High-precision texture production method based on femtosecond laser processing

Abstract

The invention relates to the technical field of high-precision texture processing, in particular to a high-precision texture production method based on femtosecond laser processing. The method comprises the following steps: firstly, based on three-dimensional data of a target texture, machining a texture with a microscopic irregular convex structure on the surface of a mold cavity by adopting femtosecond laser; secondly, designing an integrated induction heating system in the mold, and carrying out iterative optimization on the layout of the integrated induction heating system by utilizing thermal simulation software, so as to ensure that the temperature of a cavity is highly uniform during injection molding; thirdly, the optimized mold is used, under the dynamic temperature control assistance of an induction heating system, a thermoplastic polyurethane elastomer is adopted for injection molding, and the texture is perfectly copied; and finally, performing quantitative verification on the surface optical performance and the touch performance of the product, and forming feedback correction on the mold or the process according to a verification result. The invention provides a set of complete closed-loop production process, and high fidelity, high consistency and stable mass production of high-precision textures are realized.

Description

Technical Field

[0001] This invention relates to the field of femtosecond laser processing technology, and specifically to a method for producing high-precision textures based on femtosecond laser processing. Background Technology

[0002] With the increasing pursuit of aesthetics and user experience in consumer electronics, automotive interiors, and high-end home appliances, the visual texture and tactile experience of product surfaces have become important differentiating factors. Among these, a "suede texture" or high-precision velvet effect, characterized by a unique velvety feel and extremely low gloss, is highly favored by the market for its ability to imbue products with a luxurious, soft, and skin-friendly quality. This type of surface is not a simple planar coating, but rather a functional texture with a specific microscopic topological structure constructed on the surface of plastic products, with a texture depth typically ranging from submicron to micrometer. Achieving this effect faces two core technical challenges: first, how to efficiently, accurately, and repeatedly process this microscopically irregular, non-periodic, complex three-dimensional morphology on the mold; and second, how to ensure that the molten plastic completely fills and perfectly replicates these extremely fine, aspect ratio-high microstructures on the mold during injection molding, thereby achieving a high-fidelity transfer from mold to finished product.

[0003] In mold texture processing, traditional photochemical etching technology, limited by its process principles, struggles to precisely control three-dimensional morphology, especially when processing submicron-level structures with continuous, smooth transitions and irregular distributions. This results in poor consistency and limited design freedom. Conventional laser processing (such as nanosecond and picosecond lasers) suffers from significant heat-affected zones, easily generating slag and recast layers at the processing edges, leading to blurred texture contours and failing to meet the stringent requirements of clear boundaries and specific morphologies for high-precision textures. In injection molding replication, the replication rate of high-precision textures largely depends on the uniformity and controllability of the mold temperature field. Traditional water-based or oil-based mold temperature controllers have low heat transfer efficiency and slow response, making it difficult to achieve rapid temperature increases and precise control of the mold surface during the injection molding cycle. When the mold temperature is insufficient or uneven, the molten plastic cools and solidifies rapidly upon contact with the cavity surface, failing to flow into the fine texture grooves, resulting in incomplete replication, uneven surface gloss, a stiff feel, and low product yield. Although Alignment Induction (AIT) technology has been introduced as a localized, rapid heating method, its application often remains at the stage of empirical trial and error. It lacks systematic simulation optimization and integrated design of the heating system layout and temperature field distribution in the early stages of mold design, resulting in uneven heating efficiency, high energy consumption, and poor stability, making it difficult to achieve large-scale, stable mass production of high-precision textures. Therefore, the industry urgently needs an integrated manufacturing method that can systematically solve the challenges of the entire process, from creating precise textures to establishing a controllable process environment and achieving high-quality, stable replication.

[0004] Therefore, existing technologies still need further development. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a method for producing high-precision textures based on femtosecond laser processing, so as to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned technical objectives, according to a first aspect of the present invention, the present invention provides a method for producing high-precision textures based on femtosecond laser processing, comprising: S1. Mold texture processing stage: Based on the three-dimensional data of the target texture, a femtosecond laser is used to scan and process the surface of the mold cavity to form a textured surface with micro-irregular raised structure; S2. Mold Temperature Field Optimization Stage: An induction heating system is designed and integrated into the mold, and the layout of the induction heating system is optimized through thermal simulation analysis, so that the mold cavity can quickly reach and maintain a uniform target temperature during the injection cycle. S3. Injection Molding Replication Stage: The mold processed in steps S1 and S2 is used for injection molding. The induction heating system is used to dynamically control the temperature of the mold so that the plastic melt can completely replicate the textured surface when filling the mold. S4. Product Performance Verification Stage: Test the surface optical and tactile properties of the injection-molded product.

[0007] Specifically, in step S1, by adjusting the pulse energy, scanning spacing and scanning strategy of the femtosecond laser, a texture with submicron depth and a multi-peak continuous distribution of the micro-irregular protrusion structure is processed on the surface of the mold.

[0008] Specifically, step S2 includes: S21. Based on the 3D data of the mold, design the layout of the induction heating coil and cooling water circuit; S22. Perform temperature uniformity simulation analysis on the design using thermodynamic simulation software; S23. If the analysis results do not meet the uniformity requirements, adjust the design of the induction heating coil and cooling water circuit and re-analyze until the requirements are met.

[0009] Specifically, after the temperature uniformity requirement is met in step S23, the process also includes the integrated design and review of the complete mold drawing file. Only after the review is passed can the mold be manufactured and assembled.

[0010] Specifically, in step S3, the plastic material used for injection molding is thermoplastic polyurethane elastomer.

[0011] Specifically, in step S3, the surface temperature of the mold cavity is raised to a range higher than that of molds used for conventional injection molding of the plastic material by the induction heating system.

[0012] Specifically, in step S4, the detection of surface optical properties includes measuring the surface gloss of the product, and the detection of tactile properties includes evaluating the surface friction coefficient or subjective tactile feedback.

[0013] Specifically, if the verification result of step S4 does not meet expectations, the process returns to check the copy status of the mold texture and corrects the mold or reprocesses the texture as needed.

[0014] Specifically, the texture processed by the femtosecond laser has a micro-irregular raised structure that gives the replicated plastic product a low-gloss appearance and a velvety feel.

[0015] Specifically, the method includes the following steps in sequence: The complete cycle includes femtosecond laser processing of mold texture, simulation optimization and integration of induction heating system, manufacturing assembly mold, injection molding with thermoplastic polyurethane elastomer with induction heating assistance, and optical and tactile verification of product, the cycle including mold correction feedback path based on verification results.

[0016] Beneficial effects: The femtosecond laser processing method for producing high-precision textures provided by this invention deeply integrates ultrafast laser micro-nano processing, simulation-driven intelligent mold design, dynamic precision injection molding process and quantitative quality verification, forming a complete, closed-loop and efficient technical system, which produces significant beneficial effects at multiple levels and in a synergistic manner.

[0017] Firstly, at the texture creation level, this invention employs a femtosecond laser as the processing tool, leveraging its "cold processing" advantage due to its ultrashort pulse characteristics to directly fabricate complex three-dimensional microstructures with clear boundaries and no thermal damage on hard materials such as mold steel. By precisely controlling the laser parameters and employing a specific random scanning strategy, it is possible to programmatically manufacture submicron-level textures with continuous, multi-peak, and irregularly distributed patterns. This structure is the physical basis for generating uniform diffuse reflection light (low gloss) and a specific triboelectric vibration spectrum (velvety feel). This method overcomes the limitations of traditional etching and long-pulse lasers in terms of precision, morphological freedom, and consistency, providing a precise physical template for realizing high-performance functional surfaces.

[0018] Secondly, at the process assurance level, this invention creatively elevates the design of the induction heating (AIT) system from "experience-based adaptation" to "simulation-driven." By performing electromagnetic-thermal coupling simulation during the mold design stage and iteratively optimizing the layout of heating coils and cooling water channels, it is possible to ensure highly uniform and rapid response of the mold cavity surface temperature during injection molding in the digital world beforehand. This forward-looking design based on a physical model fundamentally avoids defects such as incomplete texture replication and uneven product appearance caused by uneven temperature, significantly improving the success rate of the first trial molding and reducing the cost and time delays caused by mold repair and modification. Combined with the optimal selection of thermoplastic polyurethane elastomer (TPU) materials and the dynamic high mold temperature injection molding process assisted by induction heating, unprecedented ideal conditions are created for high-fidelity replication, achieving a leap in texture replication rate.

[0019] Finally, regarding system reliability and quality controllability, this invention constructs a complete quality closed loop from optical and tactile quantitative detection to root cause fault diagnosis. By establishing objective evaluation standards such as gloss and coefficient of friction, subjective sensory requirements are transformed into measurable and controllable process indicators. More importantly, when product performance fails to meet standards, the method provides a clear reverse diagnostic path, quickly pinpointing whether the problem stems from mold texture loss, abnormal temperature field, or process parameter deviation, and guiding corresponding corrective measures (such as laser mold repair, design optimization, or process adjustment). This production cycle with self-feedback and corrective capabilities ensures the stability, consistency, and yield of this high-tech process in large-scale production, making it possible to transform laboratory-grade refined surface effects into commercially available products that can be mass-produced, thus giving the end product a strong market competitiveness. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the production process of high-precision textures processed by femtosecond laser provided in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the high-precision texture provided in a specific embodiment of the present invention; Figure 3 This is a schematic flowchart of a method for producing high-precision textures using femtosecond laser processing, provided in a specific embodiment of the present invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0022] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0023] First, it should be noted that this invention provides a method for systematically producing high-precision textured plastic products with a velvety feel and extremely low gloss. The core of this method lies in the deep integration of ultra-precision femtosecond laser processing technology with a closed-loop optimized induction heating (AIT) injection molding process. The method begins by obtaining a three-dimensional digital model of the mold cavity, i.e., as... Figure 1 The “3D data of the mold core” shown at the top.

[0024] Please see Figures 1-3 This invention provides a method for producing high-precision textures based on femtosecond laser processing, comprising: S1. Mold texture processing stage: Based on the three-dimensional data of the target texture, a femtosecond laser is used to scan and process the surface of the mold cavity to form a textured surface with micro-irregular raised structure; It should be further explained that in step S1, the three-dimensional data of the target texture (whose shape is similar to...) Figure 2 The complex, continuous, and irregularly undulating microscopic topography shown is input into a femtosecond laser processing device. This device, using its high-energy ultrafast pulsed laser beam, performs layer-by-layer scanning ablation on the mold steel surface based on this three-dimensional data, directly creating a master mold texture with a sub-micron depth and a biomimetic irregular protruding structure. This step corresponds to... Figure 1 In the "texture engraving" stage, but unlike traditional etching, this invention uses femtosecond lasers to achieve nanometer-level precision and arbitrary three-dimensional morphology processing.

[0025] S2. Mold Temperature Field Optimization Stage: An induction heating system is designed and integrated into the mold, and the layout of the induction heating system is optimized through thermal simulation analysis, so that the mold cavity can quickly reach and maintain a uniform target temperature during the injection cycle. It should be further explained that step S2 is a simulation-driven pre-optimization process. Its purpose is to create the optimal mold temperature environment to ensure that the precision texture processed in step S1 can be perfectly replicated. First, based on the 3D data of the mold, the spatial arrangement of the induction heating coils and cooling water channels is designed. Figure 1 The key is that this design is not based on experience, but immediately enters a simulation verification loop to "analyze temperature uniformity using COMSOL". Specifically, the complete assembly model, including the coil, water circuit, and mold, needs to be imported into finite element analysis software (such as COMSOL Multiphysics). Material thermophysical parameters, the electromagnetic-thermal coupling physical field of induction heating, and the convective heat transfer boundary conditions of the cooling water circuit are set, and transient thermal analysis is performed. The simulation simulates the temperature change of the mold cavity surface during a complete injection molding cycle. If the simulation results show that the maximum temperature difference ΔT_max of the target area on the cavity surface is greater than a preset threshold (e.g., 10°C) at the set heating time point, it is judged as "temperature uniformity NG". In this case, it is necessary to go back and modify the coil shape, number of turns, arrangement, or water circuit layout, and then re-simulate. Figure 1 The left loop is shown. This iterative process is repeated until the simulation results show that ΔT_max is less than or equal to the threshold, at which point the temperature field design is considered "OK".

[0026] S3. Injection Molding Replication Stage: The mold processed in steps S1 and S2 is used for injection molding. The induction heating system is used to dynamically control the temperature of the mold so that the plastic melt can completely replicate the textured surface when filling the mold. It should be further noted that step S3 is the physical implementation stage. After the simulation optimization is successful, the process proceeds to... Figure 1 The implementation process shown on the right is as follows: Based on the optimized design, the mold factory completes the "mold design of a complete mold" including the AIT system, followed by "pre-integration drawing review". The review verifies the manufacturability, assemblability, and safety of the design. If the review fails ("drawing NG"), the mold factory will revise the drawing and re-review it; if it passes ("drawing OK"), "integration", "material ordering", "processing and ordering mold accessories", and "mold assembly" will proceed. The assembled mold is installed on the injection molding machine. After "preparing for mass production", the first trial molding (corresponding to "T0") is conducted. At this stage, the integrated induction heating system rapidly heats the mold cavity surface to a temperature far exceeding that of conventional water temperature machines before injection (e.g., 100-140°C for specific materials), greatly reducing the melt viscosity and allowing it to completely flow into and conform to every nanometer-scale groove on the mold. After injection and holding pressure, the process is quickly switched to cooling mode to allow the product to cool and solidify before demolding.

[0027] S4. Product performance verification stage: Test the surface optical properties and tactile properties of the injection-molded product; It should be further explained that step S4 is the quality closed-loop control stage. For the product obtained from the "T0" trial molding, a routine "dimensional OK" inspection is first performed. More importantly, specialized optical and tactile performance testing is required. If both dimensions and functional effects meet the standards, mass production preparation can begin. If dimensions or functional effects do not meet the standards ("dimensional NG"), the feedback process is initiated, i.e., the subsequent analysis indicated by "T1...", and may require "mold modification or repair," such as... Figure 1 As shown at the bottom. This invention specifically emphasizes that the "mold modification" here not only addresses size issues, but also covers optical and tactile issues caused by poor texture replication, which may require going back to step S1 (texture repair) or step S2 (temperature field adjustment).

[0028] Understandably, the beneficial effect of this invention lies in constructing a complete technical closed loop from texture creation, process optimization, precise replication, and quantitative verification. Femtosecond lasers achieve complex and high-precision texture processing that is unattainable by traditional methods; simulation-based AIT design optimization fundamentally ensures the uniform and controllable mold temperature field required for high replication rates; and the final quantitative verification of the effect transforms subjective appearance and tactile requirements into objective process control standards, ensuring the superior quality and consistency of the product.

[0029] Specifically, in step S1, by adjusting the pulse energy, scanning spacing and scanning strategy of the femtosecond laser, a texture with submicron depth and a multi-peak continuous distribution of the micro-irregular protrusion structure is processed on the surface of the mold.

[0030] It should be further explained that the femtosecond laser processing in step S1 is the physical basis for this method to achieve specific surface functions. The texture described as having a "multi-peak continuous distribution" has the following morphological characteristics in three-dimensional space: Figure 2 As shown, the surface consists of countless microscopic protrusions ("peaks") randomly distributed laterally (XY plane) and varying in height longitudinally (Z-axis direction). These peaks are connected by gentle slopes rather than steep cliffs, forming an overall undulating topological structure resembling velvet or fine sandpaper. This specific structure is the direct cause of light scattering (low gloss) and a soft tactile feel.

[0031] Furthermore, to achieve this morphology, precise and coordinated control of the laser processing parameters is required. The "pulse energy" refers to the energy carried by a single femtosecond laser pulse, preferably ranging from 5 microjoules (μJ) to 20 microjoules (μJ). This range is chosen because: below 5 μJ, the material removal per pulse is too small, resulting in extremely low processing efficiency and difficulty in forming effective structural depth on hard materials such as mold steel; above 20 μJ, excessively strong plasma shielding effects and thermal diffusion may occur, exacerbating the melting and recasting phenomenon at the edges of the processed area, damaging the clarity and steepness of the sidewalls, and making it impossible to form the required fine contour. A more preferred pulse energy is 8-15 μJ, within which an optimal balance between high efficiency and high quality can be achieved.

[0032] Furthermore, the "scanning spacing" refers to the distance between the center lines of two adjacent laser scanning trajectories, with a preferred range of 3 micrometers (μm) to 15 micrometers (μm). The reason for choosing this range is that when the spacing is greater than 15 μm, the processed structure will be too sparse, and the "valley" regions between peaks will be too large, failing to create a continuous and uniform visual and tactile experience, similar to... Figure 2 The dense, continuous morphology found in traditional materials cannot be achieved. While a spacing of less than 3 μm results in a denser structure, it also significantly increases processing time, and excessively small spacing can lead to heat accumulation and the creation of unnecessary heat-affected zones. A more preferable scanning spacing is 5-10 μm, which effectively simulates the microscopic gaps in natural velvet materials.

[0033] Furthermore, the "scanning strategy" is an algorithm that controls the movement path of the laser focus. To accurately generate... Figure 2 The irregular, non-periodic "irregular" protrusion structure shown avoids the generation of regular grating diffraction fringes. This invention employs a "random perturbation-fill scanning" strategy. The specific algorithm steps are as follows: 1. Basic path generation: Based on the boundary of the area to be processed, generate a set of parallel straight lines or concentric circles with a spacing of the set scan interval that cover the entire area as basic scan lines; 2. Random Perturbation Application: A random offset is introduced into the coordinates of a series of equally spaced points (spaced by d, e.g., 5-20 μm) on each base scan line. This offset includes a lateral offset (Δx, Δy) and a longitudinal (focus plane) offset Δz. Its mathematical expression can be described as: in, These are the actual processing point coordinates after the disturbance. These are the coordinates of the original planned path points. It is the initial focusing plane position. It is a random perturbation vector; 3. Disturbance Range Constraint: The magnitude and direction of the random disturbance vector are randomly selected within a certain range. Specifically, the lateral disturbance amplitude... Preferably, the amplitude of the longitudinal perturbation varies randomly between 10% and 40% of the scanning interval. The value of δz is preferably randomly varied between 20% and 50% of the target texture depth. For example, if the target texture depth is 500 nm, then δz can be randomly selected between ±100 nm and ±250 nm. The reason for constraining the perturbation range is to break the periodicity while ensuring the continuity of the processing path and the overall uniformity of the structure, and to avoid generating excessively large isolated bumps or deep pits. 4. Path Smoothing and Execution: Spline curve fitting is performed on the discrete point set after random perturbation to generate a smooth final laser scanning path that fluctuates randomly in three-dimensional space. The laser focus will move along this path and emit pulses, thereby ablating pits with random height and position distribution on the material surface. The collection of these pits constitutes the textured surface with "multi-peak continuous distribution".

[0034] Furthermore, through precise control of the above parameters, submicron-level textures with depths ranging from 100 nanometers (nm) to 800 nanometers (nm) can be stably processed on the mold surface. Depth is an important parameter for evaluating texture, and the reason for choosing its preferred range is as follows: when the depth is less than 100 nm, the structure's modulation effect on light and tactile perception are insufficient, and the effect is not obvious; when the depth is greater than 800 nm, although the optical and tactile effects may be stronger, it will significantly increase the difficulty of melt filling and product demolding during injection molding, which can easily lead to a decrease in replication rate and demolding damage.

[0035] Understandably, the beneficial effect of the above method is that by actively controlling the interaction between the laser and the material, a micro-morphology with a predetermined function can be programmably "written" on the surface of the mold, providing an accurate and repeatable physical template for subsequent high-fidelity replication.

[0036] Specifically, step S2 includes: S21. Designing the layout of the induction heating coil and cooling water circuit based on the 3D data of the mold; S22. Performing temperature uniformity simulation analysis on the design using thermodynamic simulation software; S23. If the analysis results do not meet the uniformity requirements, adjusting the design of the induction heating coil and cooling water circuit and re-analyzing until the requirements are met.

[0037] It should be further explained that step S2 is the key bridge connecting the design of the AIT system with its actual application effect. Its core is predictive design and optimization based on physical simulation, corresponding to... Figure 1 The process involves a cycle from "designing the induction heating wire and water circuit" to "temperature uniformity OK / NG" judgment.

[0038] Furthermore, in S21, the following specific guidelines must be followed when designing the induction heating coil: The coil is typically made of copper tubing, and its cross-sectional shape can be circular or rectangular. The coil should be placed as close as possible to the contour of the back (non-forming surface) of the mold cavity, especially for textured areas. The distance from the coil to the cavity surface is preferably 3mm to 10mm. Excessive distance will reduce heating efficiency, while insufficient distance may lead to localized overheating and installation difficulties. The number of turns of the coil is determined based on the required heating power and mold size, typically a single turn or multiple turns. The design of the cooling water channels must be coordinated with the coil layout, usually employing parallel straight-through water channels or series spiral water channels, arranged around or directly below the heating area. The water channel diameter is preferably 6mm to 10mm, and the center distance is preferably 3 to 5 times the water channel diameter to ensure uniform cooling.

[0039] Furthermore, in S22, the thermodynamic simulation analysis employs a multiphysics coupling method, with the specific steps and model as follows: 1. Geometric Model and Mesh Generation: Import the complete 3D assembly model, including the mold (mold core, mold base), induction heating coil, and cooling water channels, into the simulation software. Perform physics-controlled mesh generation on the model, refining the mesh on the cavity surface, near the coil, and on the walls of the cooling channels. Tetrahedral or hexahedral elements are preferred for the mesh, and the smallest element size should not exceed 1 / 5 of the smallest feature size in the model (such as the diameter of the cooling channel) to ensure computational accuracy.

[0040] 2. Material Property Definition: Define the temperature-dependent material properties of mold steel (e.g., 1.2344ESR), mainly including: density ρ (kg / m³), thermal conductivity k (W / (m·K)), and specific heat capacity Cp (J / (kg·K)). Define the corresponding electromagnetic and thermophysical properties for coils (copper) and water (cooling medium).

[0041] 3. Setting up physics fields and boundary conditions: ① Electromagnetic Field: A time-harmonic current load is applied to the coil, with the current frequency f preferably between 10kHz and 50kHz. The rationale for this frequency selection is that too low a frequency results in an excessively large skin depth and low heating efficiency; too high a frequency results in an insufficient skin depth, potentially leading to surface overheating while the interior remains sluggish. The effective current value I is set according to the heating power requirement and can be determined using the formula... To make an estimate, among which For the desired heating power, This is the equivalent resistance of the coil system; ② Heat transfer field: Joule heat calculated from the electromagnetic field It is input as a heat source to the solid heat transfer module. Joule heat power density. The calculation formula is: in, It is the volumetric joule heat power density, with units of W / m³. It is a current density vector, with units of A / m². It is the electric field intensity vector, with units of V / m. This indicates taking the real part of a complex number. (Symbol) This indicates complex conjugate. This formula describes the heat power generated inside a conductor due to its resistance in an alternating electromagnetic field; ③ Fluid and Convection: Forced convection heat transfer boundary conditions are applied to the walls of the cooling water channels. The convective heat transfer coefficient h (W / (m²·K)) is calculated and determined based on the flow velocity, temperature, and turbulence state of the cooling water within the channels, and is usually estimated using correlations such as Dittus-Boelter. A mixed heat dissipation boundary condition of natural convection and radiation is applied to the outer surface of the mold.

[0042] 4. Solution Setup and Result Analysis: Perform transient simulation to model a complete injection molding cycle, typically including a rapid heating phase (e.g., 10 seconds), an injection holding phase (e.g., 5 seconds), and a cooling phase (e.g., 20 seconds). After simulation, extract the temperature distribution contour map of the mold cavity surface at the start of injection. Calculate the temperature of all nodes within the target texture region (a customizable polygonal region) and identify the highest temperature. and lowest temperature And calculate the maximum temperature difference. .

[0043] Furthermore, in S23, a threshold for judging uniformity requirements is set. For the high-precision texture with a depth at the sub-micron level targeted by this invention, to ensure uniform filling of the melt, the threshold for the maximum temperature difference ΔT is preferably set to 8°C. The reason for choosing this threshold is that experience shows that when the temperature difference on the mold cavity surface exceeds 8-10°C, the melt flow front velocity in the high-temperature region is significantly faster than that in the low-temperature region, which can easily lead to fusion line position shift, local over-pressurization or under-filling, thereby affecting the uniformity of micro-texture replication and potentially forming visible gloss differences or uneven tactile texture on the product surface. If the simulation-calculated ΔT is greater than 8°C (i.e., "temperature uniformity NG"), the design needs to be adjusted back to S21, for example: increasing the cooling water channel density in the high-temperature region, adjusting the coil turn spacing in the low-temperature region to enhance heating, or modifying the coil shape to better fit the mold surface. Then, the simulation in S22 is repeated until ΔT ≤ 8°C (i.e., "temperature uniformity OK"). This iterative process may need to be repeated 3 to 5 times until the optimal design is obtained.

[0044] Understandably, the beneficial effect of the above steps is that, through digital twin technology, the temperature field is predicted and optimized before the physical mold is manufactured, avoiding expensive trial and error costs and ensuring the reliability of the AIT system's performance.

[0045] Specifically, after the temperature uniformity requirement is met in step S23, the process also includes the integrated design and review of the complete mold drawing file. Only after the review is passed can the mold be manufactured and assembled.

[0046] It should be further explained that this step is a key control point in transforming the optimized design into a manufacturable entity after the virtual simulation verification has passed. Figure 1 The process from "mold factory designing complete mold" to "drawing OK" aims to prevent design defects from flowing into the processing stage.

[0047] Furthermore, once simulation analysis confirms the temperature field design is satisfactory, the mold design engineer needs to integrate the detailed 3D model and 2D engineering drawings of the AIT system (coils, insulating components, terminals, cooling water interfaces, etc.) with all structures of the mold body, including the mold core, mold base, ejection system, and venting system, to form a complete "mold drawing file" that can be used for machining and assembly. This drawing file must clearly specify the materials, dimensions, tolerances, assembly relationships, machining processes (such as wire cutting, deep hole drilling, CNC milling), and technical requirements of all parts.

[0048] Following this, a "pre-integration drawing review" will be conducted. The review team must include mold design engineers, AIT system supplier engineers, injection molding process engineers, and quality engineers. The review should be conducted using a checklist, focusing on the following core areas: 1. Manufacturability and Assemblability: Check whether the mounting groove dimensions of the induction heating coil take into account the bending springback and thermal expansion of the coil; check whether there is spatial interference between the coil and the cooling water circuit, ejector pin, screw holes, etc., and whether the minimum safe distance is greater than 3mm; check whether the lead path of the coil is smooth and whether it will rub against moving parts; check whether the drilling depth of the cooling water circuit and the sealing structure at the intersecting holes are reliable. 2. Electrical and thermal safety: Check whether sufficient insulation is designed between the coil and the mold steel (such as using mica sheets or ceramic sleeves), and the insulation layer thickness is preferably not less than 0.5mm; check whether the coil fixing method can prevent it from vibrating under electromagnetic force; check whether the water circuit joints in high-temperature areas use high-temperature resistant sealing materials. 3. Process interface: Check whether the location of the AIT power terminal and cooling water quick interface is convenient for connecting to the injection molding machine's peripheral equipment; check whether there are thermocouple mounting holes and whether their location can accurately reflect the cavity surface temperature.

[0049] Furthermore, any issues discovered during the review process are recorded as "Drawing NG" and must be modified by the responsible party (usually the mold manufacturer). After modification, the drawing must be updated, and the modifications reviewed until all issues are resolved and the drawing is deemed "Drawing OK." Only after the drawing review is passed can subsequent work such as "material ordering," "processing," and "ordering mold components" proceed. The beneficial effect of this step is that, through cross-departmental collaborative review in the early stages, most problems that may be encountered in the manufacturing and assembly stages are resolved in advance, maximizing the success rate of the mold trial and the stability of subsequent production. It serves as a seamless bridge connecting virtual optimization and physical realization.

[0050] Specifically, in step S3, the plastic material used for injection molding is thermoplastic polyurethane elastomer.

[0051] It should be further noted that the choice of plastic material is a key material factor in achieving perfect replication of high-precision textures. This invention preferably uses thermoplastic polyurethane elastomer (TPU). TPU is a block copolymer composed of soft segments (long-chain polyols) and hard segments (diisocyanates and chain extenders). This microstructure endows it with a unique combination of properties, making it particularly suitable for the scenarios described in this invention.

[0052] Furthermore, in specific implementation, injection-grade TPU should be selected, with a Shore hardness preferably between 60A and 80A. The reason for choosing this hardness range is that materials with a hardness below 60A may be too soft, and during demolding, the high aspect ratio micro-texture structure on the product is prone to adhesion or deformation due to insufficient elastic recovery; materials with a hardness above 80A have an excessively high elastic modulus, resulting in slightly poorer melt filling compliance when replicating fine structures, and the final product will have a harder feel, affecting the "velvety" softness. In addition, grades with a melt flow rate (MFR, at 190°C / 2.16kg) in the range of 5 to 30 g / 10min should be preferred. Too low an MFR results in excessively high melt viscosity, which is not conducive to filling fine structures; too high an MFR may lead to insufficient mechanical strength of the material.

[0053] Furthermore, before use, TPU granules must be dried in a dehumidifying dryer at 80°C to 100°C for 3 to 4 hours to reduce their moisture content to below 0.03%. This prevents bubbles or silver streaks caused by moisture evaporation during injection molding, defects that are magnified on low-gloss surfaces and severely affect appearance. Compared to polypropylene (PP) or acrylonitrile-butadiene-styrene copolymer (ABS), TPU's advantages lie in its higher melt strength and excellent elastic recovery. Under the high mold temperature created by induction heating, TPU melt can better wet and fill every nanoscale groove on the mold surface; and during cooling and demolding, its good elasticity allows it to smoothly exit from these high aspect ratio microstructures without being torn, thus achieving the highest texture replication rate and the clearest detail. This is the core material basis for achieving a product surface with "distinct tactile feel" and "highest texture replication rate."

[0054] Specifically, in step S3, the surface temperature of the mold cavity is raised to a range higher than that of molds used for conventional injection molding of the plastic material by the induction heating system.

[0055] It should be further explained that this step is the specific process operation in which AIT technology plays a core role. Its essence is to create a dynamic and optimal mold temperature window to overcome the core obstacle of high-precision texture replication - the flow resistance of melt at the micro-nano scale.

[0056] Furthermore, for the selected TPU material, the recommended mold temperature for conventional injection molding (for general products) is typically between 30°C and 60°C, at which temperature the TPU melt has a suitable length and cooling rate for normal flow. However, for replicating complex microtextures with depths of 100-800 nm, at this temperature, the melt front will freeze rapidly upon contact with the cold mold wall when entering narrow texture grooves, resulting in incomplete filling.

[0057] Therefore, in this invention, an optimized and integrated induction heating system is used to rapidly and precisely heat the mold cavity within a short period after mold closing and before injection begins. The "range higher than the mold temperature used in conventional injection molding" is a precisely controlled process window. Specifically, the temperature of the mold cavity surface (textured area) is rapidly increased from an initial temperature (typically 40-60°C controlled by a water temperature controller) to a specific high-temperature setpoint. This setpoint The preferred range is determined by the following formula: in, It is the target high temperature set point on the surface of the cavity, in °C. It is the glass transition temperature of the TPU material used, in °C. It is an empirically optimized temperature rise, measured in °C, with an optimal range of 40°C to 80°C.

[0058] Understandably, the rationale for choosing this range is based on the following balance: It must be large enough so that when the TPU melt contacts the cavity surface, its surface does not immediately cool below the solidification temperature, thus allowing sufficient time and fluidity to complete the filling of the texture. Typically, This has significantly improved the filling effect. However, to achieve the highest replication rate, a higher temperature is required. The temperature should not exceed 80°C, mainly for two reasons: first, excessively high mold temperatures will excessively prolong cooling time, reducing production efficiency; second, prolonged exposure of TPU material to excessively high temperatures poses a risk of thermal degradation, potentially affecting the mechanical properties and appearance of the finished product. A typical example is: for The polyether-type TPU has a temperature of approximately -30°C, an initial mold temperature of 50°C, and is raised to 100°C within 10 seconds using induction heating. However, the actual temperature rise is 50°C from the initial 50°C (still within the preferred range), followed by injection. After the injection holding pressure is completed, the induction heating is turned off, and the cooling water circuit is fully opened to rapidly cool the mold to the ejection temperature (e.g., 60°C). This process of "localized instantaneous high temperature and overall rapid cooling" is something that traditional constant temperature mold temperature controllers cannot achieve. Its beneficial effect is that it completely solves the problem of filling fine textures, while minimizing the impact on the production cycle.

[0059] Specifically, in step S4, the detection of surface optical properties includes measuring the surface gloss of the product, and the detection of tactile properties includes evaluating the surface friction coefficient or subjective tactile feedback.

[0060] It should be further explained that step S4 is a key quality control step that objectifies and quantifies subjective sensory requirements, and it is the endpoint and evaluation criterion of the closed-loop process of this invention.

[0061] Further, the core of surface optical performance testing is gloss measurement. This is performed using a calibrated multi-angle gloss meter (such as the BYK-Gardner micro-gloss series). For the ultra-low gloss "velvet" effect pursued in this invention, the 60° gloss (GU) should be primarily measured. 60During measurement, measurements are taken at at least five representative locations, including the center and four corners of the product's textured area, and the average value is taken as the product's gloss value. Products produced using this method must have a 60° gloss value consistently below 0.2 GU, preferably below 0.1 GU, and ideally below 0.05 GU. The reason for choosing 0.1 GU as the critical threshold is that when the gloss is below this value, the human eye can barely perceive specular reflection, and the product exhibits a deep, soft, and elegant matte texture, meeting the aesthetic requirements of high-end products. When the gloss is above 0.2 GU, the surface will show a certain "plastic" or "waxy" feel, significantly reducing its quality.

[0062] Furthermore, the tactile performance is tested using a combination of subjective and objective methods. Objective testing utilizes a coefficient of friction meter, employing a 5mm diameter hemispherical silicone rubber probe (Shore hardness A50) to simulate a fingertip. The probe slides 50mm across the product surface at a speed of 100mm / min with a normal force of 0.5N, and the instrument records the coefficient of dynamic friction (COF) during the sliding process. The product produced using this method preferably has a COF between 0.25 and 0.45. This range provides a smooth but slightly damped tactile feel, similar to touching velvet. A coefficient that is too low (<0.25) feels overly slippery, like silk; a coefficient that is too high (>0.45) feels rough or scratchy.

[0063] Furthermore, subjective tactile evaluation was conducted by at least five trained sensory evaluators under standard lighting and temperature / humidity conditions. Evaluators, without knowing the sample number, physically touched the product surface and compared it to a standard reference sample (a piece of high-quality microfiber velvet) across four dimensions: "softness," "smoothness," "dryness" (the opposite of dampness or oiliness), and "overall liking." A 5-point scale (1 point - significantly worse than the standard, 5 points - significantly better than the standard) was used for scoring. Only when the product's gloss met the standard, the coefficient of dynamic friction was within the preferred range, and the average subjective evaluation score was above 3.5, could the batch of products be deemed to have passed the optical and tactile performance test.

[0064] Understandably, the beneficial effect of the above steps is that they establish precise and traceable quality standards, transforming the "velvet effect" from vague market language into measurable and controllable engineering parameters, providing a solid basis for process optimization and quality consistency.

[0065] Specifically, if the verification result of step S4 does not meet expectations, the process returns to check the copy status of the mold texture and corrects the mold or reprocesses the texture as needed.

[0066] It should be further explained that this step defines the process for systematic fault diagnosis and corrective action when product verification fails. This is a core feedback mechanism to ensure the robustness and sustainability of the entire production system, corresponding to... Figure 1 The path after "size NG" is "T1...modify mold, repair mold".

[0067] Furthermore, if the product's gloss or texture is found to be substandard in step S4, the injection molding process parameters (such as pressure and speed) should not be adjusted immediately. Instead, one should first "return to check the replication status of the mold texture." The specific diagnostic process is as follows: 1. Mold Texture Inspection: Using a high-magnification (e.g., 200X-1000X) 3D surface profilometer or white light interferometer, directly measure the texture of key areas in the mold cavity. Compare the measured actual 3D topography with... Figure 2 Compare the design target morphology shown to check whether the texture depth and contour shape have been worn, deformed, or contaminated due to multiple injection molding, cleaning, or corrosion. If key parameters such as arithmetic mean height Sa and core contour depth Sk decrease by more than 15% compared to the new mold state, it can be judged as texture wear. 2. Indirect Assessment of Replication Status: A high-resolution replica film (such as a polyvinyl butyral film, softened in a specific solvent and adhered to the mold surface, then cured and peeled off) is prepared and observed under a microscope. Because the replica film is flexible, it can replicate the mold surface without damage. By observing the integrity of the texture on the replica film, the success of the initial transfer from the mold can be indirectly determined. If the texture on the replica film is clear and complete, but the texture on the plastic product is blurry, the problem may lie in the injection molding process (e.g., insufficient mold temperature or pressure); if the texture on the replica film is no longer clear, the root cause of the problem lies in the mold itself. 3. Corrective measures: ① If the mold texture is intact but the replication rate is low, the problem is likely in the injection molding process of step S3. The induction heating parameters (such as heating time and power) should be re-examined and optimized to ensure the mold temperature reaches the preset value. Alternatively, optimize the injection speed and holding pressure to ensure that the melt is pressed deep into the texture under high pressure. ② If the mold texture is worn or contaminated: mold repair is required. For minor contamination (such as oil stains or exudates), ultrasonic cleaning with a special mold cleaner is necessary. For minor wear, local polishing with fine diamond paste can be used for restoration. For severe wear or damage, the mold must be removed from the injection molding machine and returned to step S1. Using a femtosecond laser device, the damaged area is precisely positioned for texture repair "reprocessing," or in some cases, the entire cavity surface needs to be reprocessed.

[0068] Understandably, the beneficial effect of the above steps lies in establishing a logically clear fault tree analysis (FTA) path based on data (morphological measurement data) and evidence (replica film). This guides engineers to quickly and accurately pinpoint whether the problem originates from the "mold" or the "process," thereby enabling them to take the most effective corrective measures. This avoids the time and resources wasted on blindly adjusting machines in traditional trial-and-error methods, ensuring long-term stability of the production process and consistency in product quality.

[0069] Specifically, the texture processed by the femtosecond laser has a micro-irregular raised structure that gives the replicated plastic product a low-gloss appearance and a velvety feel.

[0070] It should be further explained that there is a deterministic physical causal relationship between the surface microstructure created by the specific processing method defined in the above scheme and its final macroscopic sensory performance.

[0071] Furthermore, such as Figure 2 As shown, the surface processed by a precisely controlled femtosecond laser is a three-dimensional morphology composed of countless micro-protrusions (peaks) and depressions (valleys) with random variations in width, height, and spacing at the submicron scale, but with a statistically uniform distribution. This "microscopic irregular protrusion structure" is the source of its functionality.

[0072] Furthermore, regarding the physical mechanism of the low-gloss appearance, the present invention is specifically designed as follows: Gloss is a measure of a surface's ability to specularly reflect light. When a beam of parallel light shines on an ideal mirror surface, it will reflect in a single direction, resulting in high gloss. When light shines on a surface like... Figure 2 When the surface is rough, each microscopic protrusion acts as a tiny mirror, but because its orientation (normal direction) is randomly distributed, the incident light is scattered in almost all spatial directions. According to optical scattering theory, the root mean square roughness of the surface... With the intensity of mirror reflection The relationship can be approximated as: in, It is the light intensity in the direction of mirror reflection. It is the intensity of the incident light. It is the root mean square roughness of the surface, measured in nm. It describes the statistical average of the height deviation of the surface profile relative to the mean line. It is the angle of incidence of the light. This is the wavelength of the incident light, measured in nm. As the formula shows, when the surface roughness... With light wavelength When the exponential term is on the same order of magnitude (hundreds of nanometers), the exponential term decreases sharply, leading to a decrease in the intensity of specular reflection. It becomes extremely weak. The texture processed by this invention, its The optimal gloss value is between 150nm and 400nm, which falls within the visible light wavelength range (380-780nm). Therefore, it can strongly scatter visible light, breaking down the originally concentrated specular reflection light into uniform diffuse reflection light. This results in a deep, soft, and glare-free low-gloss appearance when observed by the human eye, with a measured gloss level of less than 0.1GU.

[0073] Furthermore, regarding the physical mechanism of the velvety feel, the present invention is specifically designed as follows: Tactile sensation is the comprehensive perception of pressure, vibration, and temperature stimuli by mechanoreceptors when skin interacts with a surface. The tactile characteristics of velvet include: a soft feel upon initial contact, and a smooth yet slightly damped "rustling" feel during gliding. The surface structure of the present invention perfectly simulates this: 1) Softness: When you press your finger on the surface, countless tiny, elastic TPU protrusions will deform together, dispersing the contact pressure and avoiding the "hard" feel of hard materials.

[0074] 2) Smoothness and Damping Sensation: When a finger glides across a surface, the gliding primarily occurs at the smooth, rounded peaks of these micro-protrusions. The randomly distributed height and spacing of these protrusions mean that the gliding process is not continuous, but rather accompanied by a series of tiny, random vibrations and changes in resistance. These high-frequency, low-amplitude random vibration signals are received by mechanoreceptors such as Pacinian corpora in the skin and interpreted by the brain as a unique tactile experience that is delicate, smooth, yet slightly "velvety" or "gripping," quite different from touching a smooth surface (low coefficient of friction but no damping) or a rough surface (high damping but a scraping sensation).

[0075] Therefore, it is understandable that the beneficial effect of this step lies in clarifying from a physical principle that the specific microstructure processed by this invention is fundamental to achieving the functionality of "high-precision texture." It not only creates a pattern but also creates a "structured surface" with predetermined optical and tactile functions, directly and scientifically linking materials, structure, and end-user experience.

[0076] Specifically, the method includes, in sequence: femtosecond laser processing of mold texture, simulation optimization and integration of induction heating system, manufacturing assembly mold, injection molding with thermoplastic polyurethane elastomer with induction heating assistance, and a complete loop of optical and tactile verification of the product, wherein the loop includes a mold correction feedback path based on the verification results.

[0077] It should be further explained that the above steps are a high-level summary and integration of the entire technical solution of the present invention, which describes a complete, closed-loop, and intelligent manufacturing ecosystem from concept to product, from design to modification.

[0078] Furthermore, the specific implementation process of the "complete cycle" is as follows, which organically integrates... Figure 1 All key nodes shown: 1. Texture Creation: Based on the target sensory effect (low gloss, velvety feel), reverse design is performed to create a texture like... Figure 2 The microscopic three-dimensional morphology data is shown. Using a femtosecond laser with the aforementioned precise parameters, this functional texture is fabricated on the mold substrate.

[0079] 2. Simulation Optimization and Integration: Based on the 3D data of the mold, an AIT system was designed. Through the aforementioned detailed simulation process (including electromagnetic-thermal coupling analysis, transient temperature field simulation, and uniformity threshold judgment), the coil and water circuit design were iteratively optimized in the computer until stringent temperature uniformity requirements (e.g., ΔT≤8°C) were met. Subsequently, through the aforementioned rigorous drawing review process, the optimized AIT system design was seamlessly integrated into the mold assembly design and sent to manufacturing.

[0080] 3. Manufacturing and Injection Molding: After the mold is processed and assembled, it is installed on the injection molding machine. TPU material is used, and the aforementioned dynamic mold temperature control strategy is applied, that is, the mold temperature is instantly raised to [temperature value missing] before injection via AIT. The high-temperature window allows for rapid cooling after injection, enabling high-fidelity injection molding replication.

[0081] 4. Verification and Feedback: For trial molded products, perform the aforementioned rigorous optical and tactile testing. If the product is qualified, the cycle is completed, process parameters are locked, and mass production can begin. If it is unqualified, the aforementioned diagnostic and feedback mechanism is activated: first, check the mold texture condition to determine the root cause of the problem. If it is due to mold texture wear, return to step 1 (femtosecond laser processing) for repair; if it is due to an AIT system problem (such as uneven heating), it may be necessary to return to step 2 (simulation optimization and integration) to check the design or assembly; if it is due to a process parameter problem, adjust the injection molding parameters in step 3. This "feedback path" transmits the terminal quality problem back to the corresponding process link at the front end, forming an intelligent closed loop of "perception-analysis-decision-execution".

[0082] Understandably, the ultimate beneficial effect of this invention is to provide a systematic engineering solution that completely solves the challenges of mass production of high-precision functional surfaces. It deeply integrates cutting-edge micro-nano fabrication technology (femtosecond lasers), state-of-the-art process control technology (simulation-driven AIT design), optimally suited materials science (TPU), and the most rigorous quality management (quantitative verification and closed-loop feedback). This method not only ensures that products achieve unprecedented sensory quality (gloss <0.1 GU, specific tactile feel), but also guarantees high consistency and stability of this quality in mass production, providing a complete, reliable, and patentable technical path from the laboratory to the mass production line for exterior component innovation in consumer electronics, automotive interiors, and high-end home appliances.

[0083] In a preferred embodiment, this application also provides an electronic device, the electronic device comprising: The computer device includes a memory and a processor, wherein the memory stores computer-readable instructions that, when executed by the processor, implement the method for producing high-precision textures using femtosecond laser processing. The computer device can be broadly categorized as a server, terminal, or any other electronic device with the necessary computing and / or processing capabilities. In one embodiment, the computer device may include a processor, memory, network interface, communication interface, etc., connected via a system bus. The processor of the computer device can be used to provide the necessary computing, processing, and / or control capabilities. The memory of the computer device may include a non-volatile storage medium and internal memory. The non-volatile storage medium may store an operating system, computer programs, etc. The internal memory can provide an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface and communication interface of the computer device can be used to connect and communicate with external devices via a network. When the computer program is executed by the processor, it performs the steps of the method of the present invention.

[0084] This invention can be implemented as a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the steps of the methods of embodiments of the invention to be performed. In one embodiment, the computer program is distributed across multiple network-coupled computer devices or processors, such that the computer program is stored, accessed, and executed in a distributed manner by one or more computer devices or processors. A single method step / operation, or two or more method steps / operations, may be executed by a single computer device or processor or by two or more computer devices or processors. One or more method steps / operations may be executed by one or more computer devices or processors, and one or more other method steps / operations may be executed by one or more other computer devices or processors. One or more computer devices or processors may execute a single method step / operation, or execute two or more method steps / operations.

[0085] Those skilled in the art will understand that the method steps of this invention can be performed by a computer program instructing related hardware, such as a computer device or processor, to perform the steps of this invention when executed. Depending on the context, any references herein to memory, storage, databases, or other media may include non-volatile and / or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0086] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0087] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for producing high-precision textures based on femtosecond laser processing, characterized in that, Includes the following steps: S1. Mold texture processing stage: Based on the three-dimensional data of the target texture, a femtosecond laser is used to scan and process the surface of the mold cavity to form a textured surface with micro-irregular raised structure; S2. Mold Temperature Field Optimization Stage: An induction heating system is designed and integrated into the mold, and the layout of the induction heating system is optimized through thermal simulation analysis, so that the mold cavity can quickly reach and maintain a uniform target temperature during the injection cycle. S3. Injection Molding Replication Stage: The mold processed in steps S1 and S2 is used for injection molding. The induction heating system is used to dynamically control the temperature of the mold so that the plastic melt can completely replicate the textured surface when filling the mold. S4. Product Performance Verification Stage: Test the surface optical and tactile properties of the injection-molded product.

2. The production method according to claim 1, characterized in that, In step S1, by adjusting the pulse energy, scanning spacing and scanning strategy of the femtosecond laser, a texture with submicron depth and a multi-peak continuous distribution of the micro-irregular protrusion structure is processed on the surface of the mold.

3. The production method according to claim 1, characterized in that, Step S2 specifically includes: S21. Based on the 3D data of the mold, design the layout of the induction heating coil and cooling water circuit; S22. Perform temperature uniformity simulation analysis on the design using thermodynamic simulation software; S23. If the analysis results do not meet the uniformity requirements, adjust the design of the induction heating coil and cooling water circuit and re-analyze until the requirements are met.

4. The production method according to claim 3, characterized in that, After the temperature uniformity requirement is met in step S23, the process also includes the integrated design and review of the complete mold drawing file. Only after the review is passed can the mold be manufactured and assembled.

5. The production method according to claim 1, characterized in that, In step S3, the plastic material used for injection molding is thermoplastic polyurethane elastomer.

6. The production method according to claim 5, characterized in that, In step S3, the surface temperature of the mold cavity is raised to a range higher than that of molds used for conventional injection molding of the plastic material by the induction heating system.

7. The production method according to claim 1, characterized in that, In step S4, the detection of surface optical properties includes measuring the surface gloss of the product, and the detection of tactile properties includes evaluating the surface friction coefficient or subjective tactile feedback.

8. The production method according to claim 7, characterized in that, If the verification result of step S4 does not meet expectations, return to check the copy status of the mold texture, and correct the mold or reprocess the texture as needed.

9. The production method according to claim 2, characterized in that, The texture processed by the femtosecond laser has a microscopic irregular protrusion structure that gives the replicated plastic product a low-gloss appearance and a velvety feel.

10. The production method according to any one of claims 4, 6 and 9, characterized in that, The method includes, in sequence: The complete cycle includes femtosecond laser processing of mold texture, simulation optimization and integration of induction heating system, manufacturing assembly mold, injection molding with thermoplastic polyurethane elastomer with induction heating assistance, and optical and tactile verification of product, the cycle including mold correction feedback path based on verification results.

Images