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CN-122007002-A - Integrated coating method, system, composite workpiece and automobile

CN122007002ACN 122007002 ACN122007002 ACN 122007002ACN-122007002-A

Abstract

The invention relates to an integrated coating method, a system, a composite workpiece and an automobile, wherein a dual-curing coating system is adopted and matched with a photo-curing process, so that structural members with different heat resistance can be subjected to collinear spraying and curing, the chromatic aberration of parts caused by the difference between independent processing and heat treatment environments is effectively avoided, the process period can be greatly shortened, the occupied area and investment cost of a production line are saved, the energy consumption level and the emission of greenhouse gases are obviously reduced, the photo-cured workpiece can undergo a non-illumination driven secondary crosslinking reaction after being separated from an irradiation environment, the finally formed paint film has excellent overall hardness and scratch resistance, the method is particularly suitable for links such as whole automobile manufacturing and after-market paint repair, and the appearance quality of the automobile in the use in a daily complex environment can be effectively ensured and prolonged.

Inventors

  • ZHAO FEI
  • SU CHUANQING
  • WANG WEI
  • HU ZHANG
  • ZHANG PAN

Assignees

  • 小米汽车科技有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. An integrated coating method, wherein the method is used for a composite workpiece, the composite workpiece comprises a first structural member and a second structural member, the first structural member and the second structural member are made of different materials, and the thermal deformation temperature of the first structural member is higher than the thermal deformation temperature of the second structural member, and the method comprises: s1, applying dual-curing paint to the inner surface and the outer surface of the composite workpiece, and flashing to obtain the composite workpiece with the dual-curing paint; S2, performing first light curing on the outer surface of the composite workpiece with the double-cured coating, and performing second light curing on the inner surface and the shadow area of the outer surface of the composite workpiece with the double-cured coating so that the double-cured coating reaches a first preset hardness, thereby obtaining a light-cured composite workpiece; S3, standing the photo-cured composite workpiece for a preset time in a natural environment to enable the dual-cured coating to reach a second preset hardness, wherein the second preset hardness is higher than the first preset hardness.
  2. 2. The method according to claim 1, wherein in the step S1, the dual-curing coating comprises, by weight, 10-30% of an acrylic oligomer, 5-10% of an acrylic monomer, 10-40% of a diluent, 0.5-3% of a photoinitiator, 10-30% of a modified acrylic resin and 5-20% of isocyanate.
  3. 3. The method according to claim 1, wherein the flash-drying condition in step S1 comprises a temperature of 40-60 ℃ for 4-10 minutes, and/or, The method further comprises the step of cooling the inner surface and the outer surface of the composite workpiece to 30-50 ℃ after the flash drying is completed in the step S1.
  4. 4. The method of claim 1, wherein in step S2, the first photo-curing the outer surface of the composite workpiece having the dual-cure coating comprises passing the composite workpiece through a first UV light source at a preset running speed, the first UV light source comprising a plurality of surface light sources, and the plurality of surface light sources being sequentially spliced to form a portal frame surrounding an outer contour of the composite workpiece; The first light curing condition comprises that the emission wavelength of the first UV light source is 250-450 nm, the peak light intensity is 0.05-5W/cm 2 , the preset running speed of the composite workpiece is 3-6 m/min, and the total irradiation energy density is 1-5J/cm 2 .
  5. 5. The method according to claim 1, wherein in step S2, the second photo-curing is performed using a multi-axis actuator carrying a second UV light source, the maximum size of the light emitting surface of the second UV light source being not more than 30cm; The second light curing condition comprises that the emission wavelength of the second UV light source is 250-450 nm, the peak light intensity is 0.1-5W/cm 2 , the moving speed of the second UV light source is 300-500 mm/s, and the total irradiation energy density is 1-5J/cm 2 .
  6. 6. The method according to claim 1, wherein the natural environment conditions in step S3 include a humidity of 30-80% and a temperature of 5-40 ℃, the preset time of 3-7 days, and/or, The first preset hardness is more than 3B, and the second preset hardness is more than HB.
  7. 7. An integrated coating system for implementing the method of any one of claims 1-6, the system comprising: the spraying unit is used for applying dual-curing coating to the inner surface and the outer surface of the composite workpiece and then flashing to obtain the composite workpiece with the dual-curing coating; the photocuring unit is used for carrying out first photocuring on the outer surface of the composite workpiece with the dual-cured coating, and carrying out second photocuring on the inner surface and the shadow area of the outer surface of the composite workpiece with the dual-cured coating so as to enable the dual-cured coating to reach a first preset hardness, so that the photocured composite workpiece is obtained; and the standing unit is used for enabling the photo-cured composite workpiece to stand for a preset time in a natural environment so as to enable the dual-cured coating to reach a second preset hardness, wherein the second preset hardness is higher than the first preset hardness.
  8. 8. A composite workpiece produced by the method of any one of claims 1 to 6 or the system of claim 7, the composite workpiece comprising a first structural member and a second structural member, the first structural member being of a different material from the second structural member and the heat distortion temperature of the first structural member being higher than the heat distortion temperature of the second structural member, the inner and outer surfaces of the composite workpiece being formed with a dual cure coating.
  9. 9. The composite workpiece of claim 8, wherein the material of the first structural member comprises a metallic material and the material of the second structural member comprises a non-metallic material, and/or, The first structural member is an automobile body, and the second structural member is an automobile exterior trim part.
  10. 10. An automobile comprising the composite workpiece of claim 8 or 9.

Description

Integrated coating method, system, composite workpiece and automobile Technical Field The present disclosure relates to an integrated coating method, system, composite workpiece, and automobile. Background The coating process in the field of automobile manufacturing mainly adopts thermosetting coating, and a paint film is formed by curing in a heating mode. In conventional whole vehicle production, a vehicle body main body is generally made of a metal material such as steel or aluminum, and exterior trim such as an exterior mirror or a bumper is often made of a nonmetal material such as plastic. Because of the difference of heat resistance of the base materials, the automobile body and the exterior trim part need to enter different spraying lines and high-temperature drying rooms respectively for independent processing, so that the occupied area of the production line and the overall investment cost are increased, and matching errors of color and glossiness can be generated for parts subjected to different coating processes. In addition, maintaining the high temperature environment of large heat convection ovens requires continuous consumption of significant energy, with high carbon emission levels. Disclosure of Invention To overcome the problems in the related art, the present disclosure provides an integrated coating method, system, composite workpiece, and automobile. The present disclosure provides an integrated coating method for a composite workpiece including a first structural member and a second structural member, the first structural member being different in material from the second structural member and the heat distortion temperature of the first structural member being higher than the heat distortion temperature of the second structural member, the method comprising: s1, applying dual-curing paint to the inner surface and the outer surface of the composite workpiece, and flashing to obtain the composite workpiece with the dual-curing paint; S2, performing first light curing on the outer surface of the composite workpiece with the double-cured coating, and performing second light curing on the inner surface and the shadow area of the outer surface of the composite workpiece with the double-cured coating so that the double-cured coating reaches a first preset hardness, thereby obtaining a light-cured composite workpiece; S3, standing the photo-cured composite workpiece for a preset time in a natural environment to enable the dual-cured coating to reach a second preset hardness, wherein the second preset hardness is higher than the first preset hardness. Optionally, in the step S1, the dual-curing coating comprises, by weight, 10-30% of an acrylic acid oligomer, 5-10% of an acrylic acid monomer, 10-40% of a diluent, 0.5-3% of a photoinitiator, 10-30% of a modified acrylic resin and 5-20% of isocyanate. Optionally, in step S1, the flash-drying condition comprises a temperature of 40-60 ℃ and a time of 4-10 minutes, and/or, The method further comprises the step of cooling the inner surface and the outer surface of the composite workpiece to 30-50 ℃ after the flash drying is completed in the step S1. Optionally, in step S2, performing a first photo-curing on the outer surface of the composite workpiece with the dual-curing coating includes passing the composite workpiece through a first UV light source at a preset running speed, where the first UV light source includes a plurality of surface light sources, and the plurality of surface light sources are sequentially spliced to form a portal structure surrounding the outer contour of the composite workpiece; The first light curing condition comprises that the emission wavelength of the first UV light source is 250-450 nm, the peak light intensity is 0.05-5W/cm 2, the preset running speed of the composite workpiece is 3-6 m/min, and the total irradiation energy density is 1-5J/cm 2. Optionally, in step S2, the second light curing is performed by using a multi-axis actuator carrying a second UV light source, and a maximum size of a light emitting surface of the second UV light source is not greater than 30cm; The second light curing condition comprises that the emission wavelength of the second UV light source is 250-450 nm, the peak light intensity is 0.1-5W/cm 2, the moving speed of the second UV light source is 300-500 mm/s, and the total irradiation energy density is 1-5J/cm 2. Optionally, in step S3, the natural environment conditions include humidity of 30-80%, temperature of 5-40 ℃, the preset time of 3-7 days, and/or, The first preset hardness is more than 3B, and the second preset hardness is more than HB. The present disclosure also provides an integrated coating system for implementing the foregoing method, the system comprising: the spraying unit is used for applying dual-curing coating to the inner surface and the outer surface of the composite workpiece and then flashing to obtain the composite workpiece with the dual-curing coating; the