A production process of WPC molded floor

Abstract

This invention relates to the field of molded flooring technology, specifically to a production process for WPC molded flooring, comprising the steps of raw material pretreatment, blending and granulation, extrusion molding, hot pressing and shaping, surface treatment, cooling and cutting, post-treatment, and quality inspection. This invention significantly improves the performance of WPC molded flooring by further refining the raw material formulation and preparation process based on existing technology. Specifically, regarding the function of the raw materials, this invention uses polyvinyl chloride resin as the matrix material to provide the flooring with basic molding properties and mechanical strength; while calcium carbonate filler increases the flooring's hardness and dimensional stability, reducing production costs; attapulgite powder imparts a natural texture and feel to the flooring. The specially treated and secondary modified attapulgite powder forms a multifunctional interface layer on its surface, greatly improving its compatibility and bonding strength with polyvinyl chloride resin.

Description

Technical Field

[0001] This invention relates to the field of molded flooring technology, specifically to a production process for WPC molded flooring. Background Technology

[0002] WPC (Wood-Plastic Composite) molded flooring is a new type of environmentally friendly flooring material made by using polyvinyl chloride (PVC) resin as a matrix and filling it with various materials such as attapulgite powder and calcium carbonate through a molding process.

[0003] Because WPC molded flooring combines the natural texture of wood with the durability of plastic, it is widely used in home decoration, commercial spaces, and public buildings. In home decoration, the widespread use of WPC molded flooring is mainly due to its easier cleaning and maintenance; in commercial spaces such as shopping malls and hotels, its wear-resistant and scratch-resistant properties meet the needs of these spaces; and in public buildings such as schools and hospitals, the environmental friendliness and anti-slip properties of WPC molded flooring help ensure the safety and health of personnel.

[0004] However, existing WPC molded flooring production technology has several technical shortcomings. At the raw material level, the bonding performance between attapulgite powder and matrix materials such as PVC resin is poor, resulting in an unstable internal structure and a tendency for delamination and cracking. The strong polarity of attapulgite powder also hinders its compatibility with the non-polar PVC resin, making it difficult to form a strong interfacial bond. In terms of production processes, traditional methods easily lead to dimensional deviations and poor surface flatness. Regarding product performance, the wear resistance and surface hardness of existing WPC molded flooring are insufficient to meet the demands of high-end applications.

[0005] As people's demands for product quality increase, they have set higher standards for the overall performance of flooring. Flooring produced using traditional processes is gradually becoming unable to meet the needs of market development.

[0006] The present invention proposes a production process for WPC molded flooring, which is intended to solve the above-mentioned technical defects. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a manufacturing process for WPC molded flooring.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A manufacturing process for WPC molded flooring includes, in sequence, raw material pretreatment, blending and granulation, extrusion molding, hot pressing and shaping, surface treatment, cooling and cutting, post-treatment and quality inspection steps;

[0010] The raw material pretreatment step is as follows: weigh and mix polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer, and stearic acid in a certain proportion.

[0011] The blending and granulation step is as follows: the raw materials in the pretreatment step are mixed sequentially by a high-speed mixer and a low-speed mixer, and then granulated by a twin-screw extruder;

[0012] The extrusion molding step is as follows: the granulated material is extruded through a single screw extruder and molded into a floor substrate through a die;

[0013] The hot pressing and shaping step is as follows: the floor substrate, the printed color film decorative layer, and the PVC wear-resistant layer are hot-pressed together in a hot press.

[0014] The surface treatment steps are as follows: UV coating and embossing are performed sequentially.

[0015] The cooling and cutting step is as follows: after cooling by a combination of air cooling and water cooling, the cutting machine is used to cut the material according to the specified dimensions.

[0016] The post-processing step is to place the cut floorboards in a constant temperature and humidity environment for aging.

[0017] The quality inspection steps are as follows: the flooring is inspected, and after passing the inspection, it is packaged and put into storage;

[0018] The process includes a pre-forming step after the blending and granulation step, where the blended and granulated material is pre-pressed through a pre-forming mold to form a floor blank; and a surface hardening step after the surface treatment step, where the floor is immersed in a hardening liquid containing nano-silica to improve surface hardness.

[0019] As a further technical solution, the raw material pretreatment step is as follows: polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer, and stearic acid are weighed and mixed in a mass ratio of 30-40:40-50:5-10:5-8:2-4:1-3, wherein the K value of polyvinyl chloride resin is 60-65.

[0020] As a further technical solution, the attapulgite powder needs to be soaked in an ethanol solution of 3-5 wt% silane coupling agent for 2-3 hours. The silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane. After soaking, it is taken out and dried at 80-90℃ until the water content is less than 1%. Then it is pulverized by an air jet mill to a particle size of 80-120 mesh. Finally, it is graded and screened by a vibrating screen to obtain primary modified attapulgite powder that passes through 80 mesh for later use.

[0021] As a further technical solution, the primary modified attapulgite powder is subjected to secondary modification: the primary modified attapulgite powder is placed in a dopamine hydrochloride Tris-HCl buffer solution with a concentration of 2-4wt%, and stirred at room temperature for 12-15h. After the reaction, it is washed multiple times with deionized water until neutral, and then vacuum dried at 60-70℃ for 8-10h. The dried attapulgite powder is then subjected to plasma treatment with a power of 80-100W and a treatment time of 3-5min. The treatment gas is neon. Through dopamine self-polymerization and plasma treatment, a multifunctional interface layer is formed on the surface of the attapulgite powder, which further improves the bonding performance of attapulgite powder with other raw materials.

[0022] The pH of the dopamine hydrochloride Tris-HCl buffer solution is 8.5-8.8.

[0023] As a further technical solution, the blending and granulation step is as follows: the mixing conditions of the high-speed mixer are 800-1000 r / min, the temperature is raised to 110-120℃, and the mixing time is 5-8 min; the mixing conditions of the low-speed mixer are 200-300 r / min, the temperature is lowered to 40-50℃, and the mixing time is 3-5 min; the temperature of the twin-screw extruder is 160-170℃ in zone 1, 170-180℃ in zone 2, 180-190℃ in zone 3, 190-200℃ in zone 4, 200-210℃ in zone 5, the die head temperature is 200-205℃, and the screw speed is 180-220 r / min.

[0024] As a further technical solution, the extrusion molding step is as follows: the temperature of the feeding section of the single screw extruder is 160-170℃, the temperature of the compression section is 170-180℃, the temperature of the metering section is 180-190℃, the temperature of the die head is 190-200℃, and the extrusion speed is 15-20m / min.

[0025] As a further technical solution, the hot pressing and shaping step involves raising the hot pressing temperature from room temperature to 150-158℃ at a heating rate of 5-8℃ / min, the pressure being 8-10MPa, the holding time being 10-12min, and then lowering the temperature to room temperature at a cooling rate of 6-8℃ / min after the holding time is completed.

[0026] As a further technical solution, in the surface treatment step, the UV coating is applied by spray coating, the coating thickness is controlled at 0.08-0.12mm, the UV paint used is polyurethane acrylate UV paint, the UV lamp power in the UV curing machine is 120-150W, the curing temperature is 75-80℃, and the curing speed is 8-12m / min; during the embossing process, the embossing roller temperature is 120-130℃, the pressure is 3-5MPa, the embossing roller pattern depth is 0.1-0.3mm, and the embossing speed is matched with the extrusion speed with an error not exceeding ±3%.

[0027] As a further technical solution, the cooling and cutting step involves an air cooling speed of 8-12 m / s, a water cooling temperature of 15-20℃, and a cutting accuracy controlled within ±0.2 mm.

[0028] As a further technical solution, in the preforming step, the pre-compression pressure is 3-5 MPa, the temperature is 130-136℃, and the pre-compression time is 1-2 min;

[0029] In the surface hardening treatment step, the hardening liquid containing nano-silica is composed of 5-5.8% nano-silica by mass, 2-2.5% silane coupling agent KH570, 0.7-0.8% dispersant sodium polyacrylate, and the balance deionized water. The average particle size of the nano-silica is 20-30nm. It is prepared by stirring evenly, the impregnation time is 15-20min, and the temperature of the hardening liquid is 40-50℃.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] This invention significantly improves the performance of WPC molded flooring by further improving the raw material formulation and preparation process based on existing technology, as detailed below:

[0032] In terms of raw material functionality, this invention uses polyvinyl chloride (PVC) resin as the matrix material, providing the flooring with basic molding properties and mechanical strength; while calcium carbonate filler increases the flooring's hardness and dimensional stability, reducing production costs. Attapulgite powder, after primary and secondary modification, forms a multifunctional interface layer on its surface, greatly improving its compatibility and bonding strength with PVC resin. Silane coupling agent treatment grafts organic groups onto the surface of the attapulgite powder, reducing surface polarity and enhancing its affinity with PVC resin; dopamine self-polymerization and plasma treatment further introduce active groups onto the surface of the attapulgite powder, forming a dense interface layer, enabling the attapulgite powder and PVC resin to bond more tightly during blending, thus improving the overall mechanical properties of the flooring. Dioctyl phthalate (DOP) acts as a plasticizer, reducing the melting temperature and melt viscosity of polyvinyl chloride resin and improving its flexibility and processing performance; calcium-zinc composite stabilizer improves the thermal stability of polyvinyl chloride resin and prevents decomposition during processing; stearic acid acts as a lubricant, reducing friction between materials during processing and improving fluidity.

[0033] In the preparation process, the strictly controlled mixing conditions, extrusion temperature, and speed during the blending and granulation steps ensure thorough and uniform mixing of the raw materials, forming a stable material system that lays the foundation for subsequent molding. High-speed mixing rapidly heats and initially disperses the materials, while low-speed mixing lowers the material temperature and achieves more uniform mixing. The temperature gradient setting of the twin-screw extruder ensures that the materials reach their optimal melting and plasticizing state at different stages. Precise temperature and speed control during extrusion molding guarantees the dimensional accuracy and surface quality of the flooring substrate. During hot pressing, precise temperature, pressure, and time control ensure a strong bond between the flooring substrate and the decorative and wear-resistant layers, forming a stable layered structure that improves the overall strength and wear resistance of the flooring.

[0034] In the surface treatment steps, UV coating and embossing further enhance the performance of the flooring. The UV coating creates a wear-resistant and stain-resistant coating, protecting the flooring surface and extending its lifespan; embossing gives the flooring a unique texture and feel, while increasing surface friction and improving slip resistance. The combination of air and water cooling during the cooling and cutting process quickly and evenly lowers the flooring temperature, preventing deformation due to temperature changes and ensuring cutting accuracy. The pre-forming step initially shapes the material, reducing the pressure and time required for subsequent hot pressing and setting, improving production efficiency, and simultaneously making the internal structure of the flooring denser. The surface hardening treatment involves impregnation with a hardening liquid containing nano-silica. The nano-silica fills the pores on the flooring surface and, with the help of silane coupling agents and dispersants, forms a strong bond with the flooring surface, significantly improving surface hardness and wear resistance. Attached Figure Description

[0035] Figure 1 This is a bar chart of wear resistance test results from the present invention. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] This invention provides a production process for WPC molded flooring, which includes, in sequence, raw material pretreatment, blending and granulation, extrusion molding, hot pressing and shaping, surface treatment, cooling and cutting, post-treatment and quality inspection steps.

[0038] In the raw material pretreatment step, polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer, and stearic acid are weighed and mixed in a specific ratio. Specifically, the polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer, and stearic acid are weighed and mixed in a mass ratio of 30-40:40-50:5-10:5-8:2-4:1-3, where the K value of the polyvinyl chloride resin is 60-65. The attapulgite powder needs to be soaked in a 3-5wt% silane coupling agent ethanol solution for 2-3 hours. The silane coupling agent used is γ-methacryloyloxypropyltrimethoxysilane. After soaking, it is removed and dried at 80-90℃ until the moisture content is less than 1%. Then, it is pulverized to a particle size of 80-120 mesh using an air jet mill, and finally, it is graded and screened through a vibrating screen to obtain primary modified attapulgite powder passing through 80 mesh for later use. Secondary modification of the primary modified attapulgite powder: The primary modified attapulgite powder is placed in a 2-4 wt% dopamine hydrochloride Tris-HCl buffer solution (pH=8.5-8.8), and stirred for 12-15 h at room temperature. After the reaction, it is washed several times with deionized water until neutral, and then vacuum dried at 60-70℃ for 8-10 h. The dried attapulgite powder is then subjected to plasma treatment with a power of 80-100 W and a treatment time of 3-5 min. The treatment gas is neon.

[0039] In the blending and granulation step, the raw materials from the pretreatment step are sequentially mixed in a high-speed mixer and a low-speed mixer, and then granulated using a twin-screw extruder. The mixing conditions for the high-speed mixer are 800-1000 r / min, temperature rise to 110-120℃, and mixing for 5-8 min; the mixing conditions for the low-speed mixer are 200-300 r / min, temperature drop to 40-50℃, and mixing for 3-5 min; the twin-screw extruder has the following temperature zones: Zone 1: 160-170℃, Zone 2: 170-180℃, Zone 3: 180-190℃, Zone 4: 190-200℃, Zone 5: 200-210℃, Die head temperature: 200-205℃, and Screw speed: 180-220 r / min.

[0040] In the extrusion molding step, the granulated material is extruded through a single-screw extruder and shaped into a flooring substrate through a die. The temperature of the single-screw extruder is 160-170℃ in the feed section, 170-180℃ in the compression section, 180-190℃ in the metering section, and 190-200℃ in the die head. The extrusion speed is 15-20 m / min.

[0041] The hot-pressing and shaping step involves hot-pressing the flooring substrate with the printed color film decorative layer and the PVC wear-resistant layer in a hot press. The hot-pressing temperature is increased from room temperature to 150-158℃ at a rate of 5-8℃ / min, the pressure is 8-10MPa, the holding time is 10-12min, and after the holding time is completed, the temperature is reduced to room temperature at a rate of 6-8℃ / min.

[0042] The surface treatment steps involve sequentially applying a UV coating and embossing. The UV coating is applied using a curtain coating method, with a coating thickness controlled between 0.08-0.12 mm. The UV paint used is a polyurethane acrylate-based UV paint. The UV curing machine uses a UV lamp with a power of 120-150 W, a curing temperature of 75-80℃, and a curing speed of 8-12 m / min. During embossing, the embossing roller temperature is 120-130℃, the pressure is 3-5 MPa, and the embossing roller pattern depth is 0.1-0.3 mm.

[0043] UV paint purchased from Zhanxin: ebecryl 8807 aliphatic polyurethane acrylate UV curing resin.

[0044] The cooling and cutting process involves a combination of air cooling and water cooling, followed by cutting to the specified dimensions using a cutting machine. The air cooling velocity is 8-12 m / s, and the water cooling temperature is 15-20℃.

[0045] Following the blending and granulation step, a preforming step is performed where the blended and granulated material is pre-pressed through a preforming mold to form a floor blank. The pre-pressing pressure is 3-5 MPa, the temperature is 130-136℃, and the pre-pressing time is 1-2 min.

[0046] Following the surface treatment step, a surface hardening treatment step is added, in which the floor is immersed in a hardening liquid containing nano-silica to improve surface hardness. The hardening liquid containing nano-silica consists of 5-5.8% nano-silica by mass, 2-2.5% silane coupling agent KH570, 0.7-0.8% dispersant sodium polyacrylate, and the balance deionized water. The average particle size of the nano-silica is 20-30 nm. It is prepared by stirring until homogeneous, with an immersion time of 15-20 minutes and a hardening liquid temperature of 40-50℃.

[0047] The post-processing step involves aging the cut flooring in a constant temperature and humidity environment.

[0048] The quality inspection process involves testing the flooring, including aspects such as appearance, dimensional accuracy, abrasion resistance, and fire resistance. Once qualified, the flooring is packaged and stored.

[0049] The raw materials or equipment used in the following examples are all commercially available or self-made. The calcium-zinc composite stabilizer was purchased from Shandong Ruifeng Polymer, RF-CZ100. Example 1

[0050] Raw material pretreatment: Weigh 30 parts polyvinyl chloride resin (K value 60), 40 parts calcium carbonate, 5 parts attapulgite powder, 5 parts dioctyl phthalate, 2 parts calcium-zinc composite stabilizer, and 1 part stearic acid. Soak the attapulgite powder in a 3wt% ethanol solution of silane coupling agent (γ-methacryloyloxypropyltrimethoxysilane) for 2 hours. After soaking, dry at 80℃ until the moisture content is less than 1%, then pulverize to 80 mesh using an air jet mill and sieve through a vibrating screen. Place the sieved attapulgite powder in a 2wt% Tris-HCl dopamine hydrochloride buffer solution (pH=8.5), stir at room temperature for 12 hours, wash with deionized water until neutral, vacuum dry at 60℃ for 8 hours, and then plasma treat with neon gas at 80W for 3 minutes.

[0051] Blending and granulation: The pretreated raw materials are fed into a high-speed mixer and mixed at 800 rpm. The temperature is raised to 110°C and mixed for 5 minutes. Then, the mixture is transferred to a low-speed mixer and mixed at 200 rpm. The temperature is lowered to 40°C and mixed for 3 minutes. After that, the mixture is granulated using a twin-screw extruder with the following temperatures: Zone 1: 160°C, Zone 2: 170°C, Zone 3: 180°C, Zone 4: 190°C, Zone 5: 200°C, Die head temperature: 200°C, Screw speed: 180 rpm.

[0052] Extrusion molding: The granulated material is extruded through a single screw extruder with a feed section temperature of 160℃, a compression section temperature of 170℃, a metering section temperature of 180℃, a die head temperature of 190℃, and an extrusion speed of 15m / min to form a flooring substrate.

[0053] Preforming: The blended and granulated material is pre-pressed through a preforming mold at a pressure of 3 MPa, a temperature of 130°C, and a pre-pressing time of 1 min to form a floor blank.

[0054] Hot pressing and shaping: The floor blank, printed color film decorative layer and PVC wear-resistant layer are hot-pressed together in a hot press. The hot pressing temperature is increased from room temperature to 150℃ at 5℃ / min, the pressure is 8MPa, the holding time is 10min, and after the holding time is completed, the temperature is reduced to room temperature at 6℃ / min.

[0055] Surface treatment: The UV coating is applied by spray coating, with the coating thickness controlled at 0.08mm. The UV paint used is polyurethane acrylate UV paint. The UV curing machine has a UV lamp power of 120W, a curing temperature of 75℃, and a curing speed of 8m / min. During embossing, the embossing roller temperature is 120℃, the pressure is 3MPa, and the embossing roller pattern depth is 0.1mm.

[0056] Surface hardening treatment: Prepare a hardening solution containing nano-silica, wherein the mass fraction of nano-silica is 5%, the mass fraction of silane coupling agent KH570 is 2%, the mass fraction of dispersant sodium polyacrylate is 0.7%, and the balance is deionized water. The average particle size of the nano-silica is 20nm. Stir well. Immerse the floor in the hardening solution for 15 minutes at a temperature of 40℃.

[0057] Cooling and cutting: After cooling by a combination of air cooling (wind speed 8m / s) and water cooling (temperature 15℃), the product is cut to the specified dimensions using a cutting machine.

[0058] Post-processing: Place the cut flooring in a constant temperature and humidity environment of 25℃ and 50% to age.

[0059] Quality inspection: The appearance, dimensional accuracy, wear resistance, and fire resistance of the flooring are inspected. Once qualified, the flooring is packaged and put into storage. Example 2

[0060] Raw material pretreatment: Weigh out 35 parts polyvinyl chloride resin (K value 63), 45 parts calcium carbonate, 7 parts attapulgite powder, 6 parts dioctyl phthalate, 3 parts calcium-zinc composite stabilizer, and 2 parts stearic acid. The attapulgite powder was treated in the same way as in Example 1, but the concentration of the silane coupling agent ethanol solution was 4wt%, the soaking time was 2.5 h, and it was then pulverized to 100 mesh. The concentration of dopamine hydrochloride Tris-HCl buffer solution was 3wt%, pH=8.6, the reaction time was 13 h, the vacuum drying temperature was 65℃, the plasma treatment power was 90W, and the treatment time was 4 min.

[0061] Blending and granulation: A high-speed mixer is used to mix at 900 rpm, heating to 115°C for 6 minutes; a low-speed mixer is used to mix at 250 rpm, cooling to 45°C for 4 minutes. The twin-screw extruder has the following temperatures: Zone 1: 165°C, Zone 2: 175°C, Zone 3: 185°C, Zone 4: 195°C, Zone 5: 205°C, Die head temperature: 203°C, Screw speed: 200 rpm.

[0062] Extrusion molding: single screw extruder feed section temperature 165℃, compression section temperature 175℃, metering section temperature 185℃, die head temperature 195℃, extrusion speed 17m / min.

[0063] Pre-forming: Pre-compression pressure 4MPa, temperature 133℃, pre-compression time 1.5min.

[0064] Hot pressing: The hot pressing temperature is increased from room temperature to 154℃ at a rate of 6℃ / min, the pressure is 9MPa, the holding time is 11min, and the cooling rate is 7℃ / min.

[0065] Surface treatment: UV coating thickness 0.1mm, UV lamp power 130W, curing temperature 77℃, curing speed 10m / min; embossing roller temperature 125℃, pressure 4MPa, pattern depth 0.2mm.

[0066] Surface hardening treatment: The hardening solution contains 5.4% nano-silica by mass, 2.2% silane coupling agent KH570 by mass, and 0.75% sodium polyacrylate dispersant by mass. The average particle size of the nano-silica is 25 nm. The impregnation time is 17 min and the temperature of the hardening solution is 45 °C.

[0067] Cooling and cutting: air cooling speed 10m / s, water cooling temperature 17℃.

[0068] Post-processing and quality inspection: Same as in Example 1. Example 3

[0069] Raw material pretreatment: Weigh 40 parts polyvinyl chloride resin (K value 65), 50 parts calcium carbonate, 10 parts attapulgite powder, 8 parts dioctyl phthalate, 4 parts calcium-zinc composite stabilizer, and 3 parts stearic acid. The attapulgite powder is soaked in a 5wt% ethanol solution of silane coupling agent for 3 hours, then pulverized to 120 mesh. A 4wt% Tris-HCl buffer solution of dopamine hydrochloride, pH 8.8, is used for the reaction for 15 hours. Vacuum drying is performed at 70℃, and plasma treatment is carried out at 100W for 5 minutes.

[0070] Blending and granulation: High-speed mixer at 1000 rpm, heating to 120℃, mixing for 8 minutes; low-speed mixer at 300 rpm, cooling to 50℃, mixing for 5 minutes. Twin-screw extruder temperatures: Zone 1 170℃, Zone 2 180℃, Zone 3 190℃, Zone 4 200℃, Zone 5 210℃, die head temperature 205℃, screw speed 220 rpm.

[0071] Extrusion molding: single screw extruder feed section temperature 170℃, compression section temperature 180℃, metering section temperature 190℃, die head temperature 200℃, extrusion speed 20m / min.

[0072] Pre-forming: Pre-compression pressure 5MPa, temperature 136℃, pre-compression time 2min.

[0073] Hot pressing: The hot pressing temperature is increased from room temperature to 158℃ at a rate of 8℃ / min, the pressure is 10MPa, the holding time is 12min, and the cooling rate is 8℃ / min.

[0074] Surface treatment: UV coating thickness 0.12mm, UV lamp power 150W, curing temperature 80℃, curing speed 12m / min; embossing roller temperature 130℃, pressure 5MPa, pattern depth 0.3mm.

[0075] Surface hardening treatment: The hardening solution contains 5.8% nano-silica by mass, 2.5% silane coupling agent KH570 by mass, and 0.8% sodium polyacrylate dispersant by mass. The average particle size of the nano-silica is 30 nm. The impregnation time is 20 min and the temperature of the hardening solution is 50 °C.

[0076] Cooling and cutting: air cooling speed 12m / s, water cooling temperature 20℃.

[0077] Post-processing and quality inspection: Same as in Example 1.

[0078] Comparative Example 1

[0079] WPC molded flooring was prepared according to the method in Example 1, except that the raw material pretreatment step did not involve soaking the attapulgite powder in silane coupling agent or secondary modification, and the original attapulgite powder was used directly.

[0080] Raw material pretreatment: Weigh 30 parts of polyvinyl chloride resin (K value 60), 40 parts of calcium carbonate, 5 parts of attapulgite powder, 5 parts of dioctyl phthalate, 2 parts of calcium-zinc composite stabilizer, and 1 part of stearic acid. The attapulgite powder was not pretreated.

[0081] Subsequent steps: blending and granulation, extrusion molding, preforming, hot pressing and shaping, surface treatment, surface hardening treatment, cooling and cutting, post-treatment, and quality inspection are all the same as in Example 1.

[0082] Comparative Example 2

[0083] WPC molded flooring was prepared in accordance with the method of Example 1, except that no surface hardening treatment was performed.

[0084] Comparative Example 3

[0085] WPC molded flooring was prepared according to the method in Example 1, except that no pre-forming treatment was performed.

[0086] Performance testing

[0087] Abrasion resistance test

[0088] The flooring samples from the examples and comparative examples were tested according to GB / T1768-2006 "Determination of Abrasion Resistance of Paints and Varnishes - Rotating Rubber Grinding Wheel Method". The abrasion rate was set to 2000 revolutions, and the abrasion amount was recorded. The test results are as follows:

[0089] Table 1

[0090]

[0091] As can be seen from the test results in Table 1, the flooring prepared according to the embodiments of the present invention has significantly improved wear resistance.

[0092] Surface hardness test

[0093] The surface hardness of the flooring in the examples and comparative examples was tested according to GB / T6739-2017 "Determination of Hardness of Paints and Varnishes by Pencil Method". The pencil hardness test method was used, and the hardness level was recorded. The test results are as follows:

[0094] Table 2

[0095]

[0096] As can be seen from Table 2, the floor surface prepared by the embodiments of the present invention has higher hardness. The increase in hardness can further broaden the application fields and service life of the floor.

[0097] Dimensional stability test

[0098] The floor samples from the examples and comparative examples were placed in an environment with a temperature of 50°C and a relative humidity of 80% for 7 days. The changes in the length, width, and thickness of the floor samples were measured, and the test results are as follows:

[0099] Table 3

[0100]

[0101] As can be seen from Table 3, the flooring prepared in the embodiments of the present invention has excellent dimensional stability.

[0102] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not describe all details exhaustively, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification.

Claims

1. A process for the production of WPC profiled flooring, characterized in that, Comprise the following steps in turn: Raw material pretreatment, blending granulation, extrusion molding, hot pressing, surface treatment, cooling cutting, post-processing and quality detection steps; The raw material pretreatment step is to weigh and mix polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer and stearic acid in proportion; The blending granulation step is to mix the raw materials in the pretreatment step in turn by a high-speed mixer and a low-speed mixer, and then granulate by a double-screw extruder; The extrusion molding step is to extrude the granulated material by a single-screw extruder and form a floor base material by a mold; The hot pressing step is to hot press the floor base material with a printed color film decoration layer and a PVC wear-resistant layer in a hot press; The surface treatment step is to perform UV coating and embossing treatment in turn; The cooling cutting step is to cut the floor according to the size after combined cooling by air cooling and water cooling; The post-processing step is to age the cut floor in a constant temperature and humidity environment; The quality detection step is to detect the floor and package it into the warehouse after passing the detection; Wherein, a preforming step is arranged after the blending granulation step, and the blended and granulated material is pre-pressed by a preforming mold to form a floor blank; A surface hardening treatment step is added after the surface treatment step, and the floor is immersed in a hardening liquid containing nano silicon dioxide to improve the surface hardness; The raw material pretreatment step is to weigh and mix polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer and stearic acid in proportion, wherein the mass ratio of polyvinyl chloride resin, calcium carbonate, attapulgite powder, dioctyl phthalate, calcium-zinc composite stabilizer and stearic acid is 30-40:40-50:5-10:5-8:2-4:1-3, and the K value of the polyvinyl chloride resin is 60-65; The attapulgite powder is first soaked in a silane coupling agent ethanol solution with a concentration of 3-5wt% for 2-3h, the silane coupling agent is γ-methacryloxypropyl trimethoxysilane, after soaking, it is taken out and dried at 80-90℃ until the water content is less than 1%, then it is crushed by an air flow crusher to a particle size of 80-120 mesh, and finally it is classified and screened by a vibrating screen to obtain a first modified attapulgite powder with a size of 80 mesh; The first modified attapulgite powder is secondarily modified: the first modified attapulgite powder is placed in a dopamine hydrochloride Tris-HCl buffer solution with a concentration of 2-4wt%, stirred and reacted at room temperature for 12-15h, after the reaction is completed, it is washed with deionized water until it is neutral, and then it is vacuum dried at 60-70℃ for 8-10h, the dried attapulgite powder is then subjected to plasma treatment, the power of the plasma treatment is 80-100W, the treatment time is 3-5min, and the treatment gas is neon gas; The pH of the dopamine hydrochloride Tris-HCl buffer solution is 8.5-8.

8.

2. The process for the production of WPC laminate flooring according to claim 1, characterized in that, The blending granulation step is in the middle, the high-speed mixer mixing condition is 800-1000r / min, temperature rises to 110-120℃, mixes 5-8min; The low-speed mixer mixing condition is 200-300r / min, temperature drops to 40-50℃, mixes 3-5min; The temperature of double screw extruder region is 160-170℃, the temperature of two region is 170-180℃, the temperature of three region is 180-190℃, the temperature of four region is 190-200℃, the temperature of five region is 200-210℃, the head temperature is 200-205℃, and the screw rotation speed is 180-220r / min.

3. The process for producing WPC profiled flooring according to claim 1, characterized in that, The extrusion molding step is in the middle, the temperature of single screw extruder feeding section is 160-170℃, the temperature of compression section is 170-180℃, the temperature of metering section is 180-190℃, and the temperature of die head is 190-200℃, and the extrusion speed is 15-20m / min.

4. The process for producing WPC profiled flooring according to claim 1, characterized in that, The hot pressing shaping step is in the middle, the hot pressing temperature rises from room temperature to 150-158℃ at the heating rate of 5-8℃ / min, the pressure is 8-10MPa, the pressure holding time is 10-12min, and after the pressure holding, the temperature drops to room temperature at the cooling rate of 6-8℃ / min.

5. The process for producing WPC profiled flooring according to claim 1, characterized in that, The surface treatment step is in the middle, the UV coating is coated by spraying, the coating thickness is controlled to be 0.08-0.12mm, the used UV paint is polyurethane acrylate UV paint, the power of ultraviolet lamp tube in UV curing machine is 120-150W, the curing temperature is 75-80℃, and the curing speed is 8-12m / min; When embossing, the embossing roller temperature is 120-130℃, the pressure is 3-5MPa, and the embossing roller pattern depth is 0.1-0.3mm.

6. The process for producing WPC profiled flooring according to claim 1, characterized in that, In the cooling and cutting step, the air cooling wind speed is 8-12m / s, and the water cooling temperature is 15-20℃.

7. The process for producing WPC profiled flooring according to claim 1, characterized in that, In the preforming step, the pre-pressing pressure is 3-5MPa, the temperature is 130-136℃, and the pre-pressing time is 1-2min. In the surface hardening treatment step, the hardening liquid containing nano silicon dioxide is composed of 5-5.8% of nano silicon dioxide, 2-2.5% of silane coupling agent KH570, 0.7-0.8% of dispersant sodium polyacrylate, and the balance of deionized water, the average particle size of nano silicon dioxide is 20-30nm, and the hardening liquid temperature is 40-50℃.

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