A spraying method of waterborne co-linear primer and a multi-material co-linear spraying process

Abstract

The application relates to the technical field of paint, and particularly discloses a spraying method of water-based collinear primer and a multi-material collinear spraying process. The spraying method of the water-based collinear primer provided by the application comprises the following steps: pretreatment, spraying and baking; wherein the spraying step is: adopting an automatic spraying device to automatically spray the water-based collinear primer to the surface of a pretreated composite material base material; the moving speed of a mechanical arm of the automatic spraying machine is 600-800 mm / s, and the pressure of a spraying gun is 0.3-0.5 MPa; the application further provides a composite material obtained by the spraying method of the water-based collinear primer and a multi-material collinear spraying process. The spraying method of the water-based collinear primer provided by the application can enable the composite material to have excellent surface roughness and resistivity, so that the collinear coating of the composite material and the metal material can be realized.

Description

Technical Field

[0001] This application relates to the field of coating technology, specifically to a method for spraying a water-based collinear primer and a multi-material collinear spraying process. Background Technology

[0002] With the continuous development of the automotive industry, new composite materials are being widely used in car bodies. However, due to the low surface tension, poor wetting properties, and poor adhesion of these new composite materials, oil-based primers are currently the main coatings used for them. But to meet national requirements for green and sustainable development and consumers' environmental needs, water-based coatings for automotive parts are an inevitable trend.

[0003] However, the problem of co-coating composite materials and metal materials is currently prominent. For example, electrophoretic paint is easily deposited on the surface of composite materials, the surface of composite materials after co-coating has poor clarity and gloss, and the paint film on the surface of composite materials is easy to peel off.

[0004] Therefore, in order to enable the extensive use of composite materials in car bodies, there is an urgent need to develop a spraying method for water-based collinear primers suitable for composite materials, so as to enable composite materials to obtain excellent surface roughness and resistivity, thereby ensuring the effect of collinear spraying of composite materials and metal materials. Summary of the Invention

[0005] In order to achieve collinear spraying of composite materials and metal materials, this application provides a method for spraying water-based collinear primer and a multi-material collinear spraying process.

[0006] In a first aspect, this application provides a method for spraying a water-based collinear primer, employing the following technical solution:

[0007] A method for spraying a water-based collinear primer includes the following steps: pretreatment, spraying, and baking;

[0008] Spraying: The water-based collinear primer is automatically sprayed onto the surface of the pretreated composite material substrate using an automatic spraying equipment; the moving speed of the robotic arm of the automatic spraying equipment is 600-800 mm / s, and the spray gun pressure is 0.3-0.5 MPa.

[0009] This application provides a spraying method for a water-based collinear primer applied to composite materials. The spraying method first pre-treats the composite material substrate to make the surface of the composite material substrate clean, flat, and free of grease and dust. Then, an automatic spraying device is used to automatically spray the water-based collinear primer onto the surface of the composite material substrate. Finally, by drying, a paint film is formed on the surface of the composite material substrate. The paint film has excellent surface roughness and resistivity. When the composite material with the above-mentioned water-based collinear primer is sprayed together with a metal material, electrophoretic coating is performed to ensure that electrophoretic paint is deposited on the surface of the metal material, while no electrophoretic paint is deposited on the surface of the composite material, thus achieving collinear spraying of the composite material and the metal material.

[0010] In this application, the moving speed of the robotic arm and the spray gun pressure of the automatic spraying equipment affect the surface roughness and conductivity of the water-based collinear primer film formed on the surface of the composite material substrate. Experimental investigation revealed that when the robotic arm's moving speed is too slow and the spray gun pressure is too low, the water-based collinear primer will aggregate, resulting in poor film uniformity and consequently high surface roughness and low conductivity. Conversely, when the robotic arm's moving speed is too fast and the spray gun pressure is too high, the water-based collinear primer cannot adhere uniformly to the composite material surface, leading to poor film uniformity, high surface roughness, and low conductivity. Therefore, by controlling the robotic arm's moving speed and spray gun pressure within the aforementioned ranges, this application enables the water-based collinear primer to adhere uniformly and stably to the surface of the composite material substrate, thereby obtaining a composite material with low surface roughness and a narrow resistivity range.

[0011] In some implementations, the robotic arm can move at a speed of 600-700 mm / s or 700-800 mm / s.

[0012] In one specific implementation, the moving speed of the robotic arm can also be 600mm / s, 700mm / s, or 800mm / s.

[0013] In some implementations, the spray gun pressure can be 0.3-0.4 MPa or 0.4-0.5 MPa.

[0014] In one specific implementation, the spray gun pressure can also be 0.3 MPa, 0.4 MPa, or 0.5 MPa.

[0015] Optionally, the robotic arm of the automatic spraying equipment moves at a speed of 600-700 mm / s, and the spray gun pressure is 0.4-0.5 MPa.

[0016] Optionally, the nozzle diameter of the robotic arm of the automatic spraying equipment is 1-1.4 mm, the oil supply pressure is 0.4-0.6 MPa, the fan-shaped pressure is 0.6-0.7 MPa, the atomization pressure is 0.5-0.6 MPa, and the fan-shaped amount is 3-3.5.

[0017] In one specific implementation, the nozzle diameter of the robotic arm of the automatic spraying equipment is 1.2 mm, the oil supply pressure is 0.5 MPa, the fan-shaped pressure is 0.6 MPa, the atomization pressure is 0.5 MPa, and the fan-shaped amount is 3.

[0018] Optionally, the baking temperature is 70-80℃ and the baking time is 60-80 minutes.

[0019] Secondly, this application provides a composite material.

[0020] A composite material is prepared by spraying using the water-based collinear primer spraying method according to any one of claims 1-4.

[0021] Optionally, the film thickness of the water-based collinear primer on the surface of the composite material is 20-40 μm.

[0022] In this application, the film thickness has a significant impact on the roughness and conductivity of the collinear primer. When the film thickness is small, the surface roughness of the film is large, resulting in poor surface clarity and gloss of the final product. Conversely, when the film thickness is large, the resistivity of the film is high, and the conductivity is poor. Therefore, this application has discovered through experimental research that by controlling the film thickness of the water-based collinear primer on the composite material surface within the aforementioned range, a composite material with excellent surface roughness and conductivity can be obtained.

[0023] In some embodiments, the film thickness of the aqueous collinear primer on the surface of the composite material can be 10-20μm, 10-30μm, 10-40μm, 20-30μm, 20-40μm, 20-50μm, 30-40μm, 30-50μm or 40-50μm.

[0024] In some specific implementations, the film thickness of the water-based collinear primer on the surface of the composite material can be 10μm, 20μm, 30μm, 40μm or 50μm.

[0025] Optionally, the resistivity of the composite material is <0.5MΩ.

[0026] Optionally, the surface roughness of the composite material substrate is <0.8 μm.

[0027] In this application, the surface roughness of the composite material substrate affects the surface roughness of the composite material. Experimental investigations have shown that controlling the surface roughness of the composite material substrate to below 0.8 μm can ensure that the surface roughness of the composite material reaches 0.3 μm or below.

[0028] In some embodiments, the surface roughness of the composite material before spraying can be 0.119-0.234 μm, 0.119-0.450 μm, 0.234-0.450 μm, 0.234-0.738 μm, or 0.450-0.738 μm.

[0029] In one specific implementation, the surface roughness of the composite material before spraying can also be 0.119 μm, 0.234 μm, 0.450 μm or 0.738 μm.

[0030] Thirdly, this application provides a multi-material collinear spraying process.

[0031] A multi-material collinear spraying process includes the following steps: composite material pretreatment, metal material pretreatment, and collinear spraying.

[0032] The specific steps of collinear spraying are as follows: the pretreated composite material and the pretreated metal material are placed together in an electrophoretic pool for electrophoresis, and electrophoretic paint is deposited on the surface of the metal material through an electrochemical reaction.

[0033] In this application, spraying a water-based collinear primer onto the composite material substrate enables the formation of a paint film on the surface of the composite material. This paint film ensures that no electrophoretic paint deposits on the surface of the composite material after collinear spraying with the metal material. Furthermore, the conductivity of the paint film on the surface of the composite material is improved after collinear spraying, thereby ensuring excellent workability of the composite material and the metal material in subsequent electrostatic spraying processes.

[0034] In summary, this application has the following beneficial effects:

[0035] 1. This application provides a method for spraying a water-based collinear primer, including pretreatment, spraying, baking and other steps. By adjusting the moving speed of the robotic arm of the automatic spraying equipment to 600-800 mm / s and the spray gun pressure to 0.3-0.5 MPa in the spraying step, this application enables the paint film on the surface of the composite material substrate to have excellent surface roughness and resistivity, thereby enabling the collinear spraying of composite materials and metal materials.

[0036] 2. By controlling the film thickness of the water-based collinear primer on the surface of the composite material to within the range of 20-40 μm and the surface roughness of the composite material substrate to below 0.8 μm, this application can further improve the surface roughness and conductivity of the composite material, making the surface roughness of the composite material <0.3 μm and the resistivity ≤0.4 MΩ. Detailed Implementation

[0037] A spraying process for a water-based collinear primer.

[0038] This application provides a spraying process for a water-based collinear primer, comprising the following steps:

[0039] (1) Pretreatment: First, the composite material substrate is pretreated to ensure that the surface is clean, flat and free of impurities such as grease and dust; then, white spirit is used to wipe the surface of the composite material substrate to remove impurities and dirt; finally, dust is removed by blowing to further ensure that there is no residual dust on the surface.

[0040] (2) Spraying: An automatic spraying machine (model FANUC Robot P-250iB) is used to automatically spray the water-based collinear primer onto the surface of the composite material substrate. The parameters of the robotic arm of the automatic spraying machine are set as follows: nozzle diameter 1-1.4mm, moving speed 600-800mm / s, spray gun pressure 0.3-0.5MPa, atomization pressure 0.5-0.6MPa, oil supply pressure 0.4-0.6MPa, and fan-shaped spray pattern 3-3.5.

[0041] (3) Baking: After the water-based collinear primer is sprayed, the composite material enters the leveling stage for leveling, and then enters the baking chamber and is baked at 70-80℃ for 60-80 minutes to obtain the composite material sprayed with water-based collinear primer.

[0042] A multi-material collinear spraying process includes the following steps:

[0043] (1) Composite material pretreatment (substrate treatment): The surface of the composite material to be sprayed with water-based collinear primer is pretreated to ensure cleanliness, remove grease and impurities, and obtain the pretreated composite material.

[0044] (2) Metal material pretreatment: The metal material is washed with hot water; then it is pre-degreasing, degreasing, water washing, film phosphating, pure water washing, and draining in sequence to obtain the pretreated metal material;

[0045] (3) Collinear spraying: The pretreated composite material and the pretreated metal material are placed together in an electrophoretic pool for electrophoresis. Through an electrochemical reaction, electrophoretic paint is deposited on the surface of the metal material, while no electrophoretic paint is deposited on the surface of the composite material. During the electrophoretic coating process, excess paint is collected through an overflow recovery system to reduce waste.

[0046] (4) Post-treatment: After the co-line spraying is completed, pure water spraying, pure water soaking, draining and baking are carried out in sequence. Finally, the parts are inspected and the subsequent processes are carried out after passing the inspection.

[0047] In this application, the water-based collinear primer comprises component A and component B; component A comprises the following components in parts by weight: 41-62 parts epoxy resin, 3-14 parts titanium dioxide, 3-12 parts conductive carbon black, 5-15 parts filler, 5-25 parts water, 1-2 parts dispersant, 1-7 parts film-forming aid, 0.2-1 part wetting agent, 0.4-1 part defoamer, 0.4-1 part leveling agent, and 0.5-2.5 parts thickener; component B comprises a modified amine curing agent.

[0048] The raw materials, reagents, solvents, etc. used in this application can all be obtained commercially.

[0049] The following detailed description of this application is provided in conjunction with preparation examples, embodiments, and performance testing experiments.

[0050] Preparation Example 1

[0051] Preparation Example 1 provides an aqueous collinear primer.

[0052] The preparation method of the above-mentioned water-based collinear primer is as follows:

[0053] (1) Preparation of material A

[0054] (1-1) At a speed of 500 rpm, add 18 kg of water and 5 kg of film-forming aid (Texanol) to the mixing tank; then add 0.7 kg of defoamer (BYK 024) and 1.5 kg of dispersant (Disperbyk 192) and stir for 5 min; then add 5 kg of conductive carbon black (LC-5000), 10 kg of titanium dioxide (R996) and 10 kg of talc (MS-2500), adjust the speed to 1000 rpm, and stir for 20 min to obtain a mixed slurry;

[0055] (1-2) Grind the mixed slurry to a fineness of 8μm to obtain a grinding slurry;

[0056] (1-3) Add 50 kg of epoxy resin (epoxy equivalent of 490-550 g / eq, model Araldite PZ 3961) to the grinding slurry, stir at 500 rpm for 5 min, then add 0.7 kg of wetting agent (model SURFYNOL 104), 0.7 kg of defoamer (model BYK 024) and 0.8 kg of leveling agent (model Tego Twin 4100), and stir for 10 min; finally add 0.1 kg of thickener (model RHEOBYK-L 100) and 0.6 kg of thickener (model RHEOBYK-H3300 VF), and increase the speed to 800 rpm, stir for 15 min to obtain material A.

[0057] (2) Preparation of waterborne collinear primer: Mix component A with modified amine curing agent (model Aradur 3986) at a ratio of 8:1 and stir evenly to obtain waterborne collinear primer.

[0058] Example 1

[0059] Example 1 provides a composite material car hood, which is prepared by spraying water-based co-line primer.

[0060] The above-mentioned spraying process for water-based collinear primer includes the following steps:

[0061] (1) Pretreatment: First, the SMC composite material (fiberglass composite material) car hood is pretreated to ensure that the surface of the car hood is clean, flat and free of impurities such as grease and dust; then, white spirit is used to wipe it to remove impurities and dirt from the surface of the composite material car hood; finally, dust is removed by blowing to further ensure that there is no residual dust on the surface.

[0062] (2) Spraying: An automatic spraying machine is used to automatically spray water-based collinear primer onto the surface of the composite material vehicle's hood (the surface roughness of the composite material vehicle's hood is 0.738μm), forming a paint film with a thickness of 30μm. The parameters of the robotic arm of the automatic spraying machine are set as follows: nozzle diameter 1.2mm, moving speed 700mm / s, spray gun pressure 0.4MPa, oil supply pressure 0.5MPa, fan-shaped pressure 0.6MPa, atomization pressure 0.5MPa, and fan-shaped amount 3.

[0063] (3) Baking: After the water-based co-linear primer is sprayed, the composite material vehicle hood enters the leveling stage for leveling, and then enters the baking chamber to bake at 70-80℃ for 60-80 minutes to obtain the composite material vehicle hood sprayed with water-based co-linear primer.

[0064] Example 2-3

[0065] Examples 2-3 each provide a composite material vehicle hood.

[0066] The difference between Embodiments 2-3 and Embodiment 1 is that the moving speed of the robotic arm is as shown in Table 1 below.

[0067] Comparative Examples 1-2

[0068] Comparative Examples 1 and 2 each provide a composite material car hood.

[0069] The difference between Comparative Examples 1-2 and Example 1 is that the moving speed of the robotic arm is as shown in Table 1 below.

[0070] Table 1 shows the moving speed of the robotic arm in the spraying process of Examples 1-3 and Comparative Examples 1-2.

[0071]

[0072]

[0073] Examples 4-5

[0074] Examples 4-5 each provide a composite material vehicle hood.

[0075] The difference between Examples 4-5 and Example 1 is the spray gun pressure, as shown in Table 2 below.

[0076] Comparative Examples 3-4

[0077] Comparative Examples 3 and 4 each provide a composite material car hood.

[0078] The difference between Comparative Examples 3-4 and Example 1 is the spray gun pressure, as shown in Table 2 below.

[0079] Table 2. Spray gun pressure in the spraying process of Examples 4-5 and Comparative Examples 3-4

[0080] / Spray gun pressure (MPa) Example 1 0.4 Example 4 0.3 Example 5 0.5 Comparative Example 3 0.2 Comparative Example 4 0.6

[0081] Examples 6-9

[0082] Examples 6-9 each provide a composite material vehicle hood.

[0083] The difference between Examples 6-9 and Example 1 is that the film thickness formed by the water-based collinear primer is shown in Table 3 below.

[0084] Table 3. Film thickness of water-based collinear primers formed in Examples 1 and 6-9.

[0085] / Film thickness (μm) Example 1 30 Example 6 10 Example 7 20 Example 8 40 Example 9 50

[0086] Examples 10-13

[0087] Examples 10-13 provide a composite material vehicle hood.

[0088] The difference between Examples 10-13 and Example 1 is that the surface roughness of the composite material substrate before spraying is shown in Table 4 below.

[0089] Table 4 Surface roughness of composite material substrates in Examples 1 and 10-13

[0090]

[0091] Comparative Example 5

[0092] Comparative Example 5 provides a composite material car hood.

[0093] The difference between the above comparative example and Example 1 is that the parameters of the robotic arm of the automatic spraying machine are set as follows: nozzle diameter is 0.8mm, moving speed is 500mm / s, spray gun pressure is 0.3MPa, oil supply pressure is 0.2MPa, fan pressure is 0.5MPa, atomization pressure is 0.4MPa, and fan volume is 2.5.

[0094] Comparative Example 6

[0095] Comparative Example 6 provides a composite material car hood.

[0096] The hood of the composite material vehicle in Comparative Example 6 was coated with an oil-based paint (model CHG-X-007) on the composite material substrate.

[0097] The difference between the above-mentioned composite material hood spraying process and the water-based collinear primer spraying process of Example 1 is as follows:

[0098] The parameters of the robotic arm of the automatic spraying machine are set as follows: nozzle diameter is 0.8mm, moving speed is 500mm / s, spray gun pressure is 0.3MPa, oil supply pressure is 0.2MPa, fan pressure is 0.5MPa, atomization pressure is 0.4MPa, and fan volume is 2.5.

[0099] Performance testing

[0100] The surface roughness and resistivity of the surface paint film of the composite material vehicle hoods provided in Examples 1-13 and Comparative Examples 1-6 were tested, and the results are shown in Table 5 below.

[0101] The method for testing surface roughness is based on ISO 1997; the method for testing resistivity is based on QJ 2220.2-1992.

[0102] Table 5 shows the performance test results of the composite material vehicle hoods provided in Examples 1-13 and Comparative Examples 1-6.

[0103]

[0104]

[0105] The test results of Examples 1-3 and Comparative Examples 1-2 show that as the moving speed of the robotic arm in the spraying process increases, the surface roughness and resistivity of the composite material car hood exhibit a trend of first decreasing and then increasing. In Comparative Example 1, when the moving speed of the robotic arm was controlled at 500 mm / s, the surface roughness of the resulting paint film was 0.414 μm, and the resistivity was as high as 1.1 μm. In Comparative Example 2, when the moving speed of the robotic arm was controlled at 900 mm / s, the surface roughness of the resulting paint film was 0.387 μm, and the resistivity was 0.8 μm. In Examples 1-3, when the moving speed of the robotic arm was controlled between 600-800 mm / s, the surface roughness of the resulting paint film was 0.236-0.273 μm, and the resistivity was 0.3-0.4 μm. Therefore, it is demonstrated that by controlling the moving speed of the robotic arm in the coating process within the range of 600-800 mm / s, this application can obtain composite material hangers with low surface roughness and low resistivity.

[0106] The test results of Examples 1, 4-5, and Comparative Examples 2-3 show that as the spray gun pressure increases during the coating process, the surface roughness and resistivity of the composite material car hood exhibit a trend of first decreasing and then increasing. In Comparative Example 3, when the spray gun pressure was controlled at 0.2 MPa, the surface roughness of the resulting paint film was 0.336 μm, and the resistivity was as high as 0.8 μm; when the spray gun pressure was controlled at 0.6 MPa, the surface roughness of the resulting paint film was 0.585 μm, and the resistivity was 1.3 μm; while in Examples 1 and 4-5, when the spray gun pressure was controlled between 0.3 and 0.5 MPa, the surface roughness of the resulting paint film was 0.236-0.277 μm, and the resistivity was 0.3-0.4 μm. Therefore, this application demonstrates that by controlling the spray gun pressure in the coating process within the range of 0.3-0.5 MPa, composite material hangers with low surface roughness and low resistivity can be obtained.

[0107] The test results of Examples 1 and 6-9 show that as the paint film thickness increases, the surface roughness of the composite material vehicle hood gradually decreases, and the resistivity initially decreases and then increases. Further comparison reveals that in Example 6, when the paint film thickness is 10 μm, the surface roughness is 0.281 μm and the resistivity is 0.4 μm; in Example 9, when the paint film thickness is 50 μm, the surface roughness is 0.225 μm and the resistivity is 0.5 μm; and in Examples 7-8, when the paint film thickness is 20-40 μm, the surface roughness is 0.231-0.234 μm and the resistivity is 0.3-0.4 μm. Therefore, this application demonstrates that by further controlling the paint film thickness on the composite material surface within the range of 20-40 μm, the surface roughness of the composite material can be further reduced, and its conductivity improved.

[0108] The test results of Examples 1 and 10-13 show that the surface roughness of the composite material substrate affects the surface roughness and conductivity of the composite material hanger after spraying. Comparison reveals that Example 13 used a composite material substrate with a surface roughness of 0.858 μm, resulting in a composite material surface roughness of 0.314 μm; while Examples 1 and 10-12 controlled the surface roughness of the composite material substrate to below 0.8 μm, resulting in composite materials with a surface roughness <0.3 μm. Therefore, this application demonstrates that controlling the surface roughness of the composite material substrate to below 0.8 μm in this application yields composite material hangers with better surface roughness and conductivity.

[0109] The robotic arm parameters of the automatic spraying machine in Comparative Example 5 were used to spray the composite material substrate, resulting in a composite material with a surface roughness of 0.628 μm and a resistivity of 1.8 μm. This indicates that the process parameters provided in Comparative Example 5 cannot produce composite material hangers with low surface roughness and low resistivity when spraying the composite material substrate.

[0110] Comparative Example 6 used oil-based paint from related technologies to spray the composite material substrate. The resulting composite material had a small amount of electrophoretic paint deposited locally on its surface, leading to problems such as high surface roughness and uneven surface stress distribution. Its surface roughness reached as high as 0.823 μm, and its resistivity reached as high as 6.3 μm. Therefore, it is evident that Comparative Example 6, using oil-based paint to spray the composite material substrate, is unlikely to produce composite material hangers with low roughness and low resistivity.

[0111] Application Example 1

[0112] Application Example 1 provides a collinear spraying process for composite material automobiles. The collinear spraying process includes the following steps:

[0113] (1) Composite material pretreatment (substrate treatment): The composite material car hood obtained in Example 1 is subjected to surface pretreatment to ensure cleanliness, remove grease and impurities, and obtain the pretreated composite material car hood.

[0114] (2) Metal material pretreatment: hot water washing of the metal car body; then pre-degreasing, degreasing, water washing, film phosphating, pure water washing, and draining of the car body to obtain the pretreated metal car body;

[0115] (3) Collinear Spraying: The pretreated composite material hood and the treated metal body are entered into an electrophoretic coating pool together. Through an electrochemical reaction, electrophoretic paint (grade NTB-G-3) is deposited on the surface of the metal body, while no electrophoretic paint is deposited on the surface of the composite material hood; a uniform electrophoretic paint coating is formed on the surface of the metal body. During the electrophoretic coating process, excess paint is collected through an overflow recovery system to reduce waste.

[0116] (4) Post-processing: After the co-line spraying is completed, the car body is sprayed with pure water, soaked in pure water, drained and baked in sequence. Finally, the parts are inspected and qualified. Then, a three-coat and three-bake process is carried out to obtain the painted composite material car body.

[0117] Comparative Application Example 1

[0118] Comparative Application Example 1 provides a collinear spraying process for composite material automobiles.

[0119] The difference between Application Example 1 and Application Example 2 is that the composite material car hood is derived from Comparative Example 6.

[0120] Performance testing

[0121] For example 1, the surface performance of the composite material hood of the vehicle body obtained in example 1 was tested, including long-wavelength value, short-wavelength value, sharpness, gloss, and adhesion. The test results are shown in Table 6 below.

[0122] The testing methods for long-wavelength value, short-wavelength value and sharpness are in accordance with ASTM D5767-2018; the testing method for gloss is in accordance with ASTM D523-2018; and the testing method for adhesion is in accordance with GB / T 9286-2021.

[0123] The adhesion testing method refers to GB / T 9286-2021. The adhesion grading is as follows: Grade 0 - no peeling within the mesh; Grade 1 - mesh peeling ≤ 5%; Grade 2 - mesh peeling 5-15%; Grade 3 - mesh peeling 15-35%; Grade 4 - mesh peeling 35-65%; Grade 5 - mesh peeling ≥ 65%.

[0124] Table 6 Surface Performance Test Results of Composite Material Vehicle Hoods

[0125]

[0126] As shown in Table 6, the composite material hood of Application Example 1 exhibits significantly better sharpness, gloss, and adhesion than the composite material hood of Comparative Application Example 1. This indicates that the water-based collinear primer spraying process provided in this application can achieve a composite material hood with excellent surface roughness and resistivity. When the composite material hood is electrophoretically coated together with the metal body, no electrophoretic paint is deposited on the surface of the composite material hood, and the surface properties of the composite material are excellent after electrophoresis.

[0127] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A composite material, characterized in that, The water-based collinear primer is prepared by spraying using a spraying method; the spraying method of the water-based collinear primer is characterized by including the following steps: pretreatment, spraying, and baking; Spraying: An automatic spraying device is used to automatically spray water-based collinear primer onto the surface of the pretreated composite material substrate; the moving speed of the robotic arm of the automatic spraying device is 600-800 mm / s, the spray gun pressure is 0.3-0.5 MPa, the nozzle diameter is 1-1.4 mm, the oil supply pressure is 0.4-0.6 MPa, the fan-shaped pressure is 0.6-0.7 MPa, the atomization pressure is 0.5-0.6 MPa, and the fan-shaped amount is 3-3.

5. The surface roughness of the composite material substrate is <0.8 μm; The water-based collinear primer comprises component A and component B; component A comprises the following components in parts by weight: 41-62 parts epoxy resin, 3-14 parts titanium dioxide, 3-12 parts conductive carbon black, 5-15 parts filler, 5-25 parts water, 1-2 parts dispersant, 1-7 parts film-forming aid, 0.2-1 part wetting agent, 0.4-1 part defoamer, 0.4-1 part leveling agent, and 0.5-2.5 parts thickener; component B comprises a modified amine curing agent; The film thickness of the water-based collinear primer on the surface of the composite material is 20-40 μm, the surface roughness is <0.3 μm, and the resistivity is ≤0.4 MΩ.

2. The composite material according to claim 1, characterized in that, The robotic arm of the automatic spraying equipment moves at a speed of 600-700 mm / s, and the spray gun pressure is 0.4-0.5 MPa.

3. The composite material according to claim 1, characterized in that, The baking temperature is 70-80℃ and the time is 60-80 minutes.

4. A multi-material co-line spraying process, characterized in that, The method includes the following steps: pretreating the composite material and the metal material as described in any one of claims 1-3 respectively, and then placing the pretreated composite material and the pretreated metal material together in an electrophoretic pool for electrophoresis, thereby depositing electrophoretic paint on the surface of the metal material through an electrochemical reaction.

Images