High-adhesion wind turbine nacelle inner layer gel coat spraying process

Abstract

The application relates to the technical field of wind power generator part manufacturing, in particular to a high-adhesion wind power generator cabin cover inner layer gel coat spraying process, which comprises the following steps: base pretreatment: performing dry grinding, blowing clean dust and plasma treatment on the surface of a wind power generator cabin cover glass fiber reinforced plastic base; gel coat preparation: mixing raw materials according to a formula to obtain gel coat slurry, wherein the formula comprises modified unsaturated polyester resin, composite adhesion promoter, nano composite reinforcing filler, composite curing agent, composite promoter, defoaming agent and leveling agent; the composite adhesion promoter is composed of gamma-aminopropyl triethoxysilane and glycidyl methacrylate; and the nano composite reinforcing filler is a nano powder with a surface modified by a silane coupling agent; the composite adhesion promoter compound system is adopted, the nano composite reinforcing filler and the organic modifier are matched to construct a multi-element composite modified structure, and the interface bonding capacity of the gel coat and the glass fiber reinforced plastic base is fundamentally strengthened.

Description

Technical Field

[0001] This invention relates to the field of wind turbine component manufacturing technology, specifically to a high-adhesion gel coat spraying process for the inner layer of a wind turbine nacelle cover. Background Technology

[0002] As a core piece of equipment in the clean energy sector, wind turbines have their nacelles exposed to the outdoor environment for extended periods, requiring them to withstand multiple challenges such as temperature fluctuations, wind and rain erosion, and ultraviolet radiation. The inner gelcoat, as a crucial protective and connecting structure of the nacelle, must not only achieve a tight fit with the fiberglass substrate but also possess sufficient mechanical strength, aging resistance, and corrosion resistance, directly impacting the overall service life and operational reliability of the nacelle.

[0003] Currently, the gelcoat spraying process used in the industry for the inner layer of wind turbine nacelles has significant limitations in terms of formulation design and process implementation. In terms of formulation, most solutions use a single type of adhesion promoter, which makes it difficult to form an effective interfacial interaction mechanism, resulting in insufficient bonding between the gelcoat and the substrate. Simultaneously, the lack of a scientific composite reinforcement system, relying solely on traditional resins and basic additives, limits the mechanical properties and environmental adaptability of the gelcoat layer. In terms of process, the traditional method of one-time spraying and single-temperature curing is commonly used, easily leading to uneven gelcoat layer thickness and internal stress concentration, resulting in quality problems such as cracking and blistering. The simple substrate surface pretreatment process fails to fully enhance surface activity, further weakening the interfacial bonding effect. Furthermore, the existing technology has poor adaptability, unable to meet the preparation requirements of gelcoat layers of different thicknesses, and unable to cope with harsh operating conditions such as marine salt spray and extreme climates. This leads to aging, powdering, corrosion, and peeling of the gelcoat layer during long-term use, resulting in a significant decrease in adhesion, seriously affecting the protective performance of the nacelle, and restricting the long-term stable operation of wind turbine equipment. Summary of the Invention

[0004] The primary objective of this invention is to provide a high-adhesion gel coat spraying process for the inner layer of a wind turbine nacelle.

[0005] A further objective of this invention is to provide a high-adhesion gel coat spraying process for the inner layer of a wind turbine nacelle, comprising the following steps:

[0006] (1) Substrate pretreatment: Dry grinding, dust blowing and plasma treatment are performed on the surface of the fiberglass substrate of the wind turbine nacelle.

[0007] (2) Preparation of gel coat: The raw materials are mixed according to the formula to obtain gel coat paste. The formula includes modified unsaturated polyester resin, composite adhesion promoter, nanocomposite reinforcing filler, composite curing agent, composite promoter, defoamer and leveling agent. The composite adhesion promoter is composed of γ-aminopropyltriethoxysilane and glycidyl methacrylate. The nanocomposite reinforcing filler is nanoparticles with surface modified by silane coupling agent.

[0008] (3) Segmented spraying: The gel coat slurry is sprayed in multiple stages using a high-pressure airless sprayer to reach the preset total thickness;

[0009] (4) Gradient curing: successively low temperature static curing, medium temperature heat preservation curing and high temperature heat preservation curing, and then naturally cooled to room temperature.

[0010] Preferably, in the composite adhesion promoter, the mass ratio of γ-aminopropyltriethoxysilane to glycidyl methacrylate is 1:1 to 1.5:1.

[0011] Preferably, the nanocomposite reinforcing filler contains at least nano-silica, and may also contain one or two of nano-alumina and nano-calcium carbonate.

[0012] Preferably, the formulation further includes an organic modifier, wherein the organic modifier is an epoxy resin.

[0013] Preferably, the composite curing agent is methyl ethyl ketone peroxide, or a mixture of methyl ethyl ketone peroxide and tert-butyl peroxide; the composite accelerator is cobalt naphthenate, or a mixture of cobalt naphthenate and cobalt isooctanoate.

[0014] Preferably, in step (1), dry grinding uses 180-200 mesh sandpaper, plasma treatment power is 400W-450W, treatment time is 40s-45s, and treatment distance is 7mm-8mm.

[0015] Preferably, in step (3), the number of times the segmented spraying is 2 to 3, the spraying pressure is 0.9 MPa to 1.0 MPa, the spraying distance is 20 cm to 25 cm, the spray gun moving speed is 35 cm / s to 40 cm / s, and the interval between two adjacent sprayings is 5 min to 6 min.

[0016] Preferably, in step (4), the low-temperature static curing temperature is 25°C and the curing time is 2h to 3h; the medium-temperature heat preservation curing temperature is 45°C and the curing time is 4h to 5h; and the high-temperature heat preservation curing temperature is 70°C and the curing time is 2.5h.

[0017] Preferably, the defoamer is a silicone defoamer, or a mixture of a silicone defoamer and a polyether defoamer; the leveling agent is an acrylate leveling agent, or a mixture of an acrylate leveling agent and a polyether leveling agent.

[0018] Preferably, after gradient curing, a post-processing step is also included: lightly grinding the surface of the gel coat layer, rinsing and drying it, applying an interface sealant and letting it stand, wherein the interface sealant is composed of epoxy resin and curing agent.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention employs a composite adhesion promoter system, combined with nano-composite reinforcing fillers and organic modifiers to construct a multi-element composite modified structure. This fundamentally strengthens the interfacial bonding ability between the gelcoat and the fiberglass substrate, effectively solving the problem of insufficient bonding strength in traditional formulations. Simultaneously, the scientific combination of composite curing agents and promoters further optimizes the curing reaction efficiency of the gelcoat, ensuring the structural density of the gelcoat layer.

[0021] 2. The optimized substrate pretreatment process of this invention fully enhances the surface activity of the substrate, laying a good foundation for interface bonding; the segmented spraying process precisely controls the thickness of the gel coat layer, avoiding the problem of uneven thickness caused by one-time spraying; the gradient curing process effectively releases internal stress and reduces defects such as cracking and blistering; and the post-treatment steps further enhance the interface stability and corrosion resistance.

[0022] 3. This invention allows for flexible adjustment of the gel coat thickness to adapt to different working conditions and can stably withstand harsh environments such as marine salt spray and extreme temperature differences. The product possesses excellent adhesion, hardness, aging resistance, and corrosion resistance, maintaining stable performance even after long-term use and significantly extending the service life of the tank cover. Furthermore, the raw materials and equipment used in this invention are all standard industry products, and the process parameters are clear and controllable, requiring no additional investment in complex equipment, facilitating industrial-scale promotion, and possessing significant practical and economic value. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1:

[0025] Gelcoat formulation composition:

[0026] 70 parts of phthalic-modified unsaturated polyester resin, acid value 20 mg KOH / g, viscosity 400 mPa·s at 25℃; 4 parts of composite adhesion promoter, composed of 2 parts of γ-aminopropyltriethoxysilane and 2 parts of glycidyl methacrylate; 5 parts of nano-composite reinforcing filler, which is nano-silica with a surface modified by silane coupling agent and a particle size of 30 nm; 2 parts of composite curing agent, which is methyl ethyl ketone peroxide with an active oxygen content of 10%; 1 part of composite accelerator, which is cobalt naphthenate with a cobalt content of 7%; 0.3 parts of defoamer, which is an organosilicon defoamer; and 0.4 parts of leveling agent, which is an acrylate leveling agent.

[0027] Spraying process steps:

[0028] (1) Substrate pretreatment: The surface of the fiberglass substrate of the wind turbine nacelle is dry-ground with 180-grit sandpaper to remove surface impurities, oil stains and scum. Then, the surface dust is blown clean with compressed air at a pressure of 0.5MPa. Then, plasma treatment with a power of 400W is used for 45s, at a distance of 8mm from the substrate surface to improve the surface activity of the substrate.

[0029] (2) Gelcoat preparation: According to the above formula ratio, first add the modified unsaturated polyester resin into a conventional closed mixing tank, stir at 650 r / min for 8 min at room temperature, then add the composite adhesion promoter and nano-composite reinforced filler in sequence, increase the speed to 1350 r / min, stir for 25 min to ensure uniform dispersion of filler, and finally add defoamer, leveling agent and composite promoter, stir at low speed for 6 min, let stand for 2.5 min to remove air bubbles, and obtain a uniform gelcoat slurry. Before use, add composite curing agent and stir quickly for 2.5 min until uniform.

[0030] (3) Segmented spraying: Use industry-standard high-pressure airless sprayer, control the spraying pressure at 1.0MPa, spraying distance at 25cm, and spray gun moving speed at 40cm / s. Spray in two stages. The thickness of the first spray is controlled at 0.18mm. After a 6min interval, spray the second layer with a thickness of 0.22mm. The total thickness is 0.4mm. During the spraying process, the ambient temperature is maintained at 25℃ and the relative humidity at 65%.

[0031] (4) Gradient curing: After spraying, let it stand at 25°C for 3 hours to allow the gel coat layer to form initially. Then, raise the temperature to 45°C and keep it warm for 5 hours to promote the interface bonding between the gel coat and the substrate. Finally, raise the temperature to 70°C and keep it warm for 2.5 hours to complete the overall curing. Let it cool naturally to room temperature.

[0032] Example 2:

[0033] Based on Example 1, this embodiment optimizes the ratio of the composite adhesion promoter and the composition of the composite curing system, while expanding the compatibility range of the curing system. The technical solution is closely connected with Example 1 and can be stably implemented in a production environment of 15℃-30℃.

[0034] Gelcoat formulation composition:

[0035] 70 parts of phthalic-modified unsaturated polyester resin, with an acid value of 20 mg KOH / g and a viscosity of 400 mPa·s at 25℃; 3 parts of composite adhesion promoter, composed of 1.8 parts of γ-aminopropyltriethoxysilane and 1.2 parts of glycidyl methacrylate; 5 parts of nano-composite reinforcing filler, which is nano-silica with a surface modified by silane coupling agent and a particle size of 30 nm; 2.5 parts of composite curing agent, composed of 1.7 parts of methyl ethyl ketone peroxide and 0.8 parts of tert-butyl peroxide, with a total active oxygen content of 9.5%; 1.2 parts of composite accelerator, composed of 0.6 parts of cobalt naphthenate and 0.6 parts of cobalt isooctanoate, with a total cobalt content of 7.5%; 0.3 parts of defoamer, which is an organosilicon defoamer; and 0.4 parts of leveling agent, which is an acrylate leveling agent.

[0036] Spraying process steps:

[0037] (1) Matrix pretreatment: completely consistent with Example 1.

[0038] (2) Gelcoat preparation: According to the above formula ratio, first add the modified unsaturated polyester resin into a conventional closed mixing tank, stir at 650 r / min for 8 min at room temperature, then add the composite adhesion promoter and nano-composite reinforced filler in sequence, increase the speed to 1350 r / min, stir for 25 min to ensure uniform dispersion of filler, and finally add defoamer, leveling agent and composite promoter, stir at low speed for 6 min, let stand for 1.5 min to remove air bubbles, and obtain a uniform gelcoat slurry. Before use, add composite curing agent and stir quickly for 2 min until uniform.

[0039] (3) Segmented spraying: completely consistent with Example 1.

[0040] (4) Gradient curing: After spraying, let it stand at 25°C for 2 hours to allow the gel coat layer to form initially. Then, raise the temperature to 45°C and keep it warm for 4 hours to promote the interface bonding between the gel coat and the substrate. Finally, raise the temperature to 70°C and keep it warm for 2.5 hours to complete the overall curing. Let it cool naturally to room temperature.

[0041] Example 3:

[0042] Based on Example 2, this embodiment optimizes the composition of the nanocomposite reinforcing filler and the segmented spraying parameters, while expanding the adaptability range of substrate pretreatment and spraying process. The technical solution is closely connected with Example 2 and can be adapted to the preparation of gel coat layers with different thickness requirements. The total thickness of the gel coat layer can be adjusted within the range of 0.3mm-0.7mm.

[0043] Gelcoat formulation composition:

[0044] 75 parts of isophthalic modified unsaturated polyester resin, acid value 22 mg KOH / g, viscosity 450 mPa·s at 25℃; 3 parts of composite adhesion promoter, composed of 1.8 parts of γ-aminopropyltriethoxysilane and 1.2 parts of glycidyl methacrylate; 5 parts of nano-composite reinforcing filler, composed of 3 parts of nano-silica modified with silane coupling agent and 2 parts of nano-alumina, particle size 25 nm; 2.5 parts of composite curing agent, composed of 1.7 parts of methyl ethyl ketone peroxide and 0.8 parts of tert-butyl peroxide, total active oxygen content 9.5%; 1.2 parts of composite accelerator, composed of 0.6 parts of cobalt naphthenate and 0.6 parts of cobalt isooctanoate, total cobalt content 7.5%; 0.3 parts of defoamer, an organosilicon defoamer; 0.4 parts of leveling agent, an acrylate leveling agent.

[0045] Spraying process steps:

[0046] (1) Substrate pretreatment: The surface of the fiberglass substrate of the wind turbine nacelle is dry-ground with 200-grit sandpaper to remove surface impurities, oil stains and scum. Then, the surface dust is blown clean with compressed air at a pressure of 0.5MPa. Then, plasma treatment with a power of 450W is used for 40s, at a distance of 7mm from the substrate surface to improve the surface activity of the substrate.

[0047] (2) Preparation of gel coat: completely consistent with Example 2.

[0048] (3) Segmented spraying: Use industry-standard high-pressure airless sprayer, control the spraying pressure at 0.9MPa, spraying distance at 20cm, and spray gun moving speed at 35cm / s. Spray in 3 stages. The thickness of the first spray is controlled at 0.15mm. After a 5min interval, spray the second stage with a thickness of 0.2mm. After another 5min interval, spray the third stage with a thickness of 0.15mm. The total thickness is 0.5mm. During the spraying process, the ambient temperature is maintained at 23℃ and the relative humidity at 60%.

[0049] (4) Gradient curing: completely consistent with Example 2.

[0050] Example 4:

[0051] Based on Example 3, this embodiment introduces an organic modifier and optimizes the post-treatment steps. At the same time, it expands the range of additive compounding and the environmental adaptability of the formulation. The technical solution is closely connected with Example 3, forming a complete multi-component composite modification and integrated process optimization system that can be adapted to harsh environments such as marine salt spray.

[0052] Gelcoat formulation composition:

[0053] 75 parts of isophthalic modified unsaturated polyester resin, acid value 22 mg KOH / g, viscosity 450 mPa·s at 25℃; 3 parts of composite adhesion promoter, composed of 1.8 parts of γ-aminopropyltriethoxysilane and 1.2 parts of glycidyl methacrylate; 5 parts of nanocomposite reinforcing filler, composed of 2 parts of nano-silica modified with silane coupling agent, 2 parts of nano-alumina and 1 part of nano-calcium carbonate, with a particle size of 25 nm; 2.5 parts of composite curing agent, composed of methyl peroxide... The composition consists of 1.7 parts acetone and 0.8 parts tert-butyl peroxide, with a total active oxygen content of 9.5%; 1.2 parts composite accelerator, composed of 0.6 parts cobalt naphthenate and 0.6 parts cobalt isooctanoate, with a total cobalt content of 7.5%; 0.3 parts defoamer, composed of 0.15 parts silicone defoamer and 0.15 parts polyether defoamer; 0.4 parts leveling agent, composed of 0.2 parts acrylate leveling agent and 0.2 parts polyether leveling agent; and 2 parts organic modifier, which is epoxy resin E-44.

[0054] Spraying process steps:

[0055] (1): The matrix pretreatment is completely consistent with that in Example 3.

[0056] (2): Gelcoat preparation: According to the above formula ratio, first add the modified unsaturated polyester resin and organic modifier into a conventional closed stirring tank, and stir at 850 r / min for 10 min at room temperature to ensure the uniformity of the crosslinking system. Then add the composite adhesion promoter and nano-composite reinforcing filler in sequence, increase the speed to 1350 r / min, and stir for 25 min to ensure the filler is uniformly dispersed. Finally, add the defoamer, leveling agent and composite promoter, stir at low speed for 6 min, and let stand for 1.5 min to remove bubbles to obtain a uniform gelcoat slurry. Before use, add the composite curing agent and stir quickly for 2 min until uniform.

[0057] (3) Segmented spraying: completely consistent with Example 3.

[0058] (4) Gradient curing: completely consistent with Example 2.

[0059] (5) Post-treatment: After curing and cooling, use 400-grit sandpaper to lightly sand the surface of the gel coat layer to remove surface defects. Then rinse it with clean water, dry it, and apply a layer of interface sealant. The interface sealant consists of 5 parts epoxy resin and 1 part curing agent. Let it stand for 1.5 hours to further enhance the interface adhesion and corrosion resistance.

[0060] Comparative Example 1:

[0061] The gel coat formulation uses a single adhesion promoter, which is 4 parts of γ-aminopropyltriethoxysilane. The rest of the formulation composition is completely consistent with that of Example 1.

[0062] The spraying process steps are exactly the same as those in Example 1.

[0063] This comparative example simulates a conventional technical solution in the prior art that uses only a single adhesion promoter without any compounding optimization.

[0064] Comparative Example 2:

[0065] The gel coat formulation is completely identical to that of Example 1; the spraying process adopts the traditional single spraying method, spraying to a total thickness of 0.4 mm in one go, with the spraying pressure fixed at 1.0 MPa and the spraying distance fixed at 25 cm;

[0066] Curing was performed at a single temperature: 45°C for 8 hours. The remaining steps were the same as in Example 1.

[0067] This comparative simulation is a technical solution in the existing technology that uses a traditional single spraying and single temperature curing process without segmented spraying and gradient curing optimization.

[0068] Comparative Example 3:

[0069] The gel coat formulation does not contain nanocomposite reinforcing fillers or organic modifiers; the rest of the formulation composition is completely consistent with that of Example 1.

[0070] The spraying process steps are exactly the same as those in Example 1.

[0071] This comparative simulation demonstrates a technical approach that does not incorporate nano-reinforcement and organic modification, but only uses traditional resins and additives.

[0072] Comparative Example 4:

[0073] The gel coat formulation uses a simple combination of a single adhesion promoter from Comparative Example 1 and the traditional process from Comparative Example 2, namely, a single application of 4 parts of γ-aminopropyltriethoxysilane at a single temperature for curing, with the remaining formulation composition being the same as in Example 1.

[0074] This comparative simulation of existing technologies is a technical solution that simply superimposes different individual technical features without achieving synergistic optimization.

[0075] Performance testing and results analysis:

[0076] Test sample preparation:

[0077] According to the formulations and processes of Examples 1 to 4 and Comparative Examples 1 to 4, composite samples of gel coat-fiberglass substrate for the inner layer of wind turbine nacelle were prepared. The sample size was uniformly 100mm×100mm×5mm, the substrate thickness was 4mm, and the gel coat layer thickness was 0.4mm to 0.5mm.

[0078] Three parallel samples were prepared for each scheme. The preparation process parameters of the parallel samples were strictly consistent. Before testing, the samples were visually inspected, and samples with obvious surface defects were removed to ensure the consistency of the test samples.

[0079] Test items and standards:

[0080] The adhesion test is conducted according to GB / T9286-1998 "Paints and Varnishes - Cross-cut Adhesion Test" and GB / T5210-2006 "Paints and Varnishes - Pull-off Adhesion Test". The cross-cut test uses a 1mm grid spacing and the grid depth extends to the substrate surface.

[0081] The pull-off test was conducted using a hydraulic adhesion tester at a test rate of 1 mm / min. Hardness testing was performed according to GB / T6739-2006 "Paints and Varnishes - Pencil Method for Determination of Hardness of Paint Films", using 2H to 3H pencils at a test pressure of 1 kg. Aging resistance testing was performed according to GB / T1865-2009 "Paints and Varnishes - Artificial Climate Aging and Artificial Radiation Exposure", using a xenon lamp aging test chamber with an irradiation intensity of 0.51 W / m². 2 •nm, blackboard temperature 60℃±3℃, relative humidity 65%±5%, spray cycle 18min / 102min, test time 1000 hours.

[0082] The corrosion resistance test was conducted according to GB / T1763-1979 "Determination of Chemical Resistance of Coating Films". The coatings were immersed in 5% hydrochloric acid solution, 5% sodium hydroxide solution and 10% sodium chloride solution at a temperature of 25℃±2℃ for 72 hours.

[0083] The test results are shown in Table 1 below:

[0084]

[0085] The test results are analyzed as follows:

[0086] As can be seen from the above test results, the overall performance of the gel coat layer in Examples 1 to 4 is significantly better than that of the prior art and the comparative examples 1 to 4 which are simple combinations of the prior art. Moreover, there is a clear progressive optimization effect among the examples, and the synergistic effect of each technical feature is highlighted, which fully proves the rationality and application value of the technical solution of the present invention.

[0087] (1) In terms of adhesion performance, Examples 1 to 4 all stably achieved Level 1 cross-cut adhesion, with a tensile strength of not less than 6.8 MPa. Among them, the tensile strength of Example 4 reached 8.8 MPa, which was much higher than that of the comparative examples. The cross-cut adhesion of the existing simple combination scheme of Comparative Example 4 was only Level 4, with a tensile strength of only 2.1 MPa, which was less than 25% of that of Example 4. This difference fully demonstrates that the compound adhesion promoter design and the activity enhancement optimization of the substrate pretreatment of the present invention can fundamentally improve the interfacial bonding force between the gel coat layer and the substrate, and effectively improve the problem of insufficient interfacial bonding force in the prior art.

[0088] (2) Regarding hardness, aging resistance, and corrosion resistance, in Examples 3 and 4, due to the introduction of nanocomposite reinforcing fillers and organic modifiers, the pencil hardness increased from 2H in Examples 1 and 2 to 3H, the adhesion retention rate after 1000 hours of aging increased from 92% to 97%, and the adhesion retention rate after acid, alkali, and salt resistance increased from 90% to 96%. Compared with the scheme without nano-reinforcement and organic modification in Comparative Example 3, the hardness increased by two levels, and the aging resistance and corrosion resistance increased by more than 20%. This indicates that the organic-inorganic composite modification system can effectively optimize the mechanical properties and environmental stability of the gel coat layer, enabling it to better adapt to harsh outdoor environments.

[0089] (3) The effects of process optimization are also significant. Compared with the traditional single spraying and single temperature curing process of Comparative Example 2, the segmented spraying and gradient curing process used in Examples 1 to 4 improved the cross-cut adhesion level from level 2 to level 1 and the tensile strength from 5.1 MPa to over 6.8 MPa. Moreover, there were no defects such as local cracks on the surface of the gel coat layer. This shows that the synergistic adaptation of each step of the process can effectively reduce internal stress, improve the uniformity and stability of the gel coat layer, and thus improve production efficiency and product qualification rate.

[0090] (4) In summary, this invention achieves a significant improvement in the overall performance of the gel coat layer through the optimization of the compounding of each component of the formulation and the synergistic adaptation of each process step. This performance improvement cannot be achieved by simply adjusting a single parameter or adding existing technical features, but is the result of the mutual cooperation and synergistic effect of each technical feature, fully demonstrating the advanced nature and practicality of the technical solution of this invention. This invention has fully disclosed the component selection logic of the gel coat formulation, the core operation points and adaptation principles of each process step, and clarified the key technical features and synergistic relationships required to achieve the technical effect. The raw materials and equipment used are all conventionally available in the industry, and the process parameter range is clear and adapted to the actual industrial production. Those skilled in the art can fully reproduce this technical solution and achieve the expected effect based on the disclosure of the specification.

[0091] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A high-adhesion gel coat spraying process for the inner layer of a wind turbine nacelle cover, characterized in that, Includes the following steps: (1) Substrate pretreatment: Dry grinding, dust blowing and plasma treatment are performed on the surface of the fiberglass substrate of the wind turbine nacelle. (2) Preparation of gel coat: The raw materials are mixed according to the formula to obtain gel coat paste. The formula includes modified unsaturated polyester resin, composite adhesion promoter, nanocomposite reinforcing filler, composite curing agent, composite promoter, defoamer and leveling agent. The composite adhesion promoter is composed of γ-aminopropyltriethoxysilane and glycidyl methacrylate. The nanocomposite reinforcing filler is nanoparticles with surface modified by silane coupling agent. (3) Segmented spraying: The gel coat slurry is sprayed in multiple stages using a high-pressure airless sprayer to reach the preset total thickness; (4) Gradient curing: successively subjected to low-temperature static curing, medium-temperature heat preservation curing and high-temperature heat preservation curing, and then naturally cooled to room temperature; In the composite adhesion promoter, the mass ratio of γ-aminopropyltriethoxysilane to glycidyl methacrylate is 1:1 to 1.5:

1. In step (4), the low-temperature static curing temperature is 25℃, and the curing time is 2h to 3h; The medium-temperature insulation and curing temperature is 45℃, and the curing time is 4 to 5 hours. The high-temperature insulation and curing temperature is 70℃, and the curing time is 2.5h.

2. The process according to claim 1, characterized in that, The nanocomposite reinforcing filler contains at least nano-silica, and also contains one or two of nano-alumina and nano-calcium carbonate.

3. The process according to claim 1, characterized in that, The formulation also includes an organic modifier, which is an epoxy resin.

4. The process according to claim 1, characterized in that, The composite curing agent is methyl ethyl ketone peroxide, or a mixture of methyl ethyl ketone peroxide and tert-butyl peroxide; the composite accelerator is cobalt naphthenate, or a mixture of cobalt naphthenate and cobalt isooctanoate.

5. The process according to claim 1, characterized in that, In step (1), dry grinding uses 180-200 mesh sandpaper, plasma treatment power is 400W-450W, treatment time is 40s-45s, and treatment distance is 7mm-8mm.

6. The process according to claim 1, characterized in that, In step (3), the number of times the segmented spraying is 2 to 3, the spraying pressure is 0.9MPa to 1.0MPa, the spraying distance is 20cm to 25cm, the spray gun moving speed is 35cm / s to 40cm / s, and the interval between two adjacent sprayings is 5min to 6min.

7. The process according to claim 1, characterized in that, The defoamer is a silicone defoamer, or a mixture of silicone defoamer and polyether defoamer; the leveling agent is an acrylate leveling agent, or a mixture of acrylate leveling agent and polyether leveling agent.

8. The process according to claim 1, characterized in that, After gradient curing, a post-processing step is also included: lightly grinding the surface of the gel coat layer, rinsing and drying it, applying an interface sealant and letting it stand. The interface sealant is composed of epoxy resin and curing agent.

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