Surface treatment method for large-radian plastic product
After protective pretreatment and coating on the surface of large-arc plastic products, combined with laser engraving and chemical deplating processes, the surface treatment process is optimized, and the problems of long surface treatment time and high defect rate of large-arc plastic products are solved, and the operation is achieved Shorten the duration and improve product yield.
Patent Information
- Application Number
- CN202411648196.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-02-18
AI Technical Summary
The existing technology is difficult to effectively deal with the surface of large-arc plastic products, resulting in a long de-plating time and high de-de-plating rate. Chemical de-plating causes problems such as unstable and ink overflow in silk screen printing ink, resulting in high de-de-plating rate of products.
After using protective pretreatment and coating, the deplating area is determined for shielding, and the protective paint is sprayed on the non-deplating area. The non-deplating area is deplating through the radium engraving process, and then the mask is removed and the remaining areas are deplating using the chemical deplating process. Combining the advantages of the two deplating processes, the surface treatment process is optimized.
It shortens the working time of surface treatment, improves product yield, is simple and fast to operate, and is practical.
Smart Images
Figure CN119465331A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of surface treatment, and in particular to a surface treatment method for large-curvature plastic products. Background Art
[0002] Surface treatment is a process method to artificially form a surface layer on the surface of the base material with mechanical, physical and chemical properties different from those of the base material. The purpose of surface treatment is to meet the corrosion resistance, wear resistance, decoration or other special functional requirements of the product. In the field of surface treatment of plastic products, in order to make plastic products beautiful and durable and increase the added value of the products, coating is often performed on the surface of plastic products to make the surface of plastic products metallized. In the process of surface treatment of plastic products, in order to achieve the expected surface effect, in addition to electroplating, corresponding deplating is also required.
[0003] The most common deplating processes on the market are laser deplating and chemical deplating. Laser deplating is generally suitable for flat, small or small arc plastic products (arc < 180°). If the plastic product is large and the arc angle is large (arc > 360°), the operation time will be longer and the product defect rate will rise sharply. For chemical deplating, although there is no restriction on the shape of plastic products, a silk screen protective ink layer is usually required for chemical deplating. On the one hand, the silk screen ink is easily penetrated and unstable, and the surface effect of the plastic product is easy to fog; on the other hand, the edge of the silk screen ink is easy to overflow, resulting in uneven patterns or fonts, burrs, teeth and other problems, and the product defect rate will be very high. Summary of the invention
[0004] In view of this, the purpose of the present application is to provide a surface treatment method for large-curvature plastic products, so that the surface treatment method can improve the yield of large-curvature plastic products and reduce product processing time.
[0005] In order to solve the above technical problems / achieve the above objectives or at least partially solve the above technical problems / achieve the above objectives, the present application provides a surface treatment method for a large-curvature plastic product, comprising:
[0006] Carry out protective pretreatment on the surface of the large-curved plastic product to be processed, and then coat it;
[0007] Determine a deplating area on the surface of the large-curvature plastic product and mask the deplating area, and spray a protective paint on the masking area outside the deplating area;
[0008] The shielding and spraying area is stripped by laser engraving process and presents the required surface effect;
[0009] removing the shielding of the stripping area, and stripping the stripping area by using a chemical stripping process;
[0010] Clean the large-curvature plastic product after stripping, perform appearance treatment on its surface, and obtain the surface-treated product.
[0011] Optionally, the large-arc plastic product includes a structure with an arc of ≥180°.
[0012] Optionally, the protective pretreatment comprises spraying a primer and / or a protective lacquer. Further optionally, the protective lacquer comprises a UV radiation-cured lacquer.
[0013] Optionally, the coating is performed by an electroplating process. Further optionally, the electroplating process includes an NCVM process.
[0014] Optionally, the shielding is performed by setting a shielding fixture.
[0015] Optionally, the chemical deplating process includes using a chemical deplating solution for deplating.
[0016] Optionally, the appearance treatment includes spraying a topcoat.
[0017] The present application provides a surface treatment method for large-curvature plastic products, which can be applied to the surface treatment of large-curvature, multi-dimensional plastic products; the surface treatment method of the present application combines the advantages of laser deplating process and chemical deplating process, and optimizes the two deplating processes in the surface treatment process of the present application by localizing the application of laser deplating process and coordinating the large-area rapid deplating operation of the chemical deplating process. The entire process can shorten the operation time of surface treatment, improve product yield, and is simple and fast to operate, with strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application.
[0019] Figure 1 The figure shows a schematic diagram of the process of processing a Bluetooth headset charging box using the surface treatment method of the present application; A represents the front of the Bluetooth headset charging box, and B represents the back of the Bluetooth headset charging box;
[0020] Figure 2 The figure shows a physical picture of a Bluetooth headset charging box processed by two surface treatment methods, Comparative Example 1 and Comparative Example 2; A represents the laser deplating (bright finish) of Comparative Example 1, B represents the chemical deplating (bright finish) of Comparative Example 2, C represents the laser deplating (matte finish) of Comparative Example 1, and D represents the chemical deplating (matte finish) of Comparative Example 2. DETAILED DESCRIPTION
[0021] The present application discloses a surface treatment method for a large-radian plastic product. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all deemed to be included in this application. The products, methods and applications described in this application have been described through preferred embodiments. Relevant personnel can obviously modify or appropriately change and combine the products, methods and applications described in this article without departing from the content, spirit and scope of this application to implement and apply the technology of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of this application.
[0022] It should be noted that, in this article, if relational terms such as "first" and "second", "S1" and "S2", "step 1" and "step 2", and "(1)" and "(2)" appear, they are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. At the same time, the embodiments in this application and the features in the embodiments may be combined with each other without conflict.
[0023] In the deplating process of plastic products, for plastic products with large deplating areas and large curvatures, the laser engraving process needs to perform deplating on each surface in a multi-directional and non-dead angle rotation on the basis of fixing a certain surface, which requires a long time of operation, and as the deplating area increases, the defective rate caused by deplating increases significantly, generally increasing to about 30%; in chemical deplating, the non-deplating area is protected by silk screen printing, and then the deplating area is deplated by immersing in chemical deplating reagents. The silk screen protection ink has low shielding performance against chemical deplating reagents and is easy to penetrate and overflow, resulting in a product defective rate of up to about 70%. Based on these existing technical problems, the present application provides a surface treatment method for plastic products with large curvatures, including:
[0024] S1. Protectively pre-treat the surface of the large-curved plastic product to be processed, and then coat it;
[0025] S2. Determine the stripping area on the surface of the large-curvature plastic product and mask the stripping area, and spray the protective paint on the shielding area outside the stripping area;
[0026] S3. The shielding area is stripped by laser engraving process and presents the desired surface effect;
[0027] S4. removing the shielding of the stripping area and stripping the stripping area by a chemical stripping process;
[0028] S5. Clean the large-curvature plastic product after stripping, perform appearance treatment on its surface, and obtain a surface-treated product.
[0029] In the present application, by spraying protective paint on the local non-stripping area, that is, the remaining area, the shielding of the area against the chemical stripping agent is enhanced, and the permeability is higher, the metal effect of electroplating can be completely guaranteed, and the product yield is increased by about 10% to 20%. At the same time, after the surface treatment method of the present application is improved, laser engraving only needs to laser engrave a small part of the non-stripping area, the operation time is significantly shortened, and the processing efficiency can be increased by about 4 times. In addition, if the process is adjusted, for example, after the shielding is plated and then the shielding is sprayed, and then the excess part is stripped by laser engraving, the shielded part and the part stripped by laser engraving will have a more obvious color difference (especially for products with light-colored materials). This is because electroplating will cause the plastic product to turn yellow, and the color of the part covered by the fixture remains unchanged, resulting in this color difference phenomenon, and it cannot be improved.
[0030] In certain embodiments of the present application, the surface treatment method described in the present application is suitable for large-curvature plastic products including structures with a curvature ≥ 180°, and is also suitable for large-curvature plastic products including structures with a curvature ≥ 360°; these large-curvature plastic products include but are not limited to Bluetooth headset charging boxes, mobile phone cases, electronic cigarettes, etc.
[0031] In certain embodiments of the present application, the protective pretreatment includes spraying primer and / or protective paint. The protective paint includes a UV radiation-cured paint, i.e., a UV protective paint, which is a coating with ultraviolet curing function. It uses ultraviolet curing technology to complete the curing of the coating within a few seconds to a few minutes, so that the coating has excellent hardness, scratch resistance, chemical resistance, and is not easy to yellow. It can be used for primer and protective treatment on the surface of wood, metal, plastic and other materials, and can improve the surface gloss, aesthetics and coating efficiency.
[0032] In certain embodiments of the present application, the coating is formed by electroplating. The electroplating process includes NCVM process. NCVM process is also called discontinuous coating technology or non-conductive electroplating technology. It is a high-tech technology derived from ordinary vacuum electroplating. It uses the discontinuous characteristics of metal and insulating compounds to plate thin films, and obtains a final appearance with a metallic texture without affecting the wireless communication transmission effect.
[0033] In certain embodiments of the present application, the shielding is performed by setting a shielding jig, for example, a shielding jig made of a plastic material, and the shielding jig can be prepared according to the size of a large-curved plastic product.
[0034] In certain embodiments of the present application, the desired surface effects presented by laser engraving in S3 include but are not limited to presenting desired texts, letters, graphics, three-dimensional structure effects or any combination thereof.
[0035] In certain embodiments of the present application, the chemical deplating process includes using a chemical deplating solution for deplating, and the large-curvature plastic product is immersed in the chemical deplating solution. The present application uses a commercial chemical deplating solution. Currently, the commercially available chemical deplating solution generally only has a deplating effect on electroplating, and has no effect on primer and protective paint.
[0036] In certain embodiments of the present application, the large-curvature plastic product is cleaned and wiped after chemical stripping, and then subjected to appearance treatment, wherein the appearance treatment includes spraying a topcoat. The topcoat includes but is not limited to varnish and color paint, and may also be a UV radiation-cured paint.
[0037] In each group of comparative experiments provided in this application, unless otherwise specified, other experimental conditions, materials, etc. are kept consistent except for the differences indicated in each group, so as to provide comparability. In addition, all materials used in this application can be purchased through commercial channels.
[0038] The following is a further description of a surface treatment method for a large-curvature plastic product provided by the present application.
[0039] Example 1: Surface treatment of Bluetooth headset charging box
[0040] In order to better understand the surface treatment method described in this application, Figure 1 The Bluetooth headset charging box with the structure shown is used as an example for explanation;
[0041] Surface treatment process: spray primer on the whole surface → spray UV protective paint on the whole surface → NCVM electroplating on the whole surface → install masking fixture to mask the stripping area (cover Figure 1 Blue area) → Spray UV protective paint on the spray-blocked area (for Figure 1The red area shown is sprayed) → laser carving de-plating (de-plating is removed Figure 1 The green part of the spray-shielded area is stripped, that is, the laser engraved area is stripped, and the BRAND surface effect part on the front and the white rectangular surface effect part on the back are retained) → Remove the masking fixture → Chemical stripping (stripping removes Figure 1 Blue part shown) → clean and wipe → spray UV topcoat.
[0042] Comparative Example 1: Surface treatment of conventional Bluetooth headset charging box (laser carving and deplating)
[0043] right Figure 1 The Bluetooth headset charging box of the structure shown is subjected to conventional surface treatment;
[0044] Surface treatment process: spray primer on the whole surface → spray UV protective paint on the whole surface → NCVM electroplating on the whole surface → spray UV protective paint on the whole surface → laser carving de-plating (de-plating to remove Figure 1 The green masked spray area and the blue part shown, retaining the BRAND surface effect part on the front and the white rectangular surface effect part on the back) → clean and wipe → spray UV topcoat.
[0045] Comparative Example 2: Surface treatment of conventional Bluetooth headset charging box (chemical stripping)
[0046] right Figure 1 The Bluetooth headset charging box of the structure shown is subjected to conventional surface treatment;
[0047] Surface treatment process: spray primer on the whole surface → spray UV protective paint on the whole surface → NCVM electroplating on the whole surface → laser engraving and deplating to produce "BRAND" → silk screen protection Figure 1 The "BRAND" surface effect area on the front and the white rectangular surface effect part on the back are shown → soak in chemical solution for deplating (deplating removes Figure 1 The blue part and the green masked area shown, retaining the surface effect parts on the front and back) → clean and wipe → spray UV topcoat.
[0048] Experimental example:
[0049] The three surface treatment processes of Example 1, Comparative Example 1 and Comparative Example 2 were statistically analyzed in terms of operation time and product yield, as shown in Table 1 below;
[0050] Table 1
[0051] Laser carving deplating operation time (s) Product yield (%) Example 1 35s~50s 70％～80％ Comparative Example 1 130s~150s 55％～60％ Comparative Example 2 10～20s 50％～55％
[0052] In the scheme of Example 1 of the present invention, only a smaller green masking area needs to be laser engraved, and the average laser engraving time for each product is 35 to 50 seconds. After the UV protective paint is removed by laser engraving, the unprotected part is stripped using a chemical stripping solution, and the stripping speed is fast, and the stripping time is only 5 to 10 seconds.
[0053] Comparative Example 1 requires 540° laser stripping, and the average laser stripping time for each product is 130-150s. Compared with the solution in Example 1, its operation time is significantly longer; and the product yield is also significantly lower than that in Example 1. See the actual sample picture. Figure 2 ;
[0054] Since the area to be laser-engraved and de-plated in the solution of comparative example 2 is only a very small part of the surface effect (BRAND word and white rectangle), the laser-engraved de-plating operation time is the shortest, but the silk screen ink is easily penetrated and unstable, and the edges are prone to ink overflow. The product yield is the lowest among the three surface treatment methods. The actual sample picture is shown in Figure 2 .
[0055] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.
Claims
1. A surface treatment method for a large-radian plastic product, characterized in that: include: Carry out protective pretreatment on the surface of the large-curved plastic product to be processed, and then coat it; Determine a deplating area on the surface of the large-curvature plastic product and mask the deplating area, and spray a protective paint on the masking area outside the deplating area; The shielding and spraying area is stripped by laser engraving process and presents the required surface effect; removing the shielding of the stripping area, and stripping the stripping area by using a chemical stripping process; Clean the large-curvature plastic product after stripping, perform appearance treatment on its surface, and obtain the surface-treated product.
2. The surface treatment method according to claim 1, characterized in that: The large-arc plastic product includes a structure with an arc of ≥180°.
3. The surface treatment method according to claim 1, characterized in that: The protective pretreatment includes spraying a primer and / or a protective paint.
4. The surface treatment method according to claim 1, characterized in that: The protective lacquer comprises a UV radiation-curing lacquer.
5. The surface treatment method according to claim 1, characterized in that: The coating is produced by electroplating.
6. The surface treatment method according to claim 5, characterized in that: The electroplating process includes a NCVM process.
7. The surface treatment method according to claim 1, characterized in that: The shielding is performed by setting a shielding fixture.
8. The surface treatment method according to claim 1, characterized in that: The chemical deplating process includes using a chemical deplating solution for deplating.
9. The surface treatment method according to claim 1, characterized in that: The appearance treatment includes spraying topcoat.