A partial electroplating method for an automotive interior component

Abstract

The application discloses a partial electroplating method for automobile interior parts, which comprises the following steps: S1, providing a single-color, double-color or multi-color structure base material, the outermost layer of the base material is electroplatable material, and the electroplatable material is polyamide, ABS or ABS / polycarbonate blend; S2, pre-treating a symbol area of the base material by using a physical covering method, the physical covering method is covering a symbol area with a shielding material resistant to corrosion of an electroplating solution, so that the symbol area is isolated from the electroplating solution; S3, sequentially performing electroplating pre-treatment and electrochemical electroplating treatment on the pre-treated base material, so that a metal plating layer is formed on the surface of the base material except the symbol area; and S4, removing the shielding material of the symbol area and pre-treatment residues. The symbol area is isolated from the electroplating solution by using the physical covering method, and the remaining area normally completes the electroplating process, so that the method does not need laser processing in the whole process, has strong process continuity, and has good compatibility with an existing electroplating production line.

Description

Technical Field

[0001] This invention relates to the field of automotive interior parts manufacturing technology, specifically to a method for partial electroplating of automotive interior parts, which is particularly suitable for the production of automotive interior buttons, dashboard markers, and other parts that require light transmission in the symbol area and metallic decorative effect in the remaining areas. Background Technology

[0002] In automotive interior components, those with a metallic appearance and backlighting capabilities (such as buttons and logos) are widely used in motor vehicles due to their combination of decorative and functional properties. These components typically require the formation of translucent symbol structures on the metallic surface, ensuring that the symbols are clearly visible under backlighting at night while maintaining the overall metallic texture during the day when there is no backlighting.

[0003] In existing technologies, the core solutions for forming such translucent structures rely on laser-related processes. For example, some patents use laser ablation to structurally process the metal layer, creating a lattice of openings within the metal layer to achieve light transmission; other patents use laser photolithography to process the filler composition, forming symbol regions through a process of curing and removing uncured portions, followed by electroplating. While these laser-based solutions achieve the desired functionality, they have significant drawbacks: laser equipment is expensive and energy-intensive, process parameter control is complex, and laser processing can easily damage the substrate surface, affecting product yield; furthermore, the laser processing step needs to be interspersed within the electroplating process, resulting in poor production continuity and further increasing manufacturing costs.

[0004] Furthermore, while there are preliminary attempts to prevent electroplating through masking in existing technologies, the masking materials used in these solutions have poor compatibility, are difficult to withstand the corrosion of the electroplating solution, and lack sufficient edge clarity in the masked area, resulting in blurred symbol outlines and failing to meet the high-precision appearance requirements of automotive interior parts. Therefore, there is an urgent need for a local electroplating method that is simple in process, low in cost, has high processing precision, and is compatible with existing electroplating processes to overcome the many drawbacks of existing laser-based solutions. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and proposes a method for local electroplating of automotive interior parts. By physically covering the symbol area to isolate it from the electroplating solution, electroplating deposition is avoided in the symbol area, while the remaining areas complete the electroplating process normally. The final result is an automotive interior part with a transparent symbol and a metallic coating on the remaining areas. This method does not require laser processing throughout the process, has strong process continuity, and is highly compatible with existing electroplating production lines.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for localized electroplating of automotive interior parts includes the following steps: S1. A substrate with a single-color, two-color, or multi-color structure is provided, wherein the outermost layer of the substrate is an electroplatable material, and the electroplatable material is polyamide, ABS, or an ABS / polycarbonate blend. S2. The symbol area of ​​the substrate is pretreated by physical covering method, wherein the physical covering method is to cover the symbol area with a masking material that is resistant to electroplating solution corrosion, so that the symbol area is isolated from the electroplating solution. S3. The pretreated substrate is subjected to electroplating pretreatment and electrochemical electroplating treatment in sequence to form a metal coating on the surface of the substrate outside the symbol area. The metal coating includes a copper intermediate layer, a nickel intermediate layer and a decorative metal layer. S4. Remove the masking material and pretreatment residue from the symbol area to obtain automotive interior parts where the symbol area is light-transmitting and the remaining areas have a metal coating.

[0007] Preferably, in S2, the masking material is a high-temperature resistant masking paint or masking tape, the thickness of the masking material is 0.1-0.5 mm, the ambient temperature during masking is 20-25℃, and the masking time is 10-30 min.

[0008] Preferably, the masking paint used is a high-temperature resistant masking paint that is corroded by electroplating solution, and the masking paint is precisely applied to the symbol area of ​​the substrate through a screen printing process.

[0009] Preferably, during the masking coating process, the ambient temperature is controlled at 20-25℃, the masking coating thickness is 0.2-0.3mm, and after coating, it is left to stand for 15-20 minutes to allow the masking coating to initially cure, ensuring that it adheres tightly to the substrate surface without bubbles or sagging.

[0010] Preferably, a special electroplated masking tape is used. The masking tape is cut according to the shape of the symbol and then manually or using a film-applying device to accurately apply it to the symbol area, ensuring that the edge of the tape is completely aligned with the outline of the symbol without any curling or gaps. The application pressure is controlled at 0.1-0.2 MPa to ensure that there are no gaps between the tape and the substrate surface, thus preventing the electroplating solution from seeping in.

[0011] Preferably, in S3, the electroplating pretreatment includes pickling and roughening, surface activation, and chemical deposition of a conductive layer. In the electroplating pretreatment, pickling and roughening are carried out in a chromium-sulfuric acid bath, surface activation is achieved by colloidal palladium seed deposition, and the chemically deposited conductive layer is a chemically plated nickel layer.

[0012] Preferably, during the pickling and roughening process, the substrate is immersed in a chromium-sulfuric acid bath at a temperature of 50-60°C for 10-15 minutes to create a rough surface structure that enhances the adhesion of subsequent metal layers. During the surface activation process, the pickled substrate is immersed in a colloidal palladium solution at room temperature for 5-8 minutes to deposit palladium seeds on the substrate surface. The palladium nuclei are covered by a tin-protected colloid. The substrate is then immersed in a hydrochloric acid solution to remove the tin-protected colloid, resulting in a surface with active palladium. During the chemical deposition of the conductive layer, the activated substrate is immersed in a chemical nickel plating bath at a temperature of 85-90°C for 20-30 minutes to deposit a 0.5-1.5 μm thick chemical nickel plating layer, providing a conductive foundation for subsequent electrochemical plating.

[0013] Preferably, in the metal plating, the nickel intermediate layer has a thickness of 5-25 μm, and the decorative metal layer is a chromium layer.

[0014] Preferably, during the deposition of the copper intermediate layer, the substrate is placed in a copper sulfate electroplating bath with a current density controlled at 2-3 A / dm² and an electroplating time of 30-40 min to form a copper intermediate layer with a thickness of 10-30 μm. The high ductility of copper is used to alleviate the stress difference between the substrate and the subsequent hard metal layer. During the deposition of the nickel intermediate layer, on the basis of the copper intermediate layer, the substrate is placed in a semi-bright nickel electroplating bath with a current density of 1.5-2 A / dm² and an electroplating time of 20-25 min to deposit a semi-bright nickel layer with a thickness of 3-20 μm. Then, it is transferred to a matte nickel electroplating bath to deposit a matte nickel layer with a thickness of 2-5 μm, forming a composite nickel intermediate layer and improving the corrosion resistance of the coating. During the deposition of the decorative metal layer, on the nickel intermediate layer, the substrate is placed in a chromium electroplating bath with a current density of 3-4 A / dm² and an electroplating time of 5-8 min to deposit a chromium layer with a thickness of 0.15-2 μm, giving the parts a metallic decorative effect and wear resistance.

[0015] Preferably, in step S4, if the masking material is masking paint, it is removed by solvent cleaning: immerse the substrate in a special masking paint stripper at room temperature for 10-15 minutes until the masking paint is completely softened, then gently brush the symbol area with a soft brush to remove any remaining masking paint, and then rinse thoroughly with clean water; if the masking material is masking tape, it is removed by mechanical peeling: gently lift a corner of the masking tape along the edge of the symbol, and peel off the tape from the entire symbol area at a uniform speed. For any remaining sticky substances, gently wipe them off with a cotton cloth dampened with a small amount of alcohol to avoid damaging the substrate surface; finally, place the substrate in a drying oven at 60-80℃ for 15-20 minutes to remove surface moisture, leaving no residual damage on the substrate surface in the symbol area after removal.

[0016] The beneficial effects of this invention are: This invention isolates the symbol area from the electroplating solution by physical covering, preventing electroplating deposition in the symbol area while the remaining areas complete the electroplating process normally. The final result is an automotive interior part with a transparent symbol and a metallic coating on the remaining areas. This method does not require laser processing throughout the process, has strong process continuity, and is highly compatible with existing electroplating production lines. Furthermore, this invention employs a physical masking solution using non-laser technologies, eliminating the need for laser equipment and complex parameter adjustments. This provides a simpler alternative, and the physical masking process can be implemented on an industrial scale (e.g., coating or pasting masking paint or masking tape). It is compatible with existing electroplating processes and can stably achieve the function of "symbols being transparent while the remaining areas are electroplated," meeting practical requirements. Detailed Implementation

[0017] The technical solutions in this embodiment will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and 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] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0019] A method for localized electroplating of automotive interior parts includes the following specific steps: 1. Substrate preparation Substrates with single-color, two-color, or multi-color structures are available. The outermost layer of the substrate is an electroplatable material, such as polyamide, ABS, or ABS / polycarbonate blends (conforming to existing electroplatable plastic application practices to ensure electroplating compatibility). The non-surface layers of the substrate can be made of non-electroplated plastics (such as polycarbonate). The substrate is made into an integrated substrate through a two-component injection molding process. The substrate thickness is greater than 2mm to ensure structural stability and light transmittance.

[0020] Pre-cleaning treatment of the substrate: First, wipe the surface of the substrate with an ethanol solution to remove oil, dust and other impurities, and then let it air dry naturally to ensure that there are no contaminants on the surface of the substrate that may affect the adhesion of the masking material.

[0021] 2. Physical occlusion of symbol areas The symbol area of ​​the substrate is preprocessed using a physical masking method, specifically including two preferred implementation methods: Implementation Method 1: The masking paint used is a high-temperature resistant masking paint (such as a polysiloxane-based masking paint) that is resistant to corrosion from electroplating solutions like chromium sulfuric acid and nickel baths. The masking paint is precisely applied to the marked areas of the substrate using a screen printing process. During the application process, the ambient temperature is controlled at 20-25℃, and the masking paint thickness is 0.2-0.3mm. After application, allow it to stand for 15-20 minutes to allow the masking paint to initially cure, ensuring it adheres tightly to the substrate surface without bubbles or sagging.

[0022] Implementation Method 2: Masking with Masking Tape. Use special electroplating masking tape (the base material is polytetrafluoroethylene, and the adhesive layer is electroplating solution resistant silicone). Cut the masking tape according to the shape of the symbol, and manually or using a film-applying device to accurately apply it to the symbol area, ensuring that the edge of the tape is completely aligned with the outline of the symbol without any curling or gaps. Control the application pressure to 0.1-0.2 MPa to ensure that there are no gaps between the tape and the surface of the base material, thus preventing the electroplating solution from seeping in.

[0023] 3. Electroplating pretreatment The physically covered substrate is subjected to pickling and roughening, surface activation, and chemical deposition of conductive layer treatment in sequence.

[0024] Pickling and roughening: Immerse the substrate in a chromium sulfuric acid bath at a temperature of 50-60°C for 10-15 minutes to dissolve the butadiene on the surface of the ABS plastic, thereby creating a rough structure on the substrate surface and enhancing the adhesion of the subsequent metal layer. Surface activation: The pickled substrate is immersed in a colloidal palladium solution and treated at room temperature for 5-8 minutes to deposit palladium seeds (palladium nuclei) on the substrate surface. The palladium nuclei are covered by a tin protective colloid. Subsequently, the substrate is immersed in a hydrochloric acid solution to remove the tin protective colloid and obtain a surface with active palladium. Chemical deposition of conductive layer: The activated substrate is immersed in a chemical nickel plating bath at a temperature of 85-90℃ for 20-30 minutes to deposit a chemical nickel plating layer (first metal layer) with a thickness of 0.5-1.5μm, providing a conductive basis for subsequent electrochemical plating.

[0025] 4. Electrochemical plating Electrochemical electroplating is performed on a substrate with a conductive layer deposited, sequentially depositing a copper intermediate layer, a nickel intermediate layer, and a decorative metal layer.

[0026] Copper intermediate layer deposition: The substrate is placed in a copper sulfate electroplating bath, the current density is controlled at 2-3A / dm², and the electroplating time is 30-40min to form a copper intermediate layer with a thickness of 10-30μm. The high ductility of copper is used to alleviate the stress difference between the substrate and the subsequent hard metal layer. Nickel interlayer deposition: Based on the copper interlayer, place it in a semi-bright nickel electroplating bath with a current density of 1.5-2A / dm² and an electroplating time of 20-25min to deposit a semi-bright nickel layer with a thickness of 3-20μm. Then transfer it to a matte nickel electroplating bath to deposit a matte nickel layer with a thickness of 2-5μm, forming a composite nickel interlayer and improving the corrosion resistance of the coating. Decorative metal layer deposition: On the nickel intermediate layer, place it in a chromium electroplating bath with a current density of 3-4 A / dm² and an electroplating time of 5-8 min to deposit a chromium layer with a thickness of 0.15-2 μm, giving the parts a metallic decorative effect and wear resistance.

[0027] During the electroplating process, ensure that the parameters such as the temperature and pH value of the electroplating solution are consistent with those of conventional electroplating. Because the symbol area is physically covered, the electroplating solution cannot come into contact with the substrate surface, and no metal deposition occurs.

[0028] 5. Removal of masking material After electroplating is completed, the substrate is removed from the electroplating bath. First, rinse the surface with water to remove any residual electroplating solution, and then remove the masking material from the symbol area.

[0029] If masking paint is used: Immerse the substrate in a special masking paint stripper (such as an alcohol-ether mixed solvent) at room temperature for 10-15 minutes. After the masking paint has completely softened, gently brush the marked area with a soft brush to remove the masking paint residue, and then rinse it with clean water. If masking tape is used: Gently lift a corner of the masking tape along the edge of the symbol, and peel off the tape from the entire symbol area at a uniform speed. For any remaining sticky substances, gently wipe them away with a cotton cloth dampened with a small amount of alcohol to avoid damaging the substrate surface.

[0030] Finally, the substrate is placed in a drying oven at 60-80℃ for 15-20 minutes to remove surface moisture, resulting in finished automotive interior parts.

[0031] Product performance verification: The symbol area of ​​the finished parts has no residual metal plating, and the light transmittance of the substrate is ≥85%, meeting the backlighting requirements; the metal plating in the remaining areas is continuous and uniform, with a copper intermediate layer thickness of 10-30μm, a nickel intermediate layer thickness of 5-25μm, and a chromium decorative layer thickness of 0.15-2μm. The plating adhesion meets the GB / T 5270-2005 standard (no peeling in the cross-cut test); after a 48-hour neutral salt spray test (GB / T 10125-2021), the coating shows no rust or blistering; the symbol edges are highly clear, without burrs or blurring, meeting the appearance precision requirements of automotive interior parts.

[0032] Process advantages: This implementation method replaces laser processing with physical masking, avoiding the high cost of laser equipment and the risk of substrate damage; the masking material is a special material resistant to electroplating solution corrosion, ensuring reliable isolation of the symbol area; the electroplating pretreatment and electrochemical electroplating steps use existing mature process parameters, requiring no additional adjustments to the production line, reducing process switching costs; the entire process is continuous and efficient, shortening the production cycle by more than 30% compared to laser-based solutions, and increasing the product qualification rate to over 98%, demonstrating significant industrial application value.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for localized electroplating of automotive interior parts, characterized in that, Includes the following steps: S1. A substrate with a single-color, two-color, or multi-color structure is provided, wherein the outermost layer of the substrate is an electroplatable material, and the electroplatable material is polyamide, ABS, or an ABS / polycarbonate blend. S2. The symbol area of ​​the substrate is pretreated by physical covering method, wherein the physical covering method is to cover the symbol area with a masking material that is resistant to electroplating solution corrosion, so that the symbol area is isolated from the electroplating solution. S3. The pretreated substrate is subjected to electroplating pretreatment and electrochemical electroplating treatment in sequence to form a metal coating on the surface of the substrate outside the symbol area. The metal coating includes a copper intermediate layer, a nickel intermediate layer and a decorative metal layer. S4. Remove the masking material and pretreatment residue from the symbol area to obtain automotive interior parts where the symbol area is light-transmitting and the remaining areas have a metal coating.

2. The method for partial electroplating of automotive interior parts according to claim 1, characterized in that, In S2, the masking material is a high-temperature resistant masking paint or masking tape, the thickness of the masking material is 0.1-0.5mm, the ambient temperature during masking is 20-25℃, and the masking time is 10-30min.

3. The method for partial electroplating of automotive interior parts according to claim 2, characterized in that, The masking paint is made of high-temperature resistant masking paint that is corroded by electroplating solution. The masking paint is precisely applied to the symbol area of ​​the substrate through screen printing.

4. The method for partial electroplating of automotive interior parts according to claim 3, characterized in that, During the masking coating process, the ambient temperature should be controlled at 20-25℃, and the masking coating thickness should be 0.2-0.3mm. After coating, let it stand for 15-20 minutes to allow the masking coating to initially cure, ensuring that it adheres tightly to the substrate surface without bubbles or sagging.

5. The method for partial electroplating of automotive interior parts according to claim 2, characterized in that, Specialized electroplated masking tape is used. The masking tape is cut according to the shape of the symbol and then accurately pasted onto the symbol area manually or using a film-applying device. Ensure that the edges of the tape are completely aligned with the outline of the symbol, without any curling or gaps. The pasting pressure is controlled at 0.1-0.2MPa to ensure that there are no gaps between the tape and the substrate surface, thus preventing the electroplating solution from seeping in.

6. A method for localized electroplating of automotive interior parts according to claim 4 or 5, characterized in that, In S3, the electroplating pretreatment includes pickling and roughening, surface activation, and chemical deposition of a conductive layer. In the electroplating pretreatment, pickling and roughening are carried out in a chromium-sulfuric acid bath, surface activation is achieved by colloidal palladium seed deposition, and the chemically deposited conductive layer is a chemically plated nickel layer.

7. The method for partial electroplating of automotive interior parts according to claim 6, characterized in that, During the pickling and roughening process, the substrate is immersed in a chromium sulfuric acid bath at a temperature of 50-60°C for 10-15 minutes to form a rough structure on the substrate surface, thereby enhancing the adhesion of the subsequent metal layer. In the surface activation process, the acid-washed substrate is immersed in a colloidal palladium solution and treated at room temperature for 5-8 minutes to deposit palladium seeds on the substrate surface. The palladium nuclei are covered by a tin protective colloid. Subsequently, the substrate is immersed in a hydrochloric acid solution to remove the tin protective colloid, resulting in a surface with active palladium. In the chemical deposition of the conductive layer process, the activated substrate is immersed in a chemical nickel plating bath at a temperature of 85-90℃ for 20-30 minutes to deposit a chemical nickel plating layer with a thickness of 0.5-1.5μm, providing a conductive basis for subsequent electrochemical plating.

8. A method for partial electroplating of automotive interior parts according to claim 6, characterized in that, In the metal plating, the nickel intermediate layer has a thickness of 5-25 μm, and the decorative metal layer is a chromium layer.

9. A method for partial electroplating of automotive interior parts according to claim 8, characterized in that, In the process of depositing the copper intermediate layer, the substrate is placed in a copper sulfate electroplating bath with a current density controlled at 2-3 A / dm² and an electroplating time of 30-40 min to form a copper intermediate layer with a thickness of 10-30 μm. The high ductility of copper is used to alleviate the stress difference between the substrate and the subsequent hard metal layer. In the process of depositing the nickel intermediate layer, on the basis of the copper intermediate layer, the substrate is placed in a semi-bright nickel electroplating bath with a current density of 1.5-2 A / dm² and an electroplating time of 20-25 min to deposit a semi-bright nickel layer with a thickness of 3-20 μm. Then, it is transferred to a matte nickel electroplating bath to deposit a matte nickel layer with a thickness of 2-5 μm, forming a composite nickel intermediate layer, which improves the corrosion resistance of the coating. In the process of depositing the decorative metal layer, on the nickel intermediate layer, the substrate is placed in a chromium electroplating bath with a current density of 3-4 A / dm² and an electroplating time of 5-8 min to deposit a chromium layer with a thickness of 0.15-2 μm, giving the parts a metallic decorative effect and wear resistance.

10. A method for partial electroplating of automotive interior parts according to claim 2, characterized in that, In S4, if masking material is masking paint, it is removed by solvent cleaning: Immerse the substrate in a special masking paint stripper at room temperature for 10-15 minutes until the masking paint is completely softened, then gently brush the symbol area with a soft brush to remove any masking paint residue, and then rinse thoroughly with clean water. If masking material is masking tape, it is removed by mechanical peeling: Gently lift a corner of the masking tape along the edge of the symbol, and peel off the tape from the entire symbol area at a uniform speed. For any remaining sticky substances, gently wipe them off with a cotton cloth dampened with a small amount of alcohol to avoid damaging the substrate surface. Finally, place the substrate in a drying oven at 60-80℃ for 15-20 minutes to remove surface moisture. After removal, there should be no residual damage on the substrate surface of the symbol area.