Production process of car lamp decorative frame with metallic luster

Abstract

A manufacturing process for an automotive headlight trim frame with an inherent metallic luster, belonging to the field of automotive headlight trim frames, includes the following steps: Step 1: Weighing raw materials according to the specified ratio; Step 2: Adding polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for preliminary softening and mixing; Step 3: Adding di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to the sealed reactor and reacting; Step 4: Adding tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor and continuing the reaction; Step 5: Adding metal powder and color masterbatch to the sealed reactor and mixing evenly; Step 6: Removing the solvent after mixing; Step 7: Injecting the molten mixture into the corresponding mold for injection molding; Step 8: Polishing to obtain the automotive headlight trim frame with an inherent metallic luster. This invention reduces the weight of the trim frame while maintaining the inherent metallic luster, which is beneficial for vehicle lightweighting.

Description

Technical Field

[0001] This invention belongs to the field of automotive headlight decorative frames, specifically a manufacturing process for automotive headlight decorative frames with an inherent metallic luster. Background Technology

[0002] Car headlight trim frames are an important part of automotive exterior decoration. They not only beautify the headlight outline but also need to possess excellent weather resistance, wear resistance, and structural stability to cope with complex conditions such as high temperatures, ultraviolet radiation, and collisions during vehicle operation. Currently, the main materials for car headlight trim frames are metal and polymer plastics. While metal can present a natural metallic luster, it suffers from being heavy, having complex processing techniques, and high production costs. Polymer plastics, although lighter, have a significantly lower surface gloss compared to metal, affecting aesthetics. Therefore, a metallic coating is often applied to the surface to enhance its appearance. However, this also presents problems: poor adhesion between the coating and the plastic substrate, and susceptibility to environmental influences, leading to peeling, fading, and cracking after long-term use. Coating processing typically involves spraying, vacuum plating, and other steps, adding to the existing production process, extending production time, and reducing efficiency. Summary of the Invention

[0003] This invention provides a manufacturing process for automotive headlight decorative frames with an inherent metallic luster, thereby overcoming the deficiencies in the prior art.

[0004] This invention is achieved through the following technical solution: A manufacturing process for an automotive headlight trim frame with an inherent metallic luster includes the following steps: Step 1: Weigh the following ingredients according to the specified ratio: metal powder, polybutadiene rubber, styrene, acrylonitrile, color masterbatch, tert-butyl methacrylate, N-phenylmaleimide, di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol. Step 2: Add polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for initial softening and mixing; Step 3: Add di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to a sealed reactor and proceed with the reaction. Step 4: Add tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor to continue the reaction; Step 5: Add metal powder and color masterbatch powder to the sealed reactor and mix thoroughly; Step Six: Remove unreacted solvent after mixing; Step 7: Inject the molten mixture into the corresponding mold for injection molding; Step 8: After injection molding is completed, remove the injection molded part and polish it to obtain a car headlight decorative frame with a metallic luster.

[0005] The manufacturing process of a car headlight decorative frame with a metallic luster as described above, wherein the mass proportions of each substance in step one are as follows: 4-6 parts metal powder, 12-16 parts polybutadiene rubber, 30-40 parts styrene, 23-27 parts acrylonitrile, 2-4 parts color masterbatch, 3-5 parts tert-butyl methacrylate, 2-4 parts N-phenylmaleimide, 0.1-0.2 parts di-tert-butyl peroxide, 0.08-0.12 parts tert-dodecyl mercaptan, and 0.2-0.4 parts 2,6-di-tert-butyl-p-cresol.

[0006] The manufacturing process of a car headlight decorative frame with a metallic luster as described above, wherein the metal powder in step one is either copper gold powder or aluminum silver powder, the particle size of the metal powder is <1μm, the cis structure content of the polybutadiene rubber is ≥95%, the Mooney viscosity is 45-55, and the particle size of the color masterbatch is <1μm.

[0007] In the production process of the automotive headlight decorative frame with a metallic luster as described above, the mixing temperature in step two is 60-70℃, the mixing speed is 100-120 rad / min, the mixing pressure is 0.1-0.2 MPa, and the mixing time is 40-50 min.

[0008] The production process of the automotive headlight decorative frame with a metallic luster as described above, wherein the reaction temperature in step three is 100-110℃, the reaction stirring speed is 140-180 rad / min, the reaction pressure is 0.2-0.3 MPa, and the reaction time is 100-120 min.

[0009] The production process of the automotive headlight decorative frame with a metallic luster as described above, wherein the reaction temperature in step four is 120-130℃, the reaction pressure is 0.3-0.4MPa, the reaction stirring speed is 120-160rad / min, and the reaction time is 130-150min.

[0010] In the production process of the automotive headlight decorative frame with a metallic luster as described above, the mixing temperature in step five is 130-140℃, the mixing speed is 200-220 rad / min, and the mixing time is 50-60 min.

[0011] The production process of the automotive headlight decorative frame with a metallic luster as described above, wherein the unreacted solvent removal operation in step six is ​​as follows: first, the temperature is raised to 200-220℃, and the vacuum degree in the sealed reactor is maintained at 6-10kPa through an external negative pressure device, the stirring speed is 150-170rad / min, and the processing time is 8-10min; then the temperature is raised to 220-240℃, the vacuum degree in the sealed reactor is reduced to 1-3kPa, the stirring speed is 150-170rad / min, and the processing time is 6-8min.

[0012] As described above, the production process of a car headlight decorative frame with a metallic luster includes the following steps: In step seven, the temperature of the injection molding machine barrel is controlled at 180-200℃ in the front section, 190-210℃ in the middle section, 200-220℃ in the rear section, and 195-215℃ in the nozzle; the mold preheating temperature is 60-80℃; the injection pressure is 80-100MPa; after injection molding, pressure holding and cooling are performed at 50-70MPa for 15-25s; water cooling is used for cooling at a rate of 3-5℃ / s; and demolding is performed after cooling to room temperature.

[0013] In the production process of the automotive headlight decorative frame with a metallic luster as described above, step eight involves first rough polishing the surface of the injection molded part with 800-grit sandpaper at a speed of 1000-1500 r / min for 3-5 minutes; then fine polishing with 1500-grit sandpaper at a speed of 2000-2200 r / min for 2-3 minutes; finally, fine polishing is performed using a wool wheel and polishing wax at a speed of 1800-2000 r / min for 1-2 minutes.

[0014] The advantages of this invention are: by blending metal powder with polymer materials and injection molding, this invention eliminates the need for additional metal coating, thus avoiding problems such as coating peeling, fading, and cracking, while also simplifying the production process, shortening the production cycle, and improving production efficiency; the polymer substrate and metal powder composite ensure the inherent metallic luster while reducing the weight of the decorative frame, which is beneficial for vehicle lightweighting. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1This is a schematic diagram of the automotive headlight decorative frame with a metallic luster prepared according to Embodiment 3 of the present invention; Figure 2 This is a schematic diagram comparing the gloss of Embodiments 1-3 and the comparative example of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0018] Example 1

[0019] Step 1: Accurately weigh the following according to the formula: 4 parts copper gold powder (particle size < 1 μm), 12 parts polybutadiene rubber (cis structure content 96%, Mooney viscosity 51), 30 parts styrene, 23 parts acrylonitrile, 2 parts carbon black masterbatch (particle size < 1 μm), 3 parts tert-butyl methacrylate, 2 parts N-phenylmaleimide, 0.1 parts di-tert-butyl peroxide, 0.08 parts tert-dodecyl mercaptan, and 0.2 parts 2,6-di-tert-butyl-p-cresol; Step 2: Add polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for preliminary softening and mixing. The mixing temperature is controlled at 60℃, the mixing speed is set to 100 rad / min, the mixing pressure is maintained at 0.1 MPa, and the mixing time lasts for 50 min. Step 3: Add di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to the sealed reactor and start the reaction. Maintain the reaction temperature at 100℃, adjust the stirring speed to 140 rad / min, control the reaction pressure at 0.2 MPa, and extend the reaction time to 120 min. Step 4: Add tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor and continue the reaction. Set the reaction temperature to 120℃, maintain the reaction pressure at 0.3MPa, the stirring speed at 120rad / min, and the reaction time to 150min. Step 5: Add copper gold powder and carbon black masterbatch to the sealed reactor and mix evenly. The mixing temperature is controlled at 130℃, the mixing speed is set to 200 rad / min, and the mixing time is 60 min. Step 6: After mixing, first raise the temperature to 200℃, maintain the vacuum in the sealed reactor at 10kPa using an external negative pressure device, stir at 150rad / min, and process for 10min; then raise the temperature to 220℃, reduce the vacuum in the sealed reactor to 3kPa, keep the stirring speed at 150rad / min, and process for 8min. Step 7: Inject the molten mixture into the corresponding mold for injection molding. The temperature of the front section of the injection molding machine barrel is controlled at 180℃, the middle section at 190℃, the rear section at 200℃, and the nozzle at 195℃. The mold preheating temperature is 60℃. The injection pressure is 80MPa. After injection molding, pressure holding and cooling are performed. The pressure holding pressure is 50MPa, and the holding time is 25s. Water cooling is used for cooling, and the cooling rate is controlled at 3-5℃ / s. After cooling to room temperature, demolding is performed. Step 8: After injection molding is completed, remove the injection molded part and first use 800-grit sandpaper to rough sand the surface of the injection molded part at a speed of 1000 rpm for 5 minutes; then use 1500-grit sandpaper for fine sanding at a speed of 2000 rpm for 3 minutes; finally, use a wool wheel with polishing wax for fine polishing at a speed of 1800 rpm for 2 minutes. After sanding and polishing, you will get a car headlight decorative frame with a metallic luster.

[0020] Example 2

[0021] Step 1: Weigh out the following according to the specified ratio: 6 parts copper gold powder (particle size < 1 μm), 16 parts polybutadiene rubber (cis structure content of polybutadiene rubber is 96%, Mooney viscosity is 51), 40 parts styrene, 27 parts acrylonitrile, 4 parts carbon black masterbatch (particle size < 1 μm), 5 parts tert-butyl methacrylate, 4 parts N-phenylmaleimide, 0.2 parts di-tert-butyl peroxide, 0.12 parts tert-dodecyl mercaptan, and 0.4 parts 2,6-di-tert-butyl-p-cresol; Step 2: Add polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for preliminary softening and mixing. The mixing temperature is 70℃, the mixing speed is 120 rad / min, the mixing pressure is 0.2 MPa, and the mixing time is 40 min. Step 3: Add di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to a sealed reactor and carry out the reaction. The reaction temperature is 110℃, the stirring speed is 180 rad / min, the reaction pressure is 0.3 MPa, and the reaction time is 100 min. Step 4: Add tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor and continue the reaction. The reaction temperature is 130℃, the reaction pressure is 0.4MPa, the stirring speed is 160rad / min, and the reaction time is 130min. Step 5: Add copper gold powder and carbon black masterbatch to the sealed reactor and mix evenly. The mixing temperature is 140℃, the mixing speed is 220 rad / min, and the mixing time is 50 min. Step 6: After mixing, first raise the temperature to 220℃, maintain the vacuum in the sealed reactor at 6kPa using an external negative pressure device, stir at 160rad / min, and process for 8min; then raise the temperature to 240℃, reduce the vacuum in the sealed reactor to 1kPa, stir at 170rad / min, and process for 6min. Step 7: Inject the molten mixture into the corresponding mold for injection molding. The temperature of the front section of the injection molding machine barrel is controlled at 200℃, the middle section at 210℃, the rear section at 220℃, and the nozzle at 215℃. The mold preheating temperature is 80℃. The injection pressure is 100MPa. After injection molding, pressure holding and cooling are performed. The pressure holding pressure is 70MPa, and the holding time is 15s. Water cooling is used for cooling, and the cooling rate is controlled at 3-5℃ / s. After cooling to room temperature, demolding is performed. Step 8: After injection molding is completed, remove the injection molded part and first use 800-grit sandpaper to rough sand the surface of the injection molded part at a speed of 1500 rpm for 3 minutes; then use 1500-grit sandpaper for fine sanding at a speed of 2200 rpm for 2 minutes; finally, use a wool wheel with polishing wax for fine polishing at a speed of 2000 rpm for 1 minute. After sanding and polishing, you will get a car headlight decorative frame with a metallic luster.

[0022] Example 3

[0023] Step 1: Weigh out the following according to the proportions: 5 parts copper gold powder (particle size < 1 μm), 146 parts polybutadiene rubber (cis structure content of polybutadiene rubber is 96%, Mooney viscosity is 51), 35 parts styrene, 25 parts acrylonitrile, 3 parts carbon black masterbatch (particle size < 1 μm), 4 parts tert-butyl methacrylate, 3 parts N-phenylmaleimide, 0.15 parts di-tert-butyl peroxide, 0.1 parts tert-dodecyl mercaptan, and 0.3 parts 2,6-di-tert-butyl-p-cresol. Step 2: Add polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for preliminary softening and mixing. The mixing temperature is 65℃, the mixing speed is 110 rad / min, the mixing pressure is 0.15 MPa, and the mixing time is 45 min. Step 3: Add di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to a sealed reactor and carry out the reaction. The reaction temperature is 105℃, the stirring speed is 160 rad / min, the reaction pressure is 0.25 MPa, and the reaction time is 110 min. Step 4: Add tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor and continue the reaction. The reaction temperature is 125℃, the reaction pressure is 0.35MPa, the stirring speed is 140rad / min, and the reaction time is 140min. Step 5: Add copper gold powder and carbon black masterbatch to the sealed reactor and mix evenly. The mixing temperature is 135℃, the mixing speed is 2120 rad / min, and the mixing time is 55 min. Step 6: After mixing, first raise the temperature to 210℃, maintain the vacuum in the sealed reactor at 8kPa using an external negative pressure device, stir at 160rad / min, and process for 9min; then raise the temperature to 230℃, reduce the vacuum in the sealed reactor to 2kPa, stir at 160rad / min, and process for 7min. Step 7: Inject the molten mixture into the corresponding mold for injection molding. The temperature of the front section of the injection molding machine barrel is controlled at 1900℃, the middle section at 200℃, the rear section at 210℃, and the nozzle at 205℃. The mold preheating temperature is 70℃. The injection pressure is 90MPa. After injection molding, pressure holding and cooling are performed. The pressure holding pressure is 60MPa, and the holding time is 20s. Water cooling is used for cooling, and the cooling rate is controlled at 3-5℃ / s. After cooling to room temperature, demolding is performed. Step 8: After injection molding, remove the molded part. First, use 800-grit sandpaper to rough sand the surface of the part at a speed of 130 rpm for 4 minutes. Then, use 1500-grit sandpaper for fine sanding at a speed of 2100 rpm for 2.5 minutes. Finally, use a wool wheel with polishing wax for fine polishing at a speed of 1900 rpm for 1.5 minutes. After sanding and polishing, you will get a car headlight trim frame with a metallic luster (e.g., Figure 1 (As shown).

[0024] Comparative Example Step 1: Weigh out the following components according to the specified ratio: 146 parts of polybutadiene rubber (cis structure content of polybutadiene rubber is 96%, Mooney viscosity is 51), 35 parts of styrene, 25 parts of acrylonitrile, 3 parts of carbon black masterbatch (particle size <1μm), 4 parts of tert-butyl methacrylate, 3 parts of N-phenylmaleimide, 0.15 parts of di-tert-butyl peroxide, 0.1 parts of tert-dodecyl mercaptan, and 0.3 parts of 2,6-di-tert-butyl-p-cresol. Step 2: Add polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for preliminary softening and mixing. The mixing temperature is 65℃, the mixing speed is 110 rad / min, the mixing pressure is 0.15 MPa, and the mixing time is 45 min. Step 3: Add di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to a sealed reactor and carry out the reaction. The reaction temperature is 105℃, the stirring speed is 160 rad / min, the reaction pressure is 0.25 MPa, and the reaction time is 110 min. Step 4: Add tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor and continue the reaction. The reaction temperature is 125℃, the reaction pressure is 0.35MPa, the stirring speed is 140rad / min, and the reaction time is 140min. Step 5: Add carbon black masterbatch to the sealed reactor and mix evenly. The mixing temperature is 135℃, the mixing speed is 2120 rad / min, and the mixing time is 55 min. Step 6: After mixing, first raise the temperature to 210℃, maintain the vacuum in the sealed reactor at 8kPa using an external negative pressure device, stir at 160rad / min, and process for 9min; then raise the temperature to 230℃, reduce the vacuum in the sealed reactor to 2kPa, stir at 160rad / min, and process for 7min. Step 7: Inject the molten mixture into the corresponding mold for injection molding. The temperature of the front section of the injection molding machine barrel is controlled at 1900℃, the middle section at 200℃, the rear section at 210℃, and the nozzle at 205℃. The mold preheating temperature is 70℃. The injection pressure is 90MPa. After injection molding, pressure holding and cooling are performed. The pressure holding pressure is 60MPa, and the holding time is 20s. Water cooling is used for cooling, and the cooling rate is controlled at 3-5℃ / s. After cooling to room temperature, demolding is performed. Step 8: After injection molding, remove the injection molded part and first use 800-grit sandpaper to rough sand the surface of the injection molded part at a speed of 130 r / min for 4 minutes; then use 1500-grit sandpaper for fine sanding at a speed of 2100 r / min for 2.5 minutes; finally, use a wool wheel with polishing wax for fine polishing at a speed of 1900 r / min for 1.5 minutes. After sanding and polishing, you will get the car headlight decorative frame.

[0025] The gloss of the automotive headlight trim frames with inherent metallic luster prepared in Examples 1-3 and the comparative automotive headlight trim frames was tested (using GB / T 8807-1988, Test Method for Specular Gloss of Plastics, with a test angle of 60°). The results are as follows: Figure 2 As shown.

[0026] Depend on Figure 2The data shows that the gloss of the automotive headlight decorative frames with metallic luster prepared in Examples 1-3 is significantly higher than that of the automotive headlight decorative frames prepared in the comparative example. Therefore, the present invention can effectively increase the gloss of the plastic automotive headlight decorative frames by adding metal powder, thus meeting the high-quality requirements of the plastic automotive headlight decorative frames for appearance and texture.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A manufacturing process for an automotive headlight decorative frame with an inherent metallic luster, characterized in that: Includes the following steps: Step 1: Weigh the following ingredients according to the specified ratio: metal powder, polybutadiene rubber, styrene, acrylonitrile, color masterbatch, tert-butyl methacrylate, N-phenylmaleimide, di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol. Step 2: Add polybutadiene rubber, styrene, and acrylonitrile to a sealed reactor for initial softening and mixing; Step 3: Add di-tert-butyl peroxide, tert-dodecyl mercaptan, and 2,6-di-tert-butyl-p-cresol to a sealed reactor and proceed with the reaction. Step 4: Add tert-butyl methacrylate and N-phenylmaleimide to the sealed reactor to continue the reaction; Step 5: Add metal powder and color masterbatch powder to the sealed reactor and mix thoroughly; Step Six: Remove unreacted solvent after mixing; Step 7: Inject the molten mixture into the corresponding mold for injection molding; Step 8: After injection molding is completed, remove the injection molded part and polish it to obtain a car headlight decorative frame with a metallic luster.

2. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The mass fractions of each substance in step one are as follows: 4-6 parts metal powder, 12-16 parts polybutadiene rubber, 30-40 parts styrene, 23-27 parts acrylonitrile, 2-4 parts color masterbatch, 3-5 parts tert-butyl methacrylate, 2-4 parts N-phenylmaleimide, 0.1-0.2 parts di-tert-butyl peroxide, 0.08-0.12 parts tert-dodecyl mercaptan, and 0.2-0.4 parts 2,6-di-tert-butyl-p-cresol.

3. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The metal powder in step one is either copper gold powder or aluminum silver powder, the particle size of the metal powder is <1μm, the cis structure content of the polybutadiene rubber is ≥95%, the Mooney viscosity is 45-55, and the particle size of the color masterbatch is <1μm.

4. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The mixing temperature in step two is 60-70℃, the mixing speed is 100-120 rad / min, the mixing pressure is 0.1-0.2 MPa, and the mixing time is 40-50 min.

5. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The reaction temperature in step three is 100-110℃, the stirring speed is 140-180 rad / min, the reaction pressure is 0.2-0.3 MPa, and the reaction time is 100-120 min.

6. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The reaction temperature in step four is 120-130℃, the reaction pressure is 0.3-0.4MPa, the stirring speed is 120-160rad / min, and the reaction time is 130-150min.

7. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The mixing temperature in step five is 130-140℃, the mixing speed is 200-220 rad / min, and the mixing time is 50-60 min.

8. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: The unreacted solvent removal operation in step six is ​​as follows: First, raise the temperature to 200-220℃, maintain the vacuum degree in the sealed reactor at 6-10kPa using an external negative pressure device, stir at 150-170rad / min, and process for 8-10min; then raise the temperature to 220-240℃, reduce the vacuum degree in the sealed reactor to 1-3kPa, stir at 150-170rad / min, and process for 6-8min.

9. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: In step seven, the temperature of the injection molding machine barrel is controlled at 180-200℃ in the front section, 190-210℃ in the middle section, 200-220℃ in the rear section, and 195-215℃ in the nozzle. The mold preheating temperature is 60-80℃. The injection pressure is 80-100MPa. After injection, pressure holding and cooling are performed at 50-70MPa for 15-25s. Water cooling is used for cooling, and the cooling rate is controlled at 3-5℃ / s. After cooling to room temperature, demolding is performed.

10. The manufacturing process of a car headlight decorative frame with a metallic luster according to claim 1, characterized in that: In step eight, the surface of the injection molded part is first rough-polished with 800-grit sandpaper at a speed of 1000-1500 rpm for 3-5 minutes; then fine-polished with 1500-grit sandpaper at a speed of 2000-2200 rpm for 2-3 minutes; finally, a wool wheel with polishing wax is used for fine polishing at a speed of 1800-2000 rpm for 1-2 minutes.

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