A method for engraving a triangular pyramidal retroreflective mold

Abstract

The application discloses a kind of engraving methods of triangular pyramid retroreflective moulds. Among them, the method includes: providing a metal plate, the metal plate includes a smooth surface;The smooth surface is washed;And the tool tip angle 70.2°-70.8° tool is set above the smooth surface along a first direction, and after setting is completed, the tool tip is used as the base point, and is rotated 0°-0.6° along a second direction, and the tool is engraved and processed along a preset route on a smooth surface using the tool after rotation, and the triangular pyramid retroreflective array with side length 215-219 μm, height 97-100 μm is processed using the engraved metal plate.The tool tip angle and the deflection angle of the tool are designed according to the size characteristics of the triangular pyramid retroreflective array structure;Experimental results show that the mould prepared using the tool angle can prepare triangular pyramid retroreflective film that meets the V type film standard.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of triangular pyramid retroreflective mold processing, and particularly relates to a triangular pyramid retroreflective mold engraving method. BACKGROUND

[0002] The triangular pyramid retroreflective film is a light-reflecting material made based on the refraction and total reflection principle of triangular pyramids. The surface smoothness of each triangular pyramid is more than 5 nm, the angle error is less than 0.01 arc seconds, and there are 10,000 micro-prisms per square centimeter. It is a light-reflecting product completely realized by super-precision tooling technology and process. It has better light-reflecting effect, longer visual distance and better recognition effect than the glass micro-bead type triangular pyramid retroreflective film, and is generally used for road signs of high-grade roads.

[0003] However, at present, few triangular pyramid retroreflective films in China reach V-class standards in brightness. This is because there are great difficulties in the processing technology of the mold and the design and development of the corner angle, especially the matching of the tool angle and the size of the micro-prism unit. Once the error of the tool angle design and the size of the micro-prism unit matched therewith occurs, the mold capable of preparing the V-class standard triangular pyramid retroreflective film cannot be prepared. SUMMARY

[0004] Therefore, the present application aims to provide a triangular pyramid retroreflective mold engraving method capable of preparing a V-class standard triangular pyramid retroreflective mold.

[0005] According to one aspect of the present application, a triangular pyramid retroreflective mold engraving method is provided, which comprises: providing a metal plate comprising a smooth surface; cleaning the smooth surface; arranging a tool with a tool tip angle of 70.2°-70.8° above the smooth surface along a first direction, and after the arrangement, rotating the tool tip as a base point along a second direction by 0°-0.6°, and using the rotated tool to engrave and process the smooth surface along a preset route, and using the engraved metal plate to process a triangular pyramid retroreflective array with a side length of 215-219 μm and a height of 97-100 μm.

[0006] According to another aspect of the present application, a triangular pyramid retroreflective film original mold is provided, which is engraved by the above-mentioned triangular pyramid retroreflective mold engraving method.

[0007] According to still another aspect of the present application, a triangular pyramid retroreflective film working mold is provided, which is made by electrocasting the above-mentioned triangular pyramid retroreflective film original mold.

[0008] According to another aspect of the present application, a triangular pyramid retroreflective film is provided, which is prepared by the above-mentioned triangular pyramid retroreflective mold engraving method.

[0009] According to another aspect of the present application, a triangular pyramid retroreflective film processing cutter is provided, which has a cutter tip angle of 70.2°-70.8°, and is installed on a cutter bar, and has an angle of 0°-0.6° with the vertical direction.

[0010] It can be found that, according to the above scheme, the cutter tip angle and the offset angle of the cutter are designed according to the size characteristics of the triangular pyramid retroreflective array structure; the experimental results show that the mold prepared by using the cutter angle can prepare a triangular pyramid retroreflective film meeting the V-class film standard. The mold of the present application is made of copper, which has good heat conduction performance, ranks third among metals, has good ductility, is easy to form and process, and has good corrosion resistance. In the subsequent hot pressing process, heat can be quickly conducted to facilitate the formation of the triangular pyramid retroreflective film. At the same time, copper has good cutting performance and is easy to process the mold. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0012] Figure 1 is a flowchart of the engraving method of the triangular pyramid retroreflective mold of the present application;

[0013] Figure 2 is a cutter schematic diagram of the engraving method of the triangular pyramid retroreflective mold of the present application;

[0014] Figure 3 is a triangular pyramid size schematic diagram in the triangular pyramid retroreflective array;

[0015] Figure 4 is a processing schematic diagram of the engraving method of the triangular pyramid retroreflective mold of the present application. DETAILED DESCRIPTION

[0016] The present application will be further described in detail below in combination with the drawings and embodiments. It is particularly pointed out that the following embodiments are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following embodiments are only some embodiments of the present application, not all embodiments, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0017] The present application provides a method for engraving triangular pyramid retroreflective mold, which can realize the preparation of V-class standard triangular pyramid retroreflective mold.

[0018] Please refer to Figure 1 , Figure 1 is the flowchart of an embodiment of the method for engraving triangular pyramid retroreflective mold of the present application. It should be noted that the method of the present application is not limited to the flow order shown in Figure 1 . As shown in Figure 1 , the method comprises the following steps:

[0019] S101: providing a metal plate comprising a smooth surface.

[0020] S102: cleaning the smooth surface; and

[0021] S103: setting a tool with a tool tip angle of 70.2°-70.8° in a first direction above the smooth surface, and after setting, rotating 0°-0.6° in a second direction with the tool tip as the base point, and using the rotated tool to engrave a preset route on the smooth surface, and using the engraved metal plate to process a triangular pyramid retroreflective array with a side length of 215-219 μm and a height of 97-100 μm.

[0022] Setting a tool with a tool tip angle of 70.4° in a first direction A above the smooth surface C, and after setting, rotating 0.4° in a second direction B with the tool tip as the base point, and using the rotated tool to engrave a preset route on the smooth surface, and using the engraved metal plate to process a triangular pyramid retroreflective array with a side length of 217 μm and a height of 98 μm.

[0023] In this embodiment, the tool tip angle α and the rotation angle β, please refer to Figure 2 ; the triangular pyramid unit size of the triangular pyramid retroreflective array prepared by the mold prepared by the process please refer to Figure 3It is further understood that the tool tip angle a and the rotation angle β are found in the machining process that the chip flow to the surface to be machined at this angle, prevent scratching the machined surface, reduce the cutting of the machined area and influence. At the same time in the machining process found that the vibration amplitude at this angle is the smallest. The vibration in the general machining process reduces the quality of the machined surface. Vibration causes the vibration of the machined surface, resulting in surface roughness, especially in the case of micro-prism finishing, this roughness is extremely fatal to the processing of the template. At the same time it also makes the relative displacement between the workpiece and the tool, affects the normal motion trajectory causes the machined surface will appear similar to the wrinkled silk shape, fish scale shape and so on, reduces the quality and size accuracy of the machined surface, this situation is extremely fatal to the processing of the template. Further, in the machining process, it is found that the vibration amplitude is the smallest when machining copper plate at this angle, and the precision is the highest. At the same time, due to the smallest vibration amplitude, the service life of the tool is further improved, which can be used for continuous machining on large molds. At the same time, due to the smallest vibration amplitude, the production efficiency is further improved.

[0024] In this embodiment, please refer to Figure 4 , S103 uses the rotated tool to engrave on a smooth surface along a predetermined route, specifically, the tool engraves a first groove on a smooth surface along a third direction D and resets; the tool engraves a second groove on a smooth surface along a direction 60° of the third direction and resets; the tool engraves a third groove on a smooth surface along a direction -60° of the third direction and resets. Through the above steps, the triangular pyramid inverse reflection array is engraved on the smooth surface.

[0025] In this embodiment, the triangular pyramid inverse reflection array mold overall processing method is adopted, which allows the tool to cut V-shaped grooves of three channels on the metal substrate along three directions intersecting at 60° to obtain a triangular pyramid inverse reflection array. This processing method has high processing efficiency. It should be understood that the tool angle process proposed in the present application is suitable for overall processing method, and is not suitable for needle number binding method and thin sheet combination method. It can be understood that the angle proposed in the present application is a process improvement for the overall processing method, which is convenient for processing the mold by a low-cost method.

[0026] In this embodiment, it should be understood that the angle of the tool is designed according to the size of the triangular pyramid unit. That is, through the angle setting of the tool, triangular pyramids with a side length of 217 μm and a height of 98 μm can be engraved on the smooth surface of the mold. It should be understood that the present application adopts an ultra-precision five-axis machining equipment, which can ensure that the machining process of the tool with the above tool angle is not affected by other factors to process the product. That is, if a device with insufficient precision is used, the present application cannot guarantee that a mold meeting the V-class standard can be processed.

[0027] In the embodiment, it is understood that the angle of the cutter corresponds to a triangular pyramid with a side length of 217 μm and a height of 98 μm, and the triangular pyramid retroreflective mold processed can meet the processing standard of the V-class film. The preparation process of the triangular pyramid retroreflective original mold includes: processing of the triangular pyramid retroreflective array, chemical cleaning of the triangular pyramid retroreflective array, vacuum evaporation of the triangular pyramid retroreflective array, and the like. The purpose of the chemical cleaning and vacuum evaporation steps of the triangular pyramid retroreflective array is to further reduce the surface roughness value of the triangular pyramid retroreflective array.

[0028] In the embodiment, the size accuracy of the triangular pyramid is 1 μm, the angle accuracy is 0.2°, and the surface roughness Ra is less than 20 nm, and the maximum size is 200*200 mm, which can be achieved by using the ultra-precision five-axis machining equipment. It is understood that the ultra-precision five-axis machining equipment is used in the present application, which can ensure that the cutter machining process of the above cutter angle is not affected by other factors to process the product. That is, if a device with insufficient precision is used, the present application cannot guarantee that a mold meeting the V-class standard can be processed.

[0029] In the embodiment, the engraved metal plate is chemically cleaned and vacuum evaporated to form a triangular pyramid retroreflective film mold; the base layer is hot-pressed by using the triangular pyramid retroreflective film mold to form a triangular pyramid retroreflective array base layer with a single prism size of a side length of 217 μm and a height of 98 μm, and the triangular pyramid retroreflective array base layer is processed to form a triangular pyramid retroreflective film.

[0030] In the embodiment, the engraved metal plate is chemically cleaned and vacuum evaporated to form a triangular pyramid retroreflective film original mold, and the triangular pyramid retroreflective film working mold is obtained by electrocasting using the original mold, and the base layer is hot-pressed by using the triangular pyramid retroreflective film working mold to form a triangular pyramid retroreflective array base layer with a single prism size of a side length of 217 μm and a height of 98 μm, and the triangular pyramid retroreflective array base layer is processed to form a triangular pyramid retroreflective film.

[0031] In the embodiment, the base layer is a resin material.

[0032] It is understood that the prepared triangular pyramid retroreflective film original mold and the triangular pyramid retroreflective film working mold can be directly used to prepare a triangular pyramid retroreflective film. It is understood that the purpose of electrocasting is to reduce the processing cost, but the use of the original mold as the working mold is not excluded.

[0033] In the embodiment, the metal plate is made of elemental copper or brass. Copper has good heat conduction performance, ranking third among metals, and good ductility, easy to shape and process, and good corrosion resistance. In the subsequent hot pressing process, heat can be quickly conducted to facilitate the shaping of the triangular pyramid retroreflective film. Meanwhile, copper has good cutting performance, making it easy to process the mold.

[0034] The present application designs the tool tip angle and the tool offset angle according to the size characteristics of the triangular pyramid retroreflective array structure. Experimental results show that the mold prepared using the tool angles can prepare a triangular pyramid retroreflective film that meets the V-class film standard. The mold of the present application is made of copper, which has good heat conduction performance, ranking third among metals, and good ductility, easy to shape and process, and good corrosion resistance. In the subsequent hot pressing process, heat can be quickly conducted to facilitate the shaping of the triangular pyramid retroreflective film. Meanwhile, copper has good cutting performance, making it easy to process the mold

[0035] The preferred embodiment of the tool with a tool tip angle of 70.2°-70.8° and an offset angle of 0°-0.6° was tested, with other factors being the same. The test was performed using the measurement method defined by the JT2020 retroreflector photometric performance test method, and the results are as follows:

[0036] Preferred example 1:

[0037]

[0038]

[0039] Preferred example 2:

[0040]

[0041] In the preferred example measurement, the combinations of observation angle and incident angle are set as follows: 0.2° / -4°, 0.2° / 15°, 0.2° / 30°, and 0.5° / -4°, 0.5° / 15°, 0.5° / 30°, and 1° / -4°, 1° / 15°, 1° / 30°.

[0042] To examine the observation angle performance of the triangular pyramid retroreflective plate in the above-mentioned preferred examples, keeping the incident angle constant prevents observation of the three angles, thus allowing for the measurement of the retroreflection coefficient of the sample. Among the two preferred examples, preferred example 2 exhibits the best technical effect and the best retroreflection coefficient. It should be understood that this embodiment employs an integral machining method for the triangular pyramid retroreflective array mold. This method involves cutting three V-shaped grooves along three mutually 60° directions on the metal substrate to obtain the triangular pyramid retroreflective array, thus increasing processing efficiency. It should also be understood that the tool angle process proposed in this invention is suitable for the integral machining method but not for the pin-binding method or the thin-sheet combination method. It is understood that the angle proposed in this invention is a process improvement for the integral machining method, facilitating the production of the mold using a lower-cost method. It should be understood that this invention uses ultra-precision five-axis machining equipment, ensuring that the tool machining process at the aforementioned tool angle is unaffected by other factors. In other words, if equipment other than a five-axis machining equipment is used to clamp the tool in this invention, this invention cannot guarantee the production of a mold that meets the Class V standard. It should be understood that the angles selected in the above preferred examples are preferred angles within the tool tip angle range of 70.2°-70.8° and the deflection angle range of 0°-0.6°. It should also be understood that this invention uses the tool angle as a basis for mold carving; when this angle range is met, the mold can be carved. Similarly, it should be understood that the tool limitations mentioned in this invention are as follows:

[0043] ① Material: Carbide cutting tools or polycrystalline diamond cutting tools with a hardness greater than 91 HRC. Polycrystalline diamond cutting tools are preferred.

[0044] ② Tool forming method: One-piece forming or the basic tool is combined with nano-grinding process to process the tip angle of the basic tool.

[0045] This invention also proposes a primitive mold for a triangular pyramidal retroreflective film, which is carved using the carving method described in the above-mentioned carving method for a triangular pyramidal retroreflective mold. The carving method for this primitive mold has been described above and will not be repeated here.

[0046] This invention also proposes a working mold for a triangular pyramidal retroreflective film, which is made by electroforming from the aforementioned original mold for the triangular pyramidal retroreflective film. The engraving method of the original mold has been described above and will not be repeated here.

[0047] This invention also proposes a triangular pyramidal retroreflective film, which is prepared by the engraving method of the triangular pyramidal retroreflective mold described above. The preparation method of this triangular pyramidal retroreflective film has been described above and will not be repeated here.

[0048] This invention also proposes a cutting tool for machining triangular pyramidal retroreflective films, the tool having a tip angle of 70.2°.

[0049] -70.8°, and the tool is installed at the rear of the tool bar, and the tool has an angle of 0°-0.6° with the vertical direction. The use method of the tool has been described above, and will not be described here.

[0050] It can be found that the present application designs the tool tip angle and the deflection angle according to the size characteristics of the triangular pyramid retroreflective array structure; the experimental results show that the mold prepared by using the tool angle can prepare a triangular pyramid retroreflective film meeting the V-class film standard. The mold of the present application is made of copper, which has good heat conduction performance, ranks third among metals, has good ductility, is easy to form and process, and has good corrosion resistance. In the subsequent hot pressing process, heat can be quickly conducted to facilitate the formation of the triangular pyramid retroreflective film. At the same time, copper has good cutting performance and is easy to process the mold.

[0051] The above only describes some embodiments of the present application, and does not limit the protection scope of the present application, and any equivalent device or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for engraving a triangular pyramid retroreflective mold, characterized in that, The method includes: A metal plate is provided, the metal plate including a smooth surface; The smooth surface is cleaned; and A cutting tool with a tip angle of 70.2°-70.8° is placed above the smooth surface along a first direction. After placement, the tool is rotated 0°-0.6° along a second direction with the tip as the base point. The rotated tool is then used to engrave the smooth surface along a preset route. The engraved metal plate is then used to process a triangular pyramid retroreflective array with a side length of 215-219μm and a height of 97-100μm. The process involves using a rotating tool to carve along a predetermined path on a smooth surface. Specifically... The cutting tool carves a first groove on a smooth surface along a third direction and then resets; the cutting tool carves a second groove on a smooth surface along a 60° direction along a third direction and then resets; the cutting tool carves a third groove on a smooth surface along a -60° direction along a third direction and then resets. Offset the tool and repeat the above steps until the engraving is complete; The process of fabricating a triangular pyramid retroreflective array with a side length of 215-219 μm and a height of 97-100 μm using a carved metal plate includes: The engraved metal plate is chemically cleaned and vacuum-deposited to form a triangular pyramidal retroreflective film mold. The substrate layer was hot-pressed using the triangular pyramid retroreflective film mold to form a triangular pyramid retroreflective array substrate layer with a single prism size of 217μm side length and 98μm height; or, The engraved metal plate is chemically cleaned and vacuum-deposited to form a primitive mold for a triangular pyramid retroreflective film. The primitive mold is then electroformed to obtain a working mold for the triangular pyramid retroreflective film. The working mold is then used to hot-press the substrate layer to form a triangular pyramid retroreflective array substrate layer with a single prism size of 217 μm side length and 98 μm height. Finally, the triangular pyramid retroreflective array substrate layer is processed to form a triangular pyramid retroreflective film.

2. The engraving method for a triangular pyramid retroreflective mold as described in claim 1, characterized in that, The metal plate is made of elemental copper or brass.

3. A primitive mold for a triangular pyramidal retroreflective film, characterized in that, It is carved using the carving method described in claim 1 for a triangular pyramid retroreflective mold.

4. A working mold for a triangular pyramidal retroreflective film, characterized in that, The original mold of the triangular pyramidal retroreflective film according to claim 3 is made by electroforming.

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