Plastic structural member, preparation method therefor and electronic device

Abstract

The present application relates to the technical field of terminals, and provides a plastic structural member, a preparation method therefor and an electronic device. The plastic structural member comprises: a plastic substrate and a paint layer provided on the outer surface of the plastic substrate, the paint layer at least comprising a top coat layer; the top coat layer has a plurality of brushed textures distributed at intervals, the depth of the brushed textures being less than or equal to the thickness of the top coat layer; all of the brushed textures are distributed on the outer surface of the top coat layer in full circles, the top coat layer forming the appearance surface of the plastic structural member. Thus, there is no parting line on the outer surface of the plastic substrate of the plastic structural member, and the plurality of brushed textures macroscopically continuously distributed in full circles are provided on at least the top coat layer formed on the outer surface of the plastic substrate. These brushed textures simulate the texture of bushed metal textures, and meet product requirements for good appearance and high quality. Moreover, the top coat layer covers dirt, shrinkage and particles of the plastic substrate, thereby improving the yield and reliability.

Description

Plastic structural components and their preparation methods, electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 202411134475.X, filed on August 16, 2024, entitled "Plastic Structural Parts and Preparation Methods Thereof, Electronic Devices", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of terminal technology, and in particular to a plastic structural component and its preparation method, and electronic equipment. Background Technology

[0003] With the development of technology, mobile phones and other electronic devices are becoming increasingly important in people's lives and are being used more and more frequently. For electronic devices, an aesthetically pleasing appearance can enhance user satisfaction and attract the attention of potential consumers.

[0004] There are many ways to improve the aesthetics of electronic devices in related technologies, and brushing the surface of some structural components, such as the mid-frame, is one of them.

[0005] Traditional wire drawing processes mostly involve directly drawing wires onto the surface of a substrate to create structural components. When the structural component is made of metal, although it is possible to form a complete circle of wire patterns, the equipment and process costs are high, resulting in significant expenses. On the other hand, when the structural component is made of plastic, it is usually impossible to achieve a complete circle of wire patterns, resulting in a poor appearance. Summary of the Invention

[0006] This application provides a plastic structural component and its preparation method, as well as an electronic device. By forming a textured pattern on the topcoat layer on the outer surface of the plastic substrate, and ensuring that the outer surface of the plastic substrate is free of embedded lines, the topcoat layer can cover dirt, shrinkage, and particles on the plastic substrate, thereby significantly improving the yield and increasing reliability. At the same time, the textured pattern is distributed continuously in a full circle and has a texture similar to brushed metal, meeting the requirements for high aesthetics and high quality of products.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] In a first aspect, a plastic structural component is provided, comprising: a plastic substrate and a paint layer disposed on the outer surface of the plastic substrate, the paint layer comprising at least a topcoat layer, the topcoat layer forming the appearance surface of the plastic structural component, wherein the topcoat layer has a plurality of spaced-apart lines, the depth of the lines being less than or equal to the thickness of the topcoat layer, and all the lines being distributed in a complete circle on the outer surface of the topcoat layer.

[0009] This application provides a plastic structural component in which at least one topcoat layer is formed on the outer surface of the plastic substrate, and then the topcoat layer is brushed to form multiple continuous circular lines that are macroscopically visible. These lines have a metallic texture and can achieve the appearance effect of brushed metal substrates while avoiding the problem of surface fiber floating. At the same time, the topcoat layer can also cover dirt, shrinkage, and particles on the plastic substrate, which greatly improves the product yield, increases the product's gloss and reliability, and meets the requirements of high appearance and high quality.

[0010] In one possible implementation of the first aspect, the material of the topcoat layer includes polyurethane acrylic resin, ethyl acetate and a photoinitiator; and / or, the pencil hardness of the topcoat layer ranges from HB to 4H; and / or, the thickness of the topcoat layer ranges from 15 μm to 55 μm.

[0011] In this implementation, the topcoat layer is a transparent UV-curable paint that can be quickly cured after being irradiated by a UV lamp. It also has good abrasion resistance and a suitable thickness, which facilitates stringing and ensures that the stringing does not penetrate the topcoat layer as much as possible, while also ensuring the durability of the stringing.

[0012] In one possible implementation of the first aspect, the spacing between two adjacent filaments ranges from 4 μm to 7 μm; and / or, the maximum surface width of each filament ranges from 1 μm to 3 μm; and / or, the depth of each filament ranges from 10 μm to 55 μm.

[0013] In this implementation method, by designing the spacing, width, and depth of the silk threads, a variety of textures can be obtained, enriching the aesthetic appearance of plastic structural parts.

[0014] In one possible implementation of the first aspect, when the depth of the texture is less than the thickness of the topcoat layer, the depth of the texture ranges from 10 μm to 50 μm.

[0015] In this implementation, the texture does not penetrate the topcoat layer, ensuring the performance of the entire plastic structural component.

[0016] In one possible implementation of the first aspect, the paint layer includes a plastic substrate, a first primer layer, a second primer layer, a coating layer, a color paint layer, and a topcoat layer. The first primer layer is disposed between the plastic substrate and the second primer layer; the second primer layer is disposed between the first primer layer and the coating layer; the coating layer is disposed between the second primer layer and the color paint layer; and the color paint layer is disposed between the coating layer and the topcoat layer. The material of the first primer layer includes a first thermosetting paint, which includes a first thermosetting resin, a first curing agent, a first pigment, a first filler, a first solvent, and a first additive. The thickness of the first primer layer ranges from 10 μm to 30 μm; the material of the second primer layer includes a first UV-curable paint, which includes a first resin, a first monomer, a first photoinitiator, and a first photosensitive additive, and the thickness of the second primer layer ranges from 20 μm to 30 μm; the material of the coating layer includes indium, and the thickness of the coating layer is less than or equal to 1 μm; the material of the color paint layer includes a second UV-curable paint, which includes a second resin, a second monomer, a second photoinitiator, and a second photosensitive additive, and the thickness of the color paint layer ranges from 5 μm to 10 μm.

[0017] In this implementation method, a plastic structural component with a specific structure can be obtained.

[0018] In one possible implementation of the first aspect, the paint layer includes a plastic substrate, a second primer layer, a color paint layer, and a topcoat layer. The second primer layer is disposed between the plastic substrate and the color paint layer, and the color paint layer is disposed between the second primer layer and the topcoat layer. The material of the second primer layer includes a second thermosetting paint, which may include a second thermosetting resin, a second curing agent, a second pigment, a second filler, a second solvent, and a second additive. The thickness of the second primer layer ranges from 5 μm to 10 μm. The material of the color paint layer includes a third thermosetting paint, which may include a third thermosetting resin, a third curing agent, a third pigment, a third filler, a third solvent, and a third additive. The thickness of the color paint layer ranges from 5 μm to 10 μm.

[0019] In this implementation method, a plastic structural component with a specific structure can be obtained.

[0020] In one possible implementation of the first aspect, the paint layer includes a plastic substrate, a first primer layer, a second primer layer, a color paint layer, and a topcoat layer. The first primer layer is disposed between the plastic substrate and the second primer layer, the second primer layer is disposed between the first primer layer and the color paint layer, and the color paint layer is disposed between the second primer layer and the topcoat layer. The material of the first primer layer includes a first thermosetting paint, which includes a first thermosetting resin, a first curing agent, a first pigment, a first filler, a first solvent, and a first additive. The thickness of the first primer layer ranges from 10 μm to 15 μm. The material of the second primer layer includes a first ultraviolet-curable paint, which includes a first resin, a first monomer, a first photoinitiator, and a first photosensitizing additive. The thickness of the second primer layer ranges from 20 μm to 30 μm. The material of the color paint layer includes a second ultraviolet-curable paint, which includes a second resin, a second monomer, a second photoinitiator, and a second photosensitizing additive. The thickness of the color paint layer ranges from 5 μm to 10 μm.

[0021] In this implementation method, a plastic structural component with a specific structure can be obtained.

[0022] In one possible implementation of the first aspect, the material of the plastic matrix includes at least one of polycarbonate, polyamide, polyethyleneimine, polycarbonate and glass fiber, polyamide and glass fiber, and polyethyleneimine and glass fiber; and / or, the Vickers hardness range of the plastic matrix includes 60 HV to 90 HV.

[0023] This implementation method ensures that the resulting plastic structural parts have characteristics such as high hardness, light weight, and high plasticity.

[0024] In one possible implementation of the first aspect, the plastic substrate is an injection-molded part and the outer surface of the plastic substrate has no interlocking lines.

[0025] In this implementation, the plastic substrate is first molded and injection molded to form a plastic matrix with interlocking lines. Then, the interlocking lines on the outer surface of the plastic matrix are removed. Since there are no interlocking lines on the outer surface of the plastic matrix, the texture of the formed plastic structural parts is also free of interlocking lines, further improving the appearance and refinement.

[0026] In one possible implementation of the first aspect, the plastic structural component includes at least one of a laptop casing, a mobile phone mid-frame, a tablet computer mid-frame, and a battery cover.

[0027] In this implementation, the outer surfaces of the laptop casing, the mobile phone frame, the tablet frame, and the battery cover can be seen to have a continuous wire-like texture, achieving a brushed metal-like feel and significantly improving the appearance.

[0028] In a second aspect, an electronic device is provided, comprising a plastic structural component as described in the first aspect or any possible implementation thereof.

[0029] This application provides an electronic device in which the outer surface of the plastic structural component used in the electronic device has a continuous wire-like texture visible on a macroscopic scale, and also achieves a texture similar to brushed metal, thus meeting the requirements of high aesthetics and high quality for electronic devices.

[0030] Thirdly, a method for preparing a plastic structural component is provided. The method includes: forming a plastic substrate without interlocking lines on its outer surface; forming a paint layer on the outer surface of the plastic substrate corresponding to the area to be drawn; wherein the paint layer includes at least a topcoat layer; and drawing the topcoat layer to form a plastic structural component; wherein the topcoat layer has multiple spaced lines, the depth of which is less than or equal to the thickness of the topcoat layer, and all lines are distributed in a complete circle on the outer surface of the topcoat layer, and the topcoat layer forms the appearance surface of the plastic structural component.

[0031] This application provides a method for preparing a plastic structural component. First, a plastic substrate with interlocking lines is formed through mold forming and injection molding processes. Then, the interlocking lines on the outer surface of the plastic substrate are removed. Next, at least a topcoat layer is formed on the outer surface of the plastic substrate. Then, the topcoat layer is subjected to a brushing process to form multiple, continuously looping lines that are macroscopically visible. These lines have a metallic texture, achieving the appearance effect of brushed metal substrate surfaces while avoiding surface fiber issues. Simultaneously, the topcoat layer can also cover dirt, shrinkage, and particles on the plastic substrate, significantly improving product yield, increasing product gloss and reliability, and meeting the demands for high aesthetics and high quality. Furthermore, this method for preparing the plastic structural component is simple and easy to implement.

[0032] In one possible implementation of the third aspect, forming the plastic matrix includes: molding and injection molding a plastic raw material to form a first structural component; wherein the outer surface of the first structural component has a filament; and removing the filament to form the plastic matrix.

[0033] This implementation method can produce a plastic substrate with no embedded lines on the outer surface, ensuring that the texture of the plastic structural parts is free of embedded lines, and it is simple and easy to implement.

[0034] In one possible implementation of the third aspect, the method for removing the interlocking lines includes polishing or computer-controlled digital processing.

[0035] This implementation method effectively removes the interlocking lines and is simple and easy to implement.

[0036] In one possible implementation of the third aspect, the process of drawing the topcoat layer to form a plastic structural component includes: drawing the topcoat layer with a drawing wheel and wiping the outer surface of the topcoat layer with a brightening liquid to form a plastic structural component.

[0037] This method not only achieves a fine texture on the outer surface of the topcoat layer, but also effectively removes dirt and other contaminants from the outer surface of the topcoat layer by wiping it with a brightening liquid. This makes the product's appearance brighter and smoother, significantly improving the aesthetics of the plastic structural parts and giving them a better metallic texture and high-gloss effect.

[0038] In one possible implementation of the third aspect, the drawing wheel includes a wing wheel made of resin, nylon, and aluminum powder; and / or, the wing wheel has a Vickers hardness range of 60HV to 70HV.

[0039] In this implementation, the wing wheel is not too hard, which allows the wing wheel to break the outer surface of the topcoat layer to form a brushed texture, while also making the depth of the brushing easy to control, preventing it from going too deep and reducing or avoiding tearing the topcoat layer.

[0040] This application provides a plastic structural component and its preparation method, as well as an electronic device. First, a plastic substrate is formed into a plastic matrix with interlocking lines through mold forming and injection molding. Then, the interlocking lines on the outer surface of the plastic matrix are removed. Next, at least a topcoat layer is formed on the outer surface of the plastic matrix. Then, the topcoat layer is subjected to a brushing process to form multiple, continuously looping lines that are macroscopically visible. These lines have a metallic texture, achieving the appearance effect of brushed metal substrates while avoiding surface fiber issues. Simultaneously, the topcoat layer can also cover dirt, shrinkage, and particles on the plastic matrix, significantly improving product yield, increasing product gloss and reliability, and meeting the demands for high aesthetics and high quality. Furthermore, when applied to electronic devices, it can significantly enhance the aesthetics of the electronic device. Attached Figure Description

[0041] Figure 1 is a schematic diagram of the overall structure of an electronic device provided in an embodiment of this application;

[0042] Figure 2 is a schematic diagram of the disassembled structure of the electronic device in Figure 1;

[0043] Figure 3 is a schematic diagram of a metal wheel drawing a metal substrate using a related technology;

[0044] Figure 4 is a schematic diagram of the structure of the metal substrate in Figure 3 after wire drawing;

[0045] Figure 5 is a schematic diagram of a four-sided slider mold for drawing plastic substrates using related technologies;

[0046] Figure 6 is a schematic diagram of a plastic substrate being drawn using an upper and lower split mold provided by related technologies;

[0047] Figure 7 is a schematic diagram of the four-sided slider fixture in Figure 5;

[0048] Figure 8 is a schematic diagram of a wire drawing wheel drawing a plastic molded part according to an embodiment of this application;

[0049] Figure 9 is a structural schematic diagram of a first structural component provided in an embodiment of this application;

[0050] Figure 10 is a schematic diagram of another first structural component provided in an embodiment of this application;

[0051] Figure 11 is a structural schematic diagram of another first structural component provided in an embodiment of this application;

[0052] Figure 12 is a schematic diagram of a wire drawing wheel drawing four first structural components according to an embodiment of this application;

[0053] Figure 13 is a schematic diagram of the texture of a plastic structural component provided in an embodiment of this application;

[0054] Figure 14 is a schematic diagram of the textured structure of the first surface of the topcoat layer in Figure 13;

[0055] Figure 15 is a cross-sectional view of the topcoat layer in Figure 13;

[0056] Figure 16 is a cross-sectional view of a plastic structural component provided in an embodiment of this application.

[0057] Reference numerals: 01-Mobile phone; 100-Display screen; 101-Mid-frame; 102-Back cover; 103-Circuit board assembly; 1031-Motherboard; 1032-Electronic component; 104-Battery; 105-Battery cover; 200-Shaft; 201-Metal wheel; 202-Robotic arm; 203-Metal substrate; 204-Metal structural component; 205-Brushed metal texture; 301-First slider; 302-Second slider; 303-Third slider; 304-Fourth slider; 3051-First splicing area; 3052-Second splicing area; 3053-Third splicing area; 3054-Fourth splicing area; 3011-First textured surface; 306-Plastic substrate; 307-First plastic substrate molded part; 308-First plastic brushed texture; 309-First plastic trim; 401-Upper mold; 402-Lower mold; 404-Second plastic substrate molded part; 40 5-Second plastic trim; 406-Second plastic brushed texture; 1-Third plastic substrate molded part; 2-Fourth plastic substrate molded part; 21-Third plastic trim; 22-Fourth plastic trim; 3-Plastic substrate; 4-First structural component; 5-Brushing wheel; 6-Fixing rod; 7-Jig rod; 8-Plastic structural component; 9-Brushed texture; 10-First primer layer; 11-Second primer layer; 12-Coating layer; 13-Color paint layer; 14-Topcoat layer; 141-First surface of topcoat layer; 15-Anti-fingerprint layer. Detailed Implementation

[0058] The technical solutions in the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; the word "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0059] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, and "at least one" means one or more.

[0060] First, some terms used in the embodiments of this application will be explained to enable those skilled in the art to better understand them.

[0061] 1. Physical vapor deposition (PVD)

[0062] PVD refers to a technology that deposits atoms or ions from a solid target onto the surface of a substrate in a vacuum environment through evaporation or sputtering, forming a thin film with special functions.

[0063] PVD has advantages such as good adhesion between the film and the substrate, uniform and dense film, good controllability of film thickness, wide range of target materials (e.g., metal targets, alloy targets and ceramic targets), wide sputtering range, ability to deposit thick films, and good repeatability.

[0064] 2. Injection molding

[0065] Injection molding is a product manufacturing method that can be achieved using an injection molding machine (or injection molding machine) and a mold. It is used to make products of various shapes from thermoplastic materials, thermosetting materials, etc.

[0066] 3. Spraying

[0067] Spraying refers to the method of applying a spray gun or disc atomizer to a surface of an object by dispersing the material to be sprayed, such as paint, into uniform and fine droplets using pressure or centrifugal force.

[0068] 4. Anti-fingerprint (AF) layer

[0069] The AF layer uses a special coating material that can effectively absorb the oil and sweat left by fingerprints, making the fingerprint traces very faint. At the same time, it can also prevent the fingerprint traces from being discovered and copied by others, thus improving the security and accuracy of fingerprint recognition.

[0070] 5. Computerized numerical control (CNC)

[0071] CNC refers to a method of surface machining of parts using numerical control machining equipment, which typically includes precision machining, CNC lathes, CNC milling machines, and CNC boring and milling machines.

[0072] 6. Wire drawing

[0073] Brushing refers to a method of surface treatment of products using mechanical processing or other methods, which creates marks or lines on the product's surface to achieve a decorative effect.

[0074] The effect of wire drawing is a permanent, destructive, and irreversible process.

[0075] 7. Mold texturing

[0076] Mold texturing refers to the processing of textures on molds, typically including laser texturing. Laser texturing uses a high-energy laser beam to engrave the designed texture on the inner surface of the mold. This processing method is precise and can achieve excellent processing results, making it suitable for processing complex molds with irregular surfaces, requiring high precision and a high degree of design freedom.

[0077] 8. Non-conductive vacuum metallization (NCVM)

[0078] NCVM refers to a process in which materials are converted into particles under vacuum conditions using specific chemical and physical methods, and then deposited or adsorbed onto the surface of a substrate to form a film.

[0079] 9. Mold

[0080] Molds are various shapes and tools used in industrial production to obtain desired products through methods such as injection molding, blow molding, extrusion, die casting / forging, smelting, and stamping. In short, they are tools used to create shaped objects. There are many types of molds, such as four-sided sliding molds and split molds.

[0081] The four-sided slider mold consists of four rotatable and connected sliders. The movement of the rotating sliders can be controlled by a mechanical transmission / hydraulic device to achieve multi-directional stamping and forming.

[0082] The split mold consists of a moving mold and a fixed mold that interlock. The fixed mold is in direct contact with the structural component and is used for positioning and guiding. The moving mold can be moved and adjusted for shape processing. Specifically, when the moving mold and the fixed mold are separated, the part is removed, and when they are closed, the blank is injected into the mold cavity to form the part. In addition, the gap between the moving mold and the fixed mold can ensure the position of the blank and prevent friction, thus avoiding damage to the part.

[0083] 10. Vickers Hardness

[0084] Vickers hardness is a standard for expressing the hardness of a material. It is determined by pressing a diamond pyramid indenter with an included angle of 136° between its opposite faces into the surface of the material under a specified load. After holding the indenter for a certain period of time, the load is removed, the diagonal length of the indentation is measured, and the surface area of ​​the indentation is calculated. The average pressure on the surface area of ​​the indentation is then the Vickers hardness value of the material, denoted by the symbol HV.

[0085] 11. Plastics

[0086] Plastics, also known as plastics, refer to plastic (flexible) materials or rigid materials formed by curing and cross-linking, with high molecular weight synthetic resins as the main component and appropriate additives such as plasticizers, stabilizers, flame retardants, lubricants and colorants as the additives.

[0087] The above is a brief introduction to the terms used in the embodiments of this application, and will not be repeated below.

[0088] To facilitate understanding of the embodiments of this application, the application background of the embodiments of this application will be introduced below.

[0089] This application does not limit the specific type of electronic device. In some embodiments, the electronic device may include mobile phone, tablet, notebook, wearable device (e.g., smart bracelet, smartwatch, and headphones), laptop, handheld computer, ultra-mobile personal computer (UMPC), cellular phone, personal digital assistant (PDA), augmented reality (AR) / virtual reality (VR) device and other Internet of Things (IoT) devices, in-vehicle electronic device, and may also be a television, large screen, printer, projector, etc.

[0090] This application does not limit the specific form of the above-described electronic device. For convenience, the following description will use a mobile phone as an example.

[0091] Please refer to Figures 1 and 2. Figure 1 is an overall schematic diagram of a mobile phone 01 applicable to some embodiments of this application, and Figure 2 is a disassembled schematic diagram of the mobile phone 01 shown in Figure 1. The mobile phone 01 shown in Figures 1 and 2 is illustrated using a tablet phone as an example. In other embodiments, other types of mobile phones may also be used, such as foldable phones, depending on the actual application.

[0092] In the examples of Figures 1 and 2, the mobile phone 01 may include a display screen 100, a mid-frame 101, a back cover 102, a circuit board assembly 103, and a battery 104, etc. It is understood that Figures 1 and 2, as well as the related figures below, only schematically show some components of the mobile phone 01, and the actual shape, size, position, and structure of these components are not limited by Figures 1 and 2, as well as the figures below.

[0093] As shown in Figures 1 and 2, the display screen 100 is located on one side of the middle frame 101, and the display screen 100 can be used to display images, videos, etc.

[0094] In applications, the display screen 100 can be any of the following: liquid crystal display (LCD), organic light emitting diode (OLED) display, mini light emitting diode (Mini LED) display, micro light emitting diode (Micro LED) display, etc.

[0095] In the embodiment shown in Figure 1, the shape of the electronic device can be a rectangular plate. Of course, the shape of the electronic device can also be any other shape.

[0096] In addition, when the phone 01 is a foldable phone, the display screen 100 can be a foldable screen, depending on the actual application.

[0097] Please refer to Figure 2. The back cover 102 is located on the side of the middle frame 101 away from the display screen 100, and the back cover 102 and the middle frame 101 can form an internal accommodating space, which can be used to accommodate the circuit board assembly 103 and the battery 104, etc.

[0098] The aforementioned battery 104 can be used to provide power to components within the mobile phone 01, such as the display screen 100 and the circuit board assembly 103. Furthermore, a battery cover 105 is provided to protect the battery 104.

[0099] As shown in Figure 2, the circuit board assembly 103 may include a motherboard 1031 and electronic components 1032, etc.

[0100] The motherboard 1031 can be used to carry electronic components 1032 and to complete signal interaction with electronic components 1032. Figure 2 illustrates the circuit board assembly 103 with two electronic components 1032 as an example. Of course, the number of electronic components 1032 is not limited to two, depending on the actual application.

[0101] In practical applications, the motherboard 1031 may include printed circuit boards (PCBs), flexible printed circuit boards (FPCs), etc.

[0102] Among them, electronic components 1032 may include, but are not limited to, cameras, speakers, microphones, chips, resistors, capacitors, inductors, potentiometers, electron tubes, heat sinks, electromechanical components, connectors, semiconductor discrete devices, sensors, power supplies, switches, micro motors, electronic transformers, relays, subscriber identity modules (SIM) cards, etc.

[0103] Based on the above, mobile phone 01 may also include other structures such as microphone, speaker, and camera, which will not be specifically described here.

[0104] As frequently used items, electronic devices can enhance user satisfaction and attract the attention of potential consumers if they have an aesthetically pleasing appearance. For structural components within electronic devices, such as laptop casings, mobile phone frames, tablet frames, and battery covers, a certain level of aesthetic appeal is necessary to improve the overall appearance of the device.

[0105] There are many methods in related technologies to improve the aesthetics of structural components, and brushing the outer surface of structural components is one of them. The following uses the mid-frame 101 of a mobile phone as an example to explain the brushing process in detail. Of course, this brushing process is not limited to the mid-frame 101 of a mobile phone.

[0106] Currently, the mainstream materials for 101 mid-frames on the market include plastic and metal (such as aluminum alloy and titanium alloy). Among them, plastic has the advantages of low cost, light weight and strong plasticity; metal has the advantages of being lightweight, high strength and good heat dissipation.

[0107] Traditional wire drawing is a process where the outer surface of the substrate is directly drawn after the substrate has been formed, so as to give the outer surface of the substrate a textured appearance and improve its aesthetics.

[0108] Below are examples of two related technologies for directly drawing fibers on the outer surface of a substrate.

[0109] Example 1 (Wire drawing on the outer surface of a metal substrate):

[0110] Figure 3 illustrates a scheme for wire drawing on the outer surface of a metal substrate 203.

[0111] As shown in Figure 3, a metal wheel 201 is movably connected at the axis 200. The metal wheel 201 can also rotate around the axis 200 in the direction of the dotted arrow in Figure 3. The robot arm 202 holds the metal substrate 203 and drives the metal substrate 203 to revolve around the metal wheel 201. During this process, the metal wheel 201 rubs the outer surface of the metal substrate 203 and draws wire on the outer surface of the metal substrate 203 to form the metal structural component 204 in Figure 4. The metal structural component 204 has multiple metal wire drawing lines 205.

[0112] In application, the aforementioned metal wheel 201 can specifically be a metal wire drawing wheel, and its material is metal.

[0113] It should be noted that the metal substrate 203 in Figure 3 can rotate in the direction of the arrow in Figure 3; or, the metal substrate can be fixed in place. In this case, the metal wheel needs to rotate in the direction of the arrow in the figure while also moving along the surface of the metal substrate so that the surface corresponding to the area to be drawn in the metal substrate is drawn.

[0114] Furthermore, the size of the metal substrate 203 is typically chosen to be larger than the final metal structural component 204. This allows the metal substrate 203 to be CNC machined first to remove any residual material from its outer surface. When it is subsequently drawn, the outer surface of the metal structural component 204 will not exhibit defects such as embedded lines, thus forming a continuous, circular wire-like pattern. As a result, the outer surface of the metal structural component 204 has a non-mirror-like metallic luster, with a fine, hair-like sheen, better preserving the metallic texture and resulting in a more aesthetically pleasing and high-end product appearance.

[0115] However, the traditional method of directly drawing wires on the outer surface of the metal substrate 203 is very costly in terms of both process and equipment, which is not conducive to industrial production.

[0116] Example 2 (drawing wires on the outer surface of a plastic substrate):

[0117] The materials of the plastic substrate may include at least one of polycarbonate (PC), polyamide (PA), and polyethyleneimine (PEI). Furthermore, the materials of the plastic substrate may also contain glass fiber (GF), specifically, GF is doped into PC, or GF is doped into PA, or GF is doped into PEI.

[0118] The following example uses PC+GF as the material of the plastic substrate to illustrate the problems that exist when using the above-mentioned equipment and process for drawing the outer surface of metal substrates to draw the surface of plastic substrates.

[0119] When PC and GF particles are successively processed through melting, injection molding, and other processes to form a plastic substrate, due to the high temperature during preparation, PC and GF particles (especially GF particles) may accumulate on the outer surface of the plastic substrate at a depth of 1mm to 2mm. Microscopically, this appears as multiple messy lines. When these lines are drawn using a metal substrate drawing device as shown in Figure 3, they lift up and form relatively rough lines, making the lines invisible or indistinct. This is known as the problem of surface fiber floating. The floating fibers originate from the plastic substrate itself, and there is currently no good way to solve this problem.

[0120] Based on the above, related technologies have attempted to use other equipment and methods to directly draw fibers from the outer surface of plastic substrates. Drawing fibers from plastic substrates using a mold is one such method. As is well known, traditional molds consist of at least two sub-molds. First, a textured surface is formed on the inner surface of at least one sub-mold. When all sub-molds are open and closed, the plastic substrate is placed in the mold. When all sub-molds are closed, the plastic substrate is drawn into fibers. Finally, after opening all sub-molds, the formed structural component can be removed. Currently, there are many types of molds known, such as four-sided sliding block molds and top-and-bottom split molds.

[0121] The following sections will use four-sided slider molds and top-bottom split molds as examples to explain in detail how to directly draw wires on the outer surface of a plastic substrate.

[0122] Figure 5 shows a scheme for directly drawing wires on the outer surface of a plastic substrate using a four-sided slider die.

[0123] First, as shown in Figure 5a, prepare a four-sided slider mold, which consists of a first slider 301, a second slider 302, a third slider 303, and a fourth slider 304. These four sliders are sequentially assembled. As shown in Figure 5b, taking the first slider 301 as an example, draw the wires directly on the inner surface of the first slider 301 to form the first textured surface 3011, i.e., texture the four-sided slider mold. As shown in Figure 5c, place the plastic substrate 306 into the four-sided slider mold, and then close the slider. As shown in Figure 5d, after molding, directly injection mold the first plastic substrate molded part 307, which has the first plastic wire drawing texture 308.

[0124] It should be noted that there are no specific limitations on the shape, size, or material of the first slider 301, second slider 302, third slider 303, and fourth slider 304, as long as they can be connected. Of course, the number of sliders in the mold is not limited to four; the specific number depends on the actual application.

[0125] The textured surfaces of the second slider 302, the third slider 303, and the fourth slider 304 are not shown in Figure 5. The inner surfaces of the second slider 302, the third slider 303, and the fourth slider 304 can be textured or untextured as needed.

[0126] The mold can be textured according to the required spacing, gap, and depth of the first plastic brushed texture 308. Specifically, laser processing can be used for texturing.

[0127] Furthermore, the shape of the first plastic substrate molded part 307, the morphology of the first plastic brushed texture 308, and the number of the first plastic brushed texture 308 shown in Figure 5d are only examples, and are not limited to these. The specific details can be determined according to the actual process.

[0128] Figure 6 illustrates a scheme for drawing fibers on the outer surface of a plastic substrate using a split die.

[0129] First, as shown in Figure 6a, prepare the upper and lower split molds and the plastic substrate 306. The upper and lower split molds include an upper mold 401 and a lower mold 402 that have been textured. As shown in Figure 6b, place the plastic substrate 306 between the upper mold 401 and the lower mold 402, and close the upper mold 401 and the lower mold 402 to install the mold. As shown in Figure 6c, open the upper mold 401 and the lower mold 402, and take out the second plastic substrate molded part 404, which has a second plastic brushed texture 406.

[0130] It should be noted that, depending on the actual wire drawing requirements, only one of the upper die 401 and the lower die 402 can be textured.

[0131] Please refer to Figure 5d and Figure 6c. The outer surface of the first plastic substrate molding part 307 has a first plastic clamping line 309, and the outer surface of the second plastic substrate molding part 404 has a second plastic clamping line 405. This is because, as shown in Figure 7, in Figure 5, there is a first splicing area 3051 between the first slider 301 and the second slider 302, a second splicing area 3052 between the second slider 302 and the third slider 303, a third splicing area 3053 between the third slider 303 and the fourth slider 304, and a fourth splicing area 3054 between the fourth slider 304 and the first slider 301. Similarly, in Figure 6, the upper mold 401 and the lower mold 402 are also spliced ​​together, and there is also a splicing area between them, but it is not shown in the figure. These splicing areas will inevitably have gaps, which will inevitably result in parting lines on the surface of the plastic substrate molded parts. This means that the plastic substrate cannot achieve a continuous, full-circle texture on a macroscopic scale, and the appearance is worse compared to the texture of metal substrates.

[0132] It should be noted that the position, quantity, and direction of the first plastic clamping line 309 and the second plastic clamping line 405 can be determined according to the structure of the mold and the actual process.

[0133] Based on the above, how to balance the cost and effect of wire drawing on the outer surface of the substrate, so as to achieve both low cost and no wire clipping after wire drawing, while forming a continuous circumference of wire on a macroscopic scale, is an urgent problem to be solved.

[0134] To address the aforementioned issues, this application provides a plastic structural component. By first removing the interlocking lines on the surface of the plastic substrate, the outer surface of the formed plastic matrix is ​​free of interlocking lines. Then, at least one topcoat layer is formed on the outer surface of the plastic substrate. This topcoat layer can cover dirt, shrinkage, and particles on the plastic substrate, significantly improving yield and increasing reliability. Simultaneously, the topcoat layer is brushed, creating a continuous brushed texture that is visible macroscopically, achieving a metallic brushed feel and meeting the product's requirements for high aesthetics and high quality.

[0135] Please refer to Figures 8 to 16 for a detailed description of the wire drawing process provided in the embodiments of this application, and the plastic structural parts formed by the wire drawing process.

[0136] As shown in Figure 8, this application embodiment provides a method for preparing a plastic structural component, which includes the following steps:

[0137] S10. As shown in Figure 8a, a third plastic substrate molded part 1 and a fourth plastic substrate molded part 2 are provided respectively.

[0138] The outer surface of the third plastic substrate molded part 1 has a third plastic clamping line 21, and the outer surface of the fourth plastic substrate molded part 2 has a fourth plastic clamping line 22.

[0139] It should be noted that the third plastic substrate molded part 1 can be made by processing the plastic substrate 306 in Figure 5 through processes other than the wire drawing process. The other steps are the same as in Figure 5, and will not be repeated here. Similarly, the fourth plastic substrate molded part 2 can be made by processing the plastic substrate 306 in Figure 6 through processes other than the wire drawing process. The other steps are the same as in Figure 6, and will not be repeated here.

[0140] In application, the number and position of the third plastic clamping wire 21 and the fourth plastic clamping wire 22 can be determined according to the fixture and process.

[0141] In applications, the Vickers hardness range of the plastic substrate can be 60HV to 90HV. Typically, a Vickers hardness range of 60HV to 65HV can be selected for the plastic substrate; for example, the Vickers hardness of the plastic substrate can be 60HV, 61HV, 62HV, 63HV, 64HV, or 65HV, etc. This ensures that the formed plastic structural parts have characteristics such as high hardness, light weight, and high plasticity.

[0142] As an example, when the plastic substrate is composed of PC+GF, the volume percentage of GF in PC+GF can range from 10% to 50%. For example, the volume percentage of GF in PC+GF can be 10%, 15%, 20%, 30%, 40%, or 50%, etc.

[0143] As another example, when the plastic substrate is composed of PA+GF, the volume percentage of GF in PA+GF can range from 10% to 50%. For example, the volume percentage of GF in PA+GF can be 15%, 20%, 30%, 40%, 50%, or 55%, etc.

[0144] S11. As shown in Figure 8b, remove the interlocking lines to form the plastic substrate 3.

[0145] In applications, the methods for removing the embedded lines mentioned above may include grinding, CNC machining, etc.

[0146] Typically, the third plastic trim 21 on the outer surface of the third plastic substrate molded part 1 can be removed by grinding.

[0147] Typically, the fourth plastic clamping line 22 on the outer surface of the fourth plastic substrate molded part 2 can be removed by CNC machining.

[0148] Therefore, the plastic substrate 3 is injection molded and the outer surface of the plastic substrate has no embedded lines.

[0149] S12. As shown in Figure 8c, at least a topcoat layer 14 is formed on the surface corresponding to the area to be drawn in the plastic substrate 3 to obtain the first structural component 4.

[0150] It should be understood that, as shown in Figure 8c, the surface corresponding to the area to be drawn in the plastic substrate 3 may only have a topcoat layer 14 formed to constitute a paint layer; or, as shown in Figures 9 to 11, in addition to forming a topcoat layer 14, at least one of the following may be formed on the surface corresponding to the area to be drawn in the plastic substrate 3: a first primer layer 10, a second primer layer 11, a coating layer 12, and a color paint layer 13, to constitute a paint layer. Of course, this is not the only possibility; the specific application will determine the appropriate method.

[0151] In the application, the material of the topcoat layer 14 may include polyurethane acrylic resin, ethyl acetate and photoinitiator, thereby forming a topcoat layer 14 that is an ultraviolet (UV) curing paint. This paint is transparent and can be rapidly cured within seconds after being irradiated by a UV lamp.

[0152] Meanwhile, the pencil hardness range of the topcoat layer 14 is HB to 4H. Typically, the pencil hardness range of the topcoat layer 14 can be selected as F to 3H. At this time, the topcoat layer 14 has good wear resistance and can ensure the durability of the texture after brushing.

[0153] It should be noted that the "F" mentioned above is one of the grades in pencil hardness rating. In industry standards, pencil hardness is typically divided into 13 grades, decreasing from the hardest 6H to the softest 6B. Here, H represents hardness and B represents darkness; 6H is the hardest and lightest, while 6B is the hardest and darkest. Furthermore, pencil hardness testing is a method and measurement system for calibrating the hardness of the topcoat layer 14. It uses pencils of different hardness to test the hardness of the topcoat layer 14. During the test, the pencil is held at a 45° angle to the topcoat layer 14 and scratches a length of approximately 1 cm at a speed of 1 cm / s. The degree of damage to the topcoat layer 14 is then observed to assess its hardness. Therefore, in general, pencil hardness rating remains an important standard for describing the hardness of pencil lead and the topcoat layer 14.

[0154] As an example, the material of the topcoat layer 14 can be a mixture of polyurethane acrylate resin, ethylene glycol butyl ether, ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, and a photoinitiator. The volume percentage of polyurethane acrylate resin in the mixture can range from 35% to 45%, ethylene glycol butyl ether from 5% to 10%, ethyl acetate from 15% to 25%, butyl acetate from 10% to 20%, propylene glycol methyl ether acetate from 10% to 20%, and the photoinitiator from 0.5% to 3%.

[0155] As another example, the material of the topcoat layer 14 can be a mixture of acrylic resin, hexafunctional polyurethane resin, trifunctional polyurethane resin, propylene glycol methyl ether acetate, methyl ethyl ketone (MEK), butyl acetate, initiator 184, initiator 819, acrylic co-leveling agent, and adhesion promoter. The volume percentage of acrylic resin in the mixture can be 7%, the volume percentage of hexafunctional polyurethane resin can be 4%, the volume percentage of trifunctional polyurethane resin can be 9%, the volume percentage of propylene glycol methyl ether acetate can be 20%, the volume percentage of MEK can be 35%, the volume percentage of butyl acetate can be 19.8%, the volume percentage of initiator 184 can be 0.5% or 1%, the volume percentage of initiator 819 can be 0.5% or 1%, the volume percentage of acrylic co-leveling agent can be 0.2%, and the volume percentage of adhesion promoter can be 3%.

[0156] In application, the above-mentioned topcoat layer 14 can be formed by spraying or other methods. Specifically, it can be sprayed using a spray gun.

[0157] Furthermore, UV paint can be directly sprayed onto the surface corresponding to the area to be drawn on the plastic substrate 3 and UV cured to directly form a topcoat layer 14.

[0158] In this process, the UV dosage can range from 1000 mJ / cm. 3 ~1200mJ / cm 3 The baking time ranges from 8 to 12 minutes, the baking temperature ranges from 55°C to 65°C, the leveling time ranges from 2 to 4 minutes, the stirring time ranges from 9 to 11 minutes, and the viscosity of the UV paint ranges from 8.2S to 8.8S. Other process parameters are also possible, but will not be detailed here.

[0159] Furthermore, a first UV paint (with poor leveling and saturation) can be sprayed onto the surface of the plastic substrate 3 corresponding to the area to be drawn; then, a second UV paint (with good leveling and saturation) can be sprayed onto the first UV paint, and then UV curing can be performed to form a topcoat layer 14.

[0160] It should be noted that the components of the first UV paint and the second UV paint can be the same, and the final topcoat layer 14 does not have any layers when viewed in cross-section, which is simple and easy to achieve.

[0161] The thickness d14 of the topcoat layer 14 obtained by the above different methods along the first direction (OY direction in Figures 9 to 11) can be in the range of 15μm to 55μm. For example, d14 can be 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm or 55μm, etc.

[0162] It should be noted that the OY direction mentioned above refers to the direction from the outer surface to the inner surface of the plastic substrate 3. Here, in order to illustrate the thickness of the topcoat layer, the plastic substrate 3 is regarded as two-dimensional, but the plastic substrate 3 is actually a three-dimensional structure.

[0163] If the topcoat layer 14 is too thin, the brushed texture will easily penetrate the topcoat layer 14 during subsequent brushing. If the paint layer consists only of the topcoat layer 14, it may damage the plastic substrate 3. If the paint layer includes other layers, the brushing of those other layers will affect the brushing effect of the topcoat layer 14, resulting in a poor final brushed texture. However, if the topcoat layer 14 is too thick, the appearance will also be unattractive. In summary, a topcoat layer 14 within this thickness range can achieve a good brushing effect.

[0164] Please refer to Figure 9 again. The paint layer includes a first primer layer 10, a second primer layer 11, a coating layer 12, a color paint layer 13 and a topcoat layer 14, which are sequentially stacked on the plastic substrate 3.

[0165] The material of the first primer layer 10 may include a first thermosetting paint, which can be applied by spraying with a spray gun. The first thermosetting paint may include a first thermosetting resin, a first curing agent, a first pigment, a first filler, a first solvent, and a first additive. The first thermosetting resin may include polyurethane resin, acrylic resin, thermosetting amino resin, epoxy resin (e.g., bisphenol A type epoxy resin), and silicone resin. The first solvent may include ethyl acetate and ethylene glycol monobutyl ether. The first pigment and first filler may include iron oxide red, talc powder, and barite powder, used to provide color and enhance the physical properties of the first primer layer 10. The first additive may include accelerators, corrosion inhibitors, defoamers, dispersants, wetting agents, and surfactants. As an example, a thermosetting amino acid resin primer may contain a thermosetting amino resin composition, paraffin wax, silicone oil, sodium hydroxide, ethyl acetate, a water-based defoamer, a water-based dispersant, and deionized water. As another example, thermosetting acrylic iron oxide red includes water, ethylene glycol monobutyl ether, defoamer, surfactant, iron oxide red, dispersant, barium metaphosphate, talc, barite powder, thermosetting acrylic resin, wetting agent, dibutyl phthalate, diethylene glycol butyl ether, ammonia, and preservative. The thickness d10 of the first primer layer 10 along the OY direction can range from 10 μm to 30 μm; for example, d10 can be 10 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 30 μm, etc. The first primer layer 10 can fill defects in the plastic substrate 3 and enhance the adhesion between the subsequently sprayed paint and the plastic substrate 3.

[0166] The material of the second primer layer 11 may include a first UV-curable paint, and it can be applied by spraying with a spray gun. The first UV-curable paint may include a first resin, a first monomer, a first photoinitiator, and a first photosensitizing agent, etc. The first resin may include acrylic-modified epoxy resin, etc., and the first monomer may include a trifunctional crosslinking monomer, a difunctional diluent monomer, etc. The thickness d11 of the second primer layer 11 along the OY direction can range from 20μm to 30μm. For example, d11 can be 20μm, 22μm, 24μm, 26μm, 28μm, or 30μm, etc. The second primer layer 11 can fill the defects of the first primer layer 10 and make it easier for subsequently sprayed paint to adhere to the surface of the first primer layer 10.

[0167] It should be noted that the second primer layer 11 needs to be relatively thick to make it flatter and prevent the subsequent coating layer 12 from being too thick, which could lead to problems such as uneven reflection.

[0168] The material of the coating layer 12 may include indium (In), etc. Therefore, In can be deposited using the NCVM process to form the coating layer 12. Since the target material for NCVM is an indium wire, its natural color is a thin layer of silver (e.g., less than 1 μm), allowing the coating layer 12 to be very thin and achieving a shiny metallic texture. The thickness d12 of the coating layer 12 along the OY direction is less than or equal to 1 μm. For example, d12 can be 0.1 μm, 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, or 1 μm, etc.

[0169] The material of the color paint layer 13 may include a second ultraviolet-curable paint, which can be applied by spraying with a spray gun. This second ultraviolet-curable paint may include a second resin, a second monomer, a second photoinitiator, and a second photosensitive additive, etc. The components in the second ultraviolet-curable paint may be the same as or different from the components in the first ultraviolet-curable paint. The color paint layer 13 is a colored paint layer, and different colors of color paint layers 13 can be formed by selecting different materials, which helps to achieve personalized designs. The thickness d13 of the color paint layer 13 along the OY direction can range from 5μm to 10μm; for example, d13 can be 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm, etc.

[0170] Please refer to Figure 10 again. The paint layer includes a second primer layer 11, a color paint layer 13 and a topcoat layer 14, which are sequentially stacked on the plastic substrate 3.

[0171] Unlike the second primer layer 11 in Figure 9, the material of the second primer layer 11 in Figure 10 may include a second thermosetting paint, and it can be applied by spraying with a spray gun. This second thermosetting paint may include a second thermosetting resin, a second curing agent, a second pigment, a second filler, a second solvent, and a second additive, etc. The components in the second thermosetting paint may be the same as or different from those in the first thermosetting paint. Since no coating layer as shown in Figure 8 is provided in Figure 10, there is no subsequent reflection problem. Therefore, the second primer layer 11 can be made thinner. The thickness d11 of the second primer layer 11 along the OY direction can range from 5μm to 10μm. For example, d11 can be 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm, etc. The second primer layer 11 can fill the defects in the plastic substrate 3 and make it easier for the paint layer 13 to adhere to its surface.

[0172] Unlike the paint layer 13 in Figure 9, the paint layer 13 in Figure 10 may be made of a third thermosetting paint. This third thermosetting paint may include a third thermosetting resin, a third curing agent, a third pigment, a third filler, a third solvent, and a third additive. The components in the third thermosetting paint may be the same as or different from the components in the first thermosetting paint.

[0173] Please refer to Figure 11 again. The paint layer includes a first primer layer 10, a second primer layer 11, a color paint layer 13 and a topcoat layer 14, which are sequentially stacked on the plastic substrate 3.

[0174] Unlike the first primer layer 10 in Figure 9, the thickness d10 of the first primer layer 10 in Figure 10 along the OY direction can range from 10μm to 15μm. For example, d10 can be 10μm, 11μm, 12μm, 13μm, 14μm or 15μm, etc.

[0175] S13. As shown in Figure 8d, the wire drawing wheel 5 is rotatably connected to the fixed rod 6 and can rotate around the fixed rod 6. The first structural component 4 is sleeved on the jig rod 7 and revolves around the wire drawing wheel 5, thereby rubbing the paint layer on the surface of the first structural component 4 to perform wire drawing.

[0176] It should be noted that the wire drawing wheel 5 is used to draw the cured topcoat layer.

[0177] Alternatively, the first structural component 4 can be kept stationary, allowing only the drawing wheel 5 to rotate. The drawing wheel 5 rotates around the first structural component 4 in the direction of the arrow in diagram e of Figure 8, thereby achieving wire drawing. Of course, the drawing wheel 5 can also rotate around the first structural component 4 in a direction other than the arrow in diagram e of Figure 8, depending on the actual application.

[0178] In applications, the wire drawing wheel 5 may include a wing wheel, a metal wheel, etc.

[0179] The wing wheel can be made of composite materials such as resin, nylon and aluminum powder. The wing wheel is not too hard, so it can break the outer surface of the topcoat layer to form a brushed effect, and the depth of the brushing can be well controlled so as not to go too deep, thus reducing or avoiding tearing of the topcoat layer. Therefore, the brushing wheel 5 is preferably a wing wheel.

[0180] The Vickers hardness range of the aforementioned wing wheel can be 60HV to 70HV. For example, the Vickers hardness of the wing wheel can be 60HV, 62HV, 64HV, 66HV, 68HV, or 70HV, etc. Therefore, the wing wheel can continuously rub against the outer surface of the topcoat layer of the first structural component 4, and during this process, only slight damage may occur to the topcoat layer, ensuring the stability of the texture and the topcoat layer.

[0181] In addition, during the wire drawing process, due to the high frictional temperature between the wing wheel and the topcoat layer, it is necessary to simultaneously spray water to cool the contact surface between the wing wheel and the topcoat layer in order to reduce the temperature between the wing wheel and the topcoat layer.

[0182] It should be noted that in practical applications, there is a risk that the wing wheel may tear the paint layer, but the probability of this is very small.

[0183] S14. As shown in Figure 8e, plastic structural component 8 is formed.

[0184] Among them, the topcoat layer of the plastic structural component 8 has multiple spaced filaments 9, the depth of the filaments 9 is less than or equal to the thickness of the topcoat layer, and all the filaments 9 form a complete circle distributed on the outer surface of the topcoat layer.

[0185] This application provides a method for preparing a plastic structural component. First, a plastic substrate is formed by molding and injection molding to create a plastic matrix with interlocking lines. Then, the interlocking lines on the outer surface of the plastic matrix are removed. Next, at least a topcoat layer is formed on the outer surface of the plastic matrix. Then, the topcoat layer is subjected to a brushing process to form multiple continuous circular lines that are macroscopically visible. These lines have a metallic texture, achieving the appearance effect of brushed metal substrates while avoiding surface fiber issues. At the same time, the topcoat layer can also cover dirt, shrinkage, and particles on the plastic matrix, significantly improving product yield, increasing product gloss and reliability, and meeting the requirements for high aesthetics and high quality.

[0186] Optionally, as shown in Figure 12, in the step S13 above, where the first structural member 4 is fitted onto the jig rod 7 and revolves around the drawing wheel 5, four first structural members 4 can be fitted onto the jig rod 7 and all four first structural members 4 can revolve around the drawing wheel 5. This allows the drawing wheel 5 to simultaneously rub and draw the paint layer of the four first structural members 4.

[0187] In application, the materials, sizes, rotation directions, and rotation speeds of the four first structural components 4 mentioned above may be the same or different, depending on the actual application.

[0188] It should be noted that the number of the first structural component 4 can be multiple, but is not limited to four.

[0189] In addition, the thickness of the drawing wheel can be increased to achieve simultaneous drawing of more first structural components 4.

[0190] The metal substrates used in related technologies have high hardness, so metal wheels with equally high hardness are required to draw the metal substrates. Given the characteristics of the metal wheels and the metal substrates, the metal wheels can usually only process one metal substrate at a time, which results in low efficiency and high cost.

[0191] Based on the above, the method for preparing plastic structural parts provided in this application embodiment can simultaneously perform wire drawing on multiple first structural parts by using a wire drawing wheel. Moreover, the thicker the wire drawing wheel, the more first structural parts can be stacked for wire drawing, which has the advantages of short processing time, low cost and high production capacity.

[0192] Optionally, as an achievable method, after step S13 and before step S14, the preparation method of the plastic structural part may further include:

[0193] S15. Apply a brightening liquid to the first structural component after wire drawing to enhance its brightness.

[0194] In applications, the above-mentioned brightening treatment may include wiping the first structural component after wire drawing with at least one of nano liquid, Pledge, or intermediate polishing liquid.

[0195] Nano-liquid is a liquid made using nanotechnology. Its main components include nanoscale oxide materials and other polymer materials. Through covalent bonding of molecular bonds, it forms a nanoscale protective layer with special protective functions and a stable structure on the surface of an object. This protective layer can not only enhance the surface hardness, wear resistance and chemical corrosion resistance of the object, but also significantly improve the gloss and transparency of the object, thereby achieving a brightening effect.

[0196] Pledge is a water-based skin care and polishing agent. Its main ingredients include petroleum alkanes, silicone oil, and distilled water. It can effectively remove nano-level blemishes such as oil stains, wine stains, and coffee stains, and has a brightening effect.

[0197] Intermediate polishing solution is a water-soluble polishing agent that does not contain any sulfur, phosphorus, or chlorine additives. It has good degreasing, cleaning, and brightening properties, and can make products show a metallic texture.

[0198] It should be noted that the above-mentioned brightening liquid will not chemically react with the first structural component after wire drawing, but will increase the brightness through physical action.

[0199] Typically, after the first structural component is wire drawn, some imperfections such as haziness and blackening will inevitably appear on the outer surface of the topcoat layer. Based on this, the method for preparing plastic structural components provided in this application can effectively remove dirt and other contaminants from the outer surface of the topcoat layer by wiping it with a brightening liquid, making the product's appearance brighter and smoother, greatly improving the aesthetic appearance of the plastic structural component, and giving it a better imitation metallic texture and high gloss effect.

[0200] Please refer to Figures 13 to 15 below for a detailed description of the wire drawing process used to produce the outer surface texture of the plastic structural parts in the embodiments of this application.

[0201] As shown in Figure 13, the topcoat layer 14 includes six threads 9. The six threads 9 are distributed in a circle around the topcoat layer 14, and there is a gap between two adjacent threads 9. The six threads 9 extend in the same direction.

[0202] It should be noted that the number of threads 9 is not limited to six, and the extension direction of threads 9 can be partially the same or completely different, depending on the actual application.

[0203] Based on the above, Figure 14 shows a schematic diagram of the distribution of the fine lines 9 on the first surface 141 of the topcoat layer in Figure 13. As shown in Figure 14, the spacing w1 and w2 between two adjacent fine lines 9 can range from 4 μm to 7 μm. For example, w1 and w2 can be 4 μm, 5 μm, 6 μm, or 7 μm, etc. Further, the number of fine lines 9 within 20 μm can range from 3 to 6.

[0204] It should be noted that w1 and w2 can be the same or different, depending on the actual application.

[0205] Referring again to Figure 14, the maximum surface width k of each filament 9 along the OX direction can range from 1μm to 3μm. For example, k can be 1μm, 2μm, or 3μm, etc. It should be noted that the OX direction is perpendicular to the OY direction.

[0206] Based on the above, Figure 15 shows a cross-sectional view of the topcoat layer 14 in Figure 13. As shown in Figure 15, the depth s of the texture 9 can range from 10 μm to 55 μm, typically from 10 μm to 30 μm. Referring to Figures 13 and 15, the texture extends from the outer surface of the topcoat layer to the inner surface, forming a long, narrow opening structure with a certain depth.

[0207] Specifically, when the thickness of the topcoat layer along the OY direction is 15μm and the depth s of the texture is 10μm, the texture penetrates part of the topcoat layer; when the thickness of the topcoat layer along the OY direction is 15μm and the depth s of the texture is 15μm, the texture penetrates the entire topcoat layer, without any specific limitation here.

[0208] It should be noted that the greater the stroke of the wing wheel into the topcoat layer, the higher the rotation speed, and the more revolutions, the deeper the texture will be.

[0209] The specifications of the grain, such as spacing, density, depth and extension direction, can be adjusted according to the type of paint and thickness of the topcoat layer. For example, multiple grains can be distributed vertically, horizontally, or randomly. Random grains can be grains with at least some differences in spacing, density, depth and extension direction, but as long as they appear as a continuous circle of grains from a macroscopic perspective.

[0210] Furthermore, while some of the aforementioned silk-like patterns may appear discontinuous under a microscopic view, they are not visible to the naked eye under a macroscopic view.

[0211] This application provides a plastic structural component in which the outer surface of the topcoat layer has a continuous, circular texture that appears macroscopically, and the texture of the texture is diverse, thus enriching the aesthetic appearance of the plastic structural component.

[0212] Alternatively, as an implementation method, as shown in Figure 16, an anti-fingerprint layer 15 is also formed on the side of the topcoat layer 14 of the plastic structural component away from the plastic substrate 3.

[0213] The plastic structural component provided in this application embodiment can enhance the wear resistance of the plastic structural component through the anti-fingerprint layer. In particular, when the user rubs along the palm direction, the wear resistance is stronger, which effectively delays the failure rate and time of the plastic structural component without affecting the display and effectively improves the performance.

[0214] The above only introduces the content related to the inventive point. Other content can be obtained by referring to relevant technologies, and will not be explained in detail here.

[0215] It should be understood that the above description is merely to help those skilled in the art better understand the embodiments of this application, and is not intended to limit the scope of the embodiments of this application. Those skilled in the art can obviously make various equivalent modifications or variations based on the examples given above, or combinations of any two or more of the above embodiments. Such modifications, variations, or combinations also fall within the scope of the embodiments of this application.

[0216] It should also be understood that the above description of the embodiments of this application focuses on highlighting the differences between the various embodiments. Any similarities or differences not mentioned can be referred to each other. For the sake of brevity, they will not be repeated here.

[0217] It should also be understood that the methods, situations, categories, and classifications of embodiments in this application are for the convenience of description only and should not constitute a special limitation. Various methods, categories, situations, and features in embodiments can be combined without contradiction.

[0218] It should also be understood that, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0219] Finally, it should be noted that the above descriptions are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A plastic structural member, characterized by, include: Plastic matrix; A paint layer is disposed on the outer surface of the plastic substrate. The paint layer includes at least a topcoat layer, which forms the appearance surface of the plastic structural component. The topcoat layer has multiple spaced-apart lines, the depth of which is less than or equal to the thickness of the topcoat layer, and all lines are distributed in a complete circle on the outer surface of the topcoat layer.

2. The plastic structural member of claim 1, wherein The materials of the topcoat layer include polyurethane acrylic resin, ethyl acetate and photoinitiator; And / or, The pencil hardness range of the topcoat layer includes HB to 4H; And / or, The thickness of the topcoat layer ranges from 15μm to 55μm.

3. The plastic structural member according to claim 1 or 2, wherein The spacing between two adjacent filaments ranges from 4μm to 7μm; And / or, The maximum surface width of each filament ranges from 1μm to 3μm; And / or, The depth of each filament ranges from 10μm to 55μm.

4. The plastic structural member of claim 3, wherein The depth of the textured surface is less than the thickness of the topcoat layer, and the depth of the textured surface ranges from 10μm to 50μm.

5. The plastic structural member according to any one of claims 1 to 4, wherein The paint layer further includes a first primer layer, a second primer layer, a coating layer, and a color paint layer. The first primer layer is disposed between the plastic substrate and the second primer layer. The second primer layer is disposed between the first primer layer and the coating layer. The coating layer is disposed between the second primer layer and the color paint layer. The color paint layer is disposed between the coating layer and the topcoat layer. The material of the first primer layer includes a first thermosetting paint, which includes a first thermosetting resin, a first curing agent, a first pigment, a first filler, a first solvent, and a first additive. The thickness of the first primer layer ranges from 10 μm to 30 μm. The material of the second primer layer includes a first ultraviolet-curable paint, which includes a first resin, a first monomer, a first photoinitiator, and a first photosensitive additive. The thickness of the second primer layer ranges from 20 μm to 30 μm. The material of the coating layer includes indium, and the thickness of the coating layer is less than or equal to 1 μm; The material of the paint layer includes a second ultraviolet-curable paint, which includes a second resin, a second monomer, a second photoinitiator, and a second photosensitive additive. The thickness of the paint layer ranges from 5 μm to 10 μm.

6. The plastic structural member according to any one of claims 1 to 4, wherein The paint layer further includes a second primer layer and a color paint layer, wherein the second primer layer is disposed between the plastic substrate and the color paint layer, and the color paint layer is disposed between the second primer layer and the topcoat layer; The material of the second primer layer includes a second thermosetting paint, which may include a second thermosetting resin, a second curing agent, a second pigment, a second filler, a second solvent, and a second additive. The thickness of the second primer layer ranges from 5 μm to 10 μm. The material of the paint layer includes a third thermosetting paint, which may include a third thermosetting resin, a third curing agent, a third pigment, a third filler, a third solvent, and a third additive. The thickness of the paint layer ranges from 5 μm to 10 μm.

7. The plastic structural member according to any one of claims 1 to 4, wherein The paint layer further includes a first primer layer, a second primer layer, and a color paint layer. The first primer layer is disposed between the plastic substrate and the second primer layer. The second primer layer is disposed between the first primer layer and the color paint layer. The color paint layer is disposed between the second primer layer and the topcoat layer. The material of the first primer layer includes a first thermosetting paint, which includes a first thermosetting resin, a first curing agent, a first pigment, a first filler, a first solvent, and a first additive. The thickness of the first primer layer ranges from 10 μm to 15 μm. The material of the second primer layer includes a first ultraviolet-curable paint, which includes a first resin, a first monomer, a first photoinitiator, and a first photosensitive additive. The thickness of the second primer layer ranges from 20 μm to 30 μm. The material of the paint layer includes a second ultraviolet-curable paint, which includes a second resin, a second monomer, a second photoinitiator, and a second photosensitive additive. The thickness of the paint layer ranges from 5 μm to 10 μm.

8. The plastic structural member according to any one of claims 1 to 7, wherein, The plastic matrix material includes at least one of polycarbonate, polyamide, polyethyleneimine, polycarbonate and glass fiber, polyamide and glass fiber, and polyethyleneimine and glass fiber; And / or, The Vickers hardness range of the plastic matrix includes 60HV to 90HV.

9. The plastic structural member according to any one of claims 1 to 8, wherein, The plastic substrate is an injection-molded part and the outer surface of the plastic substrate has no embedded lines.

10. The plastic structural member according to any one of claims 1 to 9, wherein, The plastic structural component includes at least one of a laptop shell, a mobile phone mid-frame, a tablet computer mid-frame, and a battery cover.

11. An electronic device, comprising: Including plastic structural components as described in any one of claims 1 to 10.

12. A method of making a plastic structural member, comprising: include: A plastic matrix is ​​formed; wherein the outer surface of the plastic matrix has no embedded lines; A paint layer is formed on the outer surface of the plastic substrate corresponding to the area to be drawn; wherein the paint layer includes at least a topcoat layer; The topcoat layer is subjected to a wire drawing process to form the plastic structural component; wherein, the topcoat layer has multiple spaced wires, the depth of the wires is less than or equal to the thickness of the topcoat layer, all the wires are distributed in a circle on the outer surface of the topcoat layer, and the topcoat layer forms the appearance surface of the plastic structural component.

13. The method of claim 12, wherein the step of forming the plastic structure is performed by injection molding. The formation of the plastic matrix includes: A first structural component is formed by molding and injection molding a plastic raw material using a mold; wherein the outer surface of the first structural component has a clamping line. Remove the clamping wire to form the plastic matrix.

14. The method of claim 13, wherein the step of forming the plastic structure is performed by injection molding. The method for removing the clamping line includes polishing or computer-controlled digital processing.

15. The method of claim 12 to 14, wherein The step of drawing the topcoat layer to form the plastic structural component includes: The topcoat layer is brushed using a brushing wheel, and the outer surface of the topcoat layer is wiped with a gloss enhancer to form the plastic structural component.

16. The method of claim 15, wherein the step of forming the plastic structure is performed by injection molding. The wire drawing wheel includes a wing wheel; The materials of the flying wing wheel include resin, nylon, and aluminum powder; And / or, The Vickers hardness range of the wing rotor is 60HV to 70HV.

Images