Light transmission and forming process of mixed-color plastic electroplated part and switch panel

Abstract

The present application relates to a kind of mixed color plastic electroplated piece light transmission and forming process and switch panel, belong to the technical field of automotive interior parts manufacturing, comprising the following steps: step S1: in mold cavity, injection molding several light transmission materials, and the preliminary piece with different color marks is formed;Step S2: keep preliminary piece not to be removed from mold cavity, after preliminary piece cooling, rotate mold to next station, in mold cavity, injection molding electroplating base material, make electroplating base material and preliminary piece into one, form composite piece;Step S3: composite piece is removed as a whole, and baking stress relief treatment is carried out.The technical scheme is adopted, and the present application is processed to form conductive layer before electroplating, and engraving is carried out before electroplating process, removes the conductive layer of preset light transmission area, so that the area cannot deposit plating layer in subsequent electroplating process due to not conducting electricity, realizes the selective no plating layer light transmission of the surface of same part, and light transmission area can directly expose different color light transmission material base material, realizes the multiple base color light transmission effect.

Description

Technical Field

[0001] This invention belongs to the field of automotive interior parts manufacturing technology, specifically relating to a process for translucent and molding mixed-color plastic electroplated parts and a switch panel. Background Technology

[0002] In response to the diverse color requirements of automotive industry customers, single-color base material electroplating can no longer meet customer needs. Traditional multi-color injection molded parts often use multiple batches of insert injection molding, which is cumbersome, costly, and results in insufficient bonding strength of the insert injection symbols and uneven transition edges. The process is complex and yields low quality, failing to achieve the required exquisite appearance. Common electroplated parts that achieve translucency or pattern effects often use electroplating laser engraving, and the base color is often relatively simple. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a process for translucent and molding mixed-color plastic electroplated parts and a switch panel, which solves the problems of cumbersome processes, single background color, and difficulty in meeting regulatory color standards for symbols on existing automotive panels.

[0004] The technical solution of this invention: a process for translucent and molding mixed-color plastic electroplated parts, comprising the following steps: Step S1: Inject several translucent materials into the mold cavity to form preliminary parts with different colored markings; Step S2: Keep the preliminary part from coming out of the cavity. After the preliminary part cools down, rotate the mold to the next station and inject the electroplated substrate into the mold cavity to fuse the electroplated substrate with the preliminary part to form a composite part. Step S3: Demold the composite part as a whole and bake it to relieve stress; Step S4: Perform pre-plating treatment on the composite part to form a conductive layer on the surface of the composite part; Step S5: Laser engrave the front and back of the composite part to remove the conductive layer in the preset light-transmitting area; Step S6: Perform the electroplating process. The preset light-transmitting area does not have a plating layer deposited during the electroplating process because the conductive layer has been removed. A metal plating layer is formed on the surface of the remaining electroplating substrate area. Step S7: The surface of the part obtained in step S6 is printed with additional patterns using a pad printing process.

[0005] In a further embodiment of the present invention, the light-transmitting material is non-electroplated grade PC, and the electroplating substrate is electroplated grade ABS.

[0006] In a further embodiment of the present invention, the pad printing process in step S7 is applied to a light-transmitting material.

[0007] In a further embodiment of the present invention, the light-transmitting material region has a light-transmitting area with a wall thickness of 1-2 mm.

[0008] In a further embodiment of the present invention, the pretreatment for electroplating in step S4 includes a roughening process, a colloidal palladium deposition process, and a chemical nickel plating process; the roughening process is used to form microscopic anchor points on the surface of the electroplating substrate area; the chemical nickel plating process is used to form a conductive layer on the surface of the composite part.

[0009] In a further embodiment of the present invention, the electroplating process in step S6 includes pre-plating nickel, electroplating copper, electroplating semi-bright nickel, electroplating pearl matte nickel, electroplating nickel seal, and electroplating hexavalent chromium.

[0010] In a further embodiment of the present invention, the pad printing process in step S7 includes: Black base ink printing: Pad printing of black non-transparent base ink, with two printing passes; after the first printing, it is baked and cured and then naturally cooled to room temperature, and then the second black base ink printing is performed, and after the second printing, it is baked and cured again and then naturally cooled; the printing width of the black base ink is 0.1~0.2mm narrower than the width of the final topcoat. Topcoat printing: The topcoat is transferred onto the black base ink, and the number of printing passes is 2; the position of the topcoat printing is aligned with the position of the black base ink in a 1:1 ratio for the first printing, and the first operation is repeated for the second printing; the topcoat is baked and cured and then naturally cooled between and after the two printings.

[0011] In a further embodiment of the present invention, the molding shrinkage rate of the electroplated ABS is 0.4%~0.5%; its gloss (60°) after electroplating is ≥90%, and its color difference ΔE ≤1.0.

[0012] The present invention also provides a switch panel, which is made by the above-mentioned mixed-color plastic electroplating part light transmission and molding process; the surface of the switch panel has several marking areas formed by different light-transmitting materials, an electroplated decorative area formed by an electroplated substrate, a laser-engraved light-transmitting area, and a pad-printed supplementary pattern area.

[0013] In a further embodiment of the present invention, a V-shaped dividing groove is provided between the marking areas.

[0014] The beneficial effects of this invention are as follows: Through the non-demolding rotary injection molding process, the light-transmitting material and the electroplated substrate are integrally formed in the same mold. The two are fused together in the molten state, and the interface bonding force is significantly enhanced. This avoids the problems of insufficient bonding force and uneven edges caused by secondary clamping and positioning in insert injection molding, simplifies the process, and improves production efficiency and product yield. Selective light transmission is precise and controllable: by laser engraving after forming a conductive layer in the pre-plating process and before the electroplating process, the conductive layer of the preset light-transmitting area is removed, so that the area cannot be deposited with a coating in the subsequent electroplating process because it is non-conductive. This achieves selective light transmission without coating on the surface of the same part, and the light-transmitting area can directly expose the light-transmitting material substrate of different colors, achieving a multi-color light transmission effect. Balancing regulatory colors with intricate patterns: Red PC can be used as the light-transmitting material as the background color of the warning light, and combined with white topcoat paint printed by pad printing to complete the intricate patterns. This allows the warning light symbol to appear red in accordance with the regulatory color coordinates under LED backlighting, solving the problem of the traditional laser engraving solution having a single background color and difficulty in meeting regulatory color standards. Excellent anti-color mixing effect: The V-shaped dividing groove prevents color mixing of adjacent light-transmitting materials of different colors during the injection molding process, ensuring the clarity of the marking edge. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the panel in a specific embodiment of the present invention; Figure 3 This is an overall schematic diagram of the panel from another perspective in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the V-shaped dividing groove in the panel of a specific embodiment of the present invention.

[0016] In the diagram: 1. Identification area; 2. Electroplated decoration area; 3. Laser engraving light-transmitting area; 4. Pad printing supplementary pattern area; 5. V-shaped dividing groove. Detailed Implementation

[0017] The technical solutions in this embodiment will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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] This embodiment provides a process for the light transmission and molding of mixed-color plastic electroplated parts, such as... Figure 1 As shown, using several translucent materials and electroplated substrates as raw materials, selective light transmission without plating is achieved through integral injection molding without demolding, laser engraving to remove the conductive layer before electroplating, and pad printing to complete the fine pattern. The entire process can be completed through one injection molding and composite surface treatment. The specific steps are as follows: Step S1: Injection Molding of Translucent Material: Inject several translucent materials into the mold cavity to form preliminary parts with different colored markings. The translucent material is non-electroplated grade PC, including a first-color PC material and a second-color PC material. In this embodiment, the first-color PC material is red PC, used to form the background color of the red light symbol; the second-color PC material is blue PC, used to form the background color of the blue marking. The PC material has high temperature resistance, meeting the requirements of a product storage temperature of 95℃ and a working temperature of 85℃. The material has good light transmission performance, with a wall thickness of 1.5mm in the light-transmitting area, meeting the product light intensity requirement of (15±30%) cd / ㎡. In this embodiment, the translucent PC material must be fully dried at a drying temperature of 120℃ for 4-6 hours before injection molding. The injection molding temperature of the translucent material is 250℃~295℃, and the mold temperature is 70℃~110℃.

[0020] Step S2, Electroplating Substrate Injection Molding: Keep the initial part from exiting the mold cavity. After the initial part cools, rotate the mold to the next station and inject the electroplating substrate into the mold cavity, so that the electroplating substrate and the initial part are integrated to form a composite part. The electroplating substrate is electroplating grade ABS. This material has good electroplating performance and is not prone to local plating defects, pitting, or bubbles. Specifically, the electroplating grade ABS contains 10% PC material, which improves the material's temperature resistance without affecting the electroplating performance. It also needs to meet the requirement that the electroplated product has no obvious appearance change after boiling in water at 90℃ for 2 hours. The material needs to be dried at a drying temperature of 90-110℃ for 3-4 hours before injection molding. In this embodiment, the electroplating substrate is gray ABS, the injection temperature of the electroplating substrate is 240℃~260℃, and the mold temperature is 60℃~120℃. Because a V-shaped dividing groove 5 is formed between adjacent light-transmitting material areas on the initial part, it is used to prevent different colors of light-transmitting materials from mixing during the injection molding process, ensuring the clarity of the marking edge. At the same time, after molding, the adjacent red and blue colors are clearly separated, avoiding affecting light transmission.

[0021] Specifically, the light-transmitting material has an area not covered by the electroplated substrate, which is the light-transmitting area. Its thickness is 1~2mm, preferably 1.5mm. This thickness ensures that the LED light can effectively pass through the PC material to form a clear backlit sign.

[0022] Step S3, Stress Relief Baking: After demolding the composite part as a whole, bake it to relieve stress. The temperature for stress relief baking is 90℃ and the time is 4 hours to eliminate the internal stress generated during injection molding and prevent the part from deforming or the plating layer from cracking due to stress release in the subsequent electroplating process.

[0023] Step S4, Pre-plating treatment: Perform pre-plating treatment on the composite part to form a conductive layer on the surface of the composite part. The pre-plating treatment includes: Roughening process: The composite part is treated with chromic acid roughening solution to form micro-anchor points on the surface of the electroplated substrate area; in this step, the PC material area is not etched and cannot form micro-anchor points, which provides a basis for subsequent selective no-coating. Colloidal palladium deposition process: Colloidal palladium is deposited on the surface of the electroplating substrate area as a catalyst for subsequent electroless nickel plating; Chemical nickel plating process: forming a uniform conductive layer on the surface of the composite part through chemical nickel plating; thus obtaining a uniform conductive layer on the surface of the part.

[0024] Step S5, Laser Engraving: Laser engraving is performed on the front and back of the composite part to remove the conductive layer in the preset light-transmitting area. Laser engraving is performed after the chemical nickel plating process and before the pre-plating nickel process. The preset light-transmitting area is the area where a light-transmitting symbol needs to be formed, including the light-transmitting positions on the front and back. Laser engraving completely removes the conductive layer in the preset light-transmitting area, so that the area cannot be deposited with a plating layer in the subsequent electroplating process because it is non-conductive. At the same time, the electroplating substrate (ABS) layer in the area can be thinned to a light-transmitting thickness. Laser engraving uses flexible tooling for positioning to ensure precise alignment of the laser-engraved patterns on both sides.

[0025] Step S6, Electroplating Process: An electroplating process is performed. Due to its material characteristics, the translucent PC material lacks the butadiene rubber phase of ABS and cannot be etched with mechanical anchor points by the roughening solution. Therefore, it will not be electroplated. The plating layer only adheres to the surface of the ABS substrate. Furthermore, the pre-defined translucent areas on the ABS substrate have had their conductive layer removed by laser engraving, so no plating layer is deposited during the electroplating process. A metallic plating layer forms on the surface of the remaining areas of the substrate. The electroplating process includes: Pre-plating with nickel: A layer of nickel is pre-plated on the surface of the electroplating substrate to enhance the adhesion of subsequent plating layers; Copper plating: A copper layer is electroplated on top of a pre-plated nickel layer. Since the conductive layer has been removed from the pre-transparent area, no copper layer is deposited in this area during the copper plating process, thus maintaining a plating-free state. Semi-bright nickel plating: A semi-bright nickel layer is electroplated on top of the copper layer as an intermediate layer; Pearl matte nickel plating: A pearl matte nickel layer is electroplated on top of a semi-bright nickel layer, providing a soft luster effect; Electroplated nickel seal: A nickel seal layer is electroplated on top of the pearl matte nickel layer to improve the density and corrosion resistance of the coating; Electroplating with hexavalent chromium: A hexavalent chromium layer is electroplated on the outermost layer, providing high gloss and wear resistance.

[0026] Step S7, Pad Printing Process: After the part obtained in step S6 is washed, reduced, and dried, it is hung up. Its surface can be supplemented with patterns through pad printing. In this embodiment, the pad printing process is applied to a translucent material. The pad printing process includes: Black base ink printing: Pad printing of black non-transparent base ink, with two printing passes. After the first printing, the ink is baked and cured and then naturally cooled to room temperature. Then, the second black base ink printing is performed. After the second printing, the ink is baked and cured again and then naturally cooled. The printing width of the black base ink is 0.1~0.2mm narrower than the width of the final topcoat. Topcoat printing: Topcoat is transferred onto the black base ink, and the number of printing passes is 2. The first topcoat printing position is aligned with the black base ink position in a 1:1 ratio. The second operation is repeated. The topcoat is baked and cured and then naturally cooled between and after the two topcoat printings. The ink ratio for the topcoat can be adjusted according to requirements; Post-curing: After pad printing, the parts are baked and cured to ensure that the characters meet the requirements of wear resistance, chemical corrosion resistance and long-term colorfastness.

[0027] Example 2: This example provides a switch panel, which is made using the mixed three-color plastic electroplating part multi-base color light transmission and molding process described in Example 1.

[0028] like Figure 2-4 As shown, the surface of the switch panel has several marking areas 1 formed by different light-transmitting materials, an electroplated decorative area 2 formed by an electroplated substrate, a laser-engraved light-transmitting area 3, and a pad-printed supplementary pattern area 4; a V-shaped dividing groove 5 is provided between the marking areas 1 to prevent color mixing of different colored light-transmitting materials during the injection molding process.

[0029] Specifically, the signage area 1 includes a red warning light translucent symbol area and a blue functional sign translucent area. The red warning light translucent symbol area is made of red PC material and appears red in accordance with regulatory color requirements under LED backlighting. The blue functional sign translucent area is made of blue PC material and appears blue under LED backlighting.

[0030] The electroplated decorative area 2 is formed by electroplating gray ABS material. The surface has a high-gloss metallic texture, with a gloss of ≥90% at a 60° angle, a color difference ΔE≤1.0, and no flow marks or pits on the surface.

[0031] The laser-engraved light-transmitting area 3 is located in the preset light-transmitting area, which is the area on the ABS material where no coating is deposited during the electroplating process after the conductive layer is removed by laser engraving. Light can pass through the thinned ABS layer to achieve light transmission.

[0032] The pad-printed supplementary pattern area 4 is located on the surface of the red PC material. It is a supplementary pattern formed by pad printing white topcoat, which together with the red PC substrate constitutes a complete warning light symbol.

Claims

1. A process for translucent and molding mixed-color plastic electroplated parts, characterized in that: Includes the following steps: Step S1: Inject several translucent materials into the mold cavity to form preliminary parts with different colored markings; Step S2: Keep the preliminary part from coming out of the cavity. After the preliminary part cools down, rotate the mold to the next station and inject the electroplated substrate into the mold cavity to fuse the electroplated substrate with the preliminary part to form a composite part. Step S3: Demold the composite part as a whole and bake it to relieve stress; Step S4: Perform pre-plating treatment on the composite part to form a conductive layer on the surface of the composite part; Step S5: Laser engrave the front and back of the composite part to remove the conductive layer in the preset light-transmitting area; Step S6: Perform the electroplating process. The preset light-transmitting area does not have a plating layer deposited during the electroplating process because the conductive layer has been removed. A metal plating layer is formed on the surface of the remaining electroplating substrate area. Step S7: The surface of the part obtained in step S6 is printed with additional patterns using a pad printing process.

2. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 1, characterized in that: The light-transmitting material is non-electroplated grade PC, and the electroplating substrate is electroplated grade ABS.

3. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 1, characterized in that: The pad printing process in step S7 is applied to a translucent material.

4. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 2, characterized in that: The light-transmitting material area includes a light-transmitting zone with a wall thickness of 1-2 mm.

5. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 1, characterized in that: The electroplating pretreatment in step S4 includes a roughening process, a colloidal palladium deposition process, and a chemical nickel plating process; the roughening process is used to form microscopic anchor points on the surface of the electroplating substrate area; the chemical nickel plating process is used to form a conductive layer on the surface of the composite part.

6. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 1, characterized in that: The electroplating process described in step S6 includes pre-plating nickel, electroplating copper, electroplating semi-bright nickel, electroplating pearl matte nickel, electroplating nickel seal, and electroplating hexavalent chromium.

7. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 1, characterized in that: The pad printing process described in step S7 includes: Black base ink printing: Pad printing of black non-transparent base ink, with two printing passes; after the first printing, it is baked and cured and then naturally cooled to room temperature, and then the second black base ink printing is performed, and after the second printing, it is baked and cured again and then naturally cooled; the printing width of the black base ink is 0.1~0.2mm narrower than the width of the final topcoat. Topcoat printing: The topcoat is transferred onto the black base ink, and the number of printing passes is 2; the position of the topcoat printing is aligned with the position of the black base ink in a 1:1 ratio for the first printing, and the first operation is repeated for the second printing; the topcoat is baked and cured and then naturally cooled between and after the two printings.

8. The process for transmitting light and forming mixed-color plastic electroplated parts according to claim 2, characterized in that: The molding shrinkage rate of the electroplated grade ABS is 0.4%~0.5%; Its gloss (60°) after electroplating is ≥90%, and its color difference ΔE ≤1.

0.

9. A switch panel, characterized in that: The mixed-color plastic electroplating parts are manufactured using the light-transmitting and molding process described in any one of claims 1-8; The surface of the switch panel has several marking areas (1) formed by different light-transmitting materials, an electroplated decorative area (2) formed by an electroplated substrate, a laser-engraved light-transmitting area (3), and a pad-printed pattern area (4).

10. A switch panel according to claim 9, characterized in that: The marking areas (1) are separated by V-shaped dividing grooves (5).

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