A stone plastic floor and a stone plastic floor extrusion molding preparation method

Abstract

The application relates to a stone-plastic floor and an extrusion molding preparation method of the stone-plastic floor, and relates to the stone-plastic floor processing technical field.The stone-plastic floor comprises polyvinyl chloride resin, heavy calcium carbonate, calcium-zinc stabilizer, abrasive powder, internal lubricant, and external lubricant; and the preparation steps comprise feeding and mixing, extrusion, calendering, film covering, traction and cutting, and slotting; the low-temperature cold mixing realizes energy saving and consumption reduction, the stabilizer decomposition and lubricant volatilization problems caused by high temperature are avoided, the filler dispersion uniformity and interface bonding force are improved, the large-diameter specification extruder is adopted to improve the production efficiency, the material uniform plasticization is guaranteed by cooperating with the melting section cooling area, the processing stability and the finished product qualification rate are effectively improved, the stability, wear resistance and waterproofness of the stone-plastic floor are finally obviously improved, the service life is prolonged, and the stone-plastic floor has the advantages of environmental protection and production efficiency.

Description

A stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding. Technical Field

[0001] This invention relates to the field of stone-plastic flooring processing technology, and in particular to a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding. Background Technology

[0002] Stone-plastic composite (SPC) flooring, a new type of environmentally friendly floor decoration material, is a composite molding process using natural stone powder and resin as its core raw materials. It combines the high strength and stability of stone with the flexibility and ease of processing of plastic, and is widely used in diverse settings such as residential, commercial, medical, and educational facilities. Its technological system originates from the iterative upgrades of traditional PVC flooring, and through the technological accumulation of stages such as resilient flooring and wood-plastic composite flooring, it has gradually formed a core technological framework centered on composite substrate preparation, multi-layer structure lamination, and precision molding processing, becoming an important development direction in the field of flooring materials.

[0003] In existing stone-plastic flooring manufacturing processes, raw materials are generally mixed by heating. For example, Chinese invention patent application CN106587720A, published on April 25, 2017, proposes a stone-plastic flooring and its preparation method. The main solution of this patent is: using resin as a base material, heating and stirring the raw materials in proportion to mix them evenly, conveying them to a mold for molding and heat preservation, demolding, bonding the surface layer to the profile surface and hot-pressing and bonding, and finally cooling and forming. Its advantages are that it does not use any plasticizers and foaming agents, and has the characteristics of high strength, high hardness, excellent shrinkage performance, and no environmental hazards.

[0004] However, the above-mentioned approach of heating and mixing raw materials has significant disadvantages: First, it consumes a lot of energy, as the heating process requires a large amount of energy to maintain a mixing temperature of 120-140°C or higher, which increases the total production cost; Second, high-temperature mixing damages the performance of raw materials, and long-term high-temperature environment can easily lead to thermal degradation of the resin, thereby destroying the structural stability of the resin itself and indirectly weakening the overall performance reliability of the product. Summary of the Invention

[0005] In order to reduce the production energy consumption and cost of existing stone plastic flooring, while effectively avoiding resin thermal degradation to ensure its structural stability and ensuring that the product retains its original environmental advantages and excellent performance, this invention provides a stone plastic flooring and a stone plastic flooring extrusion molding preparation method. This method can achieve efficient and uniform mixing of raw materials without high-temperature heating.

[0006] Firstly, this application provides a stone-plastic flooring solution, which adopts the following technical solution:

[0007] A stone-plastic flooring includes, from top to bottom, a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate; the stone-plastic substrate comprises, by weight, 22-24 parts of PVC resin, 55-59 parts of heavy calcium carbonate, 1.5-2.0 parts of calcium-zinc stabilizer, 18-20 parts of abrasive powder, 1.5-1.7 parts of internal lubricant, and 0.7-0.8 parts of external lubricant.

[0008] By adopting the above technical solutions, polyvinyl chloride resin, as a continuous phase, constructs a dense matrix, providing basic molding support and structural integrity; a high proportion of heavy calcium carbonate forms a rigid skeleton in the form of physical filler, restricting the movement of resin molecular chains and dispersing stress, thereby improving the dimensional stability and deformation resistance of the flooring; calcium-zinc stabilizers react with substances produced by thermal decomposition of metal ions to generate stable metal chlorides, terminating the degradation chain reaction, effectively inhibiting thermal oxidative degradation during processing and use, and extending the service life of the flooring; abrasive powder is uniformly dispersed in the matrix to form a wear-resistant protective layer, extending the service life; internal lubricant penetrates into the gaps between resin molecules to weaken interchain forces, while external lubricant forms an isolation film at the interface between the melt and the equipment. The two lubricants work synergistically to improve melt flowability and increase production efficiency; at the same time, the hydrophobic properties of polyvinyl chloride combined with the dense structure formed by high filler further endow the stone plastic flooring with excellent waterproof and moisture-proof performance, ultimately achieving a comprehensive and synergistic improvement in stability, wear resistance, processability, durability, and waterproofness.

[0009] The high proportion of inorganic mineral fillers and low proportion of resin substrate in the stone-plastic composite material of this application allows for mixing of raw materials at a lower temperature. In addition, the three-layer composite structure has excellent thermal insulation performance. The surface barrier effect formed by the polyvinyl chloride colored film and the wear-resistant layer, combined with the porous composite structure formed by the inorganic fillers and resin in the stone-plastic composite material, results in a low overall thermal conductivity of the floor. In building use, this structure can effectively reduce the loss of indoor heat through the ground. During the winter heating season, it can reduce heat loss from the ground, and during the summer cooling season, it can reduce the intrusion of outdoor heat into the room through the ground, thereby reducing the operating load of air conditioning and heating equipment and reducing the energy consumption of the building's HVAC system.

[0010] Optionally, the heavy calcium carbonate is graft-modified heavy calcium carbonate, and the preparation method of the graft-modified heavy calcium carbonate is as follows:

[0011] Surface activation: Under nitrogen atmosphere, add an initiator accounting for 0.2 wt% of the calcium carbonate mass, and stir at 30–40 °C and 600–800 r / min for 6–10 min; the initiator is a composite initiation system of dilauryl peroxide and methyl ethyl ketone peroxide; the mass ratio of dilauryl peroxide to methyl ethyl ketone peroxide in the composite initiation system is 1.0–1.2:1;

[0012] Graft polymerization: Add 5 wt% of a methyl methacrylate and butyl acrylate composite, and stir at 40-45°C and 800 r / min for 30 min; the mass ratio of methyl methacrylate to butyl acrylate in the composite is 6-8:3.

[0013] In-situ end-capping: Add toluene diisocyanate at 0.5 wt% of calcium carbonate, stir at 30-40℃ and 500-700 r / min for 10 min; cool to 25-30℃ to obtain the final product.

[0014] By adopting the above technical solution, a composite initiation system of dilauryl peroxide and methyl ethyl ketone peroxide is used to efficiently decompose and generate free radicals in the temperature range of 30-40℃, ensuring the smooth occurrence of the graft polymerization reaction on the calcium carbonate surface, and completing the modification without relying on hot mixing at high temperatures. The grafted methyl methacrylate-butyl acrylate copolymer chains have excellent compatibility with polyvinyl chloride (PVC) resin, and can reduce the interfacial tension between calcium carbonate and PVC matrix through physical entanglement at low temperatures. In particular, under cold mixing process, the PVC resin is not softened and has a naturally high interfacial bonding tension. At the same time, it effectively inhibits the agglomeration of calcium carbonate particles during cold mixing, and significantly improves the dispersion uniformity of fillers in PVC matrix.

[0015] In addition, the in-situ end-capping treatment of toluene diisocyanate seals the unreacted active groups on the surface of calcium carbonate, reduces hydrogen bonding between particles, further improves the storage stability of cold-mixed materials, and avoids stratification and clumping problems before subsequent processing.

[0016] Optionally, the stone-plastic substrate further includes 0.5–0.8 parts of anionic surfactant-modified lanthanum montmorillonite; the preparation method of the anionic surfactant-modified lanthanum montmorillonite is as follows:

[0017] Pretreatment: Sodium montmorillonite was vacuum dried at 55-65℃ for 2 hours and then cooled to room temperature for use.

[0018] Intercalation reaction: Add pretreated sodium montmorillonite to deionized water, control the solid-liquid ratio at 1:45-55, and mix thoroughly; stir at 35℃ and 400-600 r / min for 15-25 min, adjust the pH to 5.0±0.1, add 0.12 mol / L lanthanum chloride aqueous solution, and continue stirring for 1.5-2.5 h; after the reaction is completed, centrifuge at 8000 r / min for 10 min, collect the precipitate, and wash it 2-3 times with deionized water;

[0019] Targeted modification: The centrifuged lanthanum intercalated montmorillonite was dispersed in deionized water at a solid-liquid ratio of 1:35–45, and the dispersion was uniform. The mixture was stirred at 38°C and 500–700 r / min for 15–25 min, and the pH was adjusted to 8.0 ± 0.1. A 0.05 mol / L sodium ricinoleate aqueous solution was added, and the reaction was continued with stirring for 1–2 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 10 min, the precipitate was collected, and washed 2–3 times with deionized water.

[0020] Post-processing: Dry to constant weight at 60℃ and vacuum degree -0.08MPa, then grind and sieve to obtain the final product.

[0021] By adopting the above technical solution, lanthanum ions are used to replace sodium ions in sodium-based montmorillonite, maximizing the interlayer spacing of montmorillonite and creating sufficient space for PVC molecular chains to smoothly insert into montmorillonite sheets during cold mixing. Secondly, the modification process employs 35℃ intercalation and 38℃ directional modification to avoid damage to the layered structure of montmorillonite at high temperatures. At the same time, the anionic surfactant modification of sodium ricinoleate changes the surface of montmorillonite from hydrophilic to hydrophobic, significantly improving its low-temperature compatibility with PVC resin. This further enables uniform dispersion of montmorillonite sheets during cold mixing, avoiding the agglomeration problem of nanofillers in the cold mixing system.

[0022] In addition, lanthanum ions form a stable coordination with chlorine atoms in the PVC molecular chain, improving the rigidity and processing fluidity of the cold-mixed compound. At the same time, modified montmorillonite further improves the dispersion efficiency of calcium-zinc stabilizers during the cold mixing process, enhancing the processing stability of the cold-mixed compound and ensuring the smooth progress of subsequent extrusion, calendering and other processes.

[0023] Secondly, this application provides a method for preparing stone-plastic flooring by extrusion molding, which adopts the following technical solution:

[0024] A method for preparing stone-plastic flooring by extrusion molding includes the following steps:

[0025] Feeding and mixing: After metering, polyvinyl chloride resin, heavy calcium carbonate, calcium-zinc stabilizer, abrasive powder, internal lubricant and external lubricant are mixed. The mixing temperature is <50℃ and the stirring speed is 500~700r / min for 15~20min.

[0026] Extrusion: The uniformly mixed material is extruded through a twin-screw extruder with a screw diameter of 110 mm; the barrel of the extruder includes, in sequence along the material conveying direction, a feeding section, a compression section, a melting section, a metering section, and a die head; the proportions of the feeding section, compression section, melting section, metering section, and die head to the total length of the screw are 20-22%, 30-33%, 20-22%, 12-13%, and 8-10%, respectively; the temperatures of the feeding section, compression section, melting section, metering section, and die head are set to 130-140℃, 160-165℃, 170-175℃, 172-178℃, and 165-170℃, respectively.

[0027] Calendering: The extruded product is pressed into shape on a calender plate, and the calendering temperature is controlled at 150-155℃;

[0028] Coating: The polyvinyl chloride colored film and wear-resistant layer are heated and molded with the product after pressing, and then cooled;

[0029] Traction and Cutting: The cooled product is tractioned by the traction system and cut after length measurement;

[0030] Grooving: Grooving is performed on the cut product to create the desired button shape.

[0031] By adopting the above technical solutions, the PVC particle morphology is maintained in a low-temperature environment, allowing the copolymer chains of grafted modified heavy calcium carbonate and the hydrophobic chains of anionic surfactant-modified lanthanum montmorillonite to be uniformly adsorbed onto the PVC particle surface by van der Waals forces, forming a monomolecular adsorption layer and further enhancing the interfacial bonding force. A twin-screw (110SPS) extruder with a screw diameter of 110mm is used, which increases the screw diameter and barrel volume, further improving production efficiency. The long compression section of the extruder enhances material densification and air discharge, while the short metering section reduces PVC degradation caused by excessive shearing, ultimately achieving uniform extrusion of the material without local overheating or unmelted particles.

[0032] The mild plasticizing and environmentally friendly layered structure of lanthanum montmorillonite fully leverages the nano-reinforcing effect, significantly improving the flexural strength and wear resistance of the finished stone-plastic flooring. The calendering temperature is lower than the extrusion temperature, maintaining material flexibility while suppressing dimensional shrinkage caused by over-plasticization, significantly improving dimensional stability. The heating and cooling process of the coating allows the PVC film, wear-resistant layer, and substrate to form a strong chemical bond through molecular chain diffusion, preventing delamination. Traction, cutting, and grooving ensure the sealing of the interlocking joints. Ultimately, this results in improved product processing stability, mechanical properties, and wear and water resistance.

[0033] Optionally, in the extrusion step, the barrel of the extruder further includes a melting section cooling zone along the material conveying direction. The melting section cooling zone is located after the compression section and before the melting section. The temperature of the melting section cooling zone is set to 155-160℃. The proportions of the feed section, compression section, melting section cooling zone, melting section, metering section, and die head to the total length of the screw are 20%, 30%, 10%, 20%, 12%, and 8%, respectively.

[0034] By adopting the above technical solution and increasing the cooling zone of the melting section, on the one hand, the partial shear heat generated by the material in the compression section is reduced, and the accumulated residual heat is quickly released through temperature adjustment, which inhibits the excessive heating of the outer layer material in the later stage of the compression section. On the other hand, sufficient heat transfer time is reserved for the inner layer material, which promotes the inner and outer layers material to approach a uniform plasticization state at the same time. This further weakens the problem of uneven heat transfer caused by the increase of screw diameter, significantly improves the dimensional stability of the extruded sheet, reduces the risk of warping in the calendering and coating process and the hidden danger of cracking in the use of finished products, and achieves the optimization of processing stability and product mechanical properties when extruding high-filled stone plastic flooring with a large-diameter screw.

[0035] Optionally, the mixture may also include a pre-drying step, which is set after the feeding and mixing step and before the extrusion step; the pre-drying step is as follows: the uniformly mixed material is vacuum dried at 80-90℃ and a vacuum degree of -0.06 to -0.08MPa for 2-3 hours; after drying, it is cooled to ≤40℃.

[0036] By adopting the above technical solution, the pre-drying step removes adsorbed free water and residual air from the mixture, so that the pressure is evenly distributed during melt plasticization and the shrinkage of each area is consistent during the cooling process. This further makes the internal stress distribution uniform, thereby eliminating defects such as bubbles and pinholes caused by water vaporization and air expansion during the subsequent extrusion process and improving the density of the sheet.

[0037] Optionally, the process also includes a calender cooling and shaping step, wherein the calender cooling and shaping step is set after the calendering step and before the coating step; the calender cooling and shaping step is as follows: the calendered product is cooled in stages, first by water cooling at 60-70°C for 3-5 minutes, and then by water cooling at 25-30°C for 2-3 minutes.

[0038] By adopting the above technical solution, the 60-70℃ warm water section slowly releases the internal stress generated by shearing and temperature gradient during calendering, avoiding the interface stress concentration caused by the difference in thermal expansion coefficients between inorganic fillers and PVC resin. At the same time, it promotes the appropriate relaxation and rearrangement of molecular chains, strengthens the interfacial bonding force between inorganic fillers and resin matrix, and prevents delamination and cracking during subsequent processing or use. The 25-30℃ cold water section fixes the formed structure of the board by rapid cooling, suppresses the dimensional changes caused by secondary migration of molecular chains, and further avoids thermal degradation or thermal shrinkage deformation of PVC color film and wear-resistant layer caused by high temperature board during subsequent lamination.

[0039] Optionally, in the coating step, the forming method is as follows: first, pre-press and bond at 80-90℃ and 0.8-1.2MPa for 30s, then heat to 120-130℃ and pressurize and cure at 2.0-2.5MPa for 60s.

[0040] By adopting the above technical solution, the pre-pressing temperature of 80-90℃ is lower than the melting temperature of the PVC substrate and the color film. This not only avoids uneven shrinkage or surface wrinkling caused by excessive softening of the film and substrate in advance, but also effectively removes air between the substrate and film interface, preventing defects such as bubbles and pinholes from occurring during subsequent curing. This further enables the film and substrate surfaces to form a preliminary physical bond. Heating to 120-130℃ activates the mobility of PVC molecular chains, promotes the diffusion and entanglement of molecular chains between the substrate, PVC color film, and wear-resistant layer, compresses the interface gap, ensures that the molecular chains diffuse fully and form a stable shape, and ultimately achieves a strong and integrated bond between the color film, wear-resistant layer, and substrate.

[0041] Optionally, it also includes a curing step, which is set after the coating step and before the traction and cutting step; the curing step is: to cure the coated and cooled product at a constant temperature, controlling the temperature at 40-50℃, the relative humidity at 40-60%, and the curing time at 24-48h.

[0042] By adopting the above technical solutions and adding a curing step, the internal stress release and interfacial bonding ability of the material are promoted: on the one hand, the residual internal stress during high-temperature processing such as extrusion, calendering, and lamination is effectively eliminated, avoiding warping and cracking of the board due to stress concentration during subsequent traction cutting or use, thus improving dimensional stability; on the other hand, the slow diffusion and entanglement of molecular chains at the interface between the PVC film, wear-resistant layer and substrate are promoted, strengthening the interlayer chemical bonding effect and solving the interlayer peeling problem that is prone to occur in traditional lamination processes. The curing time of 24 to 48 hours ensures that the internal stress is fully released and the interfacial bonding reaches a stable state, ultimately improving the product's structural stability, interlayer bonding force and service durability.

[0043] Optionally, it also includes a trimming step, which is set after the traction and cutting step and before the grooving step; the trimming step is to trim the cut product to remove edge burrs and flash, and control the trimming amount to 0.5-1mm.

[0044] By adopting the above technical solution, the trimming step removes burrs, flash, and minor deformation areas from the edges of the cut board, avoiding problems such as uneven force on the grooving tool and dimensional deviations in the snap-fit ​​processing caused by burrs, thus improving the splicing sealing performance. The removed flash further reduces the risk of burrs falling off and scratching during use, improving the surface texture and safety of the product.

[0045] In summary, this application includes at least one of the following beneficial technical effects:

[0046] 1. By adopting low-temperature cold mixing, energy saving and consumption reduction and improved mixing uniformity are achieved; the problems of calcium and zinc stabilizer decomposition and lubricant volatilization failure caused by high temperature in traditional hot mixing process are avoided, reducing production energy consumption from the source; at the same time, the low-temperature intercalation modification process of grafted modified heavy calcium carbonate and anionic surfactant modified lanthanum montmorillonite effectively inhibits the agglomeration of inorganic fillers, improves the interfacial bonding force, and improves the uniformity of filler dispersion in the cold mixing system.

[0047] 2. By adopting a 110SPS extruder, the screw diameter is increased and the barrel volume is improved, further enhancing production efficiency; the cooling zone of the melting section can effectively release the shear heat generated by the compression section, weakening the problem of uneven heat transfer in large-diameter screws, and achieving uniform plasticization and extrusion of materials; significantly improving processing stability and finished product qualification rate.

[0048] 3. By adopting the pre-pressure degassing and temperature curing processes in the film coating process, the wear-resistant layer, color film and substrate form a strong chemical bond, avoiding delamination and significantly extending the service life; the hydrophobic properties of PVC resin combined with the dense structure formed by high filling improve the stability, wear resistance and water resistance of stone plastic flooring. Attached Figure Description

[0049] Figure 1 is a process flow diagram of the preparation of a stone-plastic flooring provided in Embodiment 1 of this application. Detailed Implementation

[0050] The present invention will be further described in detail below with reference to the embodiments.

[0051] Unless otherwise specified, the experimental methods used in the embodiments of this application are conventional methods, and the materials used are commercially available unless otherwise specified.

[0052] Example 1: This example discloses a stone plastic flooring and a method for preparing stone plastic flooring by extrusion molding.

[0053] A stone-plastic flooring includes a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate, which are sequentially composited from top to bottom. The stone-plastic substrate comprises the following components by weight: 22 parts polyvinyl chloride resin, 59 parts heavy calcium carbonate, 2.0 parts calcium-zinc stabilizer, 18 parts abrasive powder, 1.7 parts internal lubricant, and 0.8 parts external lubricant.

[0054] Among them, ① the grinding powder can be one or a mixture of several of the following: quartz sand powder, alumina powder, and silica powder. In this embodiment, quartz sand powder is selected; ② the internal lubricant can be one or a mixture of several of the following: stearic acid, pentaerythritol stearate, epoxidized soybean oil, and butyl stearate. In this embodiment, pentaerythritol stearate is selected; ③ the external lubricant can be one or a mixture of several of the following: paraffin wax, polyethylene wax, oxidized polyethylene wax, and stearamide. In this embodiment, oxidized polyethylene wax is selected.

[0055] The preparation method of stone-plastic flooring by extrusion molding includes the following steps, as shown in Figure 1:

[0056] Feeding and mixing: Polyvinyl chloride resin, heavy calcium carbonate, calcium-zinc stabilizer, abrasive powder, internal lubricant and external lubricant are mixed after being metered. The mixing temperature is <50℃, and the mixture is stirred at 600r / min for 18min. After mixing, there is no obvious clumping of the material.

[0057] Extrusion: The uniformly mixed material is extruded through a twin-screw extruder with a screw diameter of 110 mm; the extruder barrel includes, in sequence along the material conveying direction, a feeding section, a compression section, a melting section, a metering section, and a die head; the feeding section, compression section, melting section, metering section, and die head account for 22%, 33%, 22%, 13%, and 10% of the total screw length, respectively; the temperatures of the feeding section, compression section, melting section, metering section, and die head are set to 135℃, 162℃, 172℃, 175℃, and 168℃, respectively; the screw speed is 40 r / min, and the die head outlet pressure is 20 MPa;

[0058] Calendering: The extruded product is pressed into shape, and the calendering temperature is controlled at 152℃; the calendering pressure is 20MPa, the calendering linear speed is 1.0m / min, and the thickness of the substrate after forming is 4±1mm.

[0059] Coating: The polyvinyl chloride colored film and wear-resistant layer are heated and molded with the product after pressing, and then cooled at 30°C for 5 minutes; the molding method is as follows: heating temperature 130°C, composite pressure 2.5MPa, and holding time 130s;

[0060] Traction and Cutting: The cooled product is tractioned by the traction system and cut after length measurement; the traction speed is 1.0 m / min and the traction tension is 6 kN; the waste scraps after cutting are collected, crushed, and can be returned to the feeding and mixing step for continued use;

[0061] Grooving: The cut product is grooved to form the desired button shape; the groove depth is 2.0±0.5mm and the groove width is 2.5±0.5mm; after passing inspection, it is packaged and put into storage.

[0062] The following indicators were tested on the prepared stone plastic flooring: tensile strength, flexural strength, water absorption dimensional change rate, and cold resistance; all tests were conducted in accordance with the GB / T40859-2021 standard for stone plastic flooring.

[0063] ① Tensile strength (MPa): Reflects the material toughness of SPC flooring; ② Flexural strength (MPa): Reflects the resistance to deformation of SPC flooring under vertical load, and is the core evaluation index of the rigidity of flooring materials; ③ Water absorption dimensional change rate (%): Evaluates the moisture resistance and environmental adaptability of SPC flooring, and is a key indicator of long-term stability; ④ Cold resistance (%): Reflects the ability of SPC flooring to retain toughness in low-temperature environments. Low temperatures cause the movement of PVC molecular chains to slow down, leading to the material becoming brittle.

[0064] Example 2: This example discloses a stone plastic flooring and a method for preparing stone plastic flooring by extrusion molding.

[0065] A stone-plastic flooring includes a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate, which are sequentially composited from top to bottom. The stone-plastic substrate comprises the following components by weight: 24 parts polyvinyl chloride resin, 55 parts heavy calcium carbonate, 1.5 parts calcium-zinc stabilizer, 20 parts abrasive powder, 1.5 parts internal lubricant, and 0.7 parts external lubricant.

[0066] Everything else is exactly the same as in Example 1.

[0067] Example 3: This example discloses a stone plastic flooring and a method for preparing stone plastic flooring by extrusion molding.

[0068] A stone-plastic flooring includes a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate, which are sequentially composited from top to bottom. The stone-plastic substrate comprises the following components by weight: 23 parts polyvinyl chloride resin, 57 parts heavy calcium carbonate, 1.75 parts calcium-zinc stabilizer, 19 parts abrasive powder, 1.6 parts internal lubricant, and 0.75 parts external lubricant.

[0069] Everything else is exactly the same as in Example 1.

[0070] The stone-plastic flooring prepared in Examples 1-3 was tested respectively, and the test results are shown in Table 1:

[0071] Table 1:

[0072] Test Indicators Example 1 Example 2 Example 3 Tensile Strength (MPa) 12.8 15.3 14.5 Flexural Strength (MPa) 28.6 24.2 26.8 Water Absorption Dimensional Change Rate (%) 0.3 20.2 50.2 8 Cold Resistance (%) 82.5 88.3 86.1 surface

[0073] Comparing the data from Examples 1-3, it can be seen that Example 1 has the highest content of heavy calcium carbonate, thus exhibiting the highest flexural strength among the three examples. However, it also has the lowest content of polyvinyl chloride (PVC) resin, resulting in the worst tensile strength and cold resistance. Example 2 has the highest PVC resin content, leading to the best tensile strength and cold resistance, but the lowest content of heavy calcium carbonate, resulting in the lowest degree of bending. Example 3 has a balanced formulation, and all indicators are relatively balanced. Overall, all three examples meet the requirements of the above-mentioned test indicators for stone plastic flooring.

[0074] Example 4: This example discloses a stone plastic flooring and a method for preparing stone plastic flooring by extrusion molding.

[0075] In this embodiment, the heavy calcium carbonate in the stone-plastic substrate is graft-modified heavy calcium carbonate, with the mass fraction remaining unchanged, and all other aspects are the same as in Example 3; wherein, the preparation method of the graft-modified heavy calcium carbonate is as follows:

[0076] Surface activation: Under nitrogen flow rate of 25 mL / min, an initiator accounting for 0.2 wt% of calcium carbonate was added, and the mixture was stirred at 35℃ and 700 r / min for 8 min; the initiator was a composite initiation system of dilauryl peroxide and methyl ethyl ketone peroxide; the mass ratio of dilauryl peroxide to methyl ethyl ketone peroxide in the composite initiation system was 1.1:1;

[0077] Graft polymerization: While maintaining a nitrogen atmosphere, add a methyl methacrylate and butyl acrylate composite at 5 wt% of calcium carbonate, and stir at 42°C and 800 r / min for 30 min; the mass ratio of methyl methacrylate to butyl acrylate in the composite is 7:3.

[0078] In-situ end-capping: Add toluene diisocyanate at 0.5 wt% of calcium carbonate, stir at 35°C and 600 r / min for 10 min; cool to 28°C, filter, and vacuum dry at 60°C and -0.09 MPa for 2 h to obtain the final product.

[0079] Everything else is exactly the same as in Example 3.

[0080] Example 5: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0081] In this embodiment, the stone-plastic substrate of the stone-plastic flooring also includes 0.65 parts of anionic surfactant-modified lanthanum montmorillonite; the preparation method of the anionic surfactant-modified lanthanum montmorillonite is as follows:

[0082] Pretreatment: Sodium-based montmorillonite with a particle size ≤2μm was vacuum dried at 60℃ and a vacuum degree of -0.06MPa for 2h, cooled to room temperature and sealed for later use;

[0083] Intercalation reaction: Pretreated sodium-based montmorillonite was added to deionized water, and the solid-liquid ratio (mass-volume ratio, g / mL) was controlled at 1:50. The mixture was thoroughly mixed. The mixture was placed in a constant temperature water bath and stirred at 35℃ and 500 r / min for 20 min. The pH was adjusted to 5.0±0.1 with 0.1 mol / L hydrochloric acid solution. Lanthanum chloride aqueous solution was added at a molar ratio of lanthanum ions to montmorillonite cation exchange of 1.2:1. The reaction was continued with stirring for 2.0 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 10 min, and the precipitate was collected and washed three times with deionized water.

[0084] Targeted modification: The centrifuged lanthanum intercalated montmorillonite was dispersed in deionized water at a solid-liquid ratio (mass-volume ratio, g / mL) of 1:40, and the dispersion was uniform. The mixture was placed in a constant temperature water bath and stirred at 38℃ and 600 r / min for 20 min. The pH was adjusted to 8.0±0.1 with 0.1 mol / L sodium hydroxide solution. 0.05 mol / L sodium ricinoleate aqueous solution was added at a molar ratio of ricinoleate ions to lanthanum ions of 1.2:1, and the reaction was continued with stirring for 1.5 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 10 min, the precipitate was collected, and washed three times with deionized water.

[0085] Post-treatment: The washed precipitate was placed in a vacuum drying oven and dried to constant weight at 60℃ and a vacuum of -0.08MPa. It was then ground in a planetary ball mill for 30 minutes and passed through a 200-mesh sieve to obtain anionic surfactant-modified lanthanum montmorillonite.

[0086] Everything else is exactly the same as in Example 4.

[0087] Example 6: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0088] In this embodiment, in the extrusion step of the preparation method of stone-plastic flooring extrusion molding, the barrel of the extruder further includes a melting section cooling zone along the material conveying direction. The melting section cooling zone is located after the compression section and before the melting section. The temperature of the melting section cooling zone is set to 158°C. The proportions of the feeding section, compression section, melting section cooling zone, melting section, metering section, and die head to the total length of the screw are 20%, 30%, 10%, 20%, 12%, and 8%, respectively. The screw speed is 40 r / min, and the die head outlet pressure is 20 MPa.

[0089] Everything else is exactly the same as in Example 5.

[0090] Example 7: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0091] In this embodiment, the preparation steps of extrusion molding of stone plastic flooring further include: a pre-drying step of the mixture, which is set after the feeding and mixing step and before the extrusion step; the pre-drying step of the mixture is: vacuum drying the uniformly mixed material at 85°C and vacuum degree -0.07MPa for 2.5h; and cooling it to ≤40°C after drying.

[0092] Everything else is exactly the same as in Example 6.

[0093] The stone-plastic flooring prepared in Examples 4-7 was tested, and the test results are shown in Table 2:

[0094] Table 2:

[0095] Test Indicators Example 4 Example 5 Example 6 Example 7 Tensile Strength (MPa) 16.2 17.5 17.8 17.8 Flexural Strength (MPa) 27.5 30.2 30.9 31.1 Water Absorption Dimensional Change Rate (%) 0.2 20.1 80.1 60.1 5 Cold Resistance (%) 87.2 89.5 90.9 91.1 surface

[0096] Comparing Example 4 with Example 3, it can be seen that graft modification improves compatibility with PVC resin. Example 3 uses unmodified heavy calcium carbonate, whose highly polar surface has poor compatibility with non-polar PVC resin and is prone to interfacial voids. Example 4 forms an organic shell on the surface of heavy calcium carbonate through methyl methacrylate-butyl acrylate graft polymerization, which increases the interfacial bonding tightness, facilitates stress transfer, and thus improves tensile strength and reduces the water absorption dimensional change rate. In addition, the tight interfacial bonding can inhibit excessive shrinkage of PVC molecular chains in low-temperature mixing environments, reduce interfacial cracking, and improve cold resistance.

[0097] Comparing Example 5 with Example 4, it can be seen that the stone-plastic substrate of Example 5 contains anionic surfactant-modified lanthanum montmorillonite. After lanthanum ion intercalation and directional modification with sodium ricinoleate, the interlayer spacing of the modified lanthanum montmorillonite is expanded, improving the surface oleophilicity and forming a nanoscale sheet barrier structure when mixed at a lower temperature. On the one hand, the montmorillonite sheets hinder the stress transmission path, improve the substrate's resistance to deformation, and enhance bending and tensile strength. On the other hand, the nanosheets act as a physical barrier, further hindering water penetration channels, thus reducing the water absorption dimensional change rate. In addition, the presence of lanthanum ions inhibits the crystallization and aggregation of PVC molecular chains at low temperatures, reduces brittle cracking in low-temperature environments, and improves cold resistance.

[0098] Comparing Example 6 with Example 5, it can be seen that Example 6 adds a cooling zone in the melting section. In Example 5, the compression section is directly connected to the melting section, and the melt is prone to slight over-melting due to continuous high temperature, resulting in local degradation of PVC molecular chains and the generation of a small number of micropores. However, Example 6 adds a 158°C cooling zone in the melting section after the compression section, which can mitigate the rapid temperature rise. On the one hand, it reduces the degradation of PVC molecular chains, making the melt viscosity more uniform and facilitating the densification of the substrate, thus reducing the water absorption dimensional change rate. On the other hand, it promotes the synchronous approach of uniform plasticization of the inner and outer layers, further weakening the problem of uneven heat transfer caused by the increase in screw diameter. Therefore, the tensile strength, flexural strength, and cold resistance are all improved to varying degrees.

[0099] Comparing Example 7 with Example 6, it can be seen that Example 6 did not include a pre-drying step, and the mixed material easily absorbed environmental moisture and residual trace amounts of free water. This moisture would quickly vaporize under the high temperature of extrusion, forming tiny bubbles that remained inside the substrate, becoming a performance bottleneck. Example 7 added a pre-drying treatment to remove the adsorbed and free water in the mixture in advance, avoiding the generation of water bubbles during extrusion, making the substrate structure denser, and improving tensile strength, flexural strength, and cold resistance. The data shows that the removal of moisture reduced the water penetration channels and decreased the water absorption dimensional change rate.

[0100] Example 8: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0101] In this embodiment, the preparation steps of extrusion molding of stone plastic flooring also include a calender plate cooling and shaping step, which is set after the calendering step and before the coating step; the calender plate cooling and shaping step is as follows: the calendered product is cooled in stages, first by cooling with 65°C warm water for 4 minutes, and then by cooling with 27°C water for 2.5 minutes.

[0102] Everything else is exactly the same as in Example 7.

[0103] Example 9: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0104] In this embodiment, the molding method in the film coating step of the extrusion molding of stone plastic flooring is as follows: first, pre-press and bond at 85°C and 1.0MPa for 30s, and then heat up to 125°C and 2.2MPa for 60s for pressure curing.

[0105] Everything else is exactly the same as in Example 8.

[0106] Example 10: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0107] In this embodiment, the preparation steps of the stone plastic flooring extrusion molding also include a curing step, which is set after the coating step and before the traction and cutting step; the curing step is: the product after coating and cooling is cured at a constant temperature, with the temperature controlled at 45°C, the relative humidity at 50%, and the curing time at 36h.

[0108] Everything else is exactly the same as in Example 9.

[0109] Example 11: This example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0110] In this embodiment, the preparation steps of the stone plastic flooring extrusion molding also include an edge trimming step, which is set after the traction and cutting steps and before the grooving step; the edge trimming step is: trimming the cut product to remove edge burrs and flash, and controlling the trimming amount to 0.75±0.25mm; the rest is exactly the same as in Example 10.

[0111] The stone-plastic flooring prepared in Examples 8-11 was tested, and the test results are shown in Table 3:

[0112] Table 3:

[0113] Test Indicators Example 8 Example 9 Example 10 Example 11 Tensile Strength (MPa) 18.1 18.3 18.5 18.5 Flexural Strength (MPa) 31.4 32.5 32.8 32.9 Water Absorption Dimensional Change Rate (%) 0.14 0.13 0.12 0.12 Cold Resistance (%) 91.5 92.2 93.0 93.0 surface

[0114] Comparing Example 8 with Example 7, it can be seen that in Example 7, the substrate after calendering is directly subjected to the coating step at a temperature of around 150°C. The high-temperature substrate is prone to continuous disordered movement of PVC molecular chains due to residual heat, and thermal stress is easily generated when it comes into rapid contact with the room-temperature coating layer, forming micro internal cracks or loose structural areas. In contrast, the cooling method in Example 8 first uses warm water to slowly lower the temperature of the substrate, releasing the thermal stress generated during calendering and avoiding structural defects caused by sudden cooling. Then, it uses cold water for rapid shaping, locking in a dense and stable substrate structure, thus improving the overall performance.

[0115] Comparing Example 9 with Example 8, it can be seen that Example 8 uses a single heating molding process, and air is easily left at the interface between the substrate and the wear-resistant layer and the color film during the coating process, resulting in loose interlayer bonding and the presence of tiny gaps. In contrast, the molding method of Example 9 slowly removes interlayer air under low temperature and low pressure during the pre-pressing stage, avoiding air bubble residue, while allowing the adhesive layer to initially wet the surface of the substrate and the coating layer, establishing a basic bond. Further heating activates the adhesive layer molecules, improving their fluidity and diffusion ability, promoting the penetration of adhesive layer molecules into the interface between the substrate and the coating layer, forming a stronger interlayer bonding interface, and simultaneously improving tensile strength, flexural strength, cold resistance, and water absorption dimensional change rate.

[0116] Comparing Example 10 with Example 9, it can be seen that after segmented film coating in Example 9, direct traction cutting resulted in a small amount of residual thermal and compressive stress at the interface between the film layer and the substrate, indicating minor interface defects. Example 10, by adding a curing step, provided sufficient time for the PVC molecular chains and adhesive layer molecules, avoiding structural deformation caused by stress release during subsequent use. Data shows that stress release and interlayer bonding enhancement slightly improved tensile strength and flexural strength. The elimination of interface defects resulted in better overall substrate density, further reduced moisture penetration channels, and lower water absorption dimensional change rate. Simultaneously, cold resistance was further improved.

[0117] By comparing Example 11 with Example 10, it can be seen that Example 11 adds a trimming step. Physical trimming optimizes the edge stress state without changing the substrate structure. Therefore, the data are the same, with only a slight increase in bending strength.

[0118] Comparative Example 1: This comparative example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0119] A stone-plastic flooring includes a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate, which are sequentially composited from top to bottom. The stone-plastic substrate comprises the following components by weight: 30 parts polyvinyl chloride resin, 57 parts heavy calcium carbonate, 1.75 parts calcium-zinc stabilizer, 18 parts abrasive powder, 1.6 parts internal lubricant, and 0.75 parts external lubricant.

[0120] Everything else is exactly the same as in Example 3.

[0121] Comparative Example 2: This comparative example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0122] A stone-plastic flooring includes a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate, which are sequentially composited from top to bottom. The stone-plastic substrate comprises the following components by weight: 23 parts polyvinyl chloride resin, 65 parts heavy calcium carbonate, 1.75 parts calcium-zinc stabilizer, 17 parts abrasive powder, 1.6 parts internal lubricant, and 0.75 parts external lubricant.

[0123] Everything else is exactly the same as in Example 3.

[0124] Comparative Example 3: This comparative example discloses a stone-plastic flooring and a method for preparing stone-plastic flooring by extrusion molding.

[0125] In the directional modification step of lanthanum montmorillonite prepared by modifying anionic surfactant, the reaction temperature was adjusted to 45℃, the concentration of sodium ricinoleate aqueous solution was adjusted to 0.07mol / L, and the remaining parameters and other steps were the same as in Example 3.

[0126] The stone-plastic flooring prepared in Comparative Examples 1-3 was tested, and the test results are shown in Table 4:

[0127] Table 4:

[0128] Test Indicators Comparison Example 1 Comparison Example 2 Comparison Example 3 Tensile Strength (MPa) 13.2 10.5 13.8 Flexural Strength (MPa) 22.8 32.5 23.3 Water Absorption Dimensional Change Rate (%) 0.35 0.45 0.38 Cold Resistance (%) 89.0 75.8 81.2 surface

[0129] By comparing Comparative Example 1 and Example 3, it can be seen that the excessive amount of PVC resin in Comparative Example 1 has several drawbacks. Firstly, the excessive PVC molecular chains are difficult to fully combine with the heavy calcium carbonate particles, easily forming a free PVC resin enrichment zone at the interface, which hinders stress transmission and reduces tensile strength. Secondly, the rigidity of PVC resin itself is much lower than that of heavy calcium carbonate, and the excessive addition significantly reduces the overall rigidity of the substrate, resulting in a significant decrease in flexural strength. At the same time, the hydrophilicity of the excessive PVC resin is slightly higher than that of heavy calcium carbonate, which increases the water absorption dimensional change rate and results in poor moisture resistance. The cold resistance of the excessive PVC resin is improved because the sufficient content of PVC molecular chains can alleviate brittleness at low temperatures through the flexible movement of the molecular chains.

[0130] By comparing Comparative Example 2 and Example 3, it can be seen that in Comparative Example 2, the excessive amount of heavy calcium carbonate increases the flexural strength but decreases the tensile strength, increases the water absorption dimensional change rate, and worsens the cold resistance. This is because excessive heavy calcium carbonate can easily lead to an increase in internal defects in the substrate.

[0131] By comparing Comparative Example 3 and Example 3, it can be seen that although the substrate of Example 3 was not reinforced with modified lanthanum montmorillonite, it had a stable structure and fewer internal defects. Although Comparative Example 3 added modified lanthanum montmorillonite, the modification process was affected by the change in the directional modification parameters. Excessive temperature would accelerate the decomposition of sodium ricinoleate and reduce its adsorption stability on the montmorillonite surface. Excessive concentration would easily cause montmorillonite particles to agglomerate. From the data, the tensile strength and flexural strength of Comparative Example 3 both decreased because the montmorillonite agglomerates formed stress concentration points, which disrupted the original mechanical balance. The water absorption size change rate increased, indicating that there are new water penetration channels between the agglomerated montmorillonite particles and with PVC. Due to the increase in internal defects, the cold resistance of Comparative Example 3 decreased.

[0132] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A type of stone-plastic flooring, characterized in that, The product comprises, from top to bottom, a wear-resistant layer, a polyvinyl chloride (PVC) colored film, and a stone-plastic substrate. The stone-plastic substrate comprises, by weight, 22-24 parts PVC resin, 55-59 parts heavy calcium carbonate, 1.5-2.0 parts calcium-zinc stabilizer, 18-20 parts abrasive powder, 1.5-1.7 parts internal lubricant, and 0.7-0.8 parts external lubricant. The heavy calcium carbonate is graft-modified heavy calcium carbonate, and the preparation method of the graft-modified heavy calcium carbonate is as follows: Surface activation: Under nitrogen conditions, add an initiator accounting for 0.2 wt% of the heavy calcium carbonate mass, and stir at 30-40°C and 600-800 r / min for 6-10 min. The initiator is 2,4-dioxide. A composite initiation system of lauroyl and methyl ethyl ketone peroxide; wherein the mass ratio of dilauroyl peroxide to methyl ethyl ketone peroxide in the composite initiation system is 1.0–1.2:1; graft polymerization: adding a composite of methyl methacrylate and butyl acrylate at 5 wt% of the mass of heavy calcium carbonate, stirring at 40–45°C and 800 r / min for 30 min; wherein the mass ratio of methyl methacrylate to butyl acrylate in the composite of methyl methacrylate and butyl acrylate is 6–8:3; in-situ end-capping: adding toluene diisocyanate at 0.5 wt% of the mass of heavy calcium carbonate, stirring at 30–40°C and 500–700 r / min for 10 min; cooling to 25–30°C to obtain the final product.

2. The stone-plastic flooring according to claim 1, characterized in that, The stone-plastic substrate further includes 0.5–0.8 parts of anionic surfactant-modified lanthanum montmorillonite; the preparation method of the anionic surfactant-modified lanthanum montmorillonite is as follows: Pretreatment: Sodium-based montmorillonite is vacuum dried at 55–65℃ for 2 hours, and cooled to room temperature for later use; Intercalation reaction: The pretreated sodium-based montmorillonite is added to deionized water, and the solid-liquid ratio is controlled at 1:45–55, and mixed evenly; stirring is carried out at 35℃ and 400–600 r / min for 15–25 minutes, the pH is adjusted to 5.0±0.1, 0.12 mol / L lanthanum chloride aqueous solution is added, and the reaction is continued to be stirred for 1.5–2.5 hours. After the reaction, centrifuge at 8000 r / min for 10 min, collect the precipitate, and wash it 2-3 times with deionized water; Directional modification: disperse the centrifuged lanthanum intercalated montmorillonite in deionized water, control the solid-liquid ratio at 1:35-45, and disperse evenly; stir at 38℃ and 500-700 r / min for 15-25 min, adjust the pH to 8.0±0.1, add 0.05 mol / L sodium ricinoleate aqueous solution, and continue stirring for 1-2 h; after the reaction, centrifuge at 8000 r / min for 10 min, collect the precipitate, and wash it 2-3 times with deionized water; Post-processing: Dry to constant weight at 60℃ and vacuum degree -0.08MPa, then grind and sieve to obtain the final product.

3. A method for preparing stone-plastic flooring by extrusion molding as described in claim 1 or 2, characterized in that, The process includes the following steps: Feeding and mixing: Polyvinyl chloride resin, heavy calcium carbonate, calcium-zinc stabilizer, abrasive powder, internal lubricant, and external lubricant are metered and mixed. The mixing temperature is <50℃, and the mixture is stirred at 500~700r / min for 15~20min. Extrusion: The uniformly mixed material is extruded through a twin-screw extruder with a screw diameter of 110 mm; the barrel of the extruder includes, in sequence along the material conveying direction, a feeding section, a compression section, a melting section, a metering section, and a die head; the proportions of the feeding section, compression section, melting section, metering section, and die head to the total length of the screw are 20-22%, 30-33%, 20-22%, 12-13%, and 8-10%, respectively; the temperatures of the feeding section, compression section, melting section, metering section, and die head are set to 130-140℃, 160-165℃, 170-175℃, 172-178℃, and 165-170℃, respectively. Calendering: The extruded product is pressed into shape on a calender plate, and the calendering temperature is controlled at 150-155℃; Coating: The polyvinyl chloride colored film and wear-resistant layer are heated and molded with the product after pressing, and then cooled; Traction and cutting: The cooled product is tractioned by the traction system and cut after length measurement; Grooving: The cut product is grooved to form the finished product with the required button shape.

4. The preparation method of stone-plastic flooring extrusion molding according to claim 3, characterized in that, In the extrusion step, the extruder barrel further includes a melting section cooling zone along the material conveying direction. The melting section cooling zone is located after the compression section and before the melting section. The temperature of the melting section cooling zone is set to 155-160℃. The proportions of the feed section, compression section, melting section cooling zone, melting section, metering section, and die head to the total length of the screw are 20%, 30%, 10%, 20%, 12%, and 8%, respectively.

5. The preparation method of stone-plastic flooring extrusion molding according to claim 3, characterized in that, It also includes a pre-drying step of the mixture, which is set after the feeding and mixing step and before the extrusion step; the pre-drying step of the mixture is as follows: the uniformly mixed material is vacuum dried at 80-90℃ and vacuum degree -0.06 to -0.08MPa for 2-3 hours; after drying, it is cooled to ≤40℃.

6. The preparation method of stone-plastic flooring extrusion molding according to claim 3, characterized in that, It also includes a calender cooling and shaping step, which is set after the calendering step and before the coating step; the calender cooling and shaping step is as follows: the calendered product is cooled in stages, first by water cooling at 60-70℃ for 3-5 minutes, and then by water cooling at 25-30℃ for 2-3 minutes.

7. The method for preparing stone-plastic flooring by extrusion molding according to any one of claims 3-6, characterized in that, In the coating step, the forming method is as follows: first, pre-press and bond at 80-90℃ and 0.8-1.2MPa for 30s, then heat to 120-130℃ and pressurize and cure at 2.0-2.5MPa for 60s.

8. The preparation method of stone-plastic flooring extrusion molding according to claim 3, characterized in that, It also includes a curing step, which is set after the coating step and before the traction and cutting step; the curing step is: to cure the coated and cooled product at a constant temperature, controlling the temperature at 40-50℃, the relative humidity at 40-60%, and the curing time at 24-48h.

9. The preparation method of stone-plastic flooring extrusion molding according to claim 3, characterized in that, It also includes a trimming step, which is set after the traction and cutting steps and before the grooving step; the trimming step is to trim the cut product to remove edge burrs and flash, and control the trimming amount to 0.5-1mm.

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