Highlight sagging-free spraying process for automobile air-inlet grille

Abstract

The invention relates to the technical field of automobile parts, in particular to an automobile air-inlet grille highlight sagging-free spraying process which comprises the steps of cleaning, degreasing, drying, dust removal, varnish spraying, drying and detection, UV finish paint spraying, UV curing and product detection. The pre-treatment comprises cleaning, degreasing, drying and dust removal, adhesion of follow-up spraying paint is facilitated, the spraying quality is improved, natural leveling is carried out after a varnish layer is sprayed, the uniformity of a paint surface is improved, a high-gloss wear-resistant paint surface is formed through UV finish paint, and the leveling effect and glossiness of the surface of the paint surface are guaranteed through a release protective film.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile accessories, and in particular relates to a high-gloss, non-sagging spraying process for an automobile air intake grille. Background Art

[0002] The car grille is a grid-like component on the front of the car, located between the front bumper and the front crossbar of the car body. The grille has many functions: 1) decoration, to cover the mechanical structure in the engine compartment; 2) protection, to prevent the water tank and the components in the engine compartment from being hit by foreign objects; 3) ventilation, the engine needs air to work, so the design of the air intake grille must ensure that enough air can enter the engine compartment; 4) aesthetics, different brands of cars have their own iconic grilles. In order to pursue the effects of individuality, fashion, technology and high gloss, high gloss grilles have become a new popular trend in recent years. At present, the process of producing high gloss grilles on the market is generally to first hot stamp the hot stamping area of ​​the grille, and then spray varnish on the non-hot stamping area of ​​the grille to achieve a high gloss effect. The existing spraying process is prone to paint appearance defects such as orange peel and pitting, and has poor spraying uniformity, poor surface leveling, and sagging. The surface finish, hardness and wear resistance of the produced grille are poor. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a high-gloss, non-sagging spraying process for automobile air intake grilles to solve the above-mentioned technical problems.

[0004] Technical solution: In order to achieve the above-mentioned purpose, the present invention provides a high-gloss and non-sagging spraying process for an automobile air intake grille, comprising the following steps: S1, cleaning: the grille is sent into the cleaning room, and the cleaning type of the grille is classified into light cleaning and deep cleaning according to the stains and attachments on the grille surface, and the classified grilles are treated separately, and the treated grilles are cleaned; S2, degreasing: wipe the surface of the grid with a degreasing agent; remove the grease on the surface of the grid to prevent the presence of grease from affecting the adhesion of paint during subsequent painting.

[0005] S3, Drying: The cleaned and degreased grille is placed in an air-drying area and quickly dried using a fan; moisture on the grille is removed, thereby enhancing the adhesion of the primer on the grille surface.

[0006] S4, dust removal: The grid flows into the electrostatic reciprocating dust removal equipment along the assembly line for electrostatic dust removal; the electrostatic ion wind is used to clean the dust adsorbed on the surface of the grid and remove the static electricity on the grid, thereby improving the adhesion of the primer during subsequent spraying and improving the spraying quality.

[0007] S5, varnish spraying: Use a fixture to clamp the grille, adjust the position of the spray gun, tilt the spray gun, adjust the state of the spray gun, move the grille at a constant speed after the spray gun is evenly sprayed, and spray the grille surface 2-3 times, of which the first spray is used as a primer, and the paint thickness is 30-45um; S6, drying and testing: drying the varnish layer on the grille surface. After drying, the grille enters the buffer area for buffering and cooling, and then checks whether there are any defects on the paint surface; S7: Spraying UV topcoat: Spray the UV topcoat evenly on the surface of the grille. After spraying, it will be leveled by infrared rays. Then, the release protective film will be covered on the UV topcoat layer and pressed flat. S8, UV curing: The grille is UV cured, and ultraviolet rays penetrate the release protective film to quickly cure the UV topcoat. After cooling, the release protective film and the plate are peeled off; a hardened and wear-resistant paint layer with high gloss and high flatness can be obtained on the surface of the grille.

[0008] S9, product testing: Conduct a comprehensive test on the grille to determine whether it is qualified.

[0009] Furthermore, the grille cleaning in step S1 uses snowflake dry ice cleaning. Snowflake dry ice cleaning can effectively remove oil stains and particles including various corners and gaps, while reducing the surface stress of the workpiece without affecting the structure of the overall precision workpiece; compared with ordinary cleaning, snowflake dry ice cleaning has stronger cleaning ability, laying a good foundation for paint spraying.

[0010] Furthermore, the degreasing agent in step S2 is isopropyl alcohol, and the dust removal in step S4 is repeated 8 times in total, with a given air pressure of 0.35 MPa and a distance of 25 cm.

[0011] Furthermore, the viscosity of the varnish is controlled within a range of 13-15S during spraying, and the viscosity is measured using an NK-2 viscosity cup. The viscosity of the varnish is controlled to avoid sagging during spraying due to low viscosity.

[0012] Furthermore, a forced cooling workshop is provided in the buffer area in step S6. When in the buffer area, the paint is first cooled naturally for 8-10 minutes in the leveling section and then forced cooled for 5 minutes in the forced cooling workshop, wherein the temperature of the leveling section is 26-30°C. After leveling, the varnish layer is more uniform and delicate.

[0013] Furthermore, infrared leveling specifically uses far-infrared light sources to heat the paint on the grille surface to a constant temperature of about 40°C in the tunnel, which accelerates the leveling of the paint after being heated in the leveling channel. The paint film is more uniform and delicate, and achieves the effect of defoaming and removing marks, enhancing the paint surface expression of the UV topcoat.

[0014] Furthermore, the release protective film adopts a biaxially stretched polyethylene terephthalate film, polyethylene PE or polypropylene film whose surface is not corona treated and not treated with an easy-to-adhesion coating, or a biaxially stretched polyethylene terephthalate film whose surface is hardened and wear-resistant. The biaxially stretched release protective film without corona treatment and without an easy-to-adhesion coating can avoid the poor surface quality caused by the adhesion of the UV topcoat layer and the release protective film after UV curing.

[0015] Furthermore, the detection includes using a laser orange peel tester, a laser level and an ultrasonic thickness gauge to inspect the paint surface respectively to determine whether the paint surface has orange peel, cracks and uneven thickness.

[0016] Furthermore, the drying process in step S6 includes: drying in an oven at 85-95° C. for 25-45 minutes before going offline.

[0017] It can be seen from the above technical solution that the present invention has the following beneficial effects: 1. The present invention provides a high-gloss, non-sagging spraying process for an automobile air intake grille. The pre-treatment includes cleaning, degreasing, drying and dust removal, which is beneficial to the adhesion of the subsequent sprayed paint and improves the spraying quality. After spraying the varnish layer, natural leveling is performed to improve the uniformity of the paint surface. A UV topcoat is used to form a high-gloss, wear-resistant paint surface, and a release protective film ensures the leveling effect and glossiness of the paint surface.

[0018] 2. The present invention controls the viscosity of the spray paint to avoid line sagging during spraying and improve the spraying quality.

[0019] 3. The present invention detects the paint surface after each painting process to improve the effect of subsequent painting and thus improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of the high-gloss, no-sagging spraying process for the automobile air intake grille. DETAILED DESCRIPTION

[0021] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0022] like Figure 1 As shown, a high-gloss, non-sagging spraying process for an automobile air intake grille is characterized by comprising the following steps: S1, cleaning: the grille is sent into the cleaning room, and the cleaning type of the grille is classified into light cleaning and deep cleaning according to the stains and attachments on the grille surface, and the classified grilles are treated separately, and the treated grilles are cleaned; S2, degreasing: wipe the grid surface with a degreasing agent; S3, drying: the cleaned and degreased grilles are placed in a drying area and quickly dried by a fan; S4, dust removal: the grid flows into the electrostatic reciprocating dust removal equipment along the assembly line for electrostatic dust removal; S5, varnish spraying: Use a fixture to clamp the grille, adjust the position of the spray gun, tilt the spray gun, adjust the state of the spray gun, move the grille at a constant speed after the spray gun is evenly sprayed, and spray the grille surface 2-3 times, of which the first spray is used as a primer, and the paint thickness is 30-45um; S6, drying and testing: drying the varnish layer on the grille surface. After drying, the grille enters the buffer area for buffering and cooling, and then checks whether there are any defects on the paint surface; S7: Spraying UV topcoat: Spray the UV topcoat evenly on the surface of the grille. After spraying, it will be leveled by infrared rays. Then, the release protective film will be covered on the UV topcoat layer and pressed flat. S8, UV curing: The grille is UV cured, and ultraviolet rays penetrate the release protective film to quickly cure the UV topcoat. After cooling, the release protective film and the plate are peeled off; S9, product testing: Conduct a comprehensive test on the grille to determine whether it is qualified.

[0023] In the step S1, the grille cleaning is performed by using snowflake dry ice cleaning. Snowflake dry ice cleaning can effectively remove oil stains and particles including various corners and gaps, while reducing the surface stress of the workpiece without affecting the structure of the overall precision workpiece; compared with ordinary cleaning, snowflake dry ice cleaning has stronger cleaning ability, laying a good foundation for paint spraying. In addition, pure water cleaning can also be used.

[0024] Specifically, the degreasing agent in step S2 is isopropyl alcohol, and the dust removal in step S4 is repeated 8 times in total, with a given air pressure of 0.35 MPa and a distance of 25 cm.

[0025] Specifically, the viscosity of the varnish is controlled within the range of 13-15S during spraying, and the viscosity is measured using an NK-2 viscosity cup. During use, the viscosity of the paint should be tested every two hours to ensure that the viscosity of the paint is controlled within the range of 13-15S.

[0026] Specifically, a forced cooling workshop is provided in the buffer area in step S6. When in the buffer area, it first passes through the leveling section for natural cooling for 8-10 minutes and then enters the forced cooling workshop for forced cooling for 5 minutes, wherein the temperature of the leveling section is 26-30C°.

[0027] Among them, infrared leveling specifically uses far-infrared light sources to heat the paint on the grille surface in the tunnel to a constant temperature of about 40°C, which accelerates the leveling of the paint after being heated in the leveling channel. Infrared leveling can make the paint surface more uniform and smooth, while improving the hardness and durability of the coating.

[0028] Specifically, the release protective film is made of biaxially oriented polyethylene terephthalate film, polyethylene PE or polypropylene film whose surface is not corona treated and not treated with an easy-adhesion coating, or a biaxially oriented polyethylene terephthalate film whose surface is hardened and wear-resistant.

[0029] Specifically, the detection includes using a laser orange peel tester, a laser level and an ultrasonic thickness gauge to inspect the paint surface respectively to determine whether the paint surface has orange peel, cracks and uneven thickness.

[0030] Preferably, the drying process in step S6 includes: drying in an oven at 85-95° C. for 25-45 minutes before taking the product offline.

[0031] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the protection scope of the present invention.

Claims

1. A high-gloss, no-sagging spraying process for automobile air intake grille, characterized in that: The steps include: S1, cleaning: the grille is sent into the cleaning room, and the cleaning type of the grille is classified into light cleaning and deep cleaning according to the stains and attachments on the grille surface, and the classified grilles are treated separately, and the treated grilles are cleaned; S2, degreasing: wipe the grid surface with a degreasing agent; S3, drying: the cleaned and degreased grilles are placed in a drying area and quickly dried by a fan; S4, dust removal: the grid flows into the electrostatic reciprocating dust removal equipment along the assembly line for electrostatic dust removal; S5, varnish spraying: Use a fixture to clamp the grille, adjust the position of the spray gun, tilt the spray gun, adjust the state of the spray gun, move the grille at a constant speed after the spray gun is evenly sprayed, and spray the grille surface 2-3 times, of which the first spray is used as a primer, and the paint thickness is 30-45um; S6, drying and testing: drying the varnish layer on the grille surface. After drying, the grille enters the buffer area for buffering and cooling, and then checks whether there are any defects on the paint surface; S7: Spraying UV topcoat: Spray the UV topcoat evenly on the surface of the grille. After spraying, it will be leveled by infrared rays. Then, the release protective film will be covered on the UV topcoat layer and pressed flat. S8, UV curing: The grille is UV cured, and ultraviolet rays penetrate the release protective film to quickly cure the UV topcoat. After cooling, the release protective film and the plate are peeled off; S9, product testing: Conduct a comprehensive test on the grille to determine whether it is qualified.

2. The high-gloss, no-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: In step S1, the grid is cleaned by using snowflake dry ice cleaning.

3. The high-gloss, no-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: The degreasing agent in step S2 is isopropyl alcohol, and the dust removal in step S4 is repeated 8 times in total, with a given air pressure of 0.35 MPa and a distance of 25 cm.

4. The high-gloss, no-sagging spraying process for automobile air intake grille according to claim 1, characterized in that: The viscosity of the varnish is controlled in the range of 13-15S during spraying, and the viscosity is measured using an NK-2 viscosity cup.

5. The high-gloss, no-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: The buffer area in step S6 is provided with a forced cooling workshop. When in the buffer area, it first passes through the leveling section for natural cooling for 8-10 minutes and then enters the forced cooling workshop for forced cooling for 5 minutes, wherein the temperature of the leveling section is 26-30°C.

6. The high-gloss, non-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: Infrared leveling specifically uses a far-infrared lamp source to heat the paint on the grille surface in the tunnel to a constant temperature of about 40°C, which accelerates the leveling of the paint after being heated in the leveling channel.

7. The high-gloss, non-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: The release protective film is made of biaxially stretched polyethylene terephthalate film, polyethylene PE or polypropylene film without corona treatment and easy-adhesion coating treatment on the surface, and can also be made of biaxially stretched polyethylene terephthalate film with hardened and wear-resistant surface treatment.

8. The high-gloss, no-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: The detection includes using a laser orange peel tester, a laser level and an ultrasonic thickness gauge to inspect the paint surface respectively to determine whether the paint surface has orange peel, cracks and uneven thickness.

9. The high-gloss, non-sagging spraying process for automobile air intake grille according to claim 1 is characterized in that: The drying process in step S6 includes: drying in an oven at 85-95° C. for 25-45 minutes before going offline.

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