Electrostatic dust control geomembrane and its use

Abstract

This application discloses an electrostatic dustproof geomembrane and its application, belonging to the field of geomembrane technology. The electrostatic dustproof geomembrane includes a geomembrane body and an electrostatic dustproof membrane. The electrostatic dustproof membrane covers the surface of the welded overlap area of ​​the geomembrane body, and the width of the welded overlap area is 8-15 cm. The electrostatic dustproof membrane is bonded to the welded surface of the geomembrane body primarily through electrostatic adsorption, supplemented by micro-heating. The electrostatic dustproof geomembrane provided by this application achieves long-term electrostatic adsorption through the electrostatic dustproof membrane, ensuring a tight bond with the welded surface of the geomembrane and easy peeling at high temperatures without leaving any residue. It effectively blocks dust accumulation in the welded overlap area, ensuring welding quality, preventing seepage failure, facilitating construction, and is suitable for various fields such as environmental protection seepage prevention, water conservancy and hydropower, significantly improving project durability and reducing rework costs.

Description

Technical Field

[0001] This application relates to an electrostatic dustproof geomembrane and its application, belonging to the field of geomembrane technology. Background Technology

[0002] Geomembrane, a geosynthetic material with seepage prevention and isolation functions, is widely used in environmental protection seepage prevention, water conservancy and hydropower, municipal engineering and other fields. Its construction quality directly determines the seepage prevention effect and service life of the project. In the process of geomembrane construction, welding overlap is the core process. It is usually necessary to reserve a welding overlap area with a width of 8-15cm. Adjacent geomembranes are connected by hot melt welding to ensure the integrity of the overall seepage prevention.

[0003] However, during the production, transportation, storage, and on-site laying of existing geomembranes, the surface of the welded overlap area is extremely prone to adsorbing pollutants such as dust, sand, and debris from the air. These pollutants can seriously affect the welding quality. During hot-melt welding, pollutants can hinder the fusion bonding of the geomembrane substrate, leading to defects such as incomplete welds, missed welds, and insufficient peel strength at the weld joint. This can result in seepage prevention failure, increase the cost of rework and safety hazards, and is one of the core problems that urgently need to be solved in the current application of geomembranes.

[0004] To address the dust accumulation problem in the welding overlap area, existing technologies often employ methods such as covering with dustproof cloth or plastic film for protection. However, these methods have significant drawbacks: the dustproof cloth or plastic film does not adhere tightly to the welding surface of the geomembrane, making it easy for it to be blown away or fall off by the wind, resulting in unstable dustproof performance. Furthermore, gaps can easily form between the cloth and the geomembrane after application, which can actually attract more dust. Additionally, before welding, the protective layer needs to be manually peeled off, which can easily leave residue. This residue can further affect the welding quality, increasing construction procedures and labor costs.

[0005] Existing technologies also employ adhesives for bonding and covering the geomembrane. While this provides a tight bond and prevents it from being blown away or detached by wind, the working environment for geomembranes inevitably involves high temperatures. Under high temperatures, the geomembrane is difficult to remove, and after removal, adhesive residue or fragments are easily left, contaminating the welding surface and affecting the weld strength. Therefore, developing an electrostatic dustproof geomembrane that can achieve long-term dustproofing in the welding overlap area, adhere tightly to the geomembrane, be easily peeled off at high temperatures, and leave no residue, and solve the problems of poor dustproofing effect, insufficient fit, and affected welding quality in existing technologies, has become a technical challenge that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the aforementioned issues, an electrostatic dustproof geomembrane and its application are provided. The electrostatic dustproof geomembrane provided in this application achieves long-term electrostatic adsorption by setting an electrostatic dustproof membrane. It adheres tightly to the welding surface of the geomembrane and is easily peeled off at high temperatures without leaving any residue. Overall, it can effectively block dust accumulation in the welding overlap area, ensuring welding quality, avoiding seepage failure, and is easy to construct. It is suitable for multiple fields such as environmental protection seepage prevention, water conservancy and hydropower, significantly improving the durability of the project and reducing rework costs.

[0007] According to one aspect of this application, an electrostatic dustproof geomembrane is provided, comprising a geomembrane body and an electrostatic dustproof membrane, wherein the electrostatic dustproof membrane covers the surface of the welded overlap area of ​​the geomembrane body, the width of the welded overlap area being 8-15 cm; the surface of the welded overlap area of ​​the geomembrane body is subjected to corona treatment, and the electrostatic dustproof membrane is subjected to high-voltage electret treatment; the electrostatic dustproof membrane is bonded to the welded surface of the geomembrane body by means of electrostatic adsorption as the main method and micro-heat-assisted bonding as a secondary method.

[0008] Optionally, by setting up an electrostatic dustproof membrane, areas prone to dust accumulation can be precisely covered, effectively blocking the adhesion of dust and debris. Corona treatment enhances the surface activity of the geomembrane welding surface, and high-voltage electret treatment enables the electrostatic dustproof membrane to acquire a stable electrostatic charge. The two achieve close adhesion through electrostatic adsorption of opposite charges, and micro-heating further enhances the adhesion effect, preventing detachment, ensuring the quality of subsequent hot-melt welding, avoiding incomplete welding and missed welding, improving the geomembrane's seepage prevention integrity, and reducing construction rework costs.

[0009] Optionally, the geomembrane body, by weight, comprises 85-100 parts of modified resin matrix, 2-5 parts of maleic anhydride-grafted PE, 0.3-0.5 parts of antioxidant, 0.2-0.4 parts of light stabilizer, and 2-3 parts of carbon black. The modified resin matrix is ​​obtained by blending and modifying HDPE resin, LLDPE resin, and ethylene-vinyl acetate copolymer.

[0010] Specifically, HDPE resin, LLDPE resin, and ethylene-vinyl acetate copolymer are blended and modified to obtain a modified resin matrix. The ethylene-vinyl acetate copolymer enhances the flexibility and surface activity of the matrix, and works synergistically with maleic anhydride-grafted PE to enhance the compatibility of the matrix with the electrostatic dustproof membrane. Antioxidants, light stabilizers, and carbon black work synergistically to delay the outdoor aging of the geomembrane and extend its service life. The components work synergistically to optimize the mechanical properties, weldability, and anti-aging properties of the geomembrane, making it suitable for complex outdoor working conditions.

[0011] Specifically, the grafting rate of maleic anhydride-grafted PE is 0.5-1%; the particle size of the carbon black is 20-50 nm.

[0012] Optionally, the modified resin matrix is ​​obtained by melt blending HDPE resin, LLDPE resin and ethylene-vinyl acetate copolymer at a mass ratio of (7~9):(10~12):(1~2) at 180~200°C, based on parts by weight.

[0013] Specifically, this application defines the composition and proportion of the modified resin matrix. HDPE ensures the impermeability and rigidity of the geomembrane, while LLDPE enhances its flexibility and tear resistance. A small amount of ethylene-vinyl acetate copolymer can be added to achieve uniform blending with the two, synergistically improving the surface activity of the matrix. The melt blending temperature of 180~200℃ ensures that the three resins are fully melted and the intermolecular bonds are tight, avoiding component segregation and making the modified resin matrix uniform and stable in performance. This not only ensures the core impermeability function of the geomembrane but also lays a good foundation for bonding with the electrostatic dustproof membrane.

[0014] Optionally, the antioxidant includes BHT and 1010, wherein the mass ratio of BHT to 1010 is (1~1.2):1; and the light stabilizer is UV531.

[0015] Specifically, BHT and 1010 are compounded in a specific ratio to synergistically resist thermo-oxidative aging. BHT rapidly inhibits short-term thermo-oxidative aging, while 1010 effectively delays long-term aging, preventing the geomembrane from degrading during melting and outdoor use. UV531 can effectively absorb ultraviolet rays and works synergistically with antioxidants to further enhance the anti-aging performance of the geomembrane, reduce the damage to the matrix performance caused by outdoor sunlight and temperature changes, extend the service life of the geomembrane, and ensure the long-term seepage prevention effect of the project.

[0016] Optionally, the electrostatic dustproof film, by weight, comprises 70-80 parts of LLDPE resin, 10-15 parts of LDPE resin, 5-8 parts of electret masterbatch, 0.5-1.0 parts of erucamide, 0.3-0.5 parts of glyceryl monostearate, 0.2-0.3 parts of antioxidant 1076, and 1.0-2.0 parts of polyethylene glycol monomethyl ether acrylate.

[0017] Specifically, LLDPE and LDPE blends are used as the substrate for the electrostatic dustproof membrane, balancing toughness and processing fluidity; electret masterbatch provides stable electrostatic charge, enabling electrostatic adsorption of the electrostatic dustproof membrane; erucamide improves the smoothness of the membrane surface, and glyceryl monostearate assists in antistatic properties, with the two working together to optimize the membrane processing performance; the synergistic effect of each component gives the electrostatic dustproof membrane stable adsorption, easy peeling, and anti-aging properties, making it suitable for geomembrane construction needs.

[0018] Specifically, the combined action of polyethylene glycol monomethyl ether acrylate and erucamide ensures easy peeling at high temperatures, avoiding the problem of the coating being difficult to remove or leaving residue after removal, which would affect the subsequent welding effect.

[0019] Optionally, the electret masterbatch is prepared by the following steps: after drying tourmaline powder and nano-silica, spray them with an ethanol solution of KH550, dry them, and then put them into a high-speed mixer together with LLDPE, antioxidant and lubricant, stir and mix to obtain a mixture, and place the mixture in a twin-screw extruder for extrusion granulation to obtain electret masterbatch.

[0020] Specifically, the components are uniformly mixed, and twin-screw extrusion granulation is used to fully melt and homogenize the components, allowing the electret functional components to be uniformly dispersed in the LLDPE carrier. After being sprayed with KH550, compatibility is improved and agglomeration is prevented. This preparation process ensures the stability of the electret masterbatch performance, provides long-term electrostatic adsorption capacity for the electrostatic dustproof film, and ensures the long-lasting dustproof effect.

[0021] Optionally, the mass ratio of tourmaline powder, nano-silica, and LLDPE is (20~30):(5~8):(62~75), the mass of the antioxidant is 0.4~0.8% of the mass of LLDPE, the mass of the lubricant is 0.3~0.6% of the mass of LLDPE, and the mass of KH550 is 1.5~3% of the sum of the masses of tourmaline powder and nano-silica.

[0022] Specifically, this application specifies the composition ratio of the electret masterbatch, and the synergistic effect of the proportions of each component ensures its excellent electret performance and good processing performance.

[0023] Optionally, the mixing process involves first stirring at a speed of 500-800 r / min for 5-8 minutes, and then stirring at a speed of 1200-1500 r / min for 3-5 minutes, while maintaining the material temperature at no higher than 50°C.

[0024] Optionally, the extrusion granulation temperature is 150~160℃ in the feeding section, 170~180℃ in the melting section, 180~190℃ in the homogenization section, and 175~185℃ in the die head; the extrusion pressure is 10~15MPa; and the screw speed of the twin-screw extruder is 30~50r / min.

[0025] Specifically, this application specifies the process parameters for preparing electret masterbatch to ensure that the mixture is fully homogenized and the granulation is regular, avoiding component segregation and masterbatch agglomeration, so as to obtain electret masterbatch with uniform particles and stable performance, which can be directly used for the preparation of electrostatic dustproof film.

[0026] According to another aspect of this application, the above-mentioned electrostatic dustproof geomembrane is also provided for application in environmental protection and seepage prevention, water conservancy and hydropower and municipal engineering fields.

[0027] Specifically, the electrostatic dustproof geomembrane provided in this application ensures welding quality, its high-temperature easy-peeling properties improve construction efficiency, and its anti-aging properties extend its service life. It can effectively solve the problems of dust accumulation during welding and cumbersome construction of traditional geomembranes, and can achieve stable application in various seepage prevention projects, thereby improving project quality and durability.

[0028] Specifically, the preparation method of electrostatic dustproof geomembrane includes the following steps: (1) Preparation of the geomembrane body: Modified resin matrix, maleic anhydride-grafted PE, antioxidant, light stabilizer and carbon black are added to a high-speed mixer according to the weight parts, and stirred at 1000~1200 r / min for 8~10 min until uniformly mixed; the mixture is fed into an extrusion granulation device, melted and plasticized at 180~200℃, and extruded and calendered into a geomembrane substrate. The welded overlap area of ​​the geomembrane substrate is subjected to corona treatment. The corona treatment parameters are: voltage 30~40kV, discharge gap 2~3mm, treatment speed 2~3m / min, corona power 3~5kW. After cooling to room temperature, the geomembrane body is obtained by winding. (2) Preparation of electrostatic dustproof film: LLDPE resin, LDPE resin, electret masterbatch, erucamide, glyceryl monostearate, antioxidant 1076, and polyethylene glycol monomethyl ether acrylate are added to a high-speed mixer according to the weight parts and stirred at 800~1000r / min for 6~8min until the mixture is uniform; the mixture is fed into a casting machine and melt-cast into a film at 160~180℃, with the film thickness controlled at 0.05~0.1mm. The film is subjected to high-voltage electret treatment, with the electret voltage being 50~80kV, the electret distance being 8~12mm, the electret temperature being 25~35℃, and the processing speed being 1~2m / min. After electret treatment, the film is cut to match the width of the welding overlap area to obtain electrostatic dustproof film; (3) Composite molding: The electrostatic dustproof membrane is precisely aligned with the surface of the welded overlap area of ​​the geomembrane body. The temperature is 40~60℃, the bonding pressure is 0.1~0.2MPa, and the bonding speed is 1~2m / min, so that the two are tightly bonded to obtain the electrostatic dustproof geomembrane.

[0029] The beneficial effects of this application include, but are not limited to: 1. The electrostatic dustproof geomembrane of this application, through high-voltage electret treatment of the electrostatic dustproof membrane, combined with the synergistic electret effect of tourmaline powder and nano-silica in the electret masterbatch, endows the membrane with long-term and stable electrostatic adsorption capacity, which can accurately cover the welding overlap area of ​​8~15cm wide, firmly blocking the adhesion of dust and debris; at the same time, the surface activity of the geomembrane welding surface is improved by corona treatment, combined with electrostatic adsorption as the main method and micro-heat-assisted bonding as the auxiliary method, so that the membrane and the welding surface are tightly bonded and not easy to fall off, avoiding dust from affecting the hot melt welding, eliminating defects such as incomplete welding and missing welding, ensuring the overall seepage prevention effect of the geomembrane, and reducing the cost of rework.

[0030] 2. According to the electrostatic dustproof geomembrane of this application, HDPE, LLDPE and ethylene-vinyl acetate copolymer are blended in a specific ratio in the geomembrane body, and maleic anhydride-grafted PE is added to enhance compatibility. At the same time, BHT and 1010 compound antioxidant, UV531 light stabilizer and carbon black work synergistically to effectively delay the outdoor aging and ultraviolet degradation of the geomembrane and improve mechanical properties and weldability. In the electrostatic dustproof membrane, LLDPE and LDPE are blended to balance toughness and processability, and antioxidant 1076 delays the aging of the membrane. The synergistic optimization of each component gives the entire geomembrane excellent anti-aging, tear resistance and impermeability properties, which are suitable for the long-term outdoor use needs of environmental protection seepage prevention, water conservancy and hydropower and other fields.

[0031] 3. The electrostatic dustproof geomembrane of this application, by combining it with polyethylene glycol monomethyl ether acrylate, achieves high-temperature easy peeling characteristics. The components work synergistically in precise proportions to ensure that no residue remains when the membrane is peeled off, avoiding residual debris from affecting the welding quality. Compared with traditional dustproof methods, it significantly reduces the manual laying and peeling processes, shortens the construction cycle, improves construction efficiency, and reduces labor costs. Detailed Implementation

[0032] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods or product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described in this patent are for illustrative purposes only. In the following examples and comparative examples, the grafting rate of maleic anhydride-grafted PE was 0.8%; the particle size of the carbon black was 30 nm.

[0034] Example 1: A method for preparing an electrostatic dustproof geomembrane (1) Preparation of the geomembrane body: 85 parts of modified resin matrix, 2 parts of maleic anhydride grafted PE, 0.3 parts of antioxidant (BHT and 1010 mass ratio 1:1), 0.2 parts of light stabilizer, and 2 parts of carbon black were added to a high-speed mixer and stirred at 1000 r / min for 8 min until uniformly mixed. The mixture was then fed into an extrusion granulation device, melted and plasticized at 180℃, and extruded and calendered to form a geomembrane substrate. The welded overlap area of ​​the geomembrane substrate was subjected to corona treatment with the following parameters: voltage 30kV, discharge gap 2mm, treatment speed 2m / min, and corona power 3kW. After cooling to room temperature, the geomembrane body was obtained by winding. (2) Preparation of electrostatic dustproof film: 70 parts LLDPE resin, 10 parts LDPE resin, 5 parts electret masterbatch, 0.5 parts erucamide, 0.35 parts glyceryl monostearate, 0.2 parts antioxidant 1076, and 1.0 parts polyethylene glycol monomethyl ether acrylate were put into a high-speed mixer and stirred at 800 r / min for 6 min until the mixture was uniform. The mixture was fed into a casting machine and melt-cast into a film at 160℃. The film thickness was controlled at 0.05 mm. The film was subjected to high-voltage electret treatment. The electret voltage of the high-voltage electret treatment was 50 kV, the electret distance was 8 mm, the electret temperature was 25℃, and the processing speed was 1 m / min. After electret treatment, the film was cut to match the width of the welding overlap area to obtain electrostatic dustproof film. (3) Composite molding: The electrostatic dustproof membrane is precisely aligned with the surface of the welding overlap area of ​​the geomembrane body. The temperature is 40℃, the bonding pressure is 0.1MPa, and the bonding speed is 1m / min, so that the two are tightly bonded to obtain the electrostatic dustproof geomembrane.

[0035] Preparation of modified resin matrix: HDPE resin, LLDPE resin and ethylene-vinyl acetate copolymer were melt-blended at 180℃ in a mass ratio of 7:10:1.

[0036] Preparation of electret masterbatch: Tourmaline powder and nano-silica were dried, sprayed with an ethanol solution of KH550, dried again, and then added to a high-speed mixer along with LLDPE, antioxidant, and lubricant. The mass ratio of tourmaline powder, nano-silica, and LLDPE was 20:5:62. The mass of antioxidant was 0.4% of the mass of LLDPE, the mass of lubricant was 0.3% of the mass of LLDPE, and the mass of KH550 was 1.5% of the combined mass of tourmaline powder and nano-silica. The mixture is stirred and mixed to obtain a mixture. The stirring and mixing process is as follows: first, stir at a speed of 500 r / min for 5 min, and then stir at a speed of 1200 r / min for 3 min. During this process, the material temperature is kept not higher than 50℃. The mixture is placed in a twin-screw extruder for extrusion granulation. The extrusion granulation temperature is 150℃ in the feed section, 170℃ in the melting section, 180℃ in the homogenization section, and 175℃ in the die head. The extrusion pressure is 10 MPa, and the screw speed of the twin-screw extruder is 30 r / min to obtain electret masterbatch.

[0037] Example 2: A method for preparing an electrostatic dustproof geomembrane (1) Preparation of the geomembrane body: 100 parts of modified resin matrix, 5 parts of maleic anhydride grafted PE, 0.5 parts of antioxidant (BHT to 1010 mass ratio 1.2:1), 0.4 parts of light stabilizer, and 3 parts of carbon black were added to a high-speed mixer and stirred at 1200 r / min for 10 min until uniformly mixed. The mixture was then fed into an extrusion granulation device, melted and plasticized at 200℃, and extruded and calendered to form a geomembrane substrate. The welded overlap area of ​​the geomembrane substrate was subjected to corona treatment with the following parameters: voltage 40kV, discharge gap 3mm, treatment speed 3m / min, and corona power 5kW. After cooling to room temperature, the geomembrane body was obtained by winding. (2) Preparation of electrostatic dustproof film: 80 parts LLDPE resin, 15 parts LDPE resin, 8 parts electret masterbatch, 1.0 part erucamide, 0.5 parts glyceryl monostearate, 0.3 parts antioxidant 1076, and 2.0 parts polyethylene glycol monomethyl ether acrylate were put into a high-speed mixer and stirred at 1000 r / min for 8 min until the mixture was uniform. The mixture was fed into a casting machine and melt-cast into a film at 180℃. The film thickness was controlled at 0.1 mm. The film was subjected to high-voltage electret treatment. The electret voltage of the high-voltage electret treatment was 80 kV, the electret distance was 12 mm, the electret temperature was 35℃, and the processing speed was 2 m / min. After electret treatment, the film was cut to match the width of the welding overlap area to obtain electrostatic dustproof film. (3) Composite molding: The electrostatic dustproof membrane is precisely aligned with the surface of the welding overlap area of ​​the geomembrane body. The temperature is 60℃, the bonding pressure is 0.2MPa, and the bonding speed is 2m / min, so that the two are tightly bonded to obtain the electrostatic dustproof geomembrane.

[0038] Preparation of modified resin matrix: HDPE resin, LLDPE resin and ethylene-vinyl acetate copolymer were melt-blended at 200℃ in a mass ratio of 9:12:2.

[0039] Preparation of electret masterbatch: Tourmaline powder and nano-silica were dried, then sprayed with an ethanol solution of KH550, dried again, and then added to a high-speed mixer along with LLDPE, antioxidant, and lubricant. The mass ratio of tourmaline powder, nano-silica, and LLDPE was 30:8:75. The mass of the antioxidant was 0.8% of the mass of LLDPE, the mass of the lubricant was 0.6% of the mass of LLDPE, and the mass of KH550 was 3% of the combined mass of tourmaline powder and nano-silica. The mixture was stirred... The mixture is stirred and mixed to obtain a mixture. The stirring and mixing process is as follows: first, stir at 800 r / min for 8 min, and then stir at 1500 r / min for 5 min. During this process, the material temperature is kept not higher than 50℃. The mixture is placed in a twin-screw extruder for extrusion granulation. The extrusion granulation temperature is 160℃ in the feed section, 180℃ in the melting section, 190℃ in the homogenization section, and 185℃ in the die head. The extrusion pressure is 15 MPa, and the screw speed of the twin-screw extruder is 50 r / min to obtain electret masterbatch.

[0040] Example 3: A method for preparing an electrostatic dustproof geomembrane (1) Preparation of the geomembrane body: 90 parts of modified resin matrix, 3 parts of maleic anhydride grafted PE, 0.4 parts of antioxidant (BHT and 1010 mass ratio 1:1), 0.3 parts of light stabilizer, and 2 parts of carbon black were added to a high-speed mixer and stirred at 1100 r / min for 9 min until uniformly mixed. The mixture was then fed into an extrusion granulation device, melted and plasticized at 190℃, and extruded and calendered to form a geomembrane substrate. The welded overlap area of ​​the geomembrane substrate was subjected to corona treatment with the following parameters: voltage 35kV, discharge gap 2mm, treatment speed 3m / min, and corona power 4kW. After cooling to room temperature, the geomembrane body was obtained by winding. (2) Preparation of electrostatic dustproof film: 75 parts LLDPE resin, 13 parts LDPE resin, 6 parts electret masterbatch, 0.8 parts erucamide, 0.4 parts glyceryl monostearate, 0.25 parts antioxidant 1076, and 1.5 parts polyethylene glycol monomethyl ether acrylate were put into a high-speed mixer and stirred at 900 r / min for 7 min until uniformly mixed. The mixture was fed into a casting machine and melt-cast into a film at 170℃. The film thickness was controlled at 0.08 mm. The film was subjected to high-voltage electret treatment. The electret voltage of the high-voltage electret treatment was 60 kV, the electret distance was 9 mm, the electret temperature was 30℃, and the processing speed was 1 m / min. After electret treatment, the film was cut to match the width of the welding overlap area to obtain electrostatic dustproof film. (3) Composite molding: The electrostatic dustproof membrane is precisely aligned with the surface of the welding overlap area of ​​the geomembrane body. The temperature is 50℃, the bonding pressure is 0.1MPa, and the bonding speed is 1m / min, so that the two are tightly bonded to obtain the electrostatic dustproof geomembrane.

[0041] Preparation of modified resin matrix: HDPE resin, LLDPE resin and ethylene-vinyl acetate copolymer were melt-blended at 190℃ in a mass ratio of 8:11:2.

[0042] Preparation of electret masterbatch: Tourmaline powder and nano-silica were dried, then sprayed with an ethanol solution of KH550, dried again, and then added to a high-speed mixer along with LLDPE, antioxidant, and lubricant. The mass ratio of tourmaline powder, nano-silica, and LLDPE was 25:7:70. The mass of antioxidant was 0.6% of the mass of LLDPE, the mass of lubricant was 0.5% of the mass of LLDPE, and the mass of KH550 was 2% of the combined mass of tourmaline powder and nano-silica. The mixture was stirred... The mixture is stirred and mixed to obtain a mixture. The stirring and mixing process is as follows: first, stir at 600 r / min for 6 min, and then stir at 1300 r / min for 4 min. During this process, the material temperature is kept not higher than 50℃. The mixture is placed in a twin-screw extruder for extrusion granulation. The extrusion granulation temperature is 155℃ in the feed section, 175℃ in the melting section, 185℃ in the homogenization section, and 180℃ in the die head. The extrusion pressure is 12 MPa, and the screw speed of the twin-screw extruder is 40 r / min to obtain electret masterbatch.

[0043] Example 4 The difference between Example 4 and Example 3 is that the modified resin matrix does not include ethylene-vinyl acetate, but all other aspects are the same.

[0044] Example 5 The difference between Example 5 and Example 3 is that Example 5 does not include polyethylene glycol monomethyl ether acrylate, but all other aspects are the same.

[0045] Example 6 The difference between Example 6 and Example 3 is that the mass ratio of BHT to 1010 in the antioxidant is 1:2, while the rest are the same.

[0046] Example 7 The difference between Example 7 and Example 3 is that the preparation of the electret masterbatch does not include the spraying step, but the rest are the same.

[0047] Example 8 The difference between Example 8 and Example 3 is that antioxidant 1010 is used in the geomembrane body, while the rest are the same.

[0048] Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that the latter does not include the electrostatic dustproof film, but all other aspects are the same.

[0049] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that the surface of the welded overlap area of ​​the geomembrane body was not treated with corona discharge, but the rest are the same.

[0050] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the electrostatic dustproof film was not subjected to high voltage electret treatment, but all other aspects are the same.

[0051] Experimental Example 1: Peel Strength Test Five samples of the geomembranes prepared in Examples 1-7 and Comparative Examples 1-3 were selected respectively. The bonding width of each sample was measured with a vernier caliper. The two ends of the sample were fixed on the upper and lower clamps of the tensile testing machine to ensure that the clamps and the sample were tightly bonded without slippage or displacement. The tensile testing machine was set to a tensile speed of 50 mm / min and stretched at a uniform speed until the electrostatic dustproof membrane peeled off from the welded surface of the geomembrane. The maximum peel strength of each sample was recorded and the average value of the five samples was calculated. At the same time, it was observed whether there was large-area detachment during the peeling process. The bonding area was measured with a tape measure and the actual bonding ratio was calculated. The test results are shown in Table 1.

[0052] Table 1. Peel strength test results

[0053] As shown in Table 1, the peel strength of Examples 1 to 3 is ≥0.4 N / mm and the bonding area ratio is ≥97%. Among them, Example 3 has the best performance. The bonding performance of Examples 4 and 7 is slightly reduced because they lack the ethylene-vinyl acetate and KH550 spraying steps, respectively. The peel strength and bonding area ratio of Comparative Examples 2 and 3 are significantly reduced and cannot meet the requirements.

[0054] Experimental Example 2: High Temperature Peel Strength Test Five samples of the geomembranes prepared in Examples 1-7 and Comparative Examples 1-3 were selected respectively. The bonding width of each sample was measured with vernier calipers. The samples were placed in a 60℃ constant temperature chamber and kept at that temperature for 2 hours. After being removed, they were allowed to cool naturally to room temperature (approximately 25℃). The cooled samples were then fixed on the upper and lower clamps of a tensile testing machine. The tensile speed was set to 50 mm / min, and the samples were stretched uniformly until peeling was achieved. The peel strength of each sample was recorded, and the average value of the five samples was calculated. After peeling, the welded surface of the geomembrane was observed with a magnifying glass to determine whether there were any residual fragments, and the residual condition was recorded. The test results are shown in Table 2.

[0055] Table 2. High-Temperature Peel Strength Test Results

[0056] As shown in Table 2, the high-temperature peel strength of Examples 1 to 3 is ≥0.29 N / mm, and there are no residues after peeling. Example 3 has the highest high-temperature peel strength. Although Example 5 meets the high-temperature peel strength standard due to the lack of polyethylene glycol monomethyl ether acrylate, residues are found. The high-temperature peel strength of Comparative Examples 2 and 3 is significantly reduced.

[0057] Experiment Example 3 Mechanical Property Testing Five samples were selected from the geomembrane bodies prepared in Examples 1-4, 6, and 8, respectively. The thickness of each sample was measured with vernier calipers. The samples were fixed on the fixture of a tensile testing machine, and the tensile speed was set to 50 mm / min. The samples were stretched at a uniform speed until fracture. The tensile strength at break and the elongation at break of each sample were recorded, and the average value was calculated. The test results are shown in Table 3.

[0058] Table 3 Mechanical property test results

[0059] Table 3 shows that the geomembrane bodies of Examples 1-3 and 6 have excellent mechanical properties. Among them, Example 3 has the best mechanical properties. The mechanical properties of Example 4 decreased significantly due to the lack of ethylene-vinyl acetate in the modified resin matrix. The reason for this is the lack of ethylene-vinyl acetate. Ethyl acetate can significantly improve the toughness and tensile properties of the geomembrane body and is an important component to ensure the mechanical properties of the geomembrane.

[0060] Experiment Example 4: Test of resistance to thermo-oxidative aging The geomembranes prepared in Examples 1-3 and Examples 6 and 8 were placed in an aging test chamber and the aging conditions were set as follows: temperature 80℃, relative humidity 50%, air velocity 2m / s, and aging time 1000h. After aging, the samples were taken out and allowed to cool naturally to room temperature (about 25℃). The tensile strength and elongation at break were tested respectively. The test method was the same as in Experiment 3, and the test results are shown in Table 4.

[0061] Table 4 Test of resistance to thermo-oxidative aging

[0062] As shown in Table 4, Examples 1-3 exhibited high tensile strength and elongation at break after aging, demonstrating excellent resistance to thermo-oxidative aging. Among them, Example 2 showed the best mechanical properties after aging, while Example 8, which used a single antioxidant 1010, showed a significant decrease in tensile strength and elongation at break after aging.

[0063] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. An electrostatic dustproof geomembrane, characterized in that, The device includes a geomembrane body and an electrostatic dustproof membrane. The electrostatic dustproof membrane covers the surface of the welded overlap area of ​​the geomembrane body, and the width of the welded overlap area is 8-15cm. The surface of the welded overlap area of ​​the geomembrane body is corona treated, and the electrostatic dustproof membrane is treated with high voltage electret. The electrostatic dustproof membrane is bonded to the welded surface of the geomembrane body by means of electrostatic adsorption as the main method and micro-heat-assisted bonding as a secondary method.

2. The electrostatic dustproof geomembrane according to claim 1, characterized in that, The geomembrane body, by weight, comprises 85-100 parts of modified resin matrix, 2-5 parts of maleic anhydride-grafted PE, 0.3-0.5 parts of antioxidant, 0.2-0.4 parts of light stabilizer, and 2-3 parts of carbon black. The modified resin matrix is ​​obtained by blending and modifying HDPE resin, LLDPE resin, and ethylene-vinyl acetate copolymer.

3. The electrostatic dustproof geomembrane according to claim 2, characterized in that, The modified resin matrix is ​​obtained by melt blending HDPE resin, LLDPE resin and ethylene-vinyl acetate copolymer at a mass ratio of (7~9):(10~12):(1~2) at 180~200℃, based on parts by weight.

4. The electrostatic dustproof geomembrane according to claim 2, characterized in that, The antioxidants include BHT and 1010, with a mass ratio of BHT to 1010 of (1~1.2):1; the light stabilizer is UV531.

5. The electrostatic dustproof geomembrane according to claim 1, characterized in that, The electrostatic dustproof film, by weight, comprises 70-80 parts of LLDPE resin, 10-15 parts of LDPE resin, 5-8 parts of electret masterbatch, 0.5-1.0 parts of erucamide, 0.3-0.5 parts of glyceryl monostearate, 0.2-0.3 parts of antioxidant 1076, and 1.0-2.0 parts of polyethylene glycol monomethyl ether acrylate.

6. The electrostatic dustproof geomembrane according to claim 5, characterized in that, The electret masterbatch is prepared by the following steps: after drying tourmaline powder and nano-silica, spray them with an ethanol solution of KH550, dry them, and then put them into a high-speed mixer together with LLDPE, antioxidant and lubricant. Stir and mix to obtain a mixture. Place the mixture in a twin-screw extruder and extrude and granulate to obtain the electret masterbatch.

7. The electrostatic dustproof geomembrane according to claim 6, characterized in that, The mass ratio of tourmaline powder, nano silica, and LLDPE is (20~30):(5~8):(62~75), the mass of the antioxidant is 0.4~0.8% of the mass of LLDPE, the mass of the lubricant is 0.3~0.6% of the mass of LLDPE, and the mass of KH550 is 1.5~3% of the sum of the masses of tourmaline powder and nano silica.

8. The electrostatic dustproof geomembrane according to claim 6, characterized in that, The mixing process involves first stirring at a speed of 500-800 r / min for 5-8 minutes, and then stirring at a speed of 1200-1500 r / min for 3-5 minutes, while keeping the material temperature below 50°C throughout the process.

9. The electrostatic dustproof geomembrane according to claim 6, characterized in that, The extrusion granulation temperature is 150~160℃ in the feeding section, 170~180℃ in the melting section, 180~190℃ in the homogenization section, and 175~185℃ in the die head. The extrusion pressure is 10~15MPa, and the screw speed of the twin-screw extruder is 30~50r / min.

10. The application of the electrostatic dustproof geomembrane according to any one of claims 1 to 9 in the fields of environmental protection and seepage prevention, water conservancy and hydropower, and municipal engineering.

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