Preparation method of roller mold and roller mold

Abstract

The invention belongs to the technical field of mold preparation, and particularly relates to a preparation method of a roller mold and the roller mold. The preparation method of the roller mold comprises the following steps that shaping is conducted, specifically, a fixing cylinder with a positioning cavity and a female mold with a forming cavity are prepared, a microstructure is formed in the cavity wall of the forming cavity, and the female mold is sleeved with the fixing cylinder and positioned in the positioning cavity; pouring is conducted, specifically, a fluid forming material is poured into the forming cavity, and the forming material is formed into a preset shape in the forming cavity; curing: curing the molding material to enable the molding material to copy the microstructure; and carbonization is conducted, specifically, the cured forming material is separated from the female die, and the forming material is heated so that the forming material can be carbonized to form the roller die. Through the four steps of shaping, pouring, curing and carbonizing, the forming material can accurately copy the microstructure on the female mold, the preparation precision of the roller mold is improved, the preparation cost is low, and the efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of mold preparation, and in particular relates to a preparation method of a roller mold and the roller mold. Background Art

[0002] Micro-optical components such as microlens arrays, Fresnel lenses and metasurfaces play an important role in modern optical and optoelectronic technologies and are widely used in many fields such as consumer electronics, medical imaging, optical communications and energy collection.

[0003] By making microstructures on the surface of roller molds and using roller molds to hot emboss optical glass, a new processing method for mass production of micro-optical components is being developed. In roller-to-plate hot pressing technology, roller molds not only involve shape forming, but also heating, pressure, process control, and performance improvement. Their preparation and application directly affect the quality, production efficiency, and material properties of the final product. Therefore, in practical applications, manufacturing high-quality roller molds is a key factor in ensuring successful forming.

[0004] Traditionally, integrated roller molds are mainly prepared through single-point diamond turning technology. However, this processing method has high requirements, greatly increases processing costs, and has low production efficiency. The accuracy of the surface structure is limited by the accuracy of machine tools and algorithms, and cannot meet the needs of large-scale, low-cost, and high-precision roller mold manufacturing. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a method for preparing a roller mold, aiming to solve the problem of how to improve the preparation efficiency of the roller mold and reduce the preparation cost.

[0006] To achieve the above purpose, the technical solution adopted in this application is: In a first aspect, a method for preparing a roller mold is provided, comprising the following steps: Finalizing the shape, preparing a fixed cylinder with a positioning cavity and a master mold with a molding cavity, wherein the cavity wall of the molding cavity is provided with a microstructure, and the master mold is sleeved inside the fixed cylinder and positioned in the positioning cavity; Pouring, pouring a fluid molding material into the molding cavity, wherein the molding material is molded into a predetermined shape in the molding cavity; Curing, curing the molding material so that the molding material replicates the microstructure; Carbonization, separating the solidified molding material from the master mold, and heating the molding material to carbonize the molding material to form a roller mold.

[0007] In some embodiments, the shaping step comprises: S11: preparing a flexible sheet; S12: processing the microstructure on one side surface of the flexible sheet; S13: connecting two opposite ends of the flexible sheet to curl the flexible sheet and form the master mold.

[0008] In some embodiments, the microstructure is processed on the flexible sheet by femtosecond laser technology or photolithography technology.

[0009] In some embodiments, opposite ends of the flexible sheet are spliced ​​or partially overlapped.

[0010] In some embodiments, the curing step comprises: S31: placing the fixing cylinder and the molding material in a vacuum environment and maintaining the vacuum environment for a first predetermined time; S32: placing the fixing tube and the molding material in a dry environment and heating them to a first predetermined temperature, and maintaining the temperature for a second predetermined time to solidify the molding material.

[0011] In some embodiments, the first predetermined time ranges from 72 hours to 100 hours, the second predetermined time ranges from 8 hours to 10 hours, and the first predetermined temperature ranges from 100 degrees Celsius to 105 degrees Celsius.

[0012] In some embodiments, the carbonization step comprises: S41: placing the solidified molding material in a vacuum environment; S42: heating the molding material to a second predetermined temperature at a first predetermined heating rate; S43: heating the molding material from the second predetermined temperature to a third predetermined temperature at a second predetermined heating rate, wherein the second predetermined heating rate is greater than the first predetermined heating rate, and the third predetermined temperature is greater than the second predetermined temperature; S44: keeping the molding material at the third predetermined temperature for a third predetermined time; S45: naturally cooling the molding material to obtain the roller mold.

[0013] In some embodiments, the first predetermined heating rate is 0.5°C / min, the second predetermined heating rate is 1°C / min, the second predetermined temperature is 600°C, the third predetermined temperature is 1000°C, and the third predetermined time period is 10h.

[0014] In some embodiments, the molding material includes 89.8% by mass of furan resin, 0.2% by mass of p-toluenesulfonic acid monohydrate, and 10% by mass of ethanol.

[0015] In a second aspect, a roller mold is provided, which is prepared by the preparation method of the roller mold.

[0016] The beneficial effects of the present application are as follows: through the four steps of shaping, pouring, curing and carbonization, the transition of the molding material from a fluid plastic state to a solid state is ensured, thereby ensuring the structural stability and high temperature resistance of the roller mold; the molding material in the plastic state can accurately replicate the microstructure on the master mold to achieve the replication and transfer of the microstructure, thereby improving the preparation accuracy of the roller mold, and having low preparation cost and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or exemplary technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 is a flow chart of a method for preparing a roller mold provided in an embodiment of the present application; Figure 2 is a schematic diagram of a casting step in a method for preparing a roller mold provided in another embodiment of the present application; Figure 3 It is a schematic diagram of assembling a fixing cylinder and a shaping member provided in yet another embodiment of the present application; Figure 4 is a schematic diagram of the three-dimensional structure of a fixed cylinder and a mother mold provided in yet another embodiment of the present application; Figure 5 is a schematic diagram of the three-dimensional structure of a roller mold provided by another embodiment of the present application; Figure 6 yes Figure 5 A partial enlarged view of point A.

[0019] Among them, the reference numerals in the figure are: 101. fixed cylinder; 102. mother mold; 103. molding material; 104. shaping piece; 1041. shaping tube; 1042. shaping column; 105. positioning cavity; 200. roller mold; 201. micro protrusion; 1011. half sleeve; 1021. half sheet; 1022. molding cavity; 1012. avoidance groove. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present application.

[0021] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The orientation or positional relationship indicated by words such as "upper", "lower", "left", and "right" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] See also Figures 1 to 3 The embodiment of the present application provides a method for preparing a roller mold, which is used to prepare a roller mold 200. The roller mold 200 can perform hot pressing molding on optical glass to prepare an optical element with a microstructure.

[0023] See also Figures 2 to 4 , the preparation method of the roller mold comprises the following steps: S1: Finalization, prepare a fixed cylinder 101 with a positioning cavity 105 and a mother mold 102 with a molding cavity 1022, the positioning cavity 105 has an opening, and the opening is set upward, the inner wall of the molding cavity 1022 is provided with a microstructure, the mother mold 102 is sleeved and positioned in the fixed cylinder 101, so that the outer surface of the mother mold 102 is tightly fitted with the cavity wall of the positioning cavity 105, and the mother mold 102 is fixed and supported. It can be understood that an adhesive layer can be provided on the inner wall of the fixed cylinder 101, so that the mother mold 102 is glued and positioned on the cavity wall of the positioning cavity 105; the cross-sectional shape of the positioning cavity 105 is circular, and the cross-sectional shape of the mother mold 102 is also circular. At the same cross-sectional position, the center of the cross section of the positioning cavity 105 coincides with the center of the cross section of the mother mold 102.

[0024] S2: pouring, pouring the molding material 103 in a fluid and plastic state into the molding cavity 1022 of the master mold 102, and forming the molding material 103 into a predetermined shape in the molding cavity 1022. In this embodiment, the molding material 103 is formed into a cylinder in the molding cavity 1022. It can be understood that the molding material 103 is slowly injected into the molding cavity 1022, so that the molding material 103 fills the molding cavity 1022 and immerses the uppermost microstructure of the molding cavity 1022, and finally the molding material 103 is cylindrical in the molding cavity 1022; S3: solidification, solidifying the molding material 103 in the molding cavity 1022 so that the molding material 103 replicates the microstructure; it can be understood that the molding material 103, which is in a fluid state and has viscoelasticity, has strong plasticity and can fully fill the microstructure on the master mold 102, so that the solidified molding material 103 can accurately replicate the microstructure on the master mold 102, has high replication accuracy, and realizes high-precision microstructure transfer with high efficiency.

[0025] S4: Carbonization, separation of the molding material 103 and the master mold 102, and heating the molding material 103 with the replicated microstructure to carbonize the molding material 103 and form a roller mold 200. It can be understood that the roller mold 200 after carbonization has a certain hardness and strength, and also has the property of high temperature resistance, so that subsequent hot pressing molding can be carried out.

[0026] See also Figures 1 to 3 The preparation method of the roller mold provided in the embodiment of the present application ensures the transition of the molding material 103 from a fluid state to a solid state through the four steps of shaping, pouring, curing and carbonization, thereby ensuring the structural stability and high temperature resistance of the roller mold 200. The molding material 103 can accurately replicate the microstructure on the master mold 102 to achieve the replication and transfer of the microstructure, thereby improving the preparation accuracy of the roller mold 200, and has low preparation cost and high efficiency.

[0027] Optionally, the microstructure includes a microstructure with a size of micrometer level and / or a microstructure with a size of nanometer level, and the obtained roller mold is cleaned and polished to improve its surface quality. The shape of the microstructure can be a cavity, a protrusion or a groove, which is not limited here and can be selected according to actual conditions.

[0028] Optionally, the material of the fixed cylinder 101 can be a metal material, such as stainless steel, which is a highly corrosion-resistant alloy steel whose main components are iron, chromium and carbon. Stainless steel can form a dense chromium oxide protective film in the air or water, thereby effectively preventing rust and corrosion, so that the fixed cylinder 101 can be used repeatedly, reducing the preparation cost of the roller mold 200.

[0029] Optionally, a shaping piece 104 is provided in the fixed cylinder 101, and the cross-sectional shape of the shaping piece 104 is circular, and the center of the circle coincides with the center of the cross-sectional shape of the positioning cavity. The molding material 103 is poured between the side surface of the shaping piece 104 and the inner surface of the mother mold 102, so that a roller mold 200 with a hollow structure is finally obtained.

[0030] See also Figures 1 to 3 In some embodiments, the molding material 103 includes 89.8% by mass of furan resin, 0.2% by mass of p-toluenesulfonic acid monohydrate, and 10% by mass of ethanol.

[0031] Optionally, the molding material 103 has good molding performance and carbonization effect, and the furan resin can form a high-strength carbonized structure after carbonization, thereby ensuring the stability and wear resistance of the roller mold 200 in a high temperature environment.

[0032] Toluenesulfonic acid, as a catalyst, can accelerate the solidification process of the molding material 103, while the addition of ethanol helps to improve the fluidity of the material, ensuring that the microstructure can be evenly and fully filled during the casting process.

[0033] See also Figures 1 to 3 In some embodiments, the shaping step comprises: S11: preparing a flexible sheet; S12: processing a microstructure on one side surface of the flexible sheet; S13: connecting opposite ends of the flexible sheet to curl the flexible sheet and form a mother mold 102 .

[0034] Optionally, the flexible sheet can be a PDMS (Polydimethylsiloxane) sheet, which is a flexible silicone polymer material widely used in optics, microelectronics, biomedicine, micro-electromechanical systems, etc. The PDMS sheet has a high elastic modulus and can maintain structural integrity under large deformation, so that it can be rolled into a round sleeve shape.

[0035] Optionally, a microstructure is processed on one side surface of the PDMS sheet, and two opposite ends of the PDMS sheet are butt-jointed, so that the PDMS sheet is rolled into a sleeve shape to form a master mold 102, and the microstructure is located on its inner surface.

[0036] See also Figures 1 to 3 In some embodiments, a microstructure is processed on a flexible sheet using femtosecond laser technology.

[0037] Alternatively, microstructures can be processed on PDMS sheets using femtosecond laser technology. The high precision and extremely short pulses of femtosecond lasers can be used to carve microstructures from micrometers to nanometers on the surface of PDMS sheets, and complex micro-nano patterns can be processed. Femtosecond laser technology has a short action time and concentrated energy. It can instantly deposit a large amount of energy in a small area, reducing the thermal effect of the material. Femtosecond laser processing is a non-contact process that does not apply mechanical stress to the surface of the material, avoiding stress concentration on the flexible sheet.

[0038] In some embodiments, the microstructures are fabricated on the flexible sheet by photolithography.

[0039] Alternatively, photolithography can generate high-precision microstructures on PDMS sheets, and periodic patterns and complex geometric shapes can be prepared. Femtosecond laser and photolithography can process complex microstructures on micrometer and / or nanometer scales, ensuring the accuracy and consistency of the microstructure.

[0040] See also Figures 1 to 4 In some embodiments, the two opposite ends of the flexible sheet are spliced, and glue is applied to the end surfaces of the two ends of the flexible sheet, so that the two ends of the flexible sheet are firmly connected by the glue, and the flexible sheet is curled into the mother mold 102. A first adhesive layer can also be provided at the splicing, and the two ends of the first adhesive layer are respectively bonded to the two ends of the flexible sheet, so that the two ends of the flexible sheet are spliced ​​in the form of end-to-end face, avoiding the generation of bulges at the joints of the two ends of the flexible sheet. The first adhesive layer is located between the flexible sheet and the cavity wall of the positioning cavity 105, and a first avoidance groove 1012 can also be opened at the position of the cavity wall of the positioning cavity 105 corresponding to the first adhesive layer, and the first adhesive layer is partially located in the first avoidance groove 1012, so as to reduce the influence of the thickness of the first adhesive layer on the curling shape of the mother mold.

[0041] See also Figures 1 to 3 In some embodiments, opposite ends of the flexible sheet are partially overlapped and connected.

[0042] Optionally, a second adhesive layer may be provided at the overlapping positions of the two ends of the flexible sheet, and the two side surfaces of the second adhesive layer are respectively adhered to the two ends of the flexible sheet.

[0043] It can be understood that in the subsequent hot pressing process of the roller mold on the optical glass plate, the optical glass can avoid the position of the roller mold corresponding to the first adhesive layer or the second adhesive layer, avoiding hot pressing of the optical glass at this position, that is, the rotation angle of the roller mold during the rolling process is less than 360 degrees, and can be 300 degrees, 320 degrees or 330 degrees, thereby improving the hot pressing accuracy of the optical glass.

[0044] See also Figure 4 It can be understood that the fixed cylinder 101 includes two half sleeves 1011, and the two sides of one half sleeve 1011 are respectively connected to the two sides of the other half sleeve 1011, that is, the two half sleeves 1011 are connected along the radial direction of the mother mold to form the positioning cavity 105. The two half sleeves 1011 are detachably connected, and the detachable connection of the two half sleeves 1011 can be achieved by a hoop or a connector. By separating the two half sleeves 1011, the flexible sheet and the molding material 103 can be separated from the fixed cylinder 101, and then the two ends of the flexible sheet are manually disassembled to separate the flexible sheet from the molding material 103. The flexible sheet can be reused, which reduces the preparation cost of the roller mold 200 and allows the roller mold 200 to be prepared in large quantities and on a large scale.

[0045] Optionally, the flexible sheet includes two half sheets 1021, the two half sheets 1021 are respectively located in the two half sleeves 1011, and are bent and fitted to the inner wall of the half sleeve 1011. The two half sheets 1021 can be butted together by butting the two half sleeves 1011, thereby improving the butting accuracy and efficiency of the two half sheets 1021. Moreover, the flexible sheet can be bent and fitted in the two half sleeves 1011, and the inner wall of the half sleeve 1011 can be used to position the bent shape of the half sheet 1021, so that the cross-sectional shape of the bent half sheet 1021 is a semicircle, thereby improving the shape accuracy of the final molding cavity 1022. Two avoidance grooves 1012 are provided, and the two avoidance grooves 1012 are respectively located at the two butting locations of the two half sheets 1021, and each avoidance groove 1012 is provided with a first adhesive layer.

[0046] See also Figures 1 to 3 In some embodiments, the curing step comprises: S31: placing the fixing cylinder 101 and the molding material 103 in a vacuum environment and maintaining the vacuum environment for a first predetermined time; the vacuum degree of the vacuum environment may be 0.001 Pa; S32 : placing the fixing tube 101 and the molding material 103 in a dry environment and heating them to a first predetermined temperature, and maintaining the temperature for a second predetermined time to solidify the molding material 103 .

[0047] Optionally, the fixed cylinder 101, the master mold 102 and the molding material 103 are placed in a vacuum box, and the molding material 103 is solidified in the vacuum environment of the vacuum box, thereby effectively removing the air and bubbles in the molding material 103 and ensuring the density and uniformity of the roller mold 200. The reduction of bubbles can also improve the pressure resistance and service life of the roller mold 200.

[0048] The fixing cylinder 101 is then placed in a convection drying oven. By controlling the heating temperature and maintaining the second predetermined time, the molding material 103 can be completely cured and its internal stress can be reduced, thereby preventing the molding material 103 from deforming or shrinking during subsequent processing.

[0049] See also Figure 3 The shaping piece 104 includes a tubular shaping tube 1041 and a shaping column 1042 that can be inserted into the shaping tube 1041. The shaping tube 1041 can be made of a high-temperature resistant elastic material, such as high-temperature resistant silicone. The shaping column 1042 can be made of stainless steel. The cross-sectional shapes of the shaping tube 1041 and the shaping column 1042 are both circular. In the pouring step, one end of the shaping tube 1041 is first inserted into and positioned in the molding cavity 1022. The inserted end of the shaping tube 1041 is sealed. The shaping column 1042 is then inserted into the shaping tube 1041 and has an interference fit with the shaping tube 1041. Then, the molding cavity 1022 is poured with the molding material 103 in a fluid and plastic state.

[0050] In the early stage of step S32, the molding material 103 will gradually solidify but not completely solidify. After the molding material 103 is initially formed, that is, in the later stage of step S32, the molding column 1042 is removed from the molding tube 1041, and a gas or liquid with a certain pressure is filled into the molding tube 1041 to cause the molding tube 1041 to expand radially, thereby causing the molding tube 1041 to slightly squeeze the molding material 103 outward, so that there is a certain lateral pressure between the molding material 103 and the mother mold 102, thereby ensuring that the microstructure on the molding material 103 can have the required replication accuracy and preventing the molding material 103 from shrinking too quickly due to solidification, which affects the replication accuracy of the microstructure.

[0051] Of course, the shaping member 104 may also be an expansion tube, which can expand along its radial direction.

[0052] See also Figures 1 to 3 In some embodiments, the first predetermined time ranges from 72 hours to 100 hours, the second predetermined time ranges from 8 hours to 10 hours, and the first predetermined temperature ranges from 100 degrees Celsius to 105 degrees Celsius.

[0053] Optionally, the first predetermined duration may be 72h, 80h, 85h, 95h, 99h or 100h, and the second predetermined duration may be 8h, 8.5h, 8.8h, 9h, 9.9h or 10h. There is no limitation here and the selection can be made according to actual situation.

[0054] The first predetermined temperature may be 100 degrees Celsius, 101 degrees Celsius, 102.3 degrees Celsius or 105 degrees Celsius, which is not limited here and can be selected according to actual conditions.

[0055] See also Figures 1 to 3 In some embodiments, the carbonizing step comprises: S41: placing the solidified molding material 103 in a vacuum environment or an inert gas environment; the vacuum degree of the vacuum environment may be 0.001 Pa, and the inert gas may be nitrogen or argon.

[0056] S42: heating the molding material 103 to a second predetermined temperature at a first predetermined heating rate; S43: heating the molding material 103 from the second predetermined temperature to a third predetermined temperature at a second predetermined heating rate, wherein the second predetermined heating rate is greater than the first predetermined heating rate, and the third predetermined temperature is greater than the second predetermined temperature; S44: keeping the molding material 103 at a third predetermined temperature for a third predetermined time to fully carbonize the molding material 103; S45: naturally cooling the molding material 103 to obtain the roller mold 200. The molding material 103 may be naturally cooled for 24 hours to cool the molding material 103 to room temperature.

[0057] Optionally, the first predetermined heating rate can effectively heat the molding material 103 slowly to the second predetermined temperature, which can control the shrinkage and internal stress distribution of the molding material 103, avoid cracks or internal stress concentration in the molding material 103 and the microstructure during rapid heating, and help to fully carbonize the molding material 103, ultimately improving the reliability of the roller mold 200 and the dimensional accuracy of the microstructure. The second predetermined heating rate can increase the heating rate of the molding material 103, improve the carbonization efficiency, and enable the third predetermined temperature to strengthen the carbonization of the molding material 103.

[0058] See also Figures 1 to 3 In some embodiments, the first predetermined heating rate may be 0.5°C / min; the second predetermined heating rate may be 1°C / min; the second predetermined temperature may be 600°C, the third predetermined temperature may be 1000°C, and the third predetermined time may be 10h.

[0059] Optionally, by adopting heating rates of 0.5°C / min and 1°C / min in sequence, precise control of the temperature rise process of the molding material 103 and the carbonization process are achieved. Since the thermal decomposition of the furan precursor is mainly concentrated around 600°C, the heating rate within 600°C is set to slow heating of 0.5°C / min, so that the molding material 103 is slowly heated to 600 degrees Celsius, and the molding material 103 is fully carbonized, and then the molding material 103 is heated from 600°C to 1000°C by rapid heating at 1°C / min, so as to achieve rapid heating of the molding material 103, strengthen the carbonization effect and accelerate the carbonization efficiency.

[0060] Optionally, slow heating at a first predetermined heating rate can heat the molding material 103 evenly, which can not only allow the molding material 103 to undergo sufficient thermal decomposition and ensure the uniformity of the thermal decomposition of the material, but also reduce the warping of the glassy carbon, the appearance of internal cracks and voids, improve the carbonization effect, and avoid local overheating or stress concentration, thereby ensuring the quality and structural strength of the surface microstructure of the roller mold 200.

[0061] It can also be understood that the furan precursor has strong plasticity in the viscoelastic state, and it can accurately replicate the microstructure on the master mold 102, ensuring the accuracy of the microstructure on the roller mold 200. After carbonization, the furan precursor forms high-temperature resistant and high-hardness glassy carbon, and obtains a glassy carbon integrated roller mold 200 with high dimensional accuracy, that is, the microstructure and the matrix of the roller mold 200 are integrated to ensure the overall connection strength and structural strength.

[0062] Optionally, the microstructure is subsequently transferred to the optical glass using a roller mold 200. Under the premise of ensuring the transfer accuracy, the pain points of the traditional single-point diamond turning technology, such as high cost, low efficiency and limited precision, are solved. In addition, the glass carbon roller mold 200 has low adhesion to the glass, which can reduce the defect of adhesion failure between the optical glass and the roller mold 200 during the hot pressing process, thereby improving the quality of the hot pressing products.

[0063] See also Figures 5 and 6 The present invention also proposes a roller mold 200, which is prepared by the above-mentioned roller mold preparation method. Since the roller mold 200 adopts all the technical solutions of all the above-mentioned embodiments, it also has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0064] See also Figure 6 In this embodiment, the side surface of the roller mold 200 has a microstructure, which is a microprotrusion 201 convexly provided on the side surface of the roller mold 200. The microprotrusion 201 is in the shape of a long strip and arranged along the length direction of the roller mold 200. A plurality of microprotrusions 201 are arranged at equal intervals along the circumference of the roller mold 200. In other embodiments, the microstructure may also be in the shape of a column, which is not limited here and can be selected according to actual conditions.

[0065] The above are only optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for preparing a roller mold, characterized in that: The steps include: Finalizing the shape, preparing a fixed cylinder with a positioning cavity and a master mold with a molding cavity, wherein the cavity wall of the molding cavity is provided with a microstructure, and the master mold is sleeved inside the fixed cylinder and positioned in the positioning cavity; Pouring, pouring a fluid molding material into the molding cavity, wherein the molding material is molded into a predetermined shape in the molding cavity; Curing, curing the molding material so that the molding material replicates the microstructure; Carbonization, separating the solidified molding material from the master mold, and heating the molding material to carbonize the molding material to form a roller mold.

2. The method for preparing a roller mold according to claim 1, characterized in that: The shaping step comprises: S11: preparing a flexible sheet; S12: processing the microstructure on one side surface of the flexible sheet; S13: connecting two opposite ends of the flexible sheet to curl the flexible sheet and form the master mold.

3. The method for preparing a roller mold according to claim 2, characterized in that: The microstructure is processed on the flexible sheet by using femtosecond laser technology or photolithography technology.

4. The method for preparing a roller mold according to claim 2, characterized in that: The two opposite ends of the flexible sheet are spliced ​​or partially overlapped and connected.

5. The method for preparing a roller mold according to any one of claims 1 to 4, characterized in that: The curing step comprises: S31: placing the fixing cylinder and the molding material in a vacuum environment and maintaining the vacuum environment for a first predetermined time; S32: placing the fixing tube and the molding material in a dry environment and heating them to a first predetermined temperature, and maintaining the temperature for a second predetermined time to solidify the molding material.

6. The method for preparing a roller mold according to claim 5, characterized in that: The first predetermined time ranges from 72 hours to 100 hours, the second predetermined time ranges from 8 hours to 10 hours, and the first predetermined temperature ranges from 100 degrees Celsius to 105 degrees Celsius.

7. The method for preparing a roller mold according to any one of claims 1 to 4, characterized in that: The carbonization step comprises: S41: placing the solidified molding material in a vacuum environment; S42: heating the molding material to a second predetermined temperature at a first predetermined heating rate; S43: heating the molding material from the second predetermined temperature to a third predetermined temperature at a second predetermined heating rate, wherein the second predetermined heating rate is greater than the first predetermined heating rate, and the third predetermined temperature is greater than the second predetermined temperature; S44: keeping the molding material at the third predetermined temperature for a third predetermined time; S45: naturally cooling the molding material to obtain the roller mold.

8. The method for preparing a roller mold according to claim 7, characterized in that: The first predetermined heating rate is 0.5°C / min, the second predetermined heating rate is 1°C / min, the second predetermined temperature is 600°C, the third predetermined temperature is 1000°C, and the third predetermined time is 10h.

9. The method for preparing a roller mold according to any one of claims 1 to 4, characterized in that: The molding material includes 89.8% by mass of furan resin, 0.2% by mass of p-toluenesulfonic acid monohydrate, and 10% by mass of ethanol.

10. A roller mold, characterized in that: The roller mold is prepared by the preparation method of any one of claims 1 to 9.

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