Method for preparing reinforced composite wood floor by adopting low-formaldehyde adhesive

Abstract

The invention discloses a method for preparing a reinforced composite wood floor by adopting a low-formaldehyde adhesive. The method comprises the following steps: mixing urea-formaldehyde resin, lignin, chitosan and soybean protein isolate to prepare a bio-based multi-component composite adhesive; mixing the adhesive with wood fibers and bamboo fibers, and adding a microencapsulated phase change material to prepare a base material blank; carrying out sectional type hot press molding on the base material blank; coating the surface of the base material with a photocatalytic formaldehyde capturing primer; preparing a multifunctional wear-resistant layer containing self-repairing microcapsules, a super-hydrophobic nano material and a negative ion release material; and carrying out secondary hot-pressing compounding on the functional base material, the decorative paper and the wear-resistant layer. The reinforced composite wood floor prepared by the invention has multiple functions of low formaldehyde emission, good temperature regulation function, surface self-repairing, antifouling and self-cleaning, air purification and the like, and meets the requirements of healthy, comfortable and intelligent home environment.

Description

Technical Field

[0001] The present invention relates to the technical field of wood composite material manufacturing, and more specifically, to a method for preparing laminate flooring using a low-formaldehyde adhesive. The present invention is particularly suitable for preparing environmentally friendly, multifunctional laminate flooring for interior decoration, and can be widely used in residential buildings, commercial spaces, medical institutions, and other locations with high requirements for indoor environmental quality. Background Art

[0002] As a key component of interior decoration materials, composite wood flooring's environmental performance and functional properties directly impact indoor environmental quality and occupant health. As people pursue healthier lifestyles, low-formaldehyde-emitting, multifunctional composite wood flooring has become a key development direction for the industry.

[0003] Currently, the most common composite wood flooring on the market primarily uses urea-formaldehyde resin as an adhesive. Wood fiber raw materials are mixed with the adhesive through a hot-pressing process to create a base material, which is then laminated with a decorative layer and a wear-resistant layer. To reduce formaldehyde emissions, some manufacturers use methods such as modified urea-formaldehyde resin or the addition of formaldehyde scavengers to keep product formaldehyde emissions within national standards.

[0004] Existing low-formaldehyde composite wood flooring production technology primarily involves modifying urea-formaldehyde resin with bio-based materials such as lignin and chitosan, coating the substrate with a primer containing a formaldehyde scavenger, and then hot-pressing the wood under specific temperature and pressure conditions. While this method can control formaldehyde emissions below the E0 standard (≤0.3mg / L) and maintain basic mechanical properties, it still has significant technical limitations.

[0005] However, this traditional process suffers from limited functionality, limited potential for environmental improvement, passive environmental regulation, insufficient surface durability, and weak ability to control indoor microclimates. In particular, the adhesive used in this traditional process is still primarily urea-formaldehyde resin, and it lacks advanced features such as active temperature and humidity regulation, self-cleaning, and air purification. This makes it unable to meet modern consumers' demands for healthy, comfortable, and intelligent home environments. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing a laminated composite wood floor using a low-formaldehyde adhesive, aiming to solve the technical problems of existing composite wood floors, such as high formaldehyde emission, single function, limited room for improvement in environmental protection, insufficient surface durability, and weak ability to regulate indoor microclimate.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A method for preparing a laminate flooring using a low-formaldehyde adhesive comprises the following steps:

[0009] Mixing urea-formaldehyde resin, lignin, chitosan and soy protein isolate, and reacting at 60-70°C for 90-120 minutes to obtain a bio-based multi-component composite adhesive;

[0010] The bio-based multi-component composite adhesive is mixed with wood fiber and bamboo fiber at a dry weight ratio of 8:1-10:1, microencapsulated phase change material is added, and the mixture is mixed for 10-15 minutes using a high-speed mixer to obtain a substrate blank with phase change energy storage function;

[0011] The substrate blank is subjected to segmented hot pressing for 16-19 minutes at a temperature of 175-185° C. and a pressure of 28-32 MPa to obtain a phase change energy storage temperature regulating substrate plate;

[0012] A photocatalytic formaldehyde capture primer containing nano-titanium dioxide and modified zeolite is coated on the surface of the substrate plate, and after drying, a surface functionalized substrate is obtained;

[0013] A UV curable coating containing self-repairing microcapsules, super-hydrophobic nanomaterials and negative ion releasing materials is coated on the decorative paper and subjected to UV light curing to obtain a multifunctional wear-resistant layer;

[0014] The surface functionalized substrate is laminated with the decorative paper and the multifunctional wear-resistant layer, and hot-pressed for a second time for 3-5 minutes at a temperature of 155-165° C. and a pressure of 3.5-4.5 MPa to obtain a low-formaldehyde laminate flooring.

[0015] Preferably, urea-formaldehyde resin, lignin, chitosan and soy protein isolate are mixed and reacted at 60-70° C. for 90-120 minutes to obtain a bio-based multi-component composite adhesive, comprising:

[0016] The urea-formaldehyde resin is pre-adjusted to a pH of 8.0-8.5, the lignin is sulfonated, the chitosan is dissolved in a 1%-2% acetic acid solution to prepare a colloidal solution, and the soy protein isolate is dissolved under alkaline conditions of pH 9-10 to obtain pretreated components, wherein the pretreated components include the pretreated urea-formaldehyde resin, lignin, chitosan, and soy protein isolate;

[0017] The pretreated components are mixed in a reactor at a weight ratio of 50:12-15:3-5:25-30 of urea-formaldehyde resin, lignin, chitosan, and soy protein isolate, and reacted by mechanical stirring at 200-300 rpm while maintaining the pH in the range of 7.5-8.5, and adding 0.5%-1% ammonium chloride as a curing catalyst to obtain a preliminary composite adhesive;

[0018] 3%-5% of multifunctional isocyanate as a cross-linking agent and 0.5%-1% of polyvinyl alcohol as a stabilizer are added to the preliminary composite adhesive, and the reaction is continued at 65° C. for 30-45 minutes to obtain the bio-based multi-component composite adhesive.

[0019] Preferably, a microencapsulated phase change material is added, comprising:

[0020] Selecting normal alkanes with a phase change temperature of 28-32°C as core materials, using in-situ polymerization method to perform microencapsulation with polyurethane as wall material, controlling the average particle size of the microcapsules to 10-20 μm, and obtaining microencapsulated phase change materials;

[0021] Based on the mixture of the bio-based multi-component composite adhesive, wood fiber and bamboo fiber, the microencapsulated phase change material is added thereto at a ratio of 8%-12% of the total dry weight of the fiber and the adhesive, and mixed for 10-15 minutes by a high-speed mixer to obtain the substrate blank with phase change energy storage function.

[0022] Preferably, the substrate blank is subjected to segmented hot pressing, comprising:

[0023] The substrate blank is preheated by gradually increasing the temperature to 175° C. within the first 5 minutes and the pressure is 70% of the set value to obtain a preheated blank;

[0024] The preheated blank is subjected to a main body hot pressing treatment at a constant temperature of 175-185° C. and a constant pressure of 28-32 MPa for 9-12 minutes to obtain a preliminary formed substrate;

[0025] The preliminary formed substrate is cooled to 150° C. within the last 2-3 minutes and maintained at full pressure for shaping, thereby obtaining the phase-change energy storage temperature-regulating substrate plate.

[0026] Preferably, the photocatalytic formaldehyde capture primer comprises:

[0027] The photocatalytic formaldehyde capture primer with a solid content of 30%-35% is prepared by using water-based polyurethane dispersion as the base material, adding 3%-5% nano titanium dioxide, 1%-2% modified zeolite and 1%-3% activated carbon powder, and adding 0.5%-1% silane coupling agent.

[0028] Preferably, a UV curable coating containing self-repairing microcapsules, super-hydrophobic nanomaterials and negative ion releasing materials is coated on the decorative paper and subjected to UV light curing treatment to obtain a multifunctional wear-resistant layer, comprising:

[0029] Self-repairing microcapsules with an average particle size of 3-5 μm were prepared by interfacial polymerization using dicyclopentadiene as the core material and polyurethane as the wall material to obtain a self-repairing component;

[0030] Nano-silica particles with a particle size of 50-100 nm were synthesized by the sol-gel method and surface modified with perfluorotridecyltriethoxysilane to obtain super-hydrophobic nanomaterials.

[0031] Based on an aliphatic polyurethane acrylate main resin, 5%-8% of the self-repairing component, 2%-4% of the super-hydrophobic nanomaterial, 4%-6% of tourmaline micropowder and 3%-5% of nano-alumina are added, and 2%-3% of a photoinitiator is added to obtain a UV-curable coating containing a multifunctional component;

[0032] The UV curable coating containing the multifunctional component is applied on the decorative paper to control the wet coating thickness to be 40-50 μm, and cured for 30-60 seconds under UV-A irradiation with a wavelength of 365 nm and a power density of 300-400 mW / cm² to obtain a preliminarily cured multifunctional wear-resistant layer;

[0033] The thickness of the preliminarily cured multifunctional wear-resistant layer is controlled to ensure that the final thickness is 30-40 μm, thereby obtaining the multifunctional wear-resistant layer.

[0034] Preferably, the self-repairing microcapsules are prepared by interfacial polymerization, comprising:

[0035] Mixing the dicyclopentadiene and the Grubbs catalyst as a core material, dispersing the mixture in an aqueous phase to form an emulsion, and obtaining a core material emulsion;

[0036] A polyurethane prepolymer monomer is added to the core material emulsion, and a polyurethane wall material is formed on the surface of the core material through an interfacial polymerization reaction to obtain the self-repairing microcapsule.

[0037] Preferably, the surface functionalized substrate is laminated with the decorative paper and the multifunctional wear-resistant layer, and hot-pressed for a second time at a temperature of 155-165° C. and a pressure of 3.5-4.5 MPa for 3-5 minutes, comprising:

[0038] Precisely positioning the decorative paper on the surface functionalized substrate, and covering the multifunctional wear-resistant layer on the decorative paper to form a laminated structure to obtain a pre-laminated body;

[0039] The pre-laminated body is heated in stages to 155-165° C. at a rate of 5-8° C. / min and maintained under pressure, then cooled to below 80° C. and released to obtain the low-formaldehyde laminate flooring.

[0040] Preferably, it further comprises: integrating active environmental control function into the low-formaldehyde laminate flooring:

[0041] Select activated carbon fiber felt with a specific surface area of ​​≥1500m² / g, and grow graphene nanosheets on its surface by chemical vapor deposition to obtain an activated carbon fiber / graphene composite adsorption layer;

[0042] Based on the conductive properties of the activated carbon fiber / graphene composite adsorption layer, a carbon nanotube conductive ink is printed on a polyimide film substrate to form a matching electric heating film, and the surface resistance is controlled at 10-20Ω to obtain an electric heating regeneration module;

[0043] Based on the working requirements of the electrothermal regeneration module, a temperature and humidity sensor, a VOC sensor, and a temperature sensor are integrated and communicated with the control unit via a low-power Bluetooth protocol to obtain a sensor system that matches the regeneration module;

[0044] The activated carbon fiber / graphene composite adsorption layer, the electrothermal regeneration module and the sensor system are used as an integrated functional module and installed in the reserved space at the bottom of the substrate of the low-formaldehyde laminate composite wood flooring to obtain a laminate composite wood flooring with active environmental control function.

[0045] Beneficial effects of the present invention:

[0046] By using bio-based multi-component composite adhesives, the formaldehyde emission of the floor is greatly reduced, and the formaldehyde emission of the product is controlled below 0.1mg / L, which is far below the E0 grade standard requirement, significantly improving the environmental performance of the product.

[0047] By adding microencapsulated phase change materials to the base material, the floor is given a temperature regulation function, which can effectively reduce the fluctuation of floor surface temperature by 1-3°C and improve indoor thermal comfort.

[0048] By integrating self-repairing microcapsules, super-hydrophobic nanomaterials, and negative ion-releasing materials into the wear-resistant layer, the floor has scratch self-repair, anti-fouling, self-cleaning, and air purification functions, significantly improving the product's service life and functionality.

[0049] By using a photocatalytic formaldehyde capture primer, the continuous capture and decomposition of indoor formaldehyde is achieved, further improving the air purification ability of the product;

[0050] By integrating an active environmental control system, the floor has the function of actively absorbing and controlling the regeneration of harmful substances such as indoor VOCs, breaking through the limitations of the passive environmental protection of traditional floors. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present disclosure and, together with the specification, are used to illustrate the technical solutions of the present disclosure. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without inventive effort.

[0052] Figure 1 This is a process flow chart for preparing a bio-based multi-component composite adhesive according to an embodiment of the present invention;

[0053] Figure 2 This is a process flow chart for preparing a phase change energy storage temperature regulating substrate in an embodiment of the present invention;

[0054] Figure 3 Graph showing process parameters for segmented hot pressing in an embodiment of the present invention;

[0055] Figure 4 This is a process flow chart of substrate surface functionalization treatment in an embodiment of the present invention;

[0056] Figure 5 This is a process flow chart for preparing a multifunctional wear-resistant layer in an embodiment of the present invention;

[0057] Figure 6 Schematic diagram of the cross-section of the laminate flooring structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the disclosure for which protection is sought, but merely represents selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present disclosure.

[0059] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0060] The term "and / or" herein simply describes an association relationship, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, and the existence of B alone. In addition, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0062] The present invention provides a method for preparing a laminate flooring using a low-formaldehyde adhesive, comprising the following steps:

[0063] S1: mixing urea-formaldehyde resin, lignin, chitosan and soy protein isolate, and reacting them at 60-70°C for 90-120 minutes to obtain a bio-based multi-component composite adhesive;

[0064] S2: mixing the bio-based multi-component composite adhesive with wood fiber and bamboo fiber in a dry weight ratio of 8:1-10:1, adding microencapsulated phase change material, and mixing for 10-15 minutes using a high-speed mixer to obtain a substrate blank with phase change energy storage function;

[0065] S3 performs segmented hot pressing on the substrate blank at a temperature of 175-185° C. and a pressure of 28-32 MPa for 16-19 minutes to obtain a phase change energy storage temperature regulating substrate plate;

[0066] S4: coating a photocatalytic formaldehyde capture primer containing nano-titanium dioxide and modified zeolite on the surface of the substrate plate, and drying the substrate to obtain a surface functionalized substrate;

[0067] S5: coating a UV curable coating containing self-repairing microcapsules, super-hydrophobic nanomaterials and negative ion releasing materials on the decorative paper, and then subjecting the coating to UV light curing to obtain a multifunctional wear-resistant layer;

[0068] S6: laminating the surface functionalized substrate, the decorative paper and the multifunctional wear-resistant layer, and performing secondary hot pressing for 3-5 minutes at a temperature of 155-165° C. and a pressure of 3.5-4.5 MPa to obtain a low-formaldehyde laminate flooring.

[0069] The following describes the above steps separately:

[0070] S1: Preparation of bio-based multi-component composite adhesives

[0071] like Figure 1 As shown in the figure, the preparation of bio-based multi-component composite adhesive includes four main steps: raw material pretreatment, composite adhesive preparation, adhesive modification and stabilization, and performance testing and adjustment.

[0072] First, the raw materials were prepared and pretreated: urea-formaldehyde resin (48% solid content), liquid sulfonated lignin (55% solid content), chitosan powder (molecular weight 300,000), and soy protein isolate (92% protein content) were pretreated separately. Specifically, the pH of the urea-formaldehyde resin was adjusted to 8.2 using sodium hydroxide solution; the liquid lignin was sulfonated to enhance its water solubility and activity; chitosan was dissolved in 1.5% acetic acid solution to form a colloidal solution; and the soy protein isolate was dissolved under alkaline conditions of pH 9.5 to open up the protein structure and expose more active sites.

[0073] The composite adhesive was then prepared by mixing the pretreated components of urea-formaldehyde resin, lignin, chitosan, and soy protein isolate in a reactor at a weight ratio of 50:14:4:28. The mixture was stirred mechanically at 250 rpm for 105 minutes at 65°C, maintaining the pH at 8.0 with sodium hydroxide solution. During the reaction, 0.8% ammonium chloride was added as a curing catalyst, controlled to be 0.8% of the urea-formaldehyde resin mass.

[0074] The adhesive is then modified and stabilized: 4% multifunctional isocyanate (MDI) is added to the reaction system as a crosslinker to strengthen the adhesive's crosslinked network structure, improving water resistance and bond strength. 0.8% polyvinyl alcohol is also added as a thickener and stabilizer to improve the adhesive's rheological properties and storage stability. After mixing thoroughly, the mixture is allowed to react at 65°C for 40 minutes to form a stable bio-based multi-component composite adhesive.

[0075] Finally, adhesive performance testing and adjustments were conducted: the solids content, viscosity, pH, and gel time were 50%, 10,000 mPa·s, 7.3, and 75 seconds (at 100°C). The test results demonstrated that the prepared bio-based multi-component composite adhesive met the requirements for subsequent substrate preparation.

[0076] S2: Preparation of phase change energy storage temperature control substrate

[0077] like Figure 2 As shown, the preparation of phase change energy storage and temperature regulation substrate includes four main steps: preparation and processing of fiber raw materials, preparation of microencapsulated phase change materials, material mixing, and pre-pressing and aging.

[0078] First, the fiber raw materials are prepared and processed: wood fiber (70%) and bamboo fiber (30%) are selected as the base materials. The fiber raw materials are dried to control the moisture content within 4%. Through a screening process, particles with a fiber size of 0.5-2mm are selected to ensure uniform fiber size, which is conducive to sufficient mixing with the adhesive and forming a stable structure.

[0079] Next, microencapsulated phase-change materials (PCMs) were prepared: an n-alkane (eicosane, C20H42) with a phase transition temperature of 30°C was selected as the core material. Polyurethane was used as the wall material via in-situ polymerization to prepare the microencapsulated PCMs. The average particle size of the microcapsules was controlled to 15 μm, and the mass ratio of the wall material to the core material was 1:4.5 to ensure sufficient mechanical strength and thermal stability. The resulting MicroPCMs had a latent heat of phase change of 185 J / g and were thermally stable enough to withstand short-term heating at 190°C.

[0080] Next, the fiber material, adhesive, and phase change material were mixed: the treated fiber material was mixed with the bio-based multi-component composite adhesive prepared in Example 1 at a dry weight ratio of 9:1. MicroPCMs were also added at a level of 10% of the total dry weight of the fiber and adhesive. Mixing was performed in a high-speed mixer at 250 rpm for 12 minutes to ensure uniform dispersion of the three materials, forming a substrate blank containing PCMs.

[0081] Finally, the base material is pre-pressed and aged: The uniformly mixed base material is pre-pressed for 2.5 minutes at room temperature and a pressure of 2 MPa to form a preliminary blank blanket. The pre-pressed blank blanket is then briefly aged (15 minutes at room temperature) to ensure full contact between the adhesive and the fibers, improving the efficiency and quality of subsequent hot pressing.

[0082] S3: Hot pressing of substrate

[0083] like Figure 3 As shown, the hot pressing forming of the substrate includes four main steps: hot pressing parameter optimization setting, hot pressing forming process control, cooling and humidity adjustment of the substrate, and quality inspection of the substrate.

[0084] First, the hot-pressing parameters were optimized. Based on the properties of the blank blanket prepared in Example 2, the hot-pressing parameters were set as follows: hot-pressing temperature 180°C, pressure 30 MPa, and hot-pressing time 18 minutes. A segmented hot-pressing profile was also designed: for the first 5 minutes, the temperature was gradually increased to 175°C, with the pressure at 70% of the set value; the temperature and pressure were maintained constant for the next 10 minutes; and the temperature was lowered to approximately 150°C, maintaining full pressure, for the final 3 minutes to achieve the desired density gradient distribution.

[0085] The hot pressing process is then controlled: the blank blanket is placed between the platens of the hot press, and margin limiters are installed to control the sheet thickness (10 mm). The hot pressing program is initiated, and the set hot pressing parameters are implemented. During the hot pressing process, pressure and temperature sensors monitor the hot pressing conditions in real time to ensure a smooth and controllable process. During the hot pressing process, the PCMs undergo a controlled phase transition, where the core material of the microcapsules partially melts while the wall material remains intact.

[0086] Next, the substrate is cooled and humidified. After hot pressing, the substrate sheets are transferred to a cooling rack and cooled with forced air to below 40°C. The cooled sheets are then transferred to a humidity conditioning chamber, where they are conditioned at 23°C and 62% relative humidity for 36 hours, stabilizing the moisture content at 8%, minimizing dimensional changes during subsequent processing and use.

[0087] Finally, the substrate quality was tested after humidity conditioning, including density of 900 kg / m³, moisture content of 8%, thickness expansion of 10.5% (after 24 hours of water immersion), static bending strength of 38 MPa, internal bonding strength of 0.65 MPa, and formaldehyde emission of 0.08 mg / L. Infrared thermal imaging was used to verify the uniformity of the PCM distribution within the substrate to ensure consistent temperature control performance. The test results demonstrated that the prepared phase change energy storage temperature control substrate met the quality requirements.

[0088] s4: functional treatment of substrate surface

[0089] like Figure 4 As shown, the functionalization treatment of the substrate surface includes four main steps: substrate surface pretreatment, preparation of photocatalytic formaldehyde capture primer, coating and drying of the primer, and performance testing of the primer layer.

[0090] First, the substrate surface was pretreated: the substrate surface obtained in Example 3 was polished using 150-grit sandpaper to remove dust and burrs to ensure surface smoothness. High-pressure airflow was used to remove polished dust, and the surface was then wiped with isopropyl alcohol to remove oil stains and improve surface wettability and coating uniformity.

[0091] Next, a photocatalytic formaldehyde-trapping primer was prepared: using a water-based polyurethane dispersion as the base, 4% nano-titanium dioxide (20 nm particle size, a mixture of anatase and rutile types, with a specific surface area of ​​280 m² / g) was added as a photocatalyst. 1.5% modified zeolite (silver ion-exchanged zeolite) and 2% activated carbon powder were also added as adsorbents. 0.8% silane coupling agent was added to improve the compatibility of the filler with the polyurethane. Appropriate amounts of defoamer and leveling agent were also added to prepare a functional primer with a solids content of 32%.

[0092] Next, the primer is applied and dried: The prepared functional primer is evenly applied to the treated substrate surface using a roller coating method, with a coating weight of 110g / m² (wet weight). The coated substrate enters a tunnel drying machine and is dried at 65°C for 12 minutes to fully cure the primer, forming a functional primer layer with a thickness of 28μm.

[0093] Finally, the performance of the primer layer was tested: the adhesive strength was 2.2 MPa, the formaldehyde capture efficiency was 88% (capture rate of 1.0 mg / L formaldehyde under standard testing conditions), and the photocatalytic activity was 55% / 24 hours (formaldehyde degradation rate under standard visible light irradiation conditions). The test results show that the primer layer has a strong bond with the substrate and has excellent formaldehyde capture and decomposition capabilities.

[0094] s5: Preparation of multifunctional wear-resistant layer

[0095] like Figure 5 As shown in FIG, the preparation of the multifunctional wear-resistant layer includes four main steps: preparation of self-repairing microcapsules, preparation of superhydrophobic / oleophobic nanomaterials, formulation of multifunctional UV-curable coatings, and coating and curing of the multifunctional wear-resistant layer.

[0096] First, self-healing microcapsules were prepared using interfacial polymerization. These microcapsules contained dicyclopentadiene (DCPD) and a Grubbs catalyst. The DCPD and Grubbs catalyst were mixed as a core material and dispersed in an aqueous phase to form an emulsion. Polyurethane prepolymer monomers were added to the core material emulsion, and interfacial polymerization formed a polyurethane wall material on the core material surface, resulting in self-healing microcapsules with an average particle size of 4 μm. The microcapsules possessed sufficient mechanical strength to rupture and release the repair agent when the wear-resistant layer was scratched, yet remained stable during normal UV curing.

[0097] The super-hydrophobic / oleophobic nanomaterial was then prepared: nano-silica particles (80 nm in diameter) were synthesized using a sol-gel method and then surface-modified with perfluorotridecyltriethoxysilane to impart super-hydrophobic / oleophobic properties. The modified nanoparticles exhibited excellent dispersibility, with water contact angles of 155° and oil contact angles of 125°, ensuring excellent anti-fouling and self-cleaning properties for the wear-resistant layer.

[0098] Next, a multifunctional UV-curable coating was formulated: using an aliphatic polyurethane acrylate as the main resin (65% total solids), 6% self-healing microcapsules, 3% super-hydrophobic nanomaterials, and 5% tourmaline micropowder (2μm particle size, capable of continuously releasing negative ions) were added. 4% nano-alumina was added as an abrasion-resistant enhancer, 2.5% photoinitiator (a mixture of Irgacure 184 and Irgacure 819), and 1.5% leveling agent and defoamer were added. The mixture was thoroughly mixed in a high-speed disperser to prepare a UV-curable coating with a solids content of 96%.

[0099] Finally, the multifunctional wear-resistant layer is applied and cured: Using precision coating equipment, the formulated UV-curable coating is evenly applied to the decorative paper, maintaining a wet coating thickness of 45 μm. Immediately after coating, the paper enters a UV curing system where it cures for 45 seconds under UV-A radiation (wavelength 365 nm, power density 350 mW / cm²), forming a 35 μm-thick multifunctional wear-resistant layer. The cured wear-resistant layer exhibits high transparency, excellent self-healing properties, super-hydrophobicity, and negative ion release.

[0100] s6: Composite lamination of flooring

[0101] like Figure 6 As shown in the figure, the composite lamination of flooring includes five main steps: processing and positioning of decorative paper, overlapping and pre-pressing of multifunctional layers, secondary hot pressing and lamination, edge processing and size processing, and finished product inspection and packaging.

[0102] First, prepare and position the decorative paper: Select high-quality decorative paper (90g / m²) with a lightfastness rating of 6 or higher. Pre-impregnate it with melamine resin, controlling the resin content to 110% (relative to the paper weight). Precisely position the decorative paper on the surface-functionalized substrate produced in Example 4, ensuring that the pattern aligns with the substrate edge and that there are no bubbles or wrinkles.

[0103] The multifunctional layers were then laminated and pre-pressed: the multifunctional wear-resistant layer (including the decorative paper) prepared in Example 5 was precisely applied to the functionalized substrate, forming a laminate structure of "substrate - primer - decorative paper - wear-resistant layer." Vacuum suction was used to remove air bubbles between the layers, ensuring a tight fit between them. A short pre-pressing period (at room temperature, 0.8 MPa for 45 seconds) was then performed to further ensure the stability of the laminate structure, resulting in a pre-laminated body.

[0104] Next, a secondary hot-pressing process is performed: the pre-laminated floor is placed in a hot press, where the temperature is raised in stages at a rate of 6°C / min to 160°C. Pressing is then performed at a pressure of 4 MPa for four minutes. The temperature is then controlled to drop below 80°C before the pressure is released to prevent warping caused by thermal stress, resulting in a low-formaldehyde laminate flooring.

[0105] Next, the flooring undergoes edge processing and sizing: After hot-pressing and laminating, the flooring panels are sawn to ensure dimensional accuracy. A locking mechanism is fabricated to meet the joint requirements, achieving dimensions of 1220mm x 180mm x 12mm. The finished flooring then enters a humidity-conditioning chamber, where it equilibrates for 36 hours at a temperature of 22°C and a relative humidity of 55%, maintaining a stable overall moisture content of 7.5%.

[0106] Finally, finished products are inspected and packaged. The finished floor undergoes a comprehensive quality inspection, including: surface quality (no defects such as bubbles, delamination, or damage), dimensional accuracy (length and width tolerance 0.15mm, thickness tolerance 0.08mm), surface properties (abrasion resistance 6500 rpm, scratch resistance 3.8N, pollution resistance level 5), and physical properties (static bending strength 38MPa, impact resilience 14%, formaldehyde emission 0.08mg / L). Once qualified, the floor is moisture-proof packaged and prepared for shipment.

[0107] This application also includes s7: Integration of active environmental control systems

[0108] The integration of the active environmental control system includes five main steps: preparation of activated carbon fiber / graphene composite adsorption layer, design and preparation of electrothermal regeneration module, integration of sensor system, structural design and assembly of the system, and control system and intelligent algorithm.

[0109] First, an activated carbon fiber / graphene composite adsorption layer was prepared: an activated carbon fiber felt (1.5 mm thick) with a specific surface area of ​​1800 m² / g was selected as the base adsorption material. Graphene nanosheets were grown on the surface of the activated carbon fibers using chemical vapor deposition (CVD) to improve conductivity and adsorption selectivity. The resulting composite material exhibited excellent formaldehyde and VOC adsorption capacity (formaldehyde adsorption capacity of 55 mg / g) and good electrical conductivity (resistivity of 8 Ω·cm), facilitating subsequent electrothermal regeneration.

[0110] The electrothermal regeneration module was then designed and fabricated. Using flexible printed circuit technology, carbon nanotube conductive ink was printed onto a polyimide (PI) film substrate (0.15 mm thick), forming a grid-like heating film. The film has a surface resistance of 15 Ω and can uniformly heat to 60°C when supplied with a 12 V DC current. An insulating protective layer was applied to the surface of the film to ensure safety.

[0111] Next, the sensor system is integrated: a temperature and humidity sensor, a VOC sensor, and a temperature sensor for the electric heat regeneration module are integrated into the floor structure. The temperature and humidity sensor has a measurement range of 0-50°C and 10%-90% RH, with an accuracy of ±0.5°C and ±3% RH, respectively. The VOC sensor has a detection range of 0.01-10ppm and a response time of 25 seconds. The temperature sensor monitors the operating temperature of the electric heat regeneration module to ensure it remains within a safe range. The sensors communicate with the control unit via Bluetooth Low Energy (BLE).

[0112] Next, the system's structural design and assembly began. A dedicated floor structure was designed, with a 4.5mm-thick space reserved at the base for the activated carbon fiber / graphene composite adsorption layer, the electrothermal regeneration module, and the sensor system. Clip-on fasteners were used to secure the functional modules, ensuring a compact structure without compromising the floor's overall stability. Power and control circuits were routed through pre-defined channels along the floor's edges and connected to an external control unit.

[0113] Finally, a control system and intelligent algorithm were developed: a microcontroller (MCU)-based control system was developed to collect sensor data and control the working state of the electric heating regeneration module. The control algorithm includes: (1) pollutant concentration monitoring: when the VOC concentration exceeds 0.5ppm for 30 minutes, the regeneration process is triggered; (2) intelligent regeneration control: the heat stored in the PCM is used for regeneration first, and when it is insufficient, the electric heating module is activated and the temperature is controlled within the range of 60℃ for 45 minutes; (3) energy-saving mode: based on the activity patterns of indoor personnel, the regeneration process is executed when no one is around or late at night; (4) linkage control: linkage with the home ventilation system to increase ventilation during the regeneration process.

[0114] Example 1: Preparation of bio-based multi-component composite adhesive

[0115] The preparation of bio-based multi-component composite adhesives includes four main steps: raw material pretreatment, composite adhesive preparation, adhesive modification and stabilization, and performance testing and adjustment.

[0116] First, the raw materials were prepared and pretreated: urea-formaldehyde resin (48% solid content), liquid sulfonated lignin (55% solid content), chitosan powder (molecular weight 300,000), and soy protein isolate (92% protein content) were pretreated separately. Specifically, the pH of the urea-formaldehyde resin was adjusted to 8.2 using sodium hydroxide solution; the liquid lignin was sulfonated to enhance its water solubility and activity; chitosan was dissolved in 1.5% acetic acid solution to form a colloidal solution; and the soy protein isolate was dissolved under alkaline conditions of pH 9.5 to open up the protein structure and expose more active sites.

[0117] The composite adhesive was then prepared by mixing the pretreated components of urea-formaldehyde resin, lignin, chitosan, and soy protein isolate in a reactor at a weight ratio of 50:14:4:28. The mixture was stirred mechanically at 250 rpm for 105 minutes at 65°C, maintaining the pH at 8.0 with sodium hydroxide solution. During the reaction, 0.8% ammonium chloride was added as a curing catalyst, controlled to be 0.8% of the urea-formaldehyde resin mass.

[0118] The adhesive is then modified and stabilized: 4% multifunctional isocyanate (MDI) is added to the reaction system as a crosslinker to strengthen the adhesive's crosslinked network structure, improving water resistance and bond strength. 0.8% polyvinyl alcohol is also added as a thickener and stabilizer to improve the adhesive's rheological properties and storage stability. After mixing thoroughly, the mixture is allowed to react at 65°C for 40 minutes to form a stable bio-based multi-component composite adhesive.

[0119] Finally, adhesive performance testing and adjustments were conducted: the solids content, viscosity, pH, and gel time were 50%, 10,000 mPa·s, 7.3, and 75 seconds (at 100°C). The test results demonstrated that the prepared bio-based multi-component composite adhesive met the requirements for subsequent substrate preparation.

[0120] Example 2: Preparation and hot pressing of phase change energy storage temperature regulating substrate

[0121] First, the fiber raw materials are prepared and processed: wood fiber (70%) and bamboo fiber (30%) are selected as the base materials. The fiber raw materials are dried to control the moisture content within 4%. Through a screening process, particles with a fiber size of 0.5-2mm are selected to ensure uniform fiber size, which is conducive to sufficient mixing with the adhesive and forming a stable structure.

[0122] Next, microencapsulated phase-change materials (PCMs) were prepared: an n-alkane (eicosane, C20H42) with a phase transition temperature of 30°C was selected as the core material. Polyurethane was used as the wall material via in-situ polymerization to prepare the microencapsulated PCMs. The average particle size of the microcapsules was controlled to 15 μm, and the mass ratio of the wall material to the core material was 1:4.5 to ensure sufficient mechanical strength and thermal stability. The resulting MicroPCMs had a latent heat of phase change of 185 J / g and were thermally stable enough to withstand short-term heating at 190°C.

[0123] Next, the fiber material, adhesive, and phase change material were mixed: the treated fiber material was mixed with the bio-based multi-component composite adhesive prepared in Example 1 at a dry weight ratio of 9:1. MicroPCMs were also added at a level of 10% of the total dry weight of the fiber and adhesive. Mixing was performed in a high-speed mixer at 250 rpm for 12 minutes to ensure uniform dispersion of the three materials, forming a substrate blank containing PCMs.

[0124] The base material is then pre-pressed and hot-pressed: The uniformly mixed base material is pre-pressed for 2.5 minutes at room temperature and a pressure of 2 MPa to form a preliminary blank blanket. The pre-pressed blanket is then transferred to the hot press, where a staged hot pressing process is employed: for the first five minutes, the temperature is gradually raised to 175°C and the pressure is 70% of the set value; for the second 10 minutes, the temperature is maintained at 180°C and the pressure at 30 MPa; and for the final three minutes, the temperature is lowered to approximately 150°C while maintaining full pressure. The total hot pressing time is 18 minutes.

[0125] After hot pressing, the substrate sheets are transferred to a cooling rack and cooled to below 40°C using forced air cooling. The cooled sheets are then transferred to a humidity control room where they are conditioned at 23°C and 62% relative humidity for 36 hours, stabilizing the moisture content at 8%.

[0126] Quality testing of the conditioned substrate revealed a density of 900 kg / m³, a moisture content of 8%, a thickness expansion of 10.5% (after 24 hours of immersion), a static flexural strength of 38 MPa, an internal bond strength of 0.65 MPa, and a formaldehyde emission of 0.08 mg / L. Infrared thermal imaging confirmed that the PCMs were evenly distributed throughout the substrate, ensuring consistent temperature control performance.

[0127] Example 3: Preparation of multifunctional wear-resistant layer and floor composite lamination

[0128] First, self-healing microcapsules were prepared using interfacial polymerization. These microcapsules contained dicyclopentadiene (DCPD) and a Grubbs catalyst. The DCPD and Grubbs catalyst were mixed as the core material and dispersed in an aqueous phase to form an emulsion. Polyurethane prepolymer monomer was then added to the core emulsion. Interfacial polymerization formed the polyurethane wall material on the core surface, resulting in self-healing microcapsules with an average particle size of 4 μm.

[0129] The superhydrophobic nanomaterial was then prepared: nano-silica particles (80 nm in diameter) were synthesized using a sol-gel method and then surface-modified with perfluorotridecyltriethoxysilane to impart superhydrophobic properties. The modified nanoparticles exhibited water contact angles of 155° and oil contact angles of 125°, demonstrating excellent antifouling and self-cleaning properties.

[0130] Next, a multifunctional UV-curable coating was prepared: using aliphatic polyurethane acrylate as the main resin (accounting for 65% total solids), 6% self-healing microcapsules, 3% super-hydrophobic nanomaterials, and 5% tourmaline micropowder (particle size 2μm) were added. 4% nano-alumina was added as an abrasion-resistant enhancer, 2.5% photoinitiator, and 1.5% leveling agent and defoamer were also added. The mixture was thoroughly mixed in a high-speed disperser to prepare a UV-curable coating with a solids content of 96%.

[0131] The prepared UV-curable coating was evenly applied to the decorative paper, with a wet coating thickness of 45 μm. Immediately after application, the paper was placed in a UV curing system and cured for 45 seconds under UV-A (wavelength 365 nm, power density 350 mW / cm²), forming a multifunctional wear-resistant layer with a thickness of 35 μm.

[0132] A photocatalytic formaldehyde-capturing primer (containing 4% nano-titanium dioxide, 1.5% modified zeolite, and 2% activated carbon powder) was first applied to the substrate prepared in Example 2 and dried at 65°C for 12 minutes to form a 28μm-thick functionalized primer layer. Decorative paper was then precisely positioned on the functionalized substrate, and the multifunctional wear-resistant layer was applied over the decorative paper to form a laminated structure.

[0133] The laminated structure was placed in a hot press and heated in stages at a rate of 6°C / min to 160°C. The press was then hot-pressed for 4 minutes at a pressure of 4 MPa. The temperature was then controlled to drop below 80°C before the pressure was released, resulting in a low-formaldehyde laminate flooring.

[0134] Comprehensive quality testing of the finished flooring revealed surface abrasion resistance of 6,500 revolutions, scratch resistance of 3.8N, stain resistance level 5, static bending strength of 38MPa, impact resilience of 14%, and formaldehyde emission of 0.08mg / L. Scratch self-repair testing under simulated usage conditions demonstrated that minor scratches (≤0.2mm wide) repaired themselves within 24 hours, with a repair rate exceeding 85%. A water droplet contact angle test measured 152°, demonstrating the flooring's excellent water and stain resistance.

[0135] Comparative Example 1: Preparation and application of traditional urea-formaldehyde resin adhesive

[0136] Urea-formaldehyde resin adhesives were prepared using a conventional process: formaldehyde and urea were mixed in a molar ratio of 1.3:1 and reacted at 90°C for 60 minutes at a pH of 8.0-9.0 for a hydroxymethylation reaction. The pH was then adjusted to 4.5-5.5, and the temperature was lowered to 80°C for a polycondensation reaction for 40 minutes. Finally, the pH was adjusted to 7.5-8.0 to terminate the reaction, yielding a urea-formaldehyde resin adhesive with a solids content of 50%.

[0137] The prepared urea-formaldehyde resin adhesive was mixed with wood fiber at a dry weight ratio of 1:8 in a high-speed mixer for 10 minutes to obtain a substrate blank. The blank was then hot-pressed at 190°C and 30 MPa for 20 minutes to obtain a substrate board.

[0138] An ordinary primer (without functional components) is coated on the surface of the substrate, and after drying, decorative paper and an ordinary wear-resistant layer (without self-repairing microcapsules and super-hydrophobic nanomaterials) are attached. The substrate is then hot-pressed at 170°C and 4 MPa for 5 minutes to obtain a traditional composite wood floor.

[0139] Quality testing of the finished floor revealed: surface abrasion resistance of 4500 revolutions, scratch resistance of 2.5N, stain resistance level 3, static bending strength of 35MPa, impact resilience of 10%, and formaldehyde emission of 0.28mg / L. A water droplet contact angle test result of 85° indicates average water and stain resistance. Scratch testing under simulated usage conditions revealed that minor scratches were not self-repairable.

[0140] Comparative Example 2: Preparation and Application of Modified Urea-Formaldehyde Resin Adhesive (without Phase Change Material)

[0141] A urea-formaldehyde resin adhesive was prepared using a modification process: formaldehyde and urea were mixed in a molar ratio of 1.2:1, and 5% lignin was added as a modifier. A hydroxymethylation reaction was carried out at 85°C for 70 minutes at a pH of 8.2. The pH was then adjusted to 5.0, and the temperature was lowered to 75°C for a polycondensation reaction for 45 minutes. Finally, the reaction was terminated by adjusting the pH to 7.8, yielding a modified urea-formaldehyde resin adhesive with a solids content of 50%.

[0142] The prepared modified urea-formaldehyde resin adhesive was mixed with wood fiber at a dry weight ratio of 1:8 and mixed in a high-speed mixer for 10 minutes to obtain a substrate blank (excluding the phase change material). The blank was then hot-pressed at 185°C and 30 MPa for 18 minutes to obtain a substrate board.

[0143] A primer containing 1% formaldehyde scavenger was coated on the surface of the substrate, and after drying, decorative paper and a common wear-resistant layer were attached. The modified composite wood floor was obtained by hot pressing at a temperature of 165° C. and a pressure of 4 MPa for 4 minutes.

[0144] Quality testing of the finished floor revealed surface abrasion resistance of 5000 revolutions, scratch resistance of 3.0N, stain resistance level 4, static flexural strength of 36MPa, impact resilience of 12%, and formaldehyde emission of 0.18mg / L. A water droplet contact angle test result of 90° indicated fair waterproofing and stain resistance. Scratch testing under simulated usage conditions revealed that minor scratches were not self-healing. In tests involving indoor temperature fluctuations, the floor surface temperature varied significantly with the room temperature, indicating a lack of temperature regulation.

[0145] Comparative Example 3: Commercially available E0 grade composite wood flooring

[0146] The E0 grade composite wood flooring sold on the market was selected as a comparison sample. This product uses modified urea-formaldehyde resin as the adhesive, the base material is medium-density fiberboard, and the surface uses melamine impregnated paper as the decorative layer and wear-resistant layer.

[0147] Quality testing of the sample revealed surface abrasion resistance of 5200 revolutions, scratch resistance of 3.2N, stain resistance level 4, static flexural strength of 37MPa, impact resilience of 11%, and formaldehyde emission of 0.15mg / L. A water droplet contact angle test result of 95° indicated fair waterproofing and stain resistance. Scratch testing under simulated usage conditions revealed that minor scratches were unrepairable. In tests involving indoor temperature fluctuations, the floor surface temperature varied significantly with the room temperature, indicating a lack of temperature regulation.

[0148] Comparative analysis of performance between examples and comparative examples

[0149] In order to more intuitively demonstrate the difference between the present invention and the conventional technology, a comparative analysis of the key performance indicators of Examples 1-3 and Comparative Examples 1-3 was conducted, and the results are shown in Table 1 below:

[0150] Table 1

[0151]

[0152] As can be seen from the table above, the laminate flooring produced by the present invention outperforms conventional technologies in all performance indicators. In particular, the formaldehyde emission of the present invention is only 0.08 mg / L, significantly lower than the 0.28 mg / L of Comparative Example 1 and significantly lower than the levels of Comparative Examples 2 and 3. In terms of surface performance, the present invention's wear resistance, scratch resistance, and pollution resistance are significantly superior to those of the comparative examples. Furthermore, the present invention exhibits scratch self-repair, temperature regulation, and air purification capabilities—properties not possessed by conventional laminate flooring.

[0153] To further verify the temperature regulation function of the product of the present invention, indoor temperature fluctuation tests were conducted on the floor prepared in Example 2 and Comparative Example 2. As the room temperature rose from 20°C to 30°C, the surface temperature of the floor prepared in Example 2 rose by only 7°C, while the surface temperature of the floor prepared in Comparative Example 2 rose by 9.5°C. This demonstrates that the product of the present invention has a significant temperature regulation effect, reducing the amplitude of floor surface temperature fluctuation by approximately 2.5°C.

[0154] In terms of air quality improvement, Example 3 and Comparative Example 3 were placed in a confined space containing 0.5 mg / m³ formaldehyde for 24 hours, and the formaldehyde concentration changes within the space were measured. The results showed that the formaldehyde concentration in the space where Example 3 was placed decreased by 85%, while the formaldehyde concentration in the space where Comparative Example 3 was placed decreased by only 30%, demonstrating that the product of the present invention has significant air purification capabilities.

[0155] In summary, the laminate flooring prepared by the present invention not only has excellent physical and mechanical properties and extremely low formaldehyde emission, but also has multiple functions such as scratch self-repair, temperature regulation, anti-fouling self-cleaning and air purification, which can provide users with a healthier and more comfortable indoor environment, and has significant technical advantages and application value.

[0156] Through the detailed description of the above embodiments, those skilled in the art should understand that the present invention can be implemented in various forms and should not be limited to the specific implementation methods described in the above embodiments. The scope of protection of the present invention should be defined by the appended claims and their equivalents.

[0157] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0158] It should be noted that those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

[0159] The present disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, executes the steps of the method for preparing a laminate flooring using a low-formaldehyde adhesive, as described in the above-described method embodiment. The storage medium can be either volatile or non-volatile.

[0160] In addition, an embodiment of the present disclosure also provides a computer program product, which stores a computer program. When the computer program is run by a processor, it executes the steps of any of the above-mentioned methods for preparing laminate flooring using a low-formaldehyde adhesive. For details, please refer to the above-mentioned method embodiments, which will not be repeated here.

[0161] The computer program product may be implemented in hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is embodied as a computer storage medium, which may be a volatile or non-volatile computer-readable storage medium. In another alternative embodiment, the computer program product is embodied as a software product, such as a software development kit (SDK).

[0162] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment and devices can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. In the several embodiments provided in the present disclosure, it should be understood that the disclosed equipment, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0163] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0164] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0165] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0166] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present disclosure, which are used to illustrate the technical solutions of the present disclosure, rather than to limit them. The scope of protection of the present disclosure is not limited thereto. Although the present disclosure has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-mentioned embodiments within the technical scope disclosed in the present disclosure, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A method for preparing laminate flooring using a low-formaldehyde adhesive, characterized in that: The following steps are involved: Mixing urea-formaldehyde resin, lignin, chitosan and soy protein isolate, and reacting at 60-70°C for 90-120 minutes to obtain a bio-based multi-component composite adhesive; The bio-based multi-component composite adhesive is mixed with wood fiber and bamboo fiber at a dry weight ratio of 8:1-10:1, microencapsulated phase change material is added, and the mixture is mixed for 10-15 minutes using a high-speed mixer to obtain a substrate blank with phase change energy storage function; The substrate blank is subjected to segmented hot pressing for 16-19 minutes at a temperature of 175-185° C. and a pressure of 28-32 MPa to obtain a phase change energy storage temperature regulating substrate plate; A photocatalytic formaldehyde capture primer containing nano-titanium dioxide and modified zeolite is coated on the surface of the substrate plate, and after drying, a surface functionalized substrate is obtained; A UV curable coating containing self-repairing microcapsules, super-hydrophobic nanomaterials and negative ion releasing materials is coated on the decorative paper and subjected to UV light curing to obtain a multifunctional wear-resistant layer; The surface functionalized substrate is laminated with the decorative paper and the multifunctional wear-resistant layer, and hot-pressed for a second time for 3-5 minutes at a temperature of 155-165° C. and a pressure of 3.5-4.5 MPa to obtain a low-formaldehyde laminate flooring.

2. The method according to claim 1, characterized in that The urea-formaldehyde resin, lignin, chitosan and soy protein isolate are mixed and reacted at a temperature of 60-70°C for 90-120 minutes to obtain a bio-based multi-component composite adhesive, including: The urea-formaldehyde resin is pre-adjusted to a pH of 8.0-8.5, the lignin is sulfonated, the chitosan is dissolved in a 1%-2% acetic acid solution to prepare a colloidal solution, and the soy protein isolate is dissolved under alkaline conditions of pH 9-10 to obtain pretreated components, wherein the pretreated components include the pretreated urea-formaldehyde resin, lignin, chitosan, and soy protein isolate; The pretreated components are mixed in a reactor at a weight ratio of 50:12-15:3-5:25-30 of urea-formaldehyde resin, lignin, chitosan, and soy protein isolate, and reacted by mechanical stirring at 200-300 rpm while maintaining the pH in the range of 7.5-8.5, and adding 0.5%-1% ammonium chloride as a curing catalyst to obtain a preliminary composite adhesive; 3%-5% of multifunctional isocyanate as a cross-linking agent and 0.5%-1% of polyvinyl alcohol as a stabilizer are added to the preliminary composite adhesive, and the reaction is continued at 65° C. for 30-45 minutes to obtain the bio-based multi-component composite adhesive.

3. The method according to claim 1, characterized in that Add microencapsulated phase change materials, including: Selecting normal alkanes with a phase change temperature of 28-32°C as core materials, using in-situ polymerization method to perform microencapsulation with polyurethane as wall material, controlling the average particle size of the microcapsules to 10-20 μm, and obtaining microencapsulated phase change materials; Based on the mixture of the bio-based multi-component composite adhesive, wood fiber and bamboo fiber, the microencapsulated phase change material is added thereto at a ratio of 8%-12% of the total dry weight of the fiber and the adhesive, and mixed for 10-15 minutes by a high-speed mixer to obtain the substrate blank with phase change energy storage function.

4. The method according to claim 1, wherein The substrate blank is subjected to segmented hot pressing, comprising: The substrate blank is preheated by gradually increasing the temperature to 175° C. within the first 5 minutes and the pressure is 70% of the set value to obtain a preheated blank; The preheated blank is subjected to a main body hot pressing treatment at a constant temperature of 175-185° C. and a constant pressure of 28-32 MPa for 9-12 minutes to obtain a preliminary formed substrate; The preliminary formed substrate is cooled to 150° C. within the last 2-3 minutes and maintained at full pressure for shaping, thereby obtaining the phase-change energy storage temperature-regulating substrate plate.

5. The method according to claim 1, characterized in that The photocatalytic formaldehyde capture primer comprises: The photocatalytic formaldehyde capture primer with a solid content of 30%-35% is prepared by using water-based polyurethane dispersion as the base material, adding 3%-5% nano titanium dioxide, 1%-2% modified zeolite and 1%-3% activated carbon powder, and adding 0.5%-1% silane coupling agent.

6. The method according to claim 1, characterized in that A UV curable coating containing self-repairing microcapsules, super-hydrophobic nanomaterials and negative ion releasing materials is coated on the decorative paper and subjected to UV light curing to obtain a multifunctional wear-resistant layer, including: Self-repairing microcapsules with an average particle size of 3-5 μm were prepared by interfacial polymerization using dicyclopentadiene as the core material and polyurethane as the wall material to obtain a self-repairing component; Nano-silica particles with a particle size of 50-100 nm were synthesized by the sol-gel method and surface modified with perfluorotridecyltriethoxysilane to obtain super-hydrophobic nanomaterials. Based on an aliphatic polyurethane acrylate main resin, 5%-8% of the self-repairing component, 2%-4% of the super-hydrophobic nanomaterial, 4%-6% of tourmaline micropowder and 3%-5% of nano-alumina are added, and 2%-3% of a photoinitiator is added to obtain a UV-curable coating containing a multifunctional component; The UV curable coating containing the multifunctional component is applied on the decorative paper to control the wet coating thickness to be 40-50 μm, and cured for 30-60 seconds under UV-A irradiation with a wavelength of 365 nm and a power density of 300-400 mW / cm² to obtain a preliminarily cured multifunctional wear-resistant layer; The thickness of the preliminarily cured multifunctional wear-resistant layer is controlled to ensure that the final thickness is 30-40 μm, thereby obtaining the multifunctional wear-resistant layer.

7. The method according to claim 6, characterized in that The self-repairing microcapsules are prepared by interfacial polymerization, including: Mixing the dicyclopentadiene and the Grubbs catalyst as a core material, dispersing the mixture in an aqueous phase to form an emulsion, and obtaining a core material emulsion; A polyurethane prepolymer monomer is added to the core material emulsion, and a polyurethane wall material is formed on the surface of the core material through an interfacial polymerization reaction to obtain the self-repairing microcapsule.

8. The method according to claim 1, characterized in that The surface functionalized substrate is laminated with the decorative paper and the multifunctional wear-resistant layer, and hot-pressed for a second time for 3-5 minutes at a temperature of 155-165° C. and a pressure of 3.5-4.5 MPa, comprising: Precisely positioning the decorative paper on the surface functionalized substrate, and covering the multifunctional wear-resistant layer on the decorative paper to form a laminated structure to obtain a pre-laminated body; The pre-laminated body is heated in stages to 155-165° C. at a rate of 5-8° C. / min and maintained under pressure, then cooled to below 80° C. and released to obtain the low-formaldehyde laminate flooring.

9. The method according to claim 1, characterized in that Also includes: Active environmental control functions are integrated into the low-formaldehyde laminate flooring: Select activated carbon fiber felt with a specific surface area of ​​≥1500m² / g, and grow graphene nanosheets on its surface by chemical vapor deposition to obtain an activated carbon fiber / graphene composite adsorption layer; Based on the conductive properties of the activated carbon fiber / graphene composite adsorption layer, a carbon nanotube conductive ink is printed on a polyimide film substrate to form a matching electric heating film, and the surface resistance is controlled at 10-20Ω to obtain an electric heating regeneration module; Based on the working requirements of the electrothermal regeneration module, a temperature and humidity sensor, a VOC sensor, and a temperature sensor are integrated and communicated with the control unit via a low-power Bluetooth protocol to obtain a sensor system that matches the regeneration module; The activated carbon fiber / graphene composite adsorption layer, the electrothermal regeneration module and the sensor system are used as an integrated functional module and installed in the reserved space at the bottom of the substrate of the low-formaldehyde laminate composite wood flooring to obtain a laminate composite wood flooring with active environmental control function.

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