PVC geomembrane and manufacturing method thereof

Abstract

The invention relates to the technical field of PVC geomembranes, in particular to a PVC geomembrane which comprises a surface layer, a reinforcing layer and a bottom layer, the lower surface of the surface layer is fixedly connected to the upper surface of the reinforcing layer, the lower surface of the reinforcing layer is fixedly connected to the upper surface of the bottom layer, and the reinforcing layer is arranged between the surface layer and the bottom layer. The PVC resin (SG-5), the cross-linking agent master batch, the carbon black (N330), the plasticizer (DOP), the stabilizer (calcium zinc) and the lubricant (stearic acid) are used for manufacturing the surface layer, the glass fiber cloth, the PVC resin (SG-5), the plasticizer (DOP / ESO), the stabilizer (calcium zinc) and the coupling agent (silane coupling agent KH-550) are used for manufacturing the reinforcing layer, and the glass fiber cloth, the PVC resin (SG-5), the plasticizer (DOP / ESO), the stabilizer (calcium zinc) and the coupling agent (silane coupling agent KH-550) are used for manufacturing the reinforcing layer. And the bottom layer is prepared from PVC resin (SG-5), a plasticizer (DOP / ESO), a filler (calcium carbonate), a stabilizer (calcium zinc), a lubricant (stearic acid), a foaming agent (AC foaming agent) and carbon black (N330), so that the characteristics of tightness, ultraviolet resistance, conductivity, tensile strength, puncture resistance, dimensional stability and the like of the PVC geomembrane are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC geomembranes, in particular to a PVC geomembrane and a manufacturing method thereof. Background Art

[0002] PVC geomembrane is a flexible, seepage-proof material produced through calendering or coating processes. It is widely used in water conservancy, environmental protection, civil engineering, and other fields for isolation, seepage prevention, and protection. Typically made from a single polyvinyl chloride (PVC) material, it offers chemical resistance, flexibility, and ease of construction.

[0003] The PVC geomembrane in the existing technology is made of a single polyvinyl chloride (PVC) material. Although it can achieve the characteristics of chemical corrosion resistance, good flexibility and convenient construction, its sealing, UV resistance, conductivity, tensile strength, puncture resistance and dimensional stability are poor. Summary of the Invention

[0004] In view of this, the present invention provides a PVC geomembrane and a manufacturing method thereof. The main technical problem to be solved is that conventional PVC geomembranes can only achieve the characteristics of chemical corrosion resistance, good flexibility and convenient construction, but their sealing, UV resistance, conductivity, tensile strength, puncture resistance and dimensional stability are poor.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: a PVC geomembrane, comprising a surface layer, a reinforcement layer and a bottom layer, wherein the lower surface of the surface layer is fixedly connected to the upper surface of the reinforcement layer, the lower surface of the reinforcement layer is fixedly connected to the upper surface of the bottom layer, and the reinforcement layer is placed between the surface layer and the bottom layer;

[0006] The surface layer is made of PVC resin (SG-5), cross-linking agent masterbatch, carbon black (N330), plasticizer (DOP), stabilizer (calcium zinc) and lubricant (stearic acid);

[0007] The reinforcement layer is made of glass fiber cloth, PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and coupling agent (silane coupling agent KH-550);

[0008] The bottom layer is made of PVC resin (SG-5), plasticizer (DOP / ESO), filler (calcium carbonate), stabilizer (calcium zinc), lubricant (stearic acid), foaming agent (AC foaming agent) and carbon black (N330).

[0009] By adopting the above technical solution, the surface layer, reinforcement layer and bottom layer are made of specific materials to make the PVC geomembrane, which can enhance the sealing, UV resistance, conductivity, tensile strength, puncture resistance and dimensional stability of the PVC geomembrane.

[0010] As a further description of the above technical solution: the surface layer contains 100 parts of PVC resin (SG-5), 5 to 10 parts of cross-linking agent masterbatch, 3 to 5 parts of carbon black (N330), 30 to 40 parts of plasticizer (DOP), 2 to 3 parts of stabilizer (calcium zinc) and 0.5 to 1 part of lubricant (stearic acid).

[0011] By adopting the above technical solution, PVC resin (SG-5) is used as the matrix material to provide structural strength, the cross-linking agent masterbatch can improve the molecular cross-linking degree, enhance heat resistance and creep resistance, carbon black (N330) can resist UV rays and improve conductivity, extending outdoor life, plasticizer (DOP) can improve flexibility (low temperature brittle cracking resistance), stabilizer (calcium zinc) can prevent processing thermal degradation (calcium zinc stabilizer can also play an environmental role), and lubricant (stearic acid) can reduce processing friction.

[0012] As a further description of the above technical solution: the reinforcement layer contains a glass fiber cloth weight of 100-300 g / m², 100 parts of PVC resin (SG-5), 30-40 parts of plasticizer (DOP / ESO), 2-3 parts of stabilizer (calcium zinc) and 0.5-1 part of coupling agent (silane coupling agent KH-550).

[0013] By adopting the above technical solution, the glass fiber cloth provides a high-strength skeleton to withstand mechanical stress, the PVC resin (SG-5) serves as the matrix material to bond the glass fiber cloth, the plasticizer (DOP / ESO) can improve the flexibility of PVC and facilitate compounding, the stabilizer (calcium zinc) can prevent thermal degradation during processing, and the coupling agent (silane coupling agent KH-550) enhances the interfacial bonding between PVC and glass fiber.

[0014] As a further description of the above technical solution: the bottom layer contains 100 parts of PVC resin (SG-5), 30-40 parts of plasticizer (DOP / ESO), 20-30 parts of filler (calcium carbonate), 2-3 parts of stabilizer (calcium zinc), 0.5-1 part of lubricant (stearic acid), 0.2-0.5 parts of foaming agent (AC foaming agent) and 1-2 parts of carbon black (N330).

[0015] By adopting the above technical solution, PVC resin (SG-5) is used as the matrix material to provide an anti-seepage main body, the plasticizer (DOP / ESO) can improve the flexibility of PVC, the filler (calcium carbonate) can reduce costs and increase surface roughness (particle size 5-20μm), the stabilizer (calcium zinc) can prevent processing thermal degradation, the lubricant (stearic acid) can reduce processing friction and avoid sticking to the roller, the foaming agent (AC foaming agent) can micro-foam to form a rough surface structure, and carbon black (N330) achieves anti-UV effect.

[0016] A method for manufacturing a PVC geomembrane, using the PVC geomembrane according to any one of claims 1 to 4, characterized in that it comprises the following steps:

[0017] S1. When making the surface layer:

[0018] (1) Pretreatment: Carbon black (N330) needs to be mixed with plasticizer (DOP) in a 1:1 ratio and stirred at high speed (≥1000 rpm, 30 minutes) to form a slurry to avoid agglomeration; PVC resin and filler are dried at 80 ° C for 2 hours to remove moisture (to prevent processing bubbles);

[0019] (2) Mixing and kneading: Use a high-speed mixer and an internal mixer to add the PVC resin (SG-5), plasticizer (DOP) and carbon black (N330) slurry into the high-speed mixer, heat it to 100-110°C and mix for 5 minutes, add the crosslinker masterbatch, stabilizer (calcium zinc) and lubricant (stearic acid), continue mixing to 120°C (to avoid premature reaction of the crosslinker), then transfer to the internal mixer (temperature 150-160°C), and knead for 8-10 minutes until it is completely plasticized;

[0020] (3) Calendering film: Use a four-roll calender (roller temperature 160-180℃), roller speed ratio: 1:1.2:1.5:1.8 (gradual stretching to avoid internal stress), thickness: adjusted by roller spacing (surface thickness 0.2-0.5mm), surface treatment: immediately pass through a water-cooled roller (20-30℃) after calendering to reduce thermal shrinkage;

[0021] (4) Post-treatment: Improve adhesion through corona treatment or chemical etching (such as immersion in sulfuric acid for 10 seconds); spray polyurethane / acrylic coating (thickness 10-20 μm) to further extend life.

[0022] S2. When making the enhancement layer:

[0023] (1) Pretreatment of glass fiber cloth: Immerse the glass fiber cloth in acetone or 3% NaOH solution and ultrasonically clean it for 10 minutes to remove the surface slurry (to improve wettability). Wash it with water and then dry it (100°C, 2 hours). Prepare 1% silane coupling agent (KH-550) ethanol solution, spray or impregnate the glass fiber cloth, dry it, and heat treat it at 120°C for 20 minutes to form a chemical bonding layer.

[0024] (2) Preparation of PVC mortar: Mix PVC resin (SG-5) with plasticizer (DOP / ESO) and stabilizer (calcium zinc), stir at high speed (500 rpm, 10 minutes), add solvent (THF or cyclohexanone) and adjust the viscosity to 5000-8000 cP (for easy coating);

[0025] (3) Composite process (calendering method): Use a four-roll calender and a composite oven to make a 0.3-0.5 mm thick film through a calender (roller temperature 160-170 ° C). Two PVC films need to be made. The pretreated glass fiber cloth is evenly laid on one of the prepared PVC films. It is preliminarily composited by a hot pressing roller (180 ° C, pressure 0.5 MPa). PVC slurry is scraped on the surface of the glass fiber cloth (coating amount 200-300 g / m²), covered with another layer of PVC film, and finally bonded by passing through a composite oven (190 ° C, 2 minutes). It is then quickly cooled by a water-cooled roller (20 ° C) and rolled up (tension control ≤ 10 N / cm).

[0026] S3. When making the bottom layer:

[0027] (1) Raw material pretreatment: PVC resin (SG-5) is dried at 80℃ for 2 hours, with a moisture content of ≤0.1%. The filler is activated, and calcium carbonate is surface treated with a silane coupling agent (KH-570) (1% concentration spray) to improve compatibility with PVC.

[0028] (2) Mixing and kneading: Add PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and lubricant (stearic acid) to a high-speed mixer, heat to 100-110°C and mix for 5 minutes, add filler (calcium carbonate) and carbon black, continue mixing to 120°C (to ensure uniform dispersion), transfer to a mixer (150-160°C), knead for 8-10 minutes until completely plasticized, add foaming agent, and add it in the last 2 minutes to avoid premature decomposition;

[0029] (3) Calendering (rough surface treatment): Use a four-roll calender (with patterned rollers), roller temperature: upper roller (patterned roller) 160°C, lower roller (smooth roller) 150°C, roller speed: patterned roller is 10% to 20% slower than smooth roller, enhance embossing depth, pressure: 0.3 to 0.5 MPa, ensure clear pattern, rough surface effect: concave and convex height 0.2 to 0.5 mm, friction coefficient ≥ 0.4 (dry state).

[0030] S4, hot pressing composite process:

[0031] The surface and bottom layers are softened with an infrared heater (120-140°C) to enhance adhesion. PVC adhesive (PVC resin + DOP + solvent, viscosity 5000cP) is applied to both sides of the reinforcement layer at a coating amount of 100-150g / m². The layers are then laid in the following order: surface layer → reinforcement layer → bottom layer, ensuring alignment without wrinkles. The layers are then hot-pressed and laminated using a multi-layer hot press (temperature 180-200°C, pressure 0.5-1.0MPa, time 3-5 minutes). The layers are then rapidly cooled by water-cooled rollers (20-25°C) to avoid uneven shrinkage between layers. Finally, the layers are wound up with tension controlled (≤10N / cm) to prevent tensile deformation.

[0032] By means of the above technical solution, the PVC geomembrane and the manufacturing method thereof of the present invention have at least the following beneficial effects:

[0033] 1. Compared with the existing technology, the PVC geomembrane is made of PVC resin (SG-5), cross-linking agent masterbatch, carbon black (N330), plasticizer (DOP), stabilizer (calcium zinc) and lubricant (stearic acid) to make the surface layer, glass fiber cloth, PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and coupling agent (silane coupling agent KH-550) to make the reinforcement layer, PVC resin (SG-5), plasticizer (DOP / ESO), filler (calcium carbonate), stabilizer (calcium zinc), lubricant (stearic acid), foaming agent (AC foaming agent) and carbon black (N330) to make the bottom layer, thereby enhancing the sealing, UV resistance, conductivity, tensile strength, puncture resistance and dimensional stability of the PVC geomembrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the overall structural diagram of a PVC geomembrane proposed by the present invention;

[0035] Figure 2 This is an exploded view of a PVC geomembrane proposed by the present invention;

[0036] Figure 3 A cross-sectional view of a PVC geomembrane proposed in the present invention;

[0037] Figure 4 for Figure 3 Enlarged schematic diagram of point A in the middle.

[0038] Legend:

[0039] 1. Surface layer; 2. Reinforcement layer; 3. Bottom layer. DETAILED DESCRIPTION

[0040] Reference Figure 1-4 The present invention provides a PVC geomembrane: comprising a surface layer 1, the surface layer 1 plays the role of UV resistance and wear resistance, a reinforcement layer 2 and a bottom layer 3, the reinforcement layer 2 bears mechanical stress, the bottom layer 3 plays the role of anti-slip and bonding base, the lower surface of the surface layer 1 is fixedly connected to the upper surface of the reinforcement layer 2, the lower surface of the reinforcement layer 2 is fixedly connected to the upper surface of the bottom layer 3, and the reinforcement layer 2 is placed between the surface layer 1 and the bottom layer 3;

[0041] Surface layer 1 is made of PVC resin (SG-5), crosslinker masterbatch, carbon black (N330), plasticizer (DOP), stabilizer (calcium zinc) and lubricant (stearic acid);

[0042] PVC resin (SG-5) serves as the matrix material, providing structural strength. Crosslinker masterbatch increases molecular crosslinking, enhancing heat resistance and creep resistance. Carbon black (N330) resists UV rays and improves conductivity, extending outdoor life. Plasticizer (DOP) improves flexibility (resists brittle cracking at low temperatures). Stabilizer (calcium zinc) prevents thermal degradation during processing (calcium zinc stabilizers are also environmentally friendly). Lubricant (stearic acid) reduces friction during processing.

[0043] The reinforcement layer 2 is made of glass fiber cloth, PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and coupling agent (silane coupling agent KH-550);

[0044] Glass fiber cloth provides a high-strength skeleton to withstand mechanical stress. PVC resin (SG-5) serves as the matrix material to bond the glass fiber cloth. Plasticizers (DOP / ESO) can improve the flexibility of PVC and facilitate compounding. Stabilizers (calcium zinc) can prevent thermal degradation during processing. Coupling agents (silane coupling agent KH-550) enhance the interfacial bonding between PVC and glass fiber.

[0045] The bottom layer 3 is made of PVC resin (SG-5), plasticizer (DOP / ESO), filler (calcium carbonate), stabilizer (calcium zinc), lubricant (stearic acid), foaming agent (AC foaming agent) and carbon black (N330);

[0046] PVC resin (SG-5) serves as the matrix material, providing an anti-seepage main body. Plasticizers (DOP / ESO) can improve the flexibility of PVC. Fillers (calcium carbonate) can reduce costs and increase surface roughness (particle size 5-20μm). Stabilizers (calcium zinc) can prevent thermal degradation during processing. Lubricants (stearic acid) can reduce processing friction and prevent roller sticking. Foaming agents (AC foaming agents) can form a rough surface structure through micro-foaming. Carbon black (N330) provides UV resistance.

[0047] The surface layer 1 contains 100 parts of PVC resin (SG-5), 5-10 parts of crosslinking agent masterbatch, 3-5 parts of carbon black (N330), 30-40 parts of plasticizer (DOP), 2-3 parts of stabilizer (calcium zinc) and 0.5-1 part of lubricant (stearic acid); the reinforcement layer 2 contains glass fiber cloth with a weight of 100-300g / m², 100 parts of PVC resin (SG-5), 30-40 parts of plasticizer (DOP / ESO), The stabilizer (calcium zinc) is 2 to 3 parts and the coupling agent (silane coupling agent KH-550) is 0.5 to 1 part; the bottom layer 3 contains 100 parts of PVC resin (SG-5), 30 to 40 parts of plasticizer (DOP / ESO), 20 to 30 parts of filler (calcium carbonate), 2 to 3 parts of stabilizer (calcium zinc), 0.5 to 1 part of lubricant (stearic acid), 0.2 to 0.5 parts of foaming agent (AC foaming agent) and 1 to 2 parts of carbon black (N330).

[0048] A method for manufacturing a PVC geomembrane, using the PVC geomembrane according to any one of claims 1 to 4, characterized in that it comprises the following steps:

[0049] S1. When making surface layer 1:

[0050] (1) Pretreatment: Carbon black (N330) needs to be mixed with plasticizer (DOP) in a 1:1 ratio and stirred at high speed (≥1000 rpm, 30 minutes) to form a slurry to avoid agglomeration; PVC resin and filler are dried at 80 ° C for 2 hours to remove moisture (to prevent processing bubbles);

[0051] (2) Mixing and kneading: Use a high-speed mixer and an internal mixer to add the PVC resin (SG-5), plasticizer (DOP) and carbon black (N330) slurry into the high-speed mixer, heat it to 100-110°C and mix for 5 minutes, add the crosslinker masterbatch, stabilizer (calcium zinc) and lubricant (stearic acid), continue mixing to 120°C (to avoid premature reaction of the crosslinker), then transfer to the internal mixer (temperature 150-160°C), and knead for 8-10 minutes until it is completely plasticized;

[0052] (3) Calendering film: Use a four-roll calender (roller temperature 160-180℃), roller speed ratio: 1:1.2:1.5:1.8 (gradual stretching to avoid internal stress), thickness: adjusted by roller spacing (surface thickness 0.2-0.5mm), surface treatment: immediately pass through a water-cooled roller (20-30℃) after calendering to reduce thermal shrinkage;

[0053] (4) Post-treatment: Improve adhesion through corona treatment or chemical etching (such as immersion in sulfuric acid for 10 seconds); spray polyurethane / acrylic coating (thickness 10-20 μm) to further extend life.

[0054] S2. When making enhancement layer 2:

[0055] (1) Pretreatment of glass fiber cloth: Immerse the glass fiber cloth in acetone or 3% NaOH solution and ultrasonically clean it for 10 minutes to remove the surface slurry (to improve wettability). Wash it with water and then dry it (100°C, 2 hours). Prepare 1% silane coupling agent (KH-550) ethanol solution, spray or impregnate the glass fiber cloth, dry it, and heat treat it at 120°C for 20 minutes to form a chemical bonding layer.

[0056] (2) Preparation of PVC mortar: Mix PVC resin (SG-5) with plasticizer (DOP / ESO) and stabilizer (calcium zinc), stir at high speed (500 rpm, 10 minutes), add solvent (THF or cyclohexanone) and adjust the viscosity to 5000-8000 cP (for easy coating);

[0057] (3) Composite process (calendering method): Use a four-roll calender and a composite oven to make the PVC slurry into a 0.3-0.5 mm thick film through the calender (roller temperature 160-170 ° C), and make two PVC films. The pretreated glass fiber cloth is evenly laid on one of the prepared PVC films, and initially composited through a hot pressing roller (180 ° C, pressure 0.5 MPa). PVC slurry is scraped on the surface of the glass fiber cloth (coating amount 200-300 g / m²), covered with another layer of PVC film, and finally bonded through a composite oven (190 ° C, 2 minutes), and then quickly cooled using a water-cooled roller (20 ° C), and rolled up (tension control ≤ 10 N / cm).

[0058] S3, when making bottom layer 3:

[0059] (1) Raw material pretreatment: PVC resin (SG-5) is dried at 80℃ for 2 hours, with a moisture content of ≤0.1%. The filler is activated, and calcium carbonate is surface treated with a silane coupling agent (KH-570) (1% concentration spray) to improve compatibility with PVC.

[0060] (2) Mixing and kneading: Add PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and lubricant (stearic acid) to a high-speed mixer, heat to 100-110°C and mix for 5 minutes, add filler (calcium carbonate) and carbon black, continue mixing to 120°C (to ensure uniform dispersion), transfer to a mixer (150-160°C), knead for 8-10 minutes until completely plasticized, add foaming agent, and add it in the last 2 minutes to avoid premature decomposition;

[0061] (3) Calendering (rough surface treatment): Use a four-roll calender (with patterned rollers), roller temperature: upper roller (patterned roller) 160°C, lower roller (smooth roller) 150°C, roller speed: patterned roller is 10% to 20% slower than smooth roller, enhance embossing depth, pressure: 0.3 to 0.5 MPa, ensure clear pattern, rough surface effect: concave and convex height 0.2 to 0.5 mm, friction coefficient ≥ 0.4 (dry state).

[0062] S4, hot pressing composite process:

[0063] The surface layer 1 and the bottom layer 3 are softened with an infrared heater (120-140°C) to enhance adhesion. PVC adhesive (PVC resin + DOP + solvent, viscosity 5000cP) is applied to both sides of the reinforcement layer 2 at a coating amount of 100-150g / m². The layers are then laid in the following order: surface layer 1 → reinforcement layer 2 → bottom layer 3, ensuring alignment without wrinkles. The layers are then hot-pressed and laminated using a multi-layer hot press (temperature 180-200°C, pressure 0.5-1.0MPa, time 3-5 minutes). The layers are then rapidly cooled by water-cooled rollers (20-25°C) to avoid uneven shrinkage between layers. Finally, the layers are wound up with tension controlled (≤10N / cm) to prevent tensile deformation.

[0064] Working principle: In the process of making PVC geomembrane, it needs to be divided into four major steps. First, the surface layer 1 is made. In the process of making the surface layer 1, PVC resin (SG-5), crosslinking agent masterbatch, carbon black (N330), plasticizer (DOP), stabilizer (calcium zinc) and lubricant (stearic acid) materials are selected. First, carbon black (N330) needs to be pre-mixed with plasticizer (DOP) in a 1:1 ratio and stirred at high speed (≥1000rpm, 30 minutes) to make slurry to avoid agglomeration; PVC resin and filler are dried at 80℃ for 2 hours to remove moisture (to prevent processing bubbles), and then PVC resin (SG-5), plasticizer (DOP) and carbon black (N330) are mixed in a high-speed mixer and internal mixer. 30) Add the slurry to the high-speed mixer, heat it to 100-110℃ and mix it for 5 minutes, add the crosslinker masterbatch, stabilizer (calcium zinc) and lubricant (stearic acid), continue mixing to 120℃ (to avoid premature reaction of the crosslinker), then transfer it to the internal mixer (temperature 150-160℃), mix it for 8-10 minutes until it is completely plasticized, and then use a four-roll calender (roller temperature 160-180℃) to calender the plasticized material. The roller speed ratio is: 1:1.2:1.5:1.8 (gradual stretching to avoid internal stress), and the thickness of the product is controlled by adjusting the roller distance (surface thickness 0.2-0.5mm). After calendering, it is immediately shaped by water-cooled rollers (20-30℃) to reduce thermal shrinkage, and finally passed through Corona treatment or chemical etching (such as immersion in sulfuric acid for 10 seconds) improves adhesion; spray polyurethane / acrylic coating (thickness 10-20μm) to further extend the service life, thereby completing the production of surface layer 1; the second step is to make reinforcement layer 2. During the production process of reinforcement layer 2, glass fiber cloth, PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and coupling agent (silane coupling agent KH-550) are selected. First, the glass fiber cloth is immersed in acetone or 3% NaOH solution for ultrasonic cleaning for 10 minutes to remove surface slurry (to improve wettability), washed with water and dried (100℃, 2 hours), and a 1% silane coupling agent (KH-550) ethanol solution is prepared. Spray or impregnate the glass fiber cloth, dry it, and heat treat it at 120℃ for 20 minutes to form a chemical bonding layer. Then, mix the PVC resin (SG-5) with the plasticizer (DOP / ESO) and stabilizer (calcium zinc), stir it at high speed (500rpm, 10 minutes), add solvent (THF or cyclohexanone) to adjust the viscosity to 5000-8000cP (for easy coating). Then, use a four-roll calender and a composite oven to pass the PVC slurry through the calender (roller temperature 160-170℃) to form a 0.3-0.5mm thick film. Two PVC films need to be made. The pre-treated glass fiber cloth is evenly laid on one of the prepared PVC films and passed through a hot pressing roller (180℃, pressure 0.5MPa) for preliminary compounding, PVC glue is scraped on the surface of the glass fiber cloth (coating amount 200-300g / m²), covered with another layer of PVC film, and the final bonding is completed by passing through a composite oven (190℃, 2 minutes), and then quickly cooled by a water-cooled roller (20℃), and rolled up (tension control ≤10N / cm); the third step is to make the bottom layer 3, which uses PVC resin (SG-5), plasticizer (DOP / ESO), filler (calcium carbonate), stabilizer (calcium zinc), lubricant (stearic acid), foaming agent (AC foaming agent) and carbon black (N330) materials. First, the PVC resin (SG-5) is dried and baked at 80℃ for 2 hours. The moisture content is ≤0.1%, the filler is activated, and the calcium carbonate is surface treated with a silane coupling agent (KH-570) (1% concentration spray) to improve its compatibility with PVC. Then, the PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and lubricant are added. Add the agent (stearic acid) to the high-speed mixer, heat it to 100-110℃ and mix for 5 minutes, add filler (calcium carbonate) and carbon black, continue mixing until the temperature reaches 120℃ (to ensure uniform dispersion), transfer to the internal mixer (150-160℃), mix for 8-10 minutes until it is completely plasticized, add the foaming agent, which should be added in the last 2 minutes to avoid premature decomposition, and then use a four-roll calender (with patterned rollers), with the roller temperature of the upper roller (patterned roller) at 160℃ and the lower roller (smooth roller) at 150℃. The roller speed is 10% to 20% slower than that of the smooth roller, the embossing depth is enhanced, the pressure is 0.3 to 0.5 MPa, the pattern is clear, the rough surface effect is a concave-convex height of 0.2 to 0.5 mm, and the friction coefficient is ≥ 0.4 (dry state); finally, the surface layer 1, the reinforcement layer 2 and the bottom layer 3 are hot-pressed and laminated, the surface and the bottom layer are softened by an infrared heater (120 to 140 ° C) to enhance the adhesion, and PVC adhesive (PVC resin + DOP + solvent (viscosity 5000 cP) is applied at a coating weight of 100-150 g / m². The layers are then laid in the following order: top layer → reinforcement layer → base layer, ensuring alignment and wrinkle-free. The layers are then laminated using a multi-layer hot press (temperature 180-200°C, pressure 0.5-1.0 MPa, time 3-5 minutes). The layers are then rapidly cooled by water-cooled rollers (20-25°C) to prevent uneven shrinkage between layers. Finally, the layers are rolled up, with tension controlled (≤10 N / cm) to prevent tensile deformation. This completes the PVC geomembrane, which offers improved sealing, UV resistance, conductivity, tensile strength, puncture resistance, and dimensional stability compared to existing PVC geomembranes.

[0065] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A PVC geomembrane comprising a surface layer (1), a reinforcement layer (2) and a bottom layer (3), characterized in that: The lower surface of the surface layer (1) is fixedly connected to the upper surface of the reinforcement layer (2), the lower surface of the reinforcement layer (2) is fixedly connected to the upper surface of the bottom layer (3), and the reinforcement layer (2) is placed between the surface layer (1) and the bottom layer (3); The surface layer (1) is made of PVC resin (SG-5), crosslinking agent masterbatch, carbon black (N330), plasticizer (DOP), stabilizer (calcium zinc) and lubricant (stearic acid); The reinforcing layer (2) is made of glass fiber cloth, PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and coupling agent (silane coupling agent KH-550); The bottom layer (3) is made of PVC resin (SG-5), plasticizer (DOP / ESO), filler (calcium carbonate), stabilizer (calcium zinc), lubricant (stearic acid), foaming agent (AC foaming agent) and carbon black (N330).

2. A PVC geomembrane according to claim 1, characterized in that: The surface layer (1) comprises 100 parts of PVC resin (SG-5), 5 to 10 parts of crosslinking agent masterbatch, 3 to 5 parts of carbon black (N330), 30 to 40 parts of plasticizer (DOP), 2 to 3 parts of stabilizer (calcium zinc) and 0.5 to 1 part of lubricant (stearic acid).

3. The PVC geomembrane according to claim 1, characterized in that: The reinforcing layer (2) comprises a glass fiber cloth having a weight of 100 to 300 g / m², 100 parts of PVC resin (SG-5), 30 to 40 parts of plasticizer (DOP / ESO), 2 to 3 parts of stabilizer (calcium zinc) and 0.5 to 1 part of coupling agent (silane coupling agent KH-550).

4. The PVC geomembrane according to claim 1, characterized in that: The bottom layer (3) contains 100 parts of PVC resin (SG-5), 30 to 40 parts of plasticizer (DOP / ESO), 20 to 30 parts of filler (calcium carbonate), 2 to 3 parts of stabilizer (calcium zinc), 0.5 to 1 part of lubricant (stearic acid), 0.2 to 0.5 parts of foaming agent (AC foaming agent) and 1 to 2 parts of carbon black (N330).

5. A method for manufacturing a PVC geomembrane, using the PVC geomembrane according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. When making the surface layer (1): (1) Pretreatment: Carbon black (N330) needs to be mixed with plasticizer (DOP) in a 1:1 ratio and stirred at high speed (≥1000 rpm, 30 minutes) to form a slurry to avoid agglomeration; PVC resin and filler are dried at 80 ° C for 2 hours to remove moisture (to prevent processing bubbles); (2) Mixing and kneading: Use a high-speed mixer and an internal mixer to add the PVC resin (SG-5), plasticizer (DOP) and carbon black (N330) slurry into the high-speed mixer, heat it to 100-110°C and mix for 5 minutes, add the crosslinker masterbatch, stabilizer (calcium zinc) and lubricant (stearic acid), continue mixing to 120°C (to avoid premature reaction of the crosslinker), then transfer to the internal mixer (temperature 150-160°C), and knead for 8-10 minutes until it is completely plasticized; (3) Calendering film: Use a four-roll calender (roller temperature 160-180℃), roller speed ratio: 1:1.2:1.5:1.8 (gradual stretching to avoid internal stress), thickness: adjusted by roller spacing (surface thickness 0.2-0.5mm), surface treatment: immediately pass through a water-cooled roller (20-30℃) after calendering to reduce thermal shrinkage; (4) Post-treatment: Improve adhesion through corona treatment or chemical etching (such as immersion in sulfuric acid for 10 seconds); spray polyurethane / acrylic coating (thickness 10-20 μm) to further extend life. S2. When making the enhancement layer (2): (1) Pretreatment of glass fiber cloth: Immerse the glass fiber cloth in acetone or 3% NaOH solution and ultrasonically clean it for 10 minutes to remove the surface slurry (to improve wettability). Wash it with water and then dry it (100°C, 2 hours). Prepare 1% silane coupling agent (KH-550) ethanol solution, spray or impregnate the glass fiber cloth, dry it, and heat treat it at 120°C for 20 minutes to form a chemical bonding layer. (2) Preparation of PVC mortar: Mix PVC resin (SG-5) with plasticizer (DOP / ESO) and stabilizer (calcium zinc), stir at high speed (500 rpm, 10 minutes), add solvent (THF or cyclohexanone) and adjust the viscosity to 5000-8000 cP (for easy coating); (3) Composite process (calendering method): Use a four-roll calender and a composite oven to make a 0.3-0.5 mm thick film through a calender (roller temperature 160-170 ° C). Two PVC films need to be made. The pretreated glass fiber cloth is evenly laid on one of the prepared PVC films. It is preliminarily composited by a hot pressing roller (180 ° C, pressure 0.5 MPa). PVC slurry is scraped on the surface of the glass fiber cloth (coating amount 200-300 g / m²), covered with another layer of PVC film, and finally bonded by passing through a composite oven (190 ° C, 2 minutes). It is then quickly cooled by a water-cooled roller (20 ° C) and rolled up (tension control ≤ 10 N / cm). S3. When making the bottom layer (3): (1) Raw material pretreatment: PVC resin (SG-5) is dried at 80℃ for 2 hours, with a moisture content of ≤0.1%. The filler is activated, and calcium carbonate is surface treated with a silane coupling agent (KH-570) (1% concentration spray) to improve compatibility with PVC. (2) Mixing and kneading: Add PVC resin (SG-5), plasticizer (DOP / ESO), stabilizer (calcium zinc) and lubricant (stearic acid) to a high-speed mixer, heat to 100-110°C and mix for 5 minutes, add filler (calcium carbonate) and carbon black, continue mixing to 120°C (to ensure uniform dispersion), transfer to a mixer (150-160°C), knead for 8-10 minutes until completely plasticized, add foaming agent, and add it in the last 2 minutes to avoid premature decomposition; (3) Calendering (rough surface treatment): Use a four-roll calender (with patterned rollers), roller temperature: upper roller (patterned roller) 160°C, lower roller (smooth roller) 150°C, roller speed: patterned roller is 10% to 20% slower than smooth roller, enhance embossing depth, pressure: 0.3 to 0.5 MPa, ensure clear pattern, rough surface effect: concave and convex height 0.2 to 0.5 mm, friction coefficient ≥ 0.4 (dry state). S4, hot pressing composite process: The surface layer (1) and the bottom layer (3) are softened by an infrared heater (120-140°C) to enhance the bonding property. PVC adhesive (PVC resin + DOP + solvent, viscosity 5000 cP) is coated on both sides of the reinforcement layer (2) with a coating amount of 100-150 g / m². Then, they are laid in the following order: surface layer (1) → reinforcement layer (2) → bottom layer (3), ensuring that they are aligned and wrinkle-free. Then, they are hot-pressed and laminated by a multi-layer hot press (temperature 180-200°C, pressure 0.5-1.0 MPa, time 3-5 minutes), and then quickly cooled by a water-cooled roller (20-25°C) to avoid uneven shrinkage between layers. Finally, they are rolled up and the tension is controlled (≤10 N / cm) to prevent stretching deformation.

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