A car body painting process capable of mirror defect repair

Abstract

This invention discloses a vehicle body painting process capable of repairing mirror-like defects, comprising: inspecting vehicle body surface defects; grinding the defects with a grinder; polishing the ground defects with a polishing machine; marking the mirror-like defects on the vehicle body; baking the mirror-like defects online using an electric heat gun; and spraying an isopropyl alcohol solution. This invention enables rapid online repair of localized mirror-like defects on the vehicle body, reducing rework time, minimizing subsequent rework and even scrapping, lowering costs, increasing first-pass yield, and improving workshop production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of vehicle body painting technology, specifically relating to a vehicle body painting process capable of repairing mirror defects. Background Technology

[0002] As a crucial step in automobile manufacturing, automotive painting not only gives cars their unique style and color but also plays a vital role in corrosion protection, safety enhancement, environmental compliance, and cost reduction. Therefore, ensuring the quality of the paintwork, minimizing defects, and improving the painting pass rate are of paramount importance.

[0003] Defects are unavoidable during the painting process. For individual particles, scratches, and other defects, strict adherence to polishing and finishing techniques for localized treatment minimizes the impact on the surface appearance. However, in actual painting, serious quality issues such as marks and flow lines require sanding. After polishing, these sanded areas often exhibit a mirror-like smooth surface, which, due to its inconsistency with other parts of the vehicle, is termed a "mirror defect." Mirror defects cannot be repaired online and must be addressed in a spot-repair workshop. The rework time can reach 23 minutes per vehicle, occurring 6-7 times per day, significantly impacting the first-pass yield and overall production efficiency. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention provides a vehicle body painting process capable of repairing mirror defects. This process enables rapid online repair of localized mirror defects on the vehicle body, reducing rework time, minimizing subsequent rework or even scrapping, lowering costs, increasing first-pass yield, and improving workshop production efficiency.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A vehicle body painting process capable of repairing mirror-like defects includes:

[0007] Step 1: Determine the location of defects in the vehicle body mirrors;

[0008] Step 2: Repair defects in the vehicle body mirror: The defective area of ​​the mirror is directly baked online and sprayed with isopropyl alcohol solution.

[0009] Further, step one includes:

[0010] S1. Inspect the vehicle body surface for defects;

[0011] S2. Use a grinder to grind away defects on the car body surface;

[0012] S3. Polish the sanded defects with a polishing machine;

[0013] S4. Mark defects in the vehicle body mirror surface.

[0014] Furthermore, in step S1, the light inspection requires 1000-1200 LUX, the vehicle body is inspected using an S-shaped hand-touch method, and the inspection speed is 0.2-0.3 m / s.

[0015] Furthermore, in step S1, defects such as body particles, dirt spots, scratches, and imprints are marked.

[0016] Furthermore, in step S2, the polishing machine is placed against the defective surface and polished in a circular motion for 1 to 5 seconds. The polishing slurry is wiped off and the defect is visually confirmed to be eliminated. If the defect is not eliminated, the polishing operation is repeated and the polishing is expanded outward by 1 to 2 times to the left and right of the original polishing position.

[0017] Furthermore, in step S3, a polishing machine is used to polish the defect for 10 to 15 seconds using a circular motion, and the polishing area is 1 to 2 times the area being polished.

[0018] Furthermore, step two includes:

[0019] S5. Use an electric heat gun to heat the defective mirror surface of the car body online;

[0020] S6. Spray isopropanol solution.

[0021] Furthermore, in step S5, the temperature of the electric baking gun is set to 120-125°C, the distance from the mirror defect is 15-20cm, and the baking time is 30-35s.

[0022] Furthermore, in step S6, an isopropanol solution with a ratio of 80% to 100% isopropanol and pure water is sprayed onto the baked area 2 to 3 times.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Existing methods for handling mirror-like defects involve offline grinding and repainting, which is time-consuming, has a low pass rate, wastes materials, affects production schedules, and reduces enterprise production efficiency. This invention addresses mirror-like defects on vehicle bodies by directly baking, spraying, and polishing online to achieve the desired surface finish. This solves the problem of new defects arising from spot repairs, significantly improving painting efficiency. Compared to the original spot-patch process, it substantially reduces painting production costs, lowers single-vehicle repair time by 21 minutes, and increases the first-pass yield by 4%. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0026] Figure 1 This is an overall flow chart of a car body painting process capable of repairing mirror defects, as described in this invention. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it.

[0028] like Figure 1 As shown, a car body painting process capable of repairing mirror-like defects includes:

[0029] Step 1: Determine the location of defects in the vehicle body mirrors:

[0030] S1. Inspect vehicle body surface defects:

[0031] The inspection light should be 1000-1200 LUX. The palm should be placed on the car body and covered. The S-shaped hand touch method should be used to inspect the car body. The eyes should look behind the hands and the hands and eyes should be in sync. The inspection speed should be 0.2-0.3 m / s. At critical work stations, the palm area should be covered in an overlapping manner. The edges and corners should be inspected by touching with the fingers. Defects such as particles, dirt spots, scratches, and marks should be marked.

[0032] S2. Use a grinder to polish the defects on the car body surface:

[0033] Apply polishing compound to the defect, place the grinder against the surface of the defect, and grind in a circular motion for 1 to 5 seconds. Wipe off the polishing paste and visually confirm that the defect has been eliminated.

[0034] If the defect is not eliminated, repeat the grinding operation and grind horizontally to the left and right of the original grinding position, expanding outward by 1 to 2 times. After the defect is eliminated, squeeze polishing paste onto the grinding point to mark the defect identification mark.

[0035] S3. Polish the sanded defects with a polishing machine:

[0036] Place the polisher flat on the area to be polished, keeping it in contact with the surface. Press the trigger and polish the defect in a circular motion for 10 to 15 seconds. The polishing area should be 1 to 2 times the area to be polished. Wipe it clean with a fiber towel and observe whether the defect has been eliminated. The paint surface should be free of polishing marks and in the same state as other areas. If the defect has not been eliminated, the polishing operation needs to be repeated.

[0037] Inspection: Use the light source of the line-side light box to observe and confirm from the front and side to avoid omission of defects, grinding marks, polishing shadows, and incomplete polishing, etc. If such defects are found, grinding and polishing operations must be repeated.

[0038] S4. Mark defects in the vehicle body mirror surface:

[0039] After polishing, the finish differs from other parts of the car body, presenting a mirror-like effect similar to the car body coating. Adhesive tape is then applied to mark the area.

[0040] Step 2: Repair defects in the vehicle body mirrors:

[0041] S5. Using an electric heat gun to directly heat the car body mirror surface to remove defects:

[0042] Press the power switch of the electric heat gun to start it, and adjust the temperature setting using the temperature control button. Set the temperature of the electric heat gun to 120℃~125℃, the distance from the mirror defect to 15~20cm, and the baking time to 30~35s;

[0043] S6. Spray isopropanol solution:

[0044] Spray the baked area with an isopropanol solution of 80-100% isopropanol and pure water 2-3 times.

[0045] Example 1

[0046] A vehicle body painting process capable of repairing mirror-like defects, including coatings on the outer surfaces of the hood, roof, doors, trunk lid, fenders, and pillars, is described below.

[0047] S1. Inspection:

[0048] The inspection light should be 1000-1200 LUX. The palm should be placed on the car body and covered. The S-shaped hand touch method should be used to inspect the car body. The eyes should look behind the hands and the hands and eyes should be in sync. The inspection speed should be 0.2-0.3 m / s. At critical work stations, the palm area should be covered in an overlapping manner. The edges and corners should be inspected by touching with the fingers. Defects such as particles, dirt spots, scratches, and marks should be marked.

[0049] S2. Polishing:

[0050] Apply polishing compound to the defect, place the grinder against the surface of the defect, and grind in a circular motion for 1 to 5 seconds. Wipe off the polishing paste and visually confirm that the defect has been eliminated. If it has not been eliminated, repeat the grinding operation and grind horizontally to the left and right of the original grinding position, expanding outward by 1 to 2 times. After elimination, apply polishing compound to the grinding point to mark the defect.

[0051] S3. Polishing:

[0052] Place the polisher flat on the area to be polished, keeping it in contact with the surface. Press the trigger and polish the defect in a circular motion for 10 to 15 seconds. The polishing area should be 1 to 2 times the area to be polished. Wipe it clean with a fiber towel and observe whether the defect has been eliminated. The paint surface should be free of polishing marks and in the same state as other areas. If the defect has not been eliminated, the polishing operation needs to be repeated.

[0053] Inspection: Use the light source of the line-side light box to observe and confirm from the front and side to avoid omission of defects, grinding marks, polishing shadows, and incomplete polishing, etc. If such defects are found, grinding and polishing operations must be repeated.

[0054] S4. Mark:

[0055] After polishing, the finish differs from other parts of the car body, presenting a mirror-like effect similar to the car body coating. Adhesive tape is then applied to mark the area.

[0056] In this embodiment, the orange peel texture of the car body is measured using an orange peel meter. The orange peel test results for the mirror area are 2.3≤long wave≤3 and 5.7≤short wave≤6.5. The orange peel test results for the adjacent areas of the car body are 5.5≤long wave≤6 and 7.2≤short wave≤8.3, as shown in Table 1. The numerical values ​​are significantly different from those observed visually.

[0057] Table 1. Results of Orange Peel Measurement on Vehicle Body

[0058]

[0059] In this embodiment, a repair test was conducted using a test spray plate to assess the repair effectiveness.

[0060] Take 15 spray plates and spray them according to the car body spraying process. After sanding and polishing according to steps S1 to S4, obtain 15 mirror test plates, numbered 1 to 15. The orange peel measurement results are shown in Table 2.

[0061] Table 2 Results of Orange Peel Measurement on Test Spray Plate

[0062]

[0063] S5. Baking:

[0064] Press the power switch on the electric heat gun to start it. Adjust the temperature setting using the temperature control button. Set the heat gun temperature to 110℃, 115℃, 120℃, 125℃, and 130℃, and heat test plates 1 to 5 respectively. Position the heat gun head vertically towards the mirror defect location, maintaining a distance of 15-20cm. Heat for 30-35 seconds, avoiding overheating. Adjust the angle and direction of the heat gun as needed to ensure the entire mirror defect location is fully heated. Observe the surface frequently during the heating process.

[0065] S6. Spraying:

[0066] Add 100% isopropanol solution to a spray bottle as needed, and spray evenly three times on the defective areas of the mirror surface, extending the sprayed area 1-2 cm beyond the mirror surface. After the isopropanol evaporates and dries, measure the orange peel value of the test panel. The results are shown in Table 3.

[0067] Table 3. Test results of Example 1

[0068]

[0069] As can be seen from Table 3, baking at a certain temperature between 120 and 125°C is effective in repairing mirror defects, and visually acceptable results can meet the delivery quality requirements.

[0070] Example 2

[0071] This embodiment is the same as steps S1 to S4 in embodiment 1, except that:

[0072] S5. Baking:

[0073] Press the power switch to turn on the electric heat gun and adjust the temperature setting using the temperature control button. Set the temperature to 120℃ and heat test plates 6 through 10 at a distance of 15–20 cm for 30–35 seconds.

[0074] S6. Spraying:

[0075] The corresponding test plates were sprayed once with isopropanol solutions of 100%, 80%, 60%, 40%, and 20% isopropanol and pure water, respectively. After the isopropanol evaporated and dried, the orange peel value of the test plates was measured. The results are shown in Table 4.

[0076] Table 4. Test results of Example 2

[0077]

[0078] As can be seen from Table 4, isopropanol solutions with a ratio of 80% to 100% begin to have a repairing effect, but the visual effect is still different from the car body, and it cannot be delivered.

[0079] Example 3

[0080] This embodiment is the same as steps S1 to S4 in embodiment 1, except that:

[0081] S5. Baking:

[0082] Press the power switch of the electric heat gun to start it. Adjust the temperature setting using the temperature control button. Set the temperature of the electric heat gun to 120℃ and heat test plates 11 to 15 at a distance of 15-20cm for 30-35 seconds.

[0083] S6. Spraying:

[0084] The corresponding test plates were sprayed twice with isopropanol solutions of 100%, 80%, 60%, 40%, and 20% isopropanol and pure water, respectively. After the isopropanol evaporated and dried, the orange peel value of the test plates was measured. The results are shown in Table 5.

[0085] Table 5. Test results of Example 3

[0086]

[0087] As can be seen from Table 5, a 60% isopropanol solution begins to have a repairing effect, and isopropanol solutions with a ratio of 80% to 100% have qualified measured values ​​and visually acceptable results, meeting the delivery requirements.

[0088] For the qualified plates of Examples 1 and 3, their film thickness, color difference, and adhesion properties were measured, and the results are shown in Table 6.

[0089] Table 6. Measurement Results of Spray Plate Performance in Qualified Tests

[0090]

[0091] As can be seen from Table 6, a baking temperature of 120-125℃, an isopropanol concentration of 80-100%, and 2-3 spraying times can ensure that the orange peel value is qualified after the mirror defect is repaired, the visual appearance is qualified, and it does not affect other performance of the vehicle body, thus meeting the delivery quality requirements.

[0092] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vehicle body painting process capable of repairing mirror-like defects, characterized in that, include: Step 1: Determine the location of defects in the vehicle body mirrors; Step Two: Repairing defects in the vehicle body mirror: Directly bake the defective area of ​​the mirror online and spray it with isopropyl alcohol solution; Step Two includes: S5. Use an electric heat gun to bake the defective mirror surface of the car body online; in step S5, set the temperature of the electric heat gun to 120~125℃, the distance from the defective mirror surface to 15~20cm, and the baking time to 30~35s; S6. Spray isopropanol solution; In step S6, spray the baked area with an isopropanol solution of 80-100% isopropanol and pure water, spraying 2-3 times.

2. The vehicle body painting process capable of repairing mirror-like defects as described in claim 1, characterized in that, Step one includes: S1. Inspect the vehicle body surface for defects; S2. Use a grinder to grind away defects on the car body surface; S3. Polish the sanded defects with a polishing machine; S4. Mark defects in the vehicle body mirror surface.

3. The vehicle body painting process capable of repairing mirror-like defects as described in claim 2, characterized in that, In step S1, the light inspection requires 1000~1200 LUX, the vehicle body is inspected using the S-shaped hand-touch method, and the inspection speed is 0.2~0.3 m / s.

4. The vehicle body painting process capable of repairing mirror-like defects as described in claim 2, characterized in that, In step S1, defects such as body particles, dirt spots, scratches, and imprints are marked.

5. A car body painting process capable of repairing mirror-like defects as described in claim 2, characterized in that, In step S2, the polishing machine is placed against the defective surface and polished in a circular motion for 1 to 5 seconds. The polishing slurry is wiped off and the defect is visually confirmed to be eliminated. If the defect is not eliminated, the polishing operation is repeated and the polishing is expanded outward by 1 to 2 times to the left and right of the original polishing position.

6. The vehicle body painting process capable of repairing mirror-like defects as described in claim 2, characterized in that, In step S3, a polishing machine is used to polish the defect for 10-15 seconds using a circular motion, and the polishing area is 1-2 times the area being polished.

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