Curved surface paint spraying boundary technology
By employing a step-by-step spraying method and precise removal of the release liner, the high-precision problem of multi-color painting boundary on curved workpieces was solved, reducing costs and improving production efficiency and painting quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JINYUANKANG (HUIZHOU) IND CO LTD
- Filing Date
- 2026-02-10
- Publication Date
- 2026-05-05
AI Technical Summary
In existing technologies, it is difficult to achieve high-precision separation in multi-color spray painting of curved workpieces. Moreover, the mold development cycle is long and the cost is high. The mask template does not fit tightly with the curved surface, resulting in paint mist penetration and blurring of color block edges.
The method of applying the first color layer, release layer and second color layer in steps is adopted. The release layer is removed by chemical dissolution or temperature difference peeling. Combined with automated equipment and laser engraving process, clear color block boundaries are precisely formed.
It reduces reliance on customized masking templates, lowers costs, improves production efficiency and painting accuracy, ensures that color blocks do not fade and have clear edges, and adapts to curved surface structures with different curvature parameters.
Smart Images
Figure CN121972385A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of spray painting, and in particular to a process for dividing curved surfaces in spray painting. Background Technology
[0002] In fields such as consumer electronics and automotive interiors, the requirements for the appearance and decoration of products with curved structures, such as shells and functional components, are becoming increasingly stringent. Not only is it necessary to achieve precise spraying of multiple colors on curved surfaces, but it is also required that there be clear color block boundaries between different color blocks in order to enhance the visual quality and market competitiveness of the products.
[0003] In existing related technologies, template masking spray painting process is often used to achieve the boundary of multi-color spray painting. This process involves customizing a mask template that matches the shape of the workpiece surface, blocking the non-spraying area before spraying. After the paint layer has cured, the template can be removed to form color blocks of different colors.
[0004] However, for curved workpieces, due to the continuous curvature changes on their surfaces, masking templates are often difficult to perfectly fit the curved surface. This causes paint mist to seep into the masked area through gaps during the painting process, resulting in smudging and blurring of color block edges, making it difficult to meet the product requirements for high-precision boundary separation. Furthermore, for curved workpieces with different curvature parameters, corresponding masking templates need to be designed and manufactured separately. Mold development is time-consuming and costly, making multi-color painting for boundary separation of curved structures inconvenient. Therefore, there is an urgent need for a painting process that can adapt to curved structures, achieve high-precision boundary separation in multi-color painting, and does not rely on a large number of specialized molds. Summary of the Invention
[0005] To facilitate multi-color painting for demarcating curved surfaces, this application provides a curved surface painting demarcation process.
[0006] The curved surface spray painting boundary process provided in this application adopts the following technical solution: A curved surface spray painting boundary process includes the following steps: Step S1: Spray the first color layer onto the curved surface structure; Step S2: Remove the first color layer located on the second side of the color block boundary line; Step S3: Spray a release liner onto the curved surface structure. The release liner is sprayed on the second side of the color block boundary line and the surface of the first color layer. Step S4: Remove the release liner located on the second side of the color block boundary line; Step S5: Spray the second color layer onto the curved structure. The second color layer is sprayed on the second side of the color block boundary line and the surface of the release liner. Step S6: Remove the release liner so that the second color layer sprayed on the surface of the release liner is removed, and form a first color block and a second color block on the first side and the second side of the color block boundary line, respectively.
[0007] By adopting the above technical solution, the use of customized masking templates is significantly reduced, which helps avoid problems such as paint mist penetration and blurred color block boundaries caused by poor adhesion between the masking template and the curved surface. It can adapt to curved surface structures with different curvature parameters, thereby reducing the cost of boundary painting. Furthermore, by spraying the first color layer, release layer, and second color layer in stages, and precisely removing the release layer and the second color layer on its surface, it is possible to easily form P1 and P2 color blocks with clear boundaries and uniform color on both sides of the color block boundary line of the curved surface structure.
[0008] Optionally, in step S6, the removal of the release interlayer is based on a chemical dissolution method or a temperature difference peeling method; The chemical dissolution method refers to dissolving and destroying the release interlayer located between the first color layer and the second color layer using an interlayer solvent suitable for the release interlayer; The temperature difference peeling method refers to keeping the curved structure in an environment with several different temperatures, causing the release liner to deform and crack under temperature stress, and then removing the cracked release liner and its second color layer on the surface through physical force.
[0009] By employing the above technical solution, the chemical dissolution method uses a specialized solvent matched with the release liner to directionally disrupt the molecular adhesion of the release liner. It dissolves only the release liner between the first and second color layers, without chemically reacting with the paint on color blocks P1 and P2, thus ensuring that the color blocks do not fade and that the boundary edges are burr-free. Furthermore, the chemical dissolution method can be combined with automated spraying or immersion equipment for batch processing, significantly improving the production efficiency of curved workpieces.
[0010] The thermal differential peeling method utilizes alternating temperature environments to create minute gaps and cracks between the release liner and the surfaces of P1 and the second color block due to differences in their coefficients of thermal expansion and contraction. Subsequent physical peeling only targets the cracked release liner and the surface second color layer, eliminating the need for chemical solvents and effectively avoiding solvent residue issues. This method is particularly suitable for curved workpieces with stringent environmental requirements, such as medical devices and food contact products. Furthermore, the physical peeling force is relatively controllable, effectively mitigating the risk of deformation caused by chemical corrosion or excessive erosion of curved substrates, thus further expanding the applicability of curved surface painting demarcation processes.
[0011] Optionally, in step S6, the removal of the release interlayer is based on a chemical dissolution method; The chemical dissolution method includes the following steps: Step S01: Spray the interlayer solvent onto the curved structure, or immerse the curved structure in the interlayer solvent; Step S02: Immerse the curved structure in an ultrasonic cleaning tank; Step S03: Rinse and dry the curved surface structure.
[0012] By adopting the above technical solutions, both spraying and immersion solvent application methods can be flexibly adapted to curved workpieces of different sizes and curvatures. Spraying is suitable for precise processing of small-area complex curved surfaces, while immersion enables efficient synchronous processing of large batches of curved workpieces. The cavitation effect of the ultrasonic cleaning tank allows the solvent to penetrate deep into areas prone to residue, such as curved corners and grooves, impacting the release liner and causing it to quickly separate from the paint layer, avoiding the incompleteness of manual cleaning and the risk of paint layer damage. Subsequent rinsing and drying steps can thoroughly remove residual solvent and peeling residue from the workpiece surface, preventing solvent residue from causing appearance defects such as watermarks and pinholes in the color blocks, further ensuring the flatness and smoothness of the boundary between curved color blocks, and improving product yield.
[0013] Optionally, in step S3, a release liner is sprayed onto the second side of the color block boundary line and the surface of the first color layer.
[0014] By adopting the above technical solution and setting the release liner to a concave-convex structure, the contact surface area between the release liner and the solvent can be significantly increased, accelerating the wetting and dissolution rate of the release liner in the chemical dissolution method and effectively shortening the dissolution treatment time. Simultaneously, the concave-convex structure can form tiny void channels between the release liner and the second color layer, facilitating the rapid penetration of the solvent into the bonding interface between the two layers and directionally disrupting the interlayer adhesion, thereby alleviating the problem of release liner residue in curved corners, grooves, and other areas. When using the temperature difference peeling method, stress concentration points are easily formed at the corners of the concave-convex structure, making the release liner more prone to cracking at these points when temperatures fluctuate, reducing the difficulty of physical peeling and minimizing impact damage to the P1 and P2 color blocks.
[0015] Optionally, in step S3: When spraying the release liner, a flexible mesh is applied to the curved surface structure, and the flexible mesh is removed after spraying to form a solvent drainage channel; Alternatively, after the release layer has been cured and formed, a solvent drainage groove can be formed on the release layer by laser engraving.
[0016] By adopting the above technical solution, the method of covering with flexible mesh material is simple to operate and low in cost. It does not require complicated equipment and can form uniformly distributed drainage channels on the surface of the release liner in one go. The flexible mesh material can fit the curved surface completely and adapt to workpieces with different curvatures. At the same time, the mesh material can be reused, reducing mass production costs.
[0017] Laser engraving enables high-precision forming of the solvent channel, allowing for precise control of its width, depth, and position. This is particularly suitable for scenarios requiring complex curved surfaces and high-precision color block demarcation. Furthermore, the engraving process only affects the release liner, without damaging the underlying first color layer, ensuring the integrity of the color layers. Both methods of creating solvent channels guide the solvent to quickly penetrate the interface between the release liner and the second color layer, especially in areas prone to residue, such as curved corners. This significantly improves solvent penetration efficiency and the release liner peeling speed, reducing the risk of residue and further ensuring the demarcation accuracy and product yield of multi-color painting on curved surfaces.
[0018] Optionally, in step S3, a plurality of solvent diversion channels are provided, and the plurality of solvent diversion channels extend toward the position of the color block dividing line.
[0019] By adopting the above technical solution, several solvent drainage channels extending towards the color block boundary line can form a directional solvent penetration channel, guiding the solvent to quickly and accurately converge to the release interlayer area at the color block boundary line, avoiding the random diffusion of solvent in other areas of the curved surface, thus making it less likely for irregular breaks to occur between the first color block and the second color block due to the difference in paint layer thickness, thereby reducing the occurrence of obvious unevenness in the color block boundary line.
[0020] Optionally, when a solvent channel is formed by laser engraving on the release liner, the solvent channel is located in the concave-convex area, and a leveling area is provided between the concave-convex area and the color block boundary line; In step S6, after removing the release layer located in the uneven area, the release layer and residual second color layer located in the leveling area are removed by laser engraving.
[0021] By adopting the above technical solution, the solvent drainage channel is set in the concave-convex area, and a leveling area is reserved between the concave-convex area and the color block boundary line. This avoids stress concentration caused by the drainage channel and the concave-convex structure extending directly to the color block boundary line, preventing micro-cracks in the paint layer at the boundary. Simultaneously, it ensures a smooth release liner surface in the color block boundary area, reducing burrs and irregular protrusions at the boundary edge after peeling. After removing the release liner, the remaining release liner and second color layer at the color block boundary line are precisely engraved and removed using laser engraving. This further corrects the boundary deviation caused by the curvature of the surface, making the color block edges clearer and straighter, and further reducing the occurrence of noticeably uneven color block boundary lines.
[0022] Optionally, in step S4, the release liner is removed by laser engraving.
[0023] By adopting the above technical solution and utilizing the high precision of laser engraving, the release liner on the second side of the color block boundary line can be accurately removed. By changing the laser engraving power, it can also adapt to the continuous curvature changes of the surface, accurately locate the boundary of the removal area, without damaging the release liner on the second side of the color block boundary line, and without scratching the first color layer below, effectively ensuring that the removal boundary of the release liner completely coincides with the color block boundary line.
[0024] Optionally, in step S2, after removing the first color layer located on the second side of the color block dividing line, the first color layer located on the first side of the color block dividing line extends to the second side.
[0025] By adopting the above technical solution, the first color layer on the second side of the color block dividing line extends to the second side, which makes it easier to accurately remove the release layer on the second side of the color block dividing line through laser engraving process, while retaining the release layer on the second side of the color block dividing line, reducing the release layer remaining on the surface and sides of the first color layer.
[0026] Optionally, the curved surface spray painting demarcation process further includes step S7: spraying a protective layer onto the surfaces of the first color block and the second color block.
[0027] By adopting the above technical solution, a protective layer is sprayed onto the surface of color blocks P1 and P2, which can form a uniform protective film at the boundary line of color blocks that is prone to cracking. This film effectively resists external scratches, corrosion and ultraviolet radiation, preventing color blocks from fading, losing gloss and scratching, thereby greatly improving the appearance durability and service life of curved workpieces.
[0028] In summary, this application includes at least one of the following beneficial technical effects: This significantly reduces the use of customized masking templates, making it easier to avoid problems such as paint mist penetration and blurred color block boundaries caused by poor adhesion between the masking template and the curved surface. It can adapt to curved surface structures with different curvature parameters, thereby reducing the cost of boundary painting. Furthermore, by spraying the first color layer, release layer, and second color layer in stages, and precisely removing the release layer and the second color layer on its surface, it is possible to easily form P1 and P2 color blocks with clear boundaries and uniform color on both sides of the color block boundary line of the curved surface structure. The chemical dissolution method uses a specialized solvent matched to the release liner to directionally break down the molecular adhesion of the release liner. It dissolves only the release liner between the first and second color layers, without chemically reacting with the paint on color blocks P1 and P2, thus ensuring that the color blocks do not fade and that the boundary edges are burr-free. Furthermore, the chemical dissolution method can be combined with automated spraying or immersion equipment for batch processing, significantly improving the production efficiency of curved workpieces. Designing the release liner with a concave-convex structure significantly increases the contact surface area between the release liner and the solvent, accelerating the wetting and dissolution rate of the release liner in the chemical dissolution method and effectively shortening the dissolution treatment time. Simultaneously, the concave-convex structure creates tiny voids and channels between the release liner and the second color layer, facilitating rapid solvent penetration into the bonding interface and directionally disrupting the interlayer adhesion, thereby alleviating the problem of release liner residue in curved corners and grooves. When using the temperature difference peeling method, stress concentration points easily form at the corners of the concave-convex structure, making the release liner more prone to cracking at these points during temperature fluctuations, reducing the difficulty of physical peeling and minimizing impact damage to the P1 and P2 color blocks. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the painting process on the curved surface structure of Embodiment 1 of this application.
[0030] Figure 2 This is an overall schematic diagram of the coating forming steps of the spray painting boundary process in Embodiment 1 of this application.
[0031] Figure 3 This is a schematic diagram of the release interlayer in Embodiment 2 of this application.
[0032] Figure 4 This is a schematic diagram of the release interlayer in Embodiment 3 of this application.
[0033] Figure 5 This is a partial schematic diagram of the coating forming steps of the spray painting boundary process in Embodiment 3 of this application.
[0034] Explanation of reference numerals in the attached diagram: L1, color block boundary line; P1, first color block; P2, second color block; 1, first color layer; 2, second color layer; 3, release layer; 301, solvent channel; 31, uneven area; 32, leveling area; 4, protective layer. Detailed Implementation
[0035] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.
[0036] Example 1: This application discloses a curved surface spray painting boundary process.
[0037] Reference Figure 1 The curved surface spray painting boundary process is used to spray multiple colors of paint onto curved surfaces and highlight the boundary line L1 between the first color block P1 and the second color block P2, reducing the occurrence of blurred boundary lines L1. Specifically, the first color block P1 is located on the first side of the boundary line L1, and the second color block P2 is located on the second side of the boundary line L1.
[0038] In other embodiments, the paint can be replaced with a functional coating to enable the coating on the curved surface to meet certain special requirements. For example, the first color block P1 and the second color block P2 can be replaced with a low-temperature resistant coating and a high-temperature resistant coating, respectively, thereby mitigating the effects of temperature or temperature difference in a confined space.
[0039] Specifically, refer to Figure 2 The curved surface painting boundary process described in this application embodiment includes the following technical features: Step S1: Spray the first color layer 1 onto the curved surface structure.
[0040] Step S2: After the first color layer 1 has cured and formed, the first color layer 1 located on the second side of the color block dividing line L1 is removed by laser engraving. After removing the first color layer 1 located on the second side of the color block dividing line L1, the first color layer 1 located on the first side of the color block dividing line L1 will extend to the second side, so as to facilitate the subsequent removal of the release layer 3.
[0041] Step S3: Spray release layer 3 onto the curved structure. Release layer 3 is sprayed onto the second side of the color block boundary line L1 and the surface of the first color layer 1.
[0042] Step S4: After the release layer 3 has cured and formed, the release layer 3 located on the second side of the color block dividing line L1 is removed by laser engraving process. The first color layer 1, which was extended to the second side of the color block dividing line L1 in step S2, is also removed together to ensure the flatness of the removed surface and reduce the release layer 3 accumulating on the side of the first color layer 1 during curved surface spraying. This ensures the accurate forming of the subsequent second color block P2 and reduces the appearance of burrs on the color block dividing line L1.
[0043] Step S5: Spray the second color layer 2 onto the curved structure. The second color layer 2 is sprayed onto the second side of the color block dividing line L1 and the surface of the release layer 3.
[0044] Step S6: Remove the release interlayer 3 so that the second color layer 2 sprayed on the surface of the release interlayer 3 is removed, and a first color block P1 and a second color block P2 are formed on the first and second sides of the color block dividing line L1, respectively.
[0045] The removal of the release interlayer 3 can be based on chemical dissolution or thermal stripping.
[0046] The chemical dissolution method refers to using a suitable interlayer solvent to directionally disrupt the molecular adhesion of the release interlayer 3, dissolving only the release interlayer 3 between the first color layer 1 and the second color layer 2, without chemically reacting with the paint of color blocks P1 and P2. This dissolves and destroys the release interlayer 3 between the first color layer 1 and the second color layer 2, ensuring that the color of the color blocks does not fade and the boundary edges are free of burrs. For example, the first color block P1 and the second color block P2 can be selected as an acrylic amino material, the release interlayer 3 as a water-soluble acrylic resin material, and the corresponding release solvent as an aqueous solvent.
[0047] The temperature difference peeling method refers to keeping the curved structure in an environment with several different temperatures, so that the release layer 3, whose coefficient of thermal expansion and contraction is significantly different from that of the first color block P1 and the second color block P2, deforms and cracks under temperature stress. Then, the cracked release layer 3 and the second color layer 2 on its surface are removed by physical force.
[0048] Specifically, in this embodiment, step S6 is preferably a chemical dissolution method. Furthermore, when implementing step S6, the workpiece needs to be fixed to a suitable fixture to reduce the adverse effects of workpiece movement.
[0049] The chemical dissolution method includes the following steps: Step S01: Spray the interlayer solvent onto the curved structure, or immerse the curved structure in the interlayer solvent; For areas with gentle curvature changes, spraying can be used to evenly cover the surface of the release interlayer 3 with solvent, promoting initial solvent wetting. For areas with complex structures such as curved corners or grooves that are prone to residue buildup, immersion can be used to ensure that the interlayer solvent fully penetrates the interface between the release interlayer 3 and the second color layer 2, thus ensuring effective dissolution.
[0050] Step S02: Immerse the curved structure in an ultrasonic cleaning tank.
[0051] The cavitation effect generated by ultrasound enhances the penetration and peeling of the release layer 3 by the solvent, thereby causing the release layer 3 to quickly lose its adhesive force and detach along with the second color layer 2 on its surface. Furthermore, by controlling the range of ultrasound action, the effective range can be limited to the first side of the color block boundary line L1, thus reducing the impact on the second color block P2 located on the second side.
[0052] Step S03: Rinse and dry the curved surface structure to thoroughly remove residual interlayer solvent and release interlayer residue from the workpiece surface, reducing the occurrence of watermarks, pinholes, and other defects on the workpiece surface. During drying, a gentle heating method should be used to allow the liquid on the workpiece surface to evaporate slowly, thereby ensuring the smoothness and gloss of the color block surface.
[0053] Step S7: Spray a protective layer 4 onto the surfaces of the first color block P1 and the second color block P2.
[0054] The implementation principle of the curved surface spray painting boundary process in this application embodiment is as follows: it significantly reduces the use of customized masking templates, making it easier to avoid problems such as paint mist penetration and blurred color block boundary line L1 caused by poor adhesion between the masking template and the curved surface. It can adapt to curved surface structures with different curvature parameters, thereby reducing the cost of boundary painting. Furthermore, by spraying the first color layer 1, the release layer 3, and the second color layer 2 in stages, and accurately removing the release layer 3 and the second color layer 2 on its surface, it is possible to easily form P1 and P2 color blocks with clear boundaries and uniform color on both sides of the color block boundary line L1 of the curved surface structure, thus making it easier to perform multi-color spray painting for boundarying of curved surface structures.
[0055] Example 2: This application discloses a curved surface spray painting boundary process, which, in addition to all the technical features of Example 1, also includes the following technical features: In step S3: The release interlayer 3, sprayed onto the second side of the color block boundary line L1 and the surface of the first color layer 1, has an uneven texture to increase the contact surface area between the release interlayer 3 and the solvent. This accelerates the wetting and dissolution rate of the release interlayer 3 by the solvent in the chemical dissolution method, effectively shortening the dissolution treatment time. Simultaneously, the uneven structure easily forms tiny void channels between the release interlayer 3 and the second color layer 2, facilitating the rapid penetration of the interlayer solvent into the bonding interface between the release interlayer 3 and the second color layer 2. This directionally disrupts the interlayer adhesion, thereby alleviating the problem of release interlayer 3 residue in curved corners, grooves, and other areas.
[0056] To create an uneven release layer 3 on the second side of the color block boundary line L1 and the surface of the first color layer 1, a flexible mesh can be applied to the curved surface during the application of the release layer 3. The flexible mesh creates corresponding grooves on the surface of the release layer 3. After spraying is complete and the grooves are stable, the flexible mesh is removed and finally cured to form a solvent drainage channel 301, which creates the uneven release layer 3.
[0057] Reference Figure 3Specifically, in this embodiment, to create a raised and recessed design for the release interlayer 3 sprayed on the second side of the color block boundary line L1 and the surface of the first color layer 1, a set of solvent drainage channels 301 are laser-engraved on the release interlayer 3 after it has cured. The surface of the release interlayer 3 is raised and recessed by laser engraving. All the solvent drainage channels 301 extend towards the color block boundary line L1, making it easier for the interlayer solvent to flow into the internal area of the release interlayer 3. In other embodiments, multiple sets of solvent drainage channels 301 can be additionally provided and intersected with the first set of solvent drainage channels 301, further promoting the full flow of the interlayer solvent within each solvent drainage channel 301. Laser engraving enables high-precision forming of the drainage channels and allows for precise control of their width, depth, and position, making it particularly suitable for the complex curved surface workpieces and high-precision color block boundary requirements described in this application. Example
[0058] This application discloses a curved surface spray painting boundary process, which, in addition to all the technical features of Embodiment 2, also includes the following technical features: Reference Figure 4 and Figure 5 When a set of solvent drainage grooves 301 are formed by laser engraving on the release layer 3, each solvent drainage groove 301 in the set is located in the concave-convex area 31. A leveling area 32 is provided between the concave-convex area 31 and the color block boundary line L1. That is, the laser beam does not engrave at a position close to the color block boundary line L1 during laser engraving.
[0059] In step S6, after removing the release layer 3 covering the uneven area 31, the release layer 3 and the remaining second color layer 2 in the leveling area 32 are removed by laser engraving. The remaining second color layer 2 refers to the second color layer 2 covering the release layer 3 and the second color layer 2 remaining on the second side of the color block boundary line L1, mainly the thicker second color layer 2 formed in the area of the color block boundary line L1 during curved surface spraying. After removing the release layer 3, the remaining release layer 3 and the second color layer 2 at the color block boundary line L1 are precisely engraved and removed by laser engraving, which can further correct the boundary deviation caused by the curvature of the curved surface, making the color block edge line clearer and straighter, and further reducing the occurrence of obvious unevenness of the color block boundary line L1.
[0060] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A curved surface spray painting boundary process, characterized in that: Includes the following steps: Step S1: Spray the first color layer (1) onto the curved surface structure; Step S2: Remove the first color layer (1) located on the second side of the color block dividing line (L1); Step S3: Spray a release layer (3) onto the curved structure. The release layer (3) is sprayed on the second side of the color block dividing line (L1) and the surface of the first color layer (1). Step S4: Remove the release interlayer (3) located on the second side of the color block dividing line (L1); Step S5: Spray the second color layer (2) onto the curved structure. The second color layer (2) is sprayed onto the second side of the color block dividing line (L1) and the surface of the release layer (3). Step S6: Remove the release interlayer (3) so that the second color layer (2) sprayed on the surface of the release interlayer (3) is removed accordingly, and a first color block (P1) and a second color block (P2) are formed on the first side and the second side of the color block dividing line (L1), respectively.
2. The curved surface spray painting boundary process according to claim 1, characterized in that: In step S6, the removal of the release interlayer (3) is based on chemical dissolution or thermal stripping. The chemical dissolution method refers to dissolving and destroying the release interlayer (3) located between the first color layer (1) and the second color layer (2) by using an interlayer solvent suitable for the release interlayer (3); The temperature difference peeling method refers to keeping the curved structure in an environment with several different temperatures, causing the release interlayer (3) to deform and crack under temperature stress, and then removing the cracked release interlayer (3) and its surface second color layer (2) by physical force.
3. The curved surface spray painting boundary process according to claim 2, characterized in that: In step S6, the removal of the release interlayer (3) is based on a chemical dissolution method; The chemical dissolution method includes the following steps: Step S01: Spray the interlayer solvent onto the curved structure, or immerse the curved structure in the interlayer solvent; Step S02: Immerse the curved structure in an ultrasonic cleaning tank; Step S03: Rinse and dry the curved surface structure.
4. A curved surface spray painting boundary process according to claim 2 or 3, characterized in that: In step S3, the release interlayer (3) sprayed on the second side of the color block dividing line (L1) and the surface of the first color layer (1) is provided with an uneven surface.
5. The curved surface spray painting boundary process according to claim 4, characterized in that: In step S3: When spraying the release interlayer (3), a flexible mesh is applied to the curved structure, and the flexible mesh is removed after spraying to form a solvent drainage groove (301); Alternatively, after the release layer (3) is cured and formed, a solvent drainage groove (301) can be formed on the release layer (3) by laser engraving process.
6. The curved surface spray painting boundary process according to claim 5, characterized in that: In step S3, a plurality of solvent diversion channels (301) are provided, and the plurality of solvent diversion channels (301) extend toward the position of the color block dividing line (L1).
7. The curved surface spray painting boundary process according to claim 5, characterized in that: When a solvent channel (301) is formed by laser engraving on the release layer (3), the solvent channel (301) is located in the concave-convex area (31), and a leveling area (32) is provided between the concave-convex area (31) and the color block boundary line (L1); In step S6, after removing the release layer (3) located in the uneven area (31), the release layer (3) located in the leveling area (32) and the remaining second color layer (2) are removed by laser engraving process.
8. The curved surface spray painting boundary process according to claim 1, characterized in that: In step S4, the release interlayer (3) is removed by laser engraving.
9. The curved surface spray painting boundary process according to claim 8, characterized in that: In step S2, after removing the first color layer (1) located on the second side of the color block dividing line (L1), the first color layer (1) located on the first side of the color block dividing line (L1) extends to the second side.
10. The curved surface spray painting boundary process according to claim 1, characterized in that: The curved surface spray painting boundary process also includes step S7: spraying a protective layer (4) onto the surfaces of the first color block (P1) and the second color block (P2).