw coarse fiber with 1.5 parts of Chinese fir sawdust, add 1 part of urea-formaldehyde resin adhesive (solid content 50%) and 0.3 part of zeolite complex (weight ratio of zeolite powder to tourmaline powder is 8:1), and stir at low speed in a mixer for 15 minutes. During this period, spray and humidify to control the moisture content of the material to 13%. At the same time, mix 2.5 parts of wheat straw fine fiber with 6.5 parts of eucalyptus sawdust, add 2 parts of urea-formaldehyde resin adhesive (solid content 50%) and 0.2 part of nano-silica, mix at high speed for 20 minutes and synchronously dry with hot air to a moisture content of 9% to obtain the core layer and surface layer prefabricated materials.

[0094] (3) Gradient paving and segmented hot pressing:

[0095] Use a continuous paving machine to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is precisely controlled to be 0.8 g / cm 3 , and the core layer density is 0.65 g / cm 3 . After paving, send it into a multi-layer hot press. First, pre-press at a temperature of 115°C and a pressure of 4 MPa for 12 minutes; then raise the temperature to 145°C and increase the pressure to 9 MPa and hold for 22 minutes.

[0096] (4) Functional layer spraying and curing:

[0097] Disperse 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane and 6.5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomizing spray gun to spray evenly at a distance of 30 cm from the board surface, and control the spraying amount per unit area to be 10 g / m 2 , and after forming a uniform liquid film, send it into a microwave tunnel and irradiate at a power of 2.5 kW and a frequency of 2450 MHz for 4 minutes.

[0098] Comparative Example 2

[0099] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer and a functional layer, and specifically contains the following components in parts by weight:

[0100] The core layer includes: 7.5 parts of wheat straw coarse fiber, 1.5 parts of Chinese fir sawdust, 1 part of bio-based adhesive, and 0.3 part of zeolite complex;

[0101] The surface layer includes: 2.5 parts of wheat straw fine fiber, 6.5 parts of eucalyptus sawdust, 2 parts of bio-based adhesive, and 0.2 part of nano-silica;

[0102] The functional layer includes: 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane.

[0103] The present invention also provides a method for preparing a moisture-proof and antibacterial straw composite artificial board, comprising the following steps:

[0104] (1) Raw material pretreatment and fiber classification:

[0105] Put wheat straw into a steam explosion device, and treat it under the conditions of 1.0 MPa pressure and 180 °C saturated steam for 1 minute. Use instantaneous pressure relief to destroy the silica wax layer on the surface of the straw and improve the fiber separation activity. After explosion, the material is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fibers (particle size 3.0 - 5.0 mm, aspect ratio 2 - 3:1) and wheat straw fine fibers (particle size 0.1 - 0.3 mm, aspect ratio 5 - 8:1). The sieved fibers are stored separately for later use.

[0106] (2) Preparation of core layer and surface layer materials:

[0107] Mix 7.5 parts of wheat straw coarse fibers with 1.5 parts of Chinese fir sawdust, add 1 part of a bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase, and 2 parts of nanocellulose) and 0.3 parts of a zeolite composite (weight ratio of zeolite powder to tourmaline powder is 8:1), and stir for 15 minutes. During this period, spray humidification is used to control the moisture content of the material to 13%. At the same time, mix 2.5 parts of wheat straw fine fibers with 6.5 parts of eucalyptus sawdust, add 2 parts of the bio-based adhesive and 0.2 parts of nano-silica, mix for 20 minutes and synchronously hot air dry to a moisture content of 9%.

[0108] (3) Gradient paving and segmented hot pressing:

[0109] Use a continuous paving machine to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is precisely controlled to be 0.8 g / cm 3 , and the core layer density is 0.65 g / cm 3 . After paving, send it into a multi-layer hot press. First, pre-press at a temperature of 115 °C and a pressure of 4 MPa for 12 minutes; then raise the temperature to 145 °C and increase the pressure to 9 MPa and maintain for 22 minutes.

[0110] (4) Functional layer spraying and curing:

[0111] Disperse 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomization spray gun to spray evenly at a distance of 30 cm from the board surface, and control the spraying amount per unit area to be 10 g / m 2 . After forming a uniform liquid film, send it into a microwave tunnel and irradiate at a power of 2.5 kW and a frequency of 2450 MHz for 4 minutes.

[0112] Comparative Example 3

[0113] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which is composed of a core layer, a surface layer and a functional layer, and specifically includes the following components in parts by weight:

[0114] The core layer includes: 7.5 parts of wheat straw coarse fiber, 1.5 parts of Chinese fir sawdust, 0.8 part of bio-based adhesive, and 0.3 part of zeolite composite;

[0115] The surface layer includes: 2.5 parts of wheat straw fine fiber, 6.5 parts of eucalyptus sawdust, 1.5 parts of bio-based adhesive, and 0.2 part of nano-silica;

[0116] The functional layer includes: 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane.

[0117] The present invention also provides a preparation method of the moisture-proof and antibacterial straw composite artificial board, which includes the following steps:

[0118] (1) Raw material pretreatment and fiber grading:

[0119] Put the wheat straw into a steam explosion device, process it under the conditions of 1.0 MPa pressure and 180 °C saturated steam for 1 minute, use instantaneous pressure relief to destroy the surface silica wax layer of the straw, and improve the fiber separation activity. After blasting, the material is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fiber (particle size 0.3 - 2.0 mm, length-diameter ratio 2 - 3:1) and wheat straw fine fiber (particle size 0.1 - 0.3 mm, length-diameter ratio 5 - 8:1). The screened fibers are stored separately for later use.

[0120] (2) Preparation of core layer and surface layer materials:

[0121] Mix 7.5 parts of core layer coarse fiber with 1.5 parts of Chinese fir sawdust, add 0.8 part of bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase and 2 parts of nano-cellulose) and 0.3 part of zeolite composite (weight ratio of zeolite powder to tourmaline powder is 8:1), stir in a mixer for 15 minutes, and control the moisture content of the material to 13% by spraying and humidifying during this period. At the same time, mix 2.5 parts of surface layer fine fiber with 6.5 parts of eucalyptus sawdust, add 1.5 parts of adhesive and 0.2 part of nano-silica, mix for 20 minutes and synchronously dry with hot air to a moisture content of 9%.

[0122] (3) Gradient paving and segmented hot pressing:

[0123] Use a continuous paver to lay materials in the order of "surface layer - core layer - surface layer", and accurately control the paving density of the surface layer to 0.8 g / cm 3 , and the density of the core layer is 0.65 g / cm3 After paving, it is sent to a multi-layer hot press. First, it is pre-pressed at a temperature of 115°C and a pressure of 4 MPa for 12 minutes; then the temperature is raised to 145°C and the pressure is increased to 9 MPa and maintained for 22 minutes.

[0124] (4) Functional layer spraying and curing:

[0125] Disperse 1.0 part of nano silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane and 6.5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomization spray gun to spray evenly at a distance of 30 cm from the board surface, and control the spraying amount per unit area to be 10 g / m 2 , and immediately send it into a microwave tunnel after forming a uniform liquid film, and irradiate it at a power of 2.5 kW and a frequency of 2450 MHz for 4 minutes.

[0126] Comparative Example 4

[0127] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which consists of a core layer, a surface layer and a functional layer, and specifically contains the following components in parts by weight:

[0128] The core layer includes: 7.5 parts of wheat straw coarse fiber, 1.5 parts of Chinese fir sawdust, 0.8 part of bio-based adhesive, and 0.3 part of zeolite composite;

[0129] The surface layer includes: 2.5 parts of wheat straw fine fiber, 6.5 parts of eucalyptus sawdust, 1.5 parts of bio-based adhesive, and 0.2 part of nano-silica;

[0130] The functional layer includes: 2 parts of Solanum nigrum extract, 1.0 part of nano silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane.

[0131] The present invention also provides a preparation method of a moisture-proof and antibacterial straw composite artificial board, which includes the following steps:

[0132] (1) Raw material pretreatment and fiber classification:

[0133] Put the wheat straw into a steam explosion device, treat it under the conditions of 1.0 MPa pressure and 180°C saturated steam for 1 minute, and use instantaneous pressure relief to destroy the surface silica wax layer of the straw to improve the fiber separation activity. After blasting, the material is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fiber (particle size 0.3 - 2.0 mm, aspect ratio 2 - 3:1) and wheat straw fine fiber (particle size 0.1 - 0.3 mm, aspect ratio 5 - 8:1). After screening, the fibers are stored separately for later use.

[0134] (2) Preparation of core layer and surface layer materials:

[0135] Mix 7.5 parts of core layer coarse fibers with 1.5 parts of Chinese fir sawdust, add 0.8 part of bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase, and 2 parts of nanocellulose) and 0.3 part of zeolite complex (weight ratio of zeolite powder to tourmaline powder is 8:1), stir in a mixer for 15 minutes, and control the moisture content of the material to 13% by spraying and humidifying during this period. Meanwhile, mix 2.5 parts of surface layer fine fibers with 6.5 parts of eucalyptus sawdust, add 1.5 parts of adhesive and 0.2 part of nano-silica, mix for 20 minutes and synchronously dry with hot air until the moisture content reaches 9%.

[0136] (3) Gradient paving and segmented hot pressing:

[0137] Use a continuous paving machine to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is precisely controlled to be 0.8 g / cm 3 , and the density of the core layer is 0.65 g / cm 3 . After paving, send it into a multi-layer hot press. First, pre-press at a temperature of 115 °C and a pressure of 4 MPa for 12 minutes; then raise the temperature to 145 °C and increase the pressure to 9 MPa and hold for 22 minutes.

[0138] (4) Functional layer spraying and curing:

[0139] Disperse 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomizing spray gun to spray evenly at a distance of 30 cm from the board surface, and control the spraying amount per unit area to be 16 g / m 2 , and immediately send it into a microwave tunnel after forming a uniform liquid film, and irradiate it at a power of 2.5 kW and a frequency of 2450 MHz for 4 minutes.

[0140] Comparative Example 5

[0141] The present invention provides a moisture-proof and antibacterial straw composite artificial board, which consists of a core layer, a surface layer, and a functional layer, and specifically contains the following components in parts by weight:

[0142] The core layer includes: 7.5 parts of wheat straw coarse fibers, 1.5 parts of Chinese fir sawdust, 0.8 part of bio-based adhesive, and 0.3 part of zeolite complex;

[0143] The surface layer includes: 2.5 parts of wheat straw fine fibers, 6.5 parts of eucalyptus sawdust, 1.5 part of bio-based adhesive, and 0.2 part of nano-silica;

[0144] The functional layer includes: 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane.

[0145] The present invention also provides a method for preparing a moisture-proof and antibacterial straw composite artificial board, comprising the following steps:

[0146] (1) Raw material treatment and fiber classification:

[0147] The wheat straw is crushed by a hammer mill and classified by a vibrating screen to obtain two types of fibers: wheat straw coarse fibers (particle size 0.3 - 2.0 mm, length-diameter ratio 2 - 3:1) and wheat straw fine fibers (particle size 0.1 - 0.3 mm, length-diameter ratio 5 - 8:1). After screening, the fibers are stored separately for later use.

[0148] (2) Preparation of core layer and surface layer materials:

[0149] Mix 7.5 parts of core layer coarse fibers with 1.5 parts of Chinese fir sawdust, add 0.8 parts of bio-based adhesive (composed of 8 parts of soy protein, 6 parts of lignin, 1.5 parts of peroxidase, and 2 parts of nanocellulose) and 0.3 parts of zeolite complex (weight ratio of zeolite powder to tourmaline powder is 8:1), and stir in a mixer for 15 minutes. During this period, spray humidification is used to control the moisture content of the material to 13%; mix 2.5 parts of surface layer fine fibers with 6.5 parts of eucalyptus sawdust, add 1.5 parts of adhesive and 0.2 parts of nano-silica, mix for 20 minutes and simultaneously dry with hot air until the moisture content is 9%.

[0150] (3) Gradient paving and segmented hot pressing:

[0151] Use a continuous paving machine to lay materials in the order of "surface layer - core layer - surface layer". The paving density of the surface layer is accurately controlled to be 0.8 g / cm 3 , and the density of the core layer is 0.65 g / cm 3 . After paving, it is sent into a multi-layer hot press. First, pre-press at a temperature of 115 °C and a pressure of 4 MPa for 12 minutes; then raise the temperature to 145 °C, increase the pressure to 9 MPa, and maintain for 22 minutes.

[0152] (4) Spraying and curing of the functional layer:

[0153] Disperse 2 parts of Solanum nigrum extract, 1.0 part of nano-silver, 3 parts of titanium dioxide, 0.25 part of KH-550, 0.1 part of dodecafluoroheptylpropyltrimethoxysilane, and 6.5 parts of polyurethane in deionized water to prepare a functional liquid with a solid content of 20%. Use an ultrasonic atomization spray gun to spray evenly at a distance of 30 cm from the board surface, control the spraying amount per unit area to be 10 g / m 2 . After forming a uniform liquid film, immediately send it into a microwave tunnel and irradiate it at a power of 2.5 kW and a frequency of 2450 MHz for 4 minutes.

[0154] Test example

[0155] The moisture-proof and antibacterial straw composite wood-based panels prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests according to GB / T 11718-2009 and T / CNFPIA 3002-2018 of the national standard. The results are shown in Table 1.

[0156] Table 1.

[0157] It can be seen from the data in Table 1 that the comprehensive performance of the moisture-proof and antibacterial straw composite wood-based panel prepared by the present invention is significantly better than that of the comparative example

[0158] After using the urea-formaldehyde resin adhesive in Comparative Example 1, the formaldehyde release amount soared to 0.085 mg / m 3 , and the antibacterial rate decreased to 95.5%; in Comparative Example 2, the particle size of the core layer wheat straw coarse fiber was changed, resulting in a sharp drop in the modulus of rupture and a significant reduction in the moisture-proof performance; in Comparative Example 3, after deleting the extract of Solanum nigrum in the functional layer, the antibacterial rate dropped sharply to 92.0%; in Comparative Example 4, the over-standard spraying amount of the functional layer caused microcracks, resulting in the surface contact angle dropping to 138° and the water absorption expansion rate rising to 2.3%; in Comparative Example 5, after canceling the steam explosion pretreatment, the separation degree of straw fibers was insufficient, resulting in the simultaneous deterioration of the modulus of rupture and moisture-proof performance.

[0159] In summary, through the multi-level collaborative design of moisture control by zeolite composite adsorption in the core layer, hydrophobic strengthening by surface nano-silica, and targeted antibacterial of nano-silver / Solanum nigrum extract in the functional layer, combined with bio-based adhesives and gradient hot pressing process, the present invention solves the technical defects of continuous formaldehyde release, significant moisture absorption and deformation, insufficient interfacial bonding force between fiber and adhesive layer, and antibacterial performance failure in traditional wood-based panels, realizes the optimization of the mechanical properties of the panels, the enhancement of environmental adaptability and the ecological safety of the whole life cycle, and promotes the efficient and clean conversion of agricultural waste straw resources.

[0160] The raw materials and equipment used in the present invention are all common raw materials and equipment in the art unless otherwise specified; the methods used in the present invention are all conventional methods in the art unless otherwise specified. The above are only the preferred embodiments of the present invention, and do not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A moisture-proof and antibacterial straw-mixed artificial board, consisting of a core layer, a surface layer, and a functional layer, characterized in that: Contains the following components by weight: The core layer includes: 7-8 parts of wheat straw crude fiber, 1-2 parts of fir sawdust, 0.5-1 parts of adhesive, and 0.2-0.4 parts of zeolite compound; the surface layer includes: 2-3 parts of wheat straw fine fiber, 6-7 parts of eucalyptus sawdust, 1-2 parts of adhesive, and 0.1-0.3 parts of nano silicon dioxide; The functional layer comprises: 1-3 parts of plant extract, 0.5-1.5 parts of nano silver, 2-4 parts of titanium dioxide, 0.2-0.5 parts of KH-550, 0.1-0.3 parts of dodecafluoroheptylpropyltrimethoxysilane and 5-8 parts of polyurethane.

2. The moisture-proof and antibacterial straw-blended artificial board according to claim 1, characterized in that: The particle size of the wheat straw coarse fiber in the core layer is 0.3-2.0 mm, and the aspect ratio is 2-3:1; the particle size of the wheat straw fine fiber in the surface layer is 0.1-0.3 mm, and the aspect ratio is 5-8:

1.

3. The moisture-proof and antibacterial straw-blended artificial board according to claim 1, characterized in that: The zeolite composite is a composite composed of zeolite powder and nano tourmaline powder, and the weight ratio of the zeolite powder to the tourmaline powder is 6-9:

1.

4. The moisture-proof and antibacterial straw-blended artificial board according to claim 1, characterized in that: The plant extract is Solanum nigrum extract.

5. The moisture-proof and antibacterial straw-blended artificial board according to any one of claims 1 to 4, characterized in that: The adhesive is a bio-based adhesive composed of soybean protein, lignin, peroxidase and nanocellulose.

6. A method for preparing the moisture-proof and antibacterial straw-mixed artificial board according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) crushing and screening the wheat straw pretreated by steam explosion to obtain wheat straw crude fiber and wheat straw fine fiber; (2) Mixing wheat straw coarse fibers and sawdust, adding them to the remaining raw materials of the surface layer to control the moisture content to obtain the surface layer material; mixing wheat straw fine fibers and fir sawdust, adding them to the remaining raw materials of the core layer to control the moisture content to obtain the core layer material; (3) The core layer material and the surface layer material are laid in a surface layer-core layer-surface layer manner, and hot pressed in sections to obtain the artificial board; (4) The functional layer raw materials are dissolved in deionized water, sprayed onto the artificial board by ultrasonic atomization, and cured by microwaves.

7. The preparation method according to claim 6, characterized in that: The steam explosion parameters in step (1) are a pressure of 0.9-1.1 MPa, a saturated steam temperature of 170-190° C., and a pressure holding time of 0.5-1.5 min.

8. The preparation method according to claim 6, characterized in that: In the step (2), the moisture content of the surface layer material is 8-10%; the moisture content of the core layer material is 12-14%.

9. The preparation method according to claim 6, characterized in that: The paving density of the surface layer in step (3) is 0.75 to 0.85 g / cm 3 ; The core layer density is 0.6~0.7g / cm 3 ; The staged hot pressing process has a front-stage temperature of 110-120°C, a pressure of 3-5MPa, and a time of 10 to 15 minutes; and a rear-stage pressure of 8-10MPa, a temperature of 140-150°C, and a time of 20 to 25 minutes.

10. The preparation method according to any one of claims 6 to 9, characterized in that: The ultrasonic atomization spraying amount of the functional layer raw material in step (4) is 8 to 12 g / m 2 ; Microwave curing treatment, microwave power is 2~3kw, frequency is 2450MHz, and treatment time is 3~5min.

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