Construction process of anti-fouling sewage pool

Abstract

The present application relates to the field of industrial anticorrosion technology, and particularly relates to an anti-corrosion sewage tank construction process, comprising the following steps: treating a sewage tank base layer, brushing a primer on the base layer to form a permeable primer layer, spraying a sealing primer on the permeable primer layer to form a sealing primer layer; forming a plurality of middle coating cloth layers on the sealing primer layer, laying a second middle coating cloth layer after the solidification of a first middle coating cloth layer, and so on, coating a glass flake mortar layer on the uppermost middle coating cloth layer, coating an anticorrosion topcoat on the glass flake mortar layer after the solidification of the glass flake mortar layer, and then curing. The present application increases the thickness and density of the anticorrosion layer, doubles the anti-permeation time of strong corrosive media, is suitable for more severe long-term immersion environment, and enhances the tensile strength, impact resistance and compressive strength of the structure, and greatly improves the anti-deformation and cracking capacity of the base layer.

Description

Technical Field

[0001] This invention relates to the field of industrial corrosion protection technology, and in particular to a construction process for corrosion-resistant sewage tanks. Background Technology

[0002] In highly corrosive industrial environments such as electroplating, chemical processing, and wastewater treatment, corrosion protection of concrete structures is crucial. Traditional corrosion protection methods, such as applying ordinary coatings or single-layer fiberglass, often fail prematurely due to factors like corrosive media penetration, insufficient mechanical strength, or thermal stress, resulting in short protection cycles and high maintenance costs. To improve protective performance, the industry has developed composite corrosion protection processes, which exhibit superior performance compared to ordinary coatings under certain operating conditions. However, with increasingly harsh industrial corrosive environments, such as higher concentrations of acids and alkalis, continuous immersion, and temperature shocks, [further challenges arise]. Traditional composite anti-corrosion processes can no longer meet the requirements for long-term protection. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a construction process for anti-corrosion sewage tanks that extends the anti-permeability time of highly corrosive media and is suitable for more demanding long-term immersion environments.

[0004] To address the aforementioned technical problems, this application provides the following technical solution: This invention discloses a construction process for an anti-corrosion sewage tank, comprising the following steps: Step 1: Treat the base layer of the sewage tank to form a flat, solid, and clean base surface; Step 2: Apply a primer to the substrate to form a penetrating primer layer. The primer is made by mixing and stirring vinyl ester resin primer, curing agent, and accelerator in a certain proportion. Step 3: Spray a sealing primer onto the penetrating primer layer to form a sealing primer layer; Step 4: Form multiple intermediate coating fabric layers on the sealing primer layer. Each intermediate coating fabric layer includes a fiberglass cloth and a vinyl ester resin layer. Lay the fiberglass cloth on the sealing primer layer, and apply vinyl ester resin to the fiberglass cloth to impregnate it and form a vinyl ester resin layer. After the first intermediate coating fabric layer has cured, lay the second intermediate coating fabric layer, and so on. Step 5: Apply a glass flake putty layer onto the topmost intermediate coating fabric layer. The mass ratio of resin, flakes, and curing agent in the glass flake putty is 1:0.3:0.02. Step 6: After the glass flake putty layer has cured, apply an anti-corrosion topcoat to the glass flake putty layer; Step 7: The anti-corrosion topcoat should be cured for 7-14 days, and the remaining layers should be cured for at least 48 hours.

[0005] Compared with the prior art, the construction process of the anti-corrosion sewage tank of the present invention has at least the following beneficial effects: This invention discloses a construction process for an anti-corrosion sewage tank. Because multiple layers of intermediate coating fabric are formed on a sealed primer layer, with fiberglass cloth and vinyl ester resin layers forming each intermediate coating fabric layer, the thickness and density of the anti-corrosion layer are increased. This significantly extends the resistance time to strong corrosive media such as sulfuric acid, hydrochloric acid, and hydrofluoric acid, making it suitable for more demanding long-term immersion environments. The fiberglass cloth layers form a three-dimensional reinforcing network, greatly enhancing the tensile strength, impact resistance, compressive strength, and resistance to substrate deformation and cracking. The reinforced composite structure makes the anti-corrosion system more durable under the dual effects of physical and chemical corrosion, significantly reducing maintenance frequency.

[0006] The construction process of the anti-corrosion sewage tank of the present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0007] Figure 1 This is a structural schematic diagram of the construction process of a corrosion-resistant sewage tank according to the present invention. Detailed Implementation

[0008] like Figure 1 As shown, the present invention provides a construction process for an anti-corrosion sewage tank, comprising the following steps: Step 1: Treat the base layer 2 of the sewage tank to form a flat, solid, and clean base surface 1, free of oil, loose sand, and loose layer. Specifically, the base layer 2 of the sewage tank can be made of concrete or other materials. Inspect the base layer 2 of the sewage tank to ensure that its strength is >300kg / cm2 and its moisture content is ≤8%. Then clean the base surface 1: First, use a high-pressure water gun to rinse the base surface 1 to remove floating dust and loose particles, ensuring that the base surface 1 has no loose layer; for oily areas, wipe and clean with organic solvents, then rinse with clean water and let it dry. The organic solvent used is acetone. Use vinyl ester resin mortar to repair and level the depressions, holes, cracks and the entire base surface 1 to ensure that the base surface 1 is flat and solid. Step 2: Apply primer to substrate 1 to form a penetrating primer layer 3. The primer is made by mixing vinyl ester resin primer, hardener, and accelerator in a specific ratio and stirring thoroughly. For every 100 kg of vinyl ester resin primer, add: hardener: 1.5-2.5 kg, accelerator: 0.5-1.5 kg. Stir for ≥5 minutes to ensure no sedimentation or clumping. The primer should be used within its pot life, which is 20-30 minutes. Step 3: Spray a sealing primer onto the penetrating primer layer 3 to form a sealing primer layer 4; Specifically, the sealing primer is stirred thoroughly beforehand. Its composition differs from the primer in step two. The penetrating primer has low viscosity and high penetration, achieving microscopic anchoring and substrate reinforcement. The sealing primer has medium-to-high viscosity and a dense film, forming a continuous barrier and interface transition. Together, they create a "gradient transition" from the substrate to the main anti-corrosion layer, optimizing adhesion and impermeability. In step three, the sealing primer needs to be sprayed onto the anti-corrosion penetrating primer layer 3 using an airless sprayer to form the anti-corrosion sealing primer layer 4, with a thickness of 0.05mm. After spraying, visually inspect to ensure no missed areas or exposed substrate. Smooth any areas with drips or runs with a scraper. Cure for 3-4 hours until the surface is dry. The standard formulation of the sealing primer is based on the matching vinyl ester resin. Its main component is a precise premix of resin, reactive diluent (5-15%), functional pigments and fillers (20-40%), and special additives. During construction, it is necessary to strictly follow the supplier's technical instructions and add 1-2.5% curing agent and 0.5-1.5% accelerator on site, mix, and then use.

[0009] Step 4: Form multiple layers of intermediate coating fabric on the sealing primer layer 4; Fiberglass cloth 5 is laid on the sealing primer layer 4, and vinyl ester resin is applied to the fiberglass cloth 5 to impregnate the fiberglass cloth 5 and remove air bubbles to form a vinyl ester resin layer 6. The fiberglass cloth 5 and the vinyl ester resin layer 6 form the first intermediate coating cloth layer. After the first intermediate coating cloth layer is cured, the second intermediate coating cloth layer is laid until the anti-corrosion requirements are met. In this embodiment, six intermediate coating cloth layers are set, and the total thickness of the multi-layer intermediate coating cloth layer is 2.7mm ± 0.06mm. Specifically, when applying vinyl ester resin to the fiberglass cloth 5, a trowel or roller is used. During the construction of the intermediate coating cloth layer, after the first intermediate coating cloth layer is firmly bonded and completely cured, the second intermediate coating cloth layer is laid. During the laying of the second intermediate coating cloth layer, the coating and bubble-removing steps are repeated. After each layer of fiberglass cloth is laid, vinyl ester resin is immediately applied to impregnate it until the construction of six layers of fiberglass cloth is completed. Step 5: Apply glass flake putty layer 7 on the top intermediate coating fabric layer. The mass ratio of resin, flakes and curing agent in the glass flake putty is 1:0.3:0.02. Stir until the flakes are evenly dispersed and there is no agglomeration. The coating should be completed within 20 minutes after preparation. Step 6: After the glass flake putty layer 7 has cured, apply anti-corrosion topcoat 8 onto the glass flake putty layer 7. The anti-corrosion topcoat is a high-performance chemical-resistant resin (usually a matching vinyl ester) as the base material, with the addition of weather-resistant pigments, functional additives and curing system. The anti-corrosion topcoat 8 improves the surface density, impermeability and weather resistance, and extends the overall service life of the anti-corrosion sewage tank. The base material of the anti-corrosion topcoat is usually a matching vinyl ester or aliphatic polyurethane resin; the weather-resistant pigment is mainly rutile titanium dioxide; the functional additives include ultraviolet absorbers, thixotropic agents, etc.; the curing system is cobalt accelerator and peroxide curing agent. The general proportion is roughly as follows: based on 100 parts of resin, 10 - 30 parts of pigment, 1 - 5 parts of additives, and the curing agent and accelerator are added at 1 - 2.5% and 0.5 - 1.5% of the total weight of the main agent during construction.

[0010] Step 7: Cure for at least 48 hours in a suitable environment. The specific requirements for the environment are as follows: the temperature is controlled at 10 - 35°C (the best is 15 - 30°C), the relative humidity is less than 85%, the base surface temperature is higher than the dew point by more than 3°C, the ventilation is good and clean, and it is a stable environment without pollution sources and physical interference, and this state needs to be maintained for at least 48 hours. In short, it is the eight characters of "constant temperature, low humidity, ventilation, and cleanliness". Strictly following this requirement is the last key process to ensure that the anti-corrosion topcoat can exert its designed service life and protection performance. The anti-corrosion topcoat is cured for 7 - 14 days to achieve the best performance.

[0011] After the curing is completed, thickness detection, adhesion detection, and appearance detection are carried out. Specifically, a coating thickness gauge is used for thickness detection. If the total number of detection points ≥ 5, the average thickness ≥ 3.2 mm, and the minimum thickness ≥ 3.1 mm, it is qualified; the pull-off method is used for adhesion detection. If the adhesion measured by the pull-off method meets the specification requirements and there is no interlayer peeling, the adhesion detection is qualified; if there is no missed coating, cracks, bubbles, wrinkles on the surface, the color is uniform, and the flatness error ≤ 2 mm / 2 m, the appearance detection is qualified. For a construction process of an anti-corrosion sewage tank in the present invention, since multiple intermediate coating cloth layers are formed on the closed primer layer 4, and the fiberglass cloth 5 and vinyl ester resin layer 6 form each intermediate coating cloth layer, the thickness and density of the anti-corrosion layer are increased, and the anti-permeation time for strong corrosive media such as sulfuric acid, hydrochloric acid, and hydrofluoric acid is doubled, which is applicable to more demanding long-term immersion environments. Each fiberglass cloth layer forms a three-dimensional reinforcement network, greatly enhancing the tensile strength of the structure, improving the impact resistance, enhancing the compressive strength, and also significantly improving the ability to resist cracking of the base layer deformation. The enhancement of the composite structure makes the anti-corrosion system more durable under the dual action of physical and chemical corrosion, and significantly reduces the maintenance frequency.

[0012] Optionally, in Step 1, the base surface 1 is polished to enhance the coating adhesion. Specifically, a grinding machine is used for comprehensive cross-grinding to roughen the base surface. After grinding, the dust is removed to ensure that there is no residual floating dust on the base surface 1.

[0013] Optionally, in step two, when applying the primer, use a short-nap roller or trowel to apply it evenly, ensuring that the primer completely covers the substrate 1 without any missed areas or runs; after application, cure under the specified environmental conditions until the primer surface is dry and hardened, and not sticky to the touch, before proceeding to the next step; when applying the primer, the construction environment must meet the following requirements: temperature 5-40℃, relative humidity <85%, and substrate temperature more than 3℃ above the dew point.

[0014] Optionally, in step four, the fiberglass cloth of the multi-layer intermediate coating layer is laid in an interlaced manner, with the distance between the upper and lower layers of fiberglass cloth being ≥50mm. The multi-layer interlaced laying process effectively avoids overall failure caused by single-point defects, has a higher construction fault tolerance rate, and performs better in complex parts such as pool corners and joints.

[0015] Optionally, in step five, during the application of the glass flake putty layer 7, a thin coat is applied using a flat-edged trowel, with the trowel angle controlled at approximately 30°. The required angle is a 30° angle between the blade surface and the surface being coated. The coating rate is 0.2 kg / m², and the thickness is 0.2 mm. After coating, it is cured at room temperature for 8-12 hours until the glass flake putty layer is completely cured, with no indentation when pressed and no bubbles or pinholes on the surface.

[0016] Optionally, in step six, the surface of the glass flake putty layer 7 is first cleaned. During cleaning, the surface particles of the glass flake putty layer 7 are polished with 240-grit sandpaper, and the dust is removed after polishing. Optionally, in step six, the anti-corrosion topcoat is made by mixing the topcoat and the curing agent in a certain proportion. After stirring evenly, it is allowed to stand for about five minutes to defoam. Then, it is applied by roller coating or self-leveling process. After coating, the surface has good leveling properties, no trowel marks or bubbles, and uniform color. It is cured for 24 hours until it is completely dry. The thickness of the anti-corrosion topcoat 8 is 0.25mm ± 0.02mm. Optionally, in step six, after the anti-corrosion topcoat 8 dries, an anti-corrosion reinforcing topcoat containing a desiccant is applied over the anti-corrosion topcoat 8 to further improve the surface density, impermeability, and weather resistance of the anti-corrosion sewage tank, thereby extending its overall service life.

[0017] Optionally, enhance the curing of the topcoat for 7-14 days to achieve optimal performance.

[0018] Example 2 A construction process for a corrosion-resistant sewage tank includes the following steps: Step 1: Same as Example 1; Step 2: Apply primer to the base surface 1 to form a penetrating primer layer 3. Add 2.0 kg of curing agent and 1.0 kg of accelerator for every 100 kg of vinyl ester resin primer, and the rest is the same as in Example 1; Step 3: Same as Example 1; Step 4: Form a multi-layer intermediate coating fabric layer on the sealing primer layer 4. A total of four intermediate coating fabric layers are laid, with the total thickness controlled at 2.0mm ± 0.06mm. The rest is the same as in Example 1. Step 5: Same as Example 1; Step 6: Same as Example 1; Step 7: Curing the anti-corrosion topcoat for 10 days, and curing the remaining layers for at least 48 hours; Example 3 A construction process for a corrosion-resistant sewage tank includes the following steps: Step 1: Same as Example 1; Step 2: Apply primer to base surface 1 to form penetrating primer layer 3. Add 2.5 kg of curing agent and 1.5 kg of accelerator for every 100 kg of vinyl ester resin primer, and the rest is the same as in Example 1; Step 3: Same as Example 1; Step 4: Form a multi-layer intermediate coating fabric layer on the sealing primer layer 4. A total of eight intermediate coating fabric layers are laid, with the total thickness controlled at 3.2mm ± 0.06mm. The rest is the same as in Example 1. Step 5: Same as Example 1.

[0019] Step 6: After the glass flake putty layer 7 has cured, apply anti-corrosion topcoat 8 on the glass flake putty layer 7. After the anti-corrosion topcoat 8 dries, apply another layer of anti-corrosion reinforcing topcoat. The anti-corrosion reinforcing topcoat is then cured for ten days. Step 7: Curing of the anti-corrosion topcoat and the reinforced topcoat for 14 days, and curing of the remaining layers for at least 48 hours.

[0020] Comparative Example 1 (without glass flake putty layer) A construction process for a corrosion-resistant sewage tank includes the following steps: Step 1: Same as Example 1; Step 2, same as in Example 1; Step 3: Same as Example 1; Step 4: Form a multi-layer intermediate coating fabric layer on the sealing primer layer 4, with a total of six layers, and control the total thickness at 2.7mm ± 0.06mm; Step 5: Omitted; Step 6: Apply anti-corrosion topcoat 8 directly onto the top layer of intermediate coating fabric completed in Step 4, and the rest is the same as in Example 1; Step 7: Cure the anti-corrosion topcoat for 7 days, and the remaining layers for at least 48 hours.

[0021] Comparative Example 2 (Single-layer intermediate coating with fabric) A construction process for a corrosion-resistant sewage tank includes the following steps: Step 1: Same as Example 1; Step 2, same as in Example 1; Step 3: Same as Example 1; Step 4: Form a mid-coat cloth layer on the sealing primer layer 4, including a glass fiber cloth layer 5 and a vinyl ester resin layer 6, with a thickness of 0.45mm; Step 5: Same as Example 1; Step 6: Same as Example 1; Step 7: Same as Example 1; Comparative Example 3 (without intermediate coating layer) A construction process for a corrosion-resistant sewage tank includes the following steps: Step 1: Same as Example 1; Step 2, same as in Example 1; Step 3: Same as Example 1; Step four, omitted; Step 5: Apply glass flake putty layer 7 directly onto the sealing primer layer 4, and the rest is the same as in Example 1; Step 6: Same as Example 1; Step 7: Same as Example 1; Comparative Example 4 (Traditional Single-Layer Fiberglass Process) A construction process for a corrosion-resistant sewage tank includes the following steps: Step 1: Treat the base layer of the sewage tank to form a flat, solid, and clean base surface; Step 2: Apply primer to the substrate; Step 3: Lay a layer of fiberglass cloth on the primer and apply resin to form a single layer of fiberglass. Step 4: Apply topcoat to the fiberglass layer; Step 5: Maintenance for seven days; Performance testing The anti-corrosion coatings prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3, and 4 were subjected to performance tests, and the test methods are as follows: 1. Strong acid penetration time test: Immerse each specimen in a mixed solution of 10% sulfuric acid and 10% hydrochloric acid, maintain the temperature at 60±2℃, observe once every 24 hours, and record the time it takes for the corrosive medium to penetrate to the base layer (the coating shows bubbles, discoloration or peeling).

[0022] 2. Tensile strength test: The test shall be conducted in accordance with GB / T 2567-2008 "Test Methods for Properties of Resin Castings".

[0023] 3. Impact strength test: The test shall be conducted in accordance with GB / T 1732-2020 "Test Method for Impact Resistance of Coating Film", using a 1kg weight.

[0024] 4. Test for resistance to substrate cracking: Fix the test plate coated with anti-corrosion layer on a flexible fixture, so that the substrate is deformed by 3mm displacement, and observe whether cracks or peeling appear on the coating surface.

[0025] The test results are recorded in the table below: Table 1 Performance test results of each embodiment and comparative example The test results in the table above show that: 1. Impermeability: The anti-corrosion layers prepared in Examples 1, 2, and 3 of this invention showed no penetration even after immersion in highly corrosive media for more than 90 days, while Comparative Example 1 (without glass flake mortar layer) showed penetration after 48 days, and Comparative Example 2 (single-layer intermediate coating fabric layer) failed after only 18 days. This indicates that the composite structure of "multi-layer intermediate coating fabric layer + glass flake mortar layer" used in this invention forms multiple dense impermeability barriers, significantly extending the penetration path of corrosive media and multiplying the impermeability.

[0026] 2. Mechanical Properties: The tensile strength of Examples 1, 2, and 3 all exceeded 165 MPa, and the impact strength exceeded 4.8 J, which were significantly better than Comparative Examples 2 and 4. This is because the three-dimensional reinforcing network formed by the multi-layered glass fiber cloth effectively dispersed and withstood the external load, thus greatly improving the overall mechanical strength of the structure.

[0027] 3. Crack Resistance: When the substrate underwent a 3mm displacement deformation, the coatings in the embodiments of the present invention remained intact without cracks, while Comparative Example 1 showed minor cracks, and Comparative Examples 2 and 4 experienced spalling and peeling. This demonstrates that the multi-layer intermediate coating and the glass flake adhesive layer work synergistically to give the anti-corrosion layer excellent toughness and resistance to substrate deformation, effectively coping with stress caused by factors such as temperature changes and uneven foundation settlement.

[0028] In summary, the anti-corrosion sewage tank construction process provided by this invention, through the composite design of multiple layers of intermediate coating cloth and glass flake mortar layer, achieves significantly better results than existing technologies in terms of impermeability, mechanical strength and crack resistance. It is suitable for more demanding long-term immersion environments, can greatly extend the service life of sewage tanks and reduce maintenance frequency.

[0029] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A construction process for an anti-corrosion sewage tank, characterized in that, Includes the following steps: Step 1: Treat the base layer of the sewage tank (2) to form a flat, solid and clean base surface (1) on the surface of the base layer of the sewage tank (2); Step 2: Apply primer to the base surface (1) to form a penetrating primer layer (3). The primer is made by mixing vinyl ester resin primer, curing agent and accelerator in proportion and stirring evenly. For every 100 kg of vinyl ester resin primer, add: curing agent: 1.5-2.5 kg, accelerator: 0.5-1.5 kg. Step 3: Spray a sealing primer onto the penetrating primer layer (3) to form a sealing primer layer (4); Step 4: Form multiple intermediate coating fabric layers on the sealing primer layer (4). Each intermediate coating fabric layer includes a fiberglass cloth (5) and a vinyl ester resin layer (6). Lay the fiberglass cloth (5) on the sealing primer layer (4), and apply vinyl ester resin to the fiberglass cloth (5) to impregnate the fiberglass cloth (5) and form a vinyl ester resin layer (6). After the first intermediate coating fabric layer is cured, lay the second intermediate coating fabric layer, and so on. Step 5: Apply a glass flake putty layer (7) to the topmost intermediate coating fabric layer. The mass ratio of resin, flakes and curing agent in the glass flake putty is 1:0.3:0.

02. Step 6: After the glass flake putty layer (7) has cured, apply an anti-corrosion topcoat (8) to the glass flake putty layer (7); Step 7: The anti-corrosion topcoat (8) is cured for 7-14 days, and the remaining layers are cured for at least 48 hours.

2. The construction process for the anti-corrosion sewage tank according to claim 1, characterized in that, In step one, the base surface (1) is polished to enhance the adhesion of the coating.

3. The construction process for the anti-corrosion sewage tank according to claim 2, characterized in that, In step two, when applying the primer, use a short-nap roller or trowel. The ambient temperature for application should be 5℃-40℃, the relative humidity should be <85%, and the surface temperature should be at least 3℃ above the dew point.

4. The construction process for the anti-corrosion sewage tank according to claim 3, characterized in that, In step four, the fiberglass cloth of the multi-layer intermediate coating is laid in an interlaced manner, with the distance between the upper and lower layers of fiberglass cloth being ≥50mm.

5. The construction process for the anti-corrosion sewage tank according to claim 4, characterized in that, In step five, during the application of the glass flake putty layer (7), a flat trowel is used for application, with the trowel angled at 30°. The required angle is that the blade plane forms a 30° angle with the surface to be coated during the scraping operation.

6. The construction process for the anti-corrosion sewage tank according to claim 5, characterized in that, In step six, the glass flake putty layer (7) is first cleaned and then coated with anti-corrosion topcoat (8).

7. The construction process for the anti-corrosion sewage tank according to claim 6, characterized in that, In step six, the anti-corrosion topcoat is made by mixing the topcoat and the curing agent in a certain proportion, and then applying it by roller coating or self-leveling process. The thickness of the anti-corrosion topcoat (8) is 0.25mm ± 0.02mm.

8. The construction process for the anti-corrosion sewage tank according to claim 7, characterized in that, In step six, after the anti-corrosion topcoat (8) dries, an anti-corrosion reinforcing topcoat is applied over the anti-corrosion topcoat (8).

9. The construction process for the anti-corrosion sewage tank according to claim 8, characterized in that, The anti-corrosion reinforced topcoat requires 7-14 days of curing.

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