Surface cleaning method for glass fiber reinforced plastic shell

Abstract

The invention relates to the technical field of surface treatment, and discloses a surface cleaning method for a glass fiber reinforced plastic shell, which comprises the following steps: pretreating the glass fiber reinforced plastic shell, and dividing the aging grade of the shell according to the pretreatment result; determining cleaning parameters of the shell according to the shell aging grade; preparing a cleaning agent according to the stain type of the shell; during cleaning, the surface of the shell is wiped firstly, and then the gap is subjected to deep treatment; detecting the stain residue condition on the surface of the shell, and if the stain residue condition exceeds the standard, repeatedly spraying and drying; and carrying out post-treatment on the cleaned shell. The problems that in the prior art, cleaning parameter adaptability is poor, cleaning agent pertinence is insufficient, gap treatment is not in place, residue detection is missing, and post-treatment is incomplete can be solved.

Description

Technical Field

[0001] This invention relates to the field of surface treatment technology, and more specifically, to a method for cleaning the surface of a glass fiber reinforced plastic shell. Background Technology

[0002] Fiberglass reinforced plastics (FRP) are widely used in wind turbine blades, marine equipment, and industrial storage tanks due to their lightweight and corrosion-resistant properties. However, their outer shells are prone to accumulating oil, resin residue, and other contaminants during use. Since FRP is a composite of resin and fiberglass, the interfacial bonding strength is sensitive to cleaning operations, requiring appropriate cleaning methods to avoid structural damage. The need for cleaning is becoming increasingly urgent as application scenarios expand.

[0003] Traditional FRP shell cleaning methods do not pre-treat the shell or classify its aging level. The cleaning parameters are fixed values ​​and cannot be adapted to shells with different aging states. The cleaning agents are not specifically formulated according to the type of stain and are prone to corroding the interface coupling agent. The cleaning is rough in the treatment of gaps and the surface residue is not detected. The post-treatment is not adjusted according to the aging level and vulnerable parts, making it difficult to ensure the long-term structural stability of the shell.

[0004] Therefore, this invention proposes a surface cleaning method for glass fiber reinforced plastic shells to solve the problems of poor adaptability of cleaning parameters, insufficient targeting of cleaning agents, inadequate treatment of gaps, lack of residue detection, and imperfect post-treatment in the prior art. Summary of the Invention

[0005] In view of this, the present invention proposes a surface cleaning method for glass fiber reinforced plastic shells, which aims to solve the problems of poor adaptability of cleaning parameters, insufficient targeting of cleaning agents, inadequate treatment of gaps, lack of residue detection and imperfect post-treatment in the prior art.

[0006] In one aspect, the present invention provides a method for cleaning the surface of a glass fiber reinforced plastic shell, comprising: The glass fiber reinforced plastic shell is pretreated, and the aging level of the shell is classified according to the pretreatment results; Determine the cleaning parameters for the casing based on its aging level; Prepare a cleaning agent according to the type of stains on the outer casing; When cleaning, first wipe the surface of the outer shell, and then perform a deep cleaning of the gaps; Check the surface of the outer casing for residual dirt; if the level exceeds the limit, repeat the spraying and drying process. The cleaned outer casing undergoes post-processing.

[0007] Furthermore, the preprocessing includes: The outer shell is scanned to obtain structural state characteristic signals and the resonant frequency of the outer shell is detected. The classification of the aging level of the shell based on the pretreatment results includes: The quality of the casing is determined by comparing its resonant frequency with that of a new part of the same model. When the difference between the resonant frequency of the outer casing and the resonant frequency of a new part of the same model is within the preset difference range, the outer casing is deemed to be qualified. When the difference between the resonant frequency of the outer casing and the resonant frequency of a new part of the same model exceeds the preset difference range, the outer casing is deemed unqualified. When the casing is deemed unqualified, the aging level of the casing is determined based on the characteristic signal and the preset signal strength range.

[0008] Furthermore, determining the aging level of the casing includes: When the feature signal obtained by scanning is within the first preset signal strength range, the shell is classified as slightly aged. When the feature signal obtained by scanning is within the second preset signal strength range, the shell is classified as moderately aged. When the feature signal obtained by scanning is within the third preset signal strength range, the shell is classified as severely aged.

[0009] Furthermore, determining the cleaning parameters of the outer casing includes: When the outer casing is slightly aged, the cleaning parameters are determined to be the first spray pressure and low temperature; When the outer casing is moderately aged, the cleaning parameters are determined to be the second spray pressure and medium temperature; When the outer casing is severely aged, the cleaning parameters are determined to be the third spray pressure and room temperature; The third spray pressure is less than the second spray pressure, which is less than the first spray pressure, and the intermediate temperature is greater than the normal temperature.

[0010] Furthermore, the cleaning agent, formulated according to the type of stains on the casing, includes: When the stain is oily, acidic, alcoholic, or alkaline components are mixed with water, and a coupling agent is added to obtain an oil-based cleaner. When the stain is resin residue, chelating components are added to the oil stain cleaner, and the pH value of the cleaner is controlled in the neutral range to obtain a resin-based cleaner.

[0011] Furthermore, the step of first wiping the outer shell surface and then performing deep treatment on the gaps includes: Use a wiping tool to wipe the flat area; For gaps of different widths, select brush heads of different sizes and insert them into the gaps to wipe them; After wiping, use a misting nozzle to rinse the crevices.

[0012] Furthermore, the detection of residual dirt on the outer casing surface, and if the level exceeds the standard, repeated spraying and drying, includes: The content of residual components and conductivity on the surface of the outer casing are detected; If the residual component content exceeds the preset residual value or the conductivity exceeds the preset conductivity value, the outer shell will be sprayed repeatedly. If the residual dirt on the surface of the casing still exceeds the standard after repeated spraying, the number of spraying cycles on the casing will be increased. After spraying, the surface of the outer shell is dried by blowing.

[0013] Furthermore, the post-processing includes: Apply passivating agent to the surface of the casing; Adjust the thickness of the passivating agent coating according to the aging level of the casing; After the passivating agent has cured, apply a sealant. Adjust the sealant coating thickness according to the environment in which the casing is used.

[0014] Furthermore, the passivating agent is an aqueous passivating agent containing 2% sodium molybdate, the spraying thickness is 8-10 μm, and the passivating agent is cured by standing at room temperature for 15 minutes; The sealant is a two-component nano-fluororubber sealant, the coating thickness is 15-20 μm, and the coating temperature is 60℃.

[0015] Furthermore, the post-processing also includes: Identify vulnerable areas of the casing; When the vulnerable part is the seam, apply tape and sealant. When the vulnerable part is the bolt hole, apply sealant around the bolt hole and cover it with a protective part.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention pre-treats the glass fiber reinforced plastic shell and classifies it into aging levels. Based on the aging level, appropriate cleaning parameters can be matched, and corresponding cleaning agents can be configured according to the type of stain. During cleaning, the surface is wiped first, and then the gaps are treated in depth. By detecting the residue, repeated spraying and drying are carried out when the residue exceeds the standard. Finally, post-treatment is performed. This can achieve the adaptation of cleaning operation to the shell condition, improve the targeting and thoroughness of cleaning, and at the same time provide subsequent protection for the shell. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating a surface cleaning method for a glass fiber reinforced plastic shell provided in an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] Traditional FRP shell cleaning methods do not pre-treat the shell or classify its aging level. The cleaning parameters are fixed values ​​and cannot be adapted to shells with different aging states. The cleaning agents are not specifically formulated according to the type of stain and are prone to corroding the interface coupling agent. The cleaning is rough in the treatment of gaps and the surface residue is not detected. The post-treatment is not adjusted according to the aging level and vulnerable parts, making it difficult to ensure the long-term structural stability of the shell.

[0020] Therefore, the present invention proposes a surface cleaning method for glass fiber reinforced plastic shells to solve the above-mentioned problems.

[0021] Reference Figure 1 As shown in some embodiments of this application, a method for cleaning the surface of a glass fiber reinforced plastic shell includes: S1. Pre-treat the glass fiber reinforced plastic shell and classify the aging level of the shell according to the pre-treatment results; S2. Determine the cleaning parameters for the casing based on its aging level; S3. Prepare a cleaning agent according to the type of stains on the outer shell; S4. When cleaning, first wipe the surface of the outer shell, and then perform deep cleaning of the gaps; S5. Check the residual dirt on the outer shell surface. If the level is exceeded, repeat the spraying and drying process. S6. Perform post-processing on the cleaned outer shell.

[0022] Specifically, the process begins with pre-treatment of the fiberglass reinforced plastic (FRP) shell. Structural condition information is obtained through testing, and this information is used to classify the shell into light, moderate, and heavy aging levels. Next, corresponding cleaning parameters, such as spray pressure and temperature, are matched to the aging level. Then, cleaning agents containing suitable ingredients are formulated based on the different types of stains on the shell surface, such as oil and resin residue. During the cleaning phase, flat areas are first treated with wiping tools, followed by deep cleaning of crevices using specialized tools. Afterward, the content of residual components and conductivity on the surface are tested; if they exceed preset values, the spraying and drying process is repeated. Finally, passivating agents and sealants are applied for post-treatment. The core of this process is to achieve synergy between cleaning and structural protection through a continuous process of "condition adaptation - precise cleaning - subsequent protection," avoiding the problems of fixed parameters and poor targeting in traditional cleaning methods.

[0023] Understandably, this method, through its comprehensive process design of "pretreatment grading - parameter adaptation - customized decontamination - deep cleaning of gaps - residue control - post-treatment protection," not only solves problems in traditional cleaning such as "micro-debonding of FRP interfaces caused by high pressure / strong solvents," "incomplete cleaning of gaps," and "fiber corrosion caused by residues," but also achieves a balance between targeted cleaning and structural protection. While improving the cleaning effect of FRP shells, it ensures the stability of their mechanical properties and extends their service life.

[0024] Reference Figure 1 As shown, in some embodiments of this application, preprocessing includes: The outer shell is scanned to obtain structural state characteristic signals and the resonant frequency of the outer shell is detected.

[0025] Specifically, the aging levels of the casing are classified based on the pretreatment results, including: The quality of the casing is determined by comparing its resonant frequency with that of a new part of the same model. When the difference between the resonant frequency of the outer casing and the resonant frequency of a new part of the same model is within the preset difference range, the outer casing is deemed to be qualified. When the difference between the resonant frequency of the outer casing and the resonant frequency of a new part of the same model exceeds the preset difference range, the outer casing is deemed unqualified. When the casing is deemed unqualified, the aging level of the casing is determined based on the characteristic signal and the preset signal strength range.

[0026] Specifically, scanning refers to using equipment such as air-coupled ultrasound to perform a full-area scan of the FRP shell, "structural state characteristic signal" refers to the interface reflection wave signal and other signals that can reflect the resin-fiber bonding state obtained during the scanning process, and "resonance frequency" refers to the natural frequency generated when the shell is excited by vibration.

[0027] It is understandable that a decrease in the integrity of an FRP structure can lead to a shift in the resonant frequency and a change in the intensity of characteristic signals.

[0028] Specifically, the characteristic signal is first scanned and acquired, then the resonant frequency of the shell is detected and compared with that of a new part of the same model. If the difference is within the preset difference range (e.g., ≤5Hz), it is deemed qualified; otherwise, it is deemed unqualified. If it is unqualified, the aging level is determined by combining the characteristic signal with the preset signal strength range.

[0029] Understandably, by scanning to obtain characteristic signals and detecting resonant frequencies, and by comparing with new parts to determine whether the shell is qualified, weak FRP shells can be identified in advance. This avoids using inappropriate cleaning methods for shells with hidden damage, provides a structural condition basis for the selection of subsequent cleaning parameters, and reduces the risk of secondary damage induced by cleaning.

[0030] Reference Figure 1 As shown, in some embodiments of this application, determining the casing aging level includes: When the feature signal obtained by scanning is within the first preset signal strength range, the shell is classified as slightly aged; when the feature signal obtained by scanning is within the second preset signal strength range, the shell is classified as moderately aged; when the feature signal obtained by scanning is within the third preset signal strength range, the shell is classified as severely aged.

[0031] Specifically, the first, second, and third preset signal strength ranges are intensity ranges set according to the scanning signal characteristics of FRPs with different aging degrees. The first preset signal strength range is a reflected wave intensity ≤15dB, the second preset signal strength range is a reflected wave intensity of 15-30dB, and the third preset signal strength range is a reflected wave intensity >30dB.

[0032] Understandably, the more severe the FRP aging, the more obvious the resin degradation and interface debonding, and the higher the intensity of the feature signal generated by scanning. The feature signal obtained from the scan is compared with three preset intervals. If it falls into the first interval, it is classified as mild aging; if it falls into the second interval, it is classified as moderate aging; and if it falls into the third interval, it is classified as severe aging. By dividing the feature signal into three preset intervals to determine the aging level, the degree of aging of the FRP shell is quantitatively classified, making the determination of the aging level more objective and accurate. This lays the foundation for the precise matching of subsequent cleaning parameters and improves the scientific nature and targeted nature of the cleaning operation.

[0033] Reference Figure 1 As shown, in some embodiments of this application, determining the cleaning parameters of the housing includes: When the outer casing is slightly aged, the cleaning parameters are determined to be the first spray pressure and low temperature; When the outer casing is moderately aged, the cleaning parameters are determined to be the second spray pressure and medium temperature; When the outer casing is severely aged, the cleaning parameters are determined to be the third spray pressure and room temperature; The third spray pressure is less than the second spray pressure, which is less than the first spray pressure, and the intermediate temperature is greater than the normal temperature.

[0034] It is understandable that the first, second, and third spray pressures represent a pressure gradient decreasing according to the aging level, while "low temperature," "medium temperature," and "normal temperature" are temperature settings adapted to different aging conditions. Lightly aged FRP has a tight interface bond and can withstand higher pressures; heavily aged FRP resin becomes brittle, requiring reduced pressure to avoid interface damage, and medium temperature can help dissolve stains without accelerating resin aging.

[0035] Specifically, when the outer shell is slightly aged, the spray pressure is set at 0.3-0.4 MPa and the temperature at <25℃; when the outer shell is moderately aged, the spray pressure is set at 0.2-0.3 MPa and the temperature at 30-40℃; when the outer shell is severely aged, the spray pressure is set at 0.1-0.2 MPa and the temperature is room temperature, i.e., 25-30℃.

[0036] Understandably, by setting decreasing spray pressure and appropriate temperature according to different aging levels, the cleaning parameters are matched with the tolerance of the FRP shell. The shell with light aging can be cleaned efficiently with higher pressure, while the shell with heavy aging can avoid interface damage with lower pressure. The medium temperature setting assists in cleaning without aggravating resin aging, thus balancing the cleaning effect and structural protection.

[0037] Reference Figure 1 As shown, in some embodiments of this application, a cleaning agent is configured according to the type of stain on the casing, including: When the stain is oily, acidic, alcoholic, and alkaline components are mixed with water, and a coupling agent is added to obtain an oil-based cleaner. When the stain is resinous residue, chelating components are added to the oil-based cleaner, and the pH value of the cleaner is controlled in the neutral range to obtain a resin-based cleaner.

[0038] Specifically, white vinegar can be used for acidic components, medical alcohol can be used for alcoholic components, food-grade baking soda can be used for alkaline components, silane coupling agents such as KH-560 can be used for coupling agents, trisodium citrate can be used for chelating components, and the neutral range refers to a pH value of 6.5-7.5.

[0039] Understandably, acidic, alcoholic, and alkaline components work together to remove oil stains, coupling agents can protect the resin-fiber interface, and chelating components can bind with metal ions in resin residues to assist in peeling.

[0040] Understandably, cleaning agents containing coupling agents or chelating components are formulated according to the type of stain. Oil-based cleaning agents effectively remove oil and protect the interface through the synergistic effect of multiple components, while resin residue cleaning agents enhance peeling ability and maintain a neutral pH through chelating components. This avoids the erosion of the resin-fiber interface by traditional strong acid, alkali and strong solvent cleaning agents, thus achieving a balance between stain removal and interface protection.

[0041] Reference Figure 1 As shown, in some embodiments of this application, the outer casing surface is wiped first, and then the gaps are treated with depth, including: Use a wiping tool to wipe the flat area; For gaps of different widths, select brush heads of different sizes and insert them into the gaps to wipe them; After wiping, use a misting nozzle to rinse the crevices.

[0042] Specifically, the wiping tools are soft nanofiber cloths, etc., and the brush heads of different sizes refer to flexible brush heads whose diameter is adapted to the width of the gap. For example, a 3-4mm diameter brush head corresponds to a narrow gap, and the atomizing nozzle is a nozzle that can produce a micron-level mist of water.

[0043] Understandably, friction damage should be avoided on flat areas, and crevices require specialized tools for thorough cleaning. Atomized water flow can reduce the impact intensity. First, use a soft nanofiber cloth dampened with a customized cleaning agent to wipe flat areas in the same direction to avoid scratches caused by back-and-forth friction. For crevices of varying widths, select a specialized brush head slightly smaller than the crevices and insert it to wipe, ensuring contact with the inner walls of the crevices. After wiping, use atomizing nozzles to rinse the crevices at low pressure, moving the nozzles at a uniform speed along the length of the crevices to ensure complete coverage.

[0044] Specifically, the atomizing nozzle produces atomized particles of 50-80 μm and a low-pressure output of 0.03-0.04 MPa.

[0045] As can be seen, using wiping tools to treat flat areas, brush heads of different sizes to clean crevices, and atomizing nozzles to rinse ensures gentle cleaning of flat areas to avoid scratches, while using special tools to reach deep into crevices to remove residual stains. Atomizing rinsing reduces the impact intensity of water flow, achieving thorough and safe cleaning of the entire FRP shell.

[0046] Reference Figure 1 As shown, in some embodiments of this application, the residual dirt on the outer casing surface is detected, and if the level exceeds the limit, the process of spraying and drying is repeated, including: The content of residual components and conductivity on the surface of the outer casing are detected; When the residual component content exceeds the preset residual value or when the conductivity exceeds the preset conductivity value, the outer shell will be sprayed repeatedly. If the residual dirt on the surface of the casing still exceeds the standard after repeated spraying, the number of spraying cycles on the casing will be increased. After spraying, the surface of the outer shell is dried by blowing.

[0047] Specifically, the residual component content refers to the content of electrolytes such as chloride ions, which can cause electrochemical corrosion of glass fibers; the conductivity can reflect the total amount of soluble residues on the surface, and indirectly reflect the amount of residues; the preset residual value and preset conductivity value are thresholds set to ensure the performance of FRP.

[0048] Specifically, use a chloride ion detector and a conductivity meter to select test points evenly on the surface of the outer shell and take the average value. If the chloride ion content is >40ppm or the conductivity is >50μS / cm, it indicates that the stain residue exceeds the standard. Repeat the spraying 1-2 times with the corresponding cleaning parameters. After spraying, use a 40-50℃ hot air gun to dry it to avoid high temperature damage to the resin. After drying, test again until it meets the standard.

[0049] Understandably, by detecting the content and conductivity of residual components and repeatedly spraying, increasing the number of times, and drying when the levels exceed the standard, harmful substances such as residual electrolytes after cleaning can be effectively removed. This prevents residual media from seeping into the FRP interior and causing electrochemical corrosion of the glass fiber, thus ensuring the long-term performance stability of the FRP shell.

[0050] Reference Figure 1 As shown, in some embodiments of this application, post-processing includes: Apply passivating agent to the surface of the casing; Adjust the thickness of the passivating agent coating according to the aging level of the casing; After the passivating agent has cured, apply a sealant. Adjust the sealant coating thickness according to the environment in which the casing is used.

[0051] Specifically, passivating agents are chemical agents that can form a protective film on the FRP surface, sealants are polymer materials that can block resin pores, and the environment in which the casing is used includes humid, dry, and corrosive environments.

[0052] Understandably, passivators inhibit fiber corrosion, and sealants prevent corrosive media from penetrating. The more severe the aging and the harsher the environment, the thicker the protective layer needs to be. Passivators are applied first, with a thinner layer for light aging and a thicker layer for heavy aging. After the passivator cures, sealants are applied, with a thicker layer for humid or other harsh environments and a thinner layer for dry environments. By dynamically adjusting the coating thickness, the post-treatment protection is better adapted to the condition of the enclosure and the usage scenario.

[0053] Specifically, the passivating agent is an aqueous passivating agent containing 2% sodium molybdate, the spraying thickness is 8-10 μm, and the passivating agent is cured by standing at room temperature for 15 minutes; The sealant is a two-component nano-fluororubber sealant, the coating thickness is 15-20 μm, and the coating temperature is 60℃.

[0054] Specifically, the two-component nano-fluororubber sealant consists of a fluororubber emulsion and an isocyanate curing agent.

[0055] Understandably, sodium molybdate can form a passivation film, nano-fluororubber has excellent sealing properties, and specific parameters can ensure stable coating performance. Specifically, first spray a water-based passivating agent, such as sodium molybdate, and adjust the thickness according to the aging level: 8μm for light aging, 9μm for medium aging, and 10μm for heavy aging, and let it cure at room temperature; after curing, apply a two-component sealant, adjusting the thickness according to the usage environment: 20μm for humid environments and 15μm for dry environments.

[0056] Understandably, adjusting the passivating agent thickness according to the aging level and the sealant thickness according to the usage environment allows the protective capabilities of the passivation film and sealing layer to be adapted to the aging state and usage scenario of the FRP housing. Housings that are severely aged or in harsh environments can obtain stronger protection, enhancing the targetedness and anti-corrosion effect of post-treatment and extending the service life of the housing.

[0057] Understandably, by specifying the exact composition, thickness, and application parameters of the passivating agent and sealant, it is possible to achieve a stable passivation film. The passivating agent containing 2% sodium molybdate can form a stable passivation film, and the two-component nano-fluororubber sealant has excellent sealing properties. Specific thickness and temperature parameters ensure the curing effect and performance stability of the coating, making the protective effect of post-treatment more reliable.

[0058] Reference Figure 1 As shown, in some embodiments of this application, post-processing further includes: Identify vulnerable areas of the casing; When the vulnerable part is the seam, apply tape and sealant. When the vulnerable part is the bolt hole, apply sealant around the bolt hole and cover it with a protective part.

[0059] Understandably, vulnerable areas refer to structural stress concentrations or areas susceptible to corrosion, such as joints and bolt holes. The tape used is fiberglass reinforced tape, and the protective components are protective sleeves that fit the bolt holes. These areas are prone to gaps or damage and require additional protection.

[0060] Understandably, additional treatments are applied to vulnerable areas such as seams and bolt holes. By using adhesive tape, applying sealant, and covering with protective components, the protection of these stress-concentrated or corrosion-prone areas is strengthened, reducing the risk of structural failure in weak areas and further improving the overall structural stability and corrosion resistance of the FRP shell.

[0061] As can be seen, the surface cleaning method for glass fiber reinforced plastic shells in the above embodiments accurately identifies the aging state and structural integrity of the FRP shells through pre-processing scanning and resonant frequency detection, providing a basis for the adaptation of cleaning pressure and temperature grading, and avoiding the application of excessive mechanical force to heavily aged or structurally weak shells; at the same time, the customized neutral cleaning agent (containing coupling agent) can not only effectively remove dirt, but also avoid the erosion of the resin-fiber interface by strong acids, alkalis / solvents, reducing the risk of interface micro-debonding induced by cleaning from the source.

[0062] This invention addresses the different needs of surfaces and crevices by employing a combination of "soft wiping + size-adaptive brush head + atomized rinsing," solving the problems of dirt accumulation in crevices and easy scratching of surfaces in traditional cleaning. Through dual detection of residual components and conductivity, as well as a repeated spraying mechanism, it eliminates the hidden danger of electrolyte residue after cleaning, avoiding the hidden risk of "clean surface but internal corrosion," and achieving the dual goals of "all-area cleaning + no residue."

[0063] The post-processing of this invention forms a multi-layered protection system consisting of a passivation film, a sealing layer, and reinforcement of weak points. At the same time, the coating thickness is dynamically adjusted according to the aging level and the usage environment. The specific components and construction parameters of the passivating agent and sealant are clearly defined to ensure the protective effect. Special reinforcement is provided for stress concentration areas such as splicing seams and bolt holes, effectively blocking the penetration path of corrosive media, delaying the electrochemical corrosion of glass fiber and resin aging, and ultimately extending the service life of the FRP shell.

[0064] Specific implementation process of the present invention: I. Preparations before implementation Object to be cleaned: 10m³ FRP storage tank shell (diameter 2.5m, height 2m), used for 3 years, with oil stains (around the tank opening), resin residue (at the welded joints), and slight discoloration in some areas.

[0065] Equipment and material preparation: Testing equipment: 2.5MHz air-coupled ultrasonic scanner, portable vibration frequency tester, chloride ion detector (accuracy 0.1ppm), conductivity meter (range 0-2000μS / cm). Cleaning equipment: handheld spray gun with pressure sensor (pressure adjustment range 0-0.5MPa), 0.03-0.04MPa rotary atomizing nozzle, 3mm / 4mm diameter flexible nylon brush head, soft nanofiber cloth, 40-50℃ hot air gun; Chemicals: white vinegar, 75% medical alcohol, food-grade baking soda, deionized water, KH-560 silane coupling agent, trisodium citrate, water-based passivating agent containing 2% sodium molybdate, two-component nano-fluororubber sealant (component A: fluororubber emulsion; component B: isocyanate curing agent), 20mm wide glass fiber reinforced tape; Auxiliary tools: coating thickness gauge, pH test paper (range 5.5-9.0), marking pen, measuring tape.

[0066] II. Specific Implementation Steps S1. Divide the FRP tank shell into five regions: top, body, upper, middle, lower sections, and bottom. Set 20 evenly distributed scanning points in each region. Start the 2.5MHz air-coupled ultrasonic scanner, keep the probe 5cm away from the shell surface, and scan at a constant speed in the horizontal direction. Record the interface reflection wave intensity at each scanning point.

[0067] Using a portable vibration frequency tester, select one measuring point above each of the four support legs (load-bearing parts) of the storage tank, apply a 10N excitation force, and record the resonant frequency of each measuring point; retrieve the standard resonant frequency (set to 50Hz) of a new FRP storage tank of the same model, and calculate the difference: the frequencies of the four measuring points are 48Hz, 49Hz, 47Hz, and 48Hz, respectively, and the difference is ≤3Hz (the preset difference range is ≤5Hz), thus determining that the outer shell substrate is qualified.

[0068] The average reflected wave intensity of each region was calculated as follows: top of tank 12dB, upper part of tank 18dB, middle part of tank 25dB, lower part of tank 32dB, bottom of tank 28dB; based on the preprocessing results, the following was determined: The top of the tank shows mild aging; the upper, middle, and bottom sections of the tank show moderate aging; and the lower section of the tank shows severe aging.

[0069] S2. The cleaning parameters for the tank top are set as follows: spray pressure 0.35MPa, spray with 20℃ low temperature cold water; The cleaning parameters for the upper, middle and lower sections of the tank are set as follows: spray pressure 0.25MPa, 35℃ warm water spray. The cleaning parameters for the lower section of the tank are set as follows: spray pressure 0.15MPa, spray with 25℃ room temperature water; S3. Identify stains on the FRP storage tank shell: the area around the tank opening is covered with machine oil stains, and the seams are covered with cured resin residue.

[0070] Prepare the oil stain cleaner: Weigh out the following by mass ratio: 5% white vinegar (50g), 75% medical alcohol (750g), 3% food-grade baking soda (30g), and 16.5% deionized water (165g). Add them to a beaker in sequence and stir for 5 minutes until dissolved. Then add 0.5% KH-560 silane coupling agent (5g) and continue stirring for 3 minutes. The pH value should be 7.0 when tested with pH paper.

[0071] Prepare a resin residue cleaner: Based on the above-mentioned oil stain cleaner, add 2% trisodium citrate (20g), stir well, and the pH value is measured to be 6.8.

[0072] S4. Apply the corresponding cleaning agent to a soft nanofiber cloth. Use oil stain cleaner on the rim of the container and adhesive cleaner on other flat surfaces. Wipe in one direction along the horizontal plane. Replace the cloth every 10cm² to prevent stains from adhering again.

[0073] Deep treatment of gaps: For gaps 3mm wide, use a 3mm diameter flexible nylon brush head, dip it in residual adhesive cleaner, insert it into the gap, and wipe back and forth 3 times along the length of the gap; for gaps 4mm wide, use a 4mm diameter brush head and repeat the same operation.

[0074] Install a 0.035MPa rotating atomizing nozzle, 5cm away from the surface of the crevice, and move it at a constant speed of 5cm / s along the length of the crevice to rinse. After rinsing, use a clean cloth to dry the surface of the crevice.

[0075] S5. Select 10 detection points evenly on the surface of the storage tank, with 2 points for each aging area, and use a chloride ion detector to detect Cl. - Content, conductivity measured with a conductivity meter: the test results show Cl at 1 point in the lower section of the tank. - The value was 45 ppm (exceeding the standard, the preset value is ≤40 ppm), and the conductivity was 40 μS / cm (qualified).

[0076] The point exceeding the standard was sprayed twice with a 0.15MPa room temperature spray gun, with the water left to stand for 1 minute after each spray, and then dried with a 45℃ hot air gun; the Cl at the point exceeding the standard was then measured again. - The content is 38 ppm. After meeting the requirements, post-processing is carried out.

[0077] S6. Using a pneumatic spray gun, spray the cleaned FRP tank shell surface with a water-based passivating agent containing 2% sodium molybdate: the spray thickness for the top of the tank is 8μm; the spray thickness for the upper, middle, and bottom sections of the tank body is 9μm; the spray thickness for the lower section of the tank body is 10μm; after spraying, let it stand at room temperature (25℃) for 15 minutes to confirm that the passivating agent is completely cured before applying the sealant: mix a two-component nano-fluororubber sealant at a ratio of 10:1 and stir for 5 minutes until uniform; then apply the sealant unidirectionally along the surface of the tank using a scraper. For use in humid environments, the coating thickness on the bottom of the can is 20 μm; for other areas, the coating thickness is 15 μm; after coating, place in a 60℃ hot air curing oven and cure for 30 minutes.

[0078] After curing, reinforce vulnerable areas: For the flange joint, apply 20mm wide fiberglass reinforced tape with the edge of the tape extending 5mm beyond the joint edge, then apply a 15μm thick layer of sealant and cure at room temperature for 10 minutes. For bolt holes (10mm in diameter), apply a 20μm thick sealant within a 5mm radius around the hole, and cover with a plastic protective sleeve after curing.

[0079] After cleaning is completed, the cleaning effect is tested. The surface of the cleaned FRP storage tank shell was inspected using existing technology, and the results are as follows: Visual inspection: The surface is free of stains and scratches, there are no residues in the gaps, and the coating is free of bubbles and peeling. Structural inspection: The resonant frequency was checked again, and the difference from that before cleaning was ≤1Hz, indicating no structural damage; Protection test: A water seepage test was conducted on the sealing layer, and no water seepage was observed.

[0080] It was ultimately confirmed that the FRP tank shell was clean and met the requirements, and that its structural performance was stable.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for cleaning the surface of a glass fiber reinforced plastic shell, characterized in that, include: The glass fiber reinforced plastic shell is pretreated, and the aging level of the shell is classified according to the pretreatment results; Determine the cleaning parameters for the casing based on its aging level; Prepare a cleaning agent according to the type of stains on the outer casing; When cleaning, first wipe the surface of the outer shell, and then perform a deep cleaning of the gaps; Check the surface of the outer casing for residual dirt; if the level exceeds the limit, repeat the spraying and drying process. The cleaned outer casing undergoes post-processing.

2. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 1, characterized in that, The preprocessing includes: The outer shell is scanned to obtain structural state characteristic signals and the resonant frequency of the outer shell is detected. The classification of the aging level of the shell based on the pretreatment results includes: The quality of the casing is determined by comparing its resonant frequency with that of a new part of the same model. When the difference between the resonant frequency of the outer casing and the resonant frequency of a new part of the same model is within the preset difference range, the outer casing is deemed to be qualified. When the difference between the resonant frequency of the outer casing and the resonant frequency of a new part of the same model exceeds the preset difference range, the outer casing is deemed unqualified. When the casing is deemed unqualified, the aging level of the casing is determined based on the characteristic signal and the preset signal strength range.

3. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 2, characterized in that, The determination of the casing aging level includes: When the feature signal obtained by scanning is within the first preset signal strength range, the shell is classified as slightly aged. When the feature signal obtained by scanning is within the second preset signal strength range, the shell is classified as moderately aged. When the feature signal obtained by scanning is within the third preset signal strength range, the shell is classified as severely aged.

4. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 3, characterized in that, The determination of the cleaning parameters for the outer casing includes: When the outer casing is slightly aged, the cleaning parameters are determined to be the first spray pressure and low temperature; When the outer casing is moderately aged, the cleaning parameters are determined to be the second spray pressure and medium temperature; When the outer casing is severely aged, the cleaning parameters are determined to be the third spray pressure and room temperature; The third spray pressure is less than the second spray pressure, which is less than the first spray pressure, and the intermediate temperature is greater than the normal temperature.

5. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 4, characterized in that, The cleaning agent, formulated according to the type of stains on the outer casing, includes: When the stain is oily, acidic, alcoholic, or alkaline components are mixed with water, and a coupling agent is added to obtain an oil-based cleaner. When the stain is resin residue, chelating components are added to the oil stain cleaner, and the pH value of the cleaner is controlled in the neutral range to obtain a resin-based cleaner.

6. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 5, characterized in that, The process of first wiping the outer surface and then performing deep treatment on the gaps includes: Use a wiping tool to wipe the flat area; For gaps of different widths, select brush heads of different sizes and insert them into the gaps to wipe them; After wiping, use a misting nozzle to rinse the crevices.

7. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 6, characterized in that, The process of detecting residual dirt on the outer casing surface, and repeating the spraying and drying if the level exceeds the limit, includes: The content of residual components and conductivity on the surface of the outer casing are detected; If the residual component content exceeds the preset residual value or the conductivity exceeds the preset conductivity value, the outer shell will be sprayed repeatedly. If the residual dirt on the surface of the casing still exceeds the standard after repeated spraying, the number of spraying cycles on the casing will be increased. After spraying, the surface of the outer shell is dried by blowing.

8. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 7, characterized in that, The post-processing includes: Apply passivating agent to the surface of the casing; Adjust the thickness of the passivating agent coating according to the aging level of the casing; After the passivating agent has cured, apply a sealant. Adjust the sealant coating thickness according to the environment in which the casing is used.

9. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 8, characterized in that, The passivating agent is an aqueous passivating agent containing 2% sodium molybdate, the spraying thickness is 8-10 μm, and the passivating agent is cured by standing at room temperature for 15 minutes. The sealant is a two-component nano-fluororubber sealant, the coating thickness is 15-20 μm, and the coating temperature is 60℃.

10. The surface cleaning method for a glass fiber reinforced plastic shell according to claim 9, characterized in that, The post-processing also includes: Identify vulnerable areas of the casing; When the vulnerable part is the seam, apply tape and sealant. When the vulnerable part is the bolt hole, apply sealant around the bolt hole and cover it with a protective part.

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