Manufacturing method of microprism reflective film mold integrating two triangular pyramids and reflective film

Abstract

The invention relates to a manufacturing method of a microprism reflective film die integrating two triangular pyramids and a reflective film, and the manufacturing method of the die comprises the following steps: 1, respectively rotating a die base material on a B-axis rotary table to 0 degree, 120 degrees and 60 degrees, and machining a first tool to a third tool by using a first tool with a tool angle alpha mounted on a fly-cutter disc; the mold base material is rotated to be located at the 0-degree position, the 120-degree position and the 60-degree position, machining of the fourth tool, the fifth tool, the sixth tool and the sixth tool is conducted, in the machining of the fourth tool, the fifth tool, the sixth tool and the sixth tool, the first tool is used for machining, the second tool is used for machining, the first tool and the second tool are symmetrical tools, and the inclination angles of the two sides are the same. While better performance indexes under different application conditions are obtained, the influence of large conical surface angle deflection angle processing or asymmetric design on optimization and balance of the retroreflection performance of 0 / 90 / 180-degree orientation of the reflective film can be reduced.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a microprism retroreflective film mold integrating two triangular pyramids and a retroreflective film. Background Art

[0002] Design of a microprism retroreflective film based on a triangular pyramid unit structure: A cutting tool is used to machine the three pyramid surfaces of a triangular pyramid. The inclination angles of the three pyramid reflecting surfaces with respect to the vertical plane are the same, as Figure 1 shown. Such a design of the microprism retroreflective film is mainly used for Class III and Class IV retroreflective films with relatively low performance requirements. When used for Class V retroreflective films, under the conditions of large viewing angles and large incident angles, the retroreflective coefficient cannot meet the standard requirements. In order to meet the performance requirements of Class V retroreflective films, different design or manufacturing solutions have been proposed at home and abroad. The 3M Company in the United States has proposed an optical design of a retroreflective film using a full prism structure. However, this design has a complex structure, high requirements for the manufacturing accuracy of the mold, and a large impact of manufacturing errors on the performance of the retroreflective film, which limits its popularization and application in China.

[0003] Specifically, there is only one optical design variable for the microprism retroreflective film in the above Figure 1 , that is, the angles of the three pyramid surfaces of each triangular pyramid are the same. It is difficult to simultaneously improve the retroreflective performance at different incident angles and viewing angles, especially wide angles, that is, different azimuth angles, and to balance the retroreflective performance between different incident angles and viewing angles, especially wide angles and small incident angles, and the balance of retroreflective performance between different azimuth angles such as 0 degrees, 90 degrees, and 180 degrees.

[0004] In the prior art, in order to obtain the isotropy of the retroreflective performance of the retroreflective film at different azimuth angles, nickel molds for four types of retroreflective films are usually mechanically spliced using two nickel molds of the retroreflective film with different orientations of 0 degrees and 90 degrees to manufacture a roller master mold; by slightly adjusting an angle to deviate from the standard pyramid reflector structure, the regulation of the retroreflective performance of the retroreflective film is realized, such as improving the wide-angle performance. However, the above method is very cumbersome to manufacture and there is a mechanical splicing error, making it difficult to achieve the expected effect.

[0005] Although the microprism retroreflective film using a full prism has a 50% higher retroreflective performance than that using a triangular pyramid microprism retroreflective film, or the effective reflection area of the triangular pyramid retroreflective film is 66.67% of the effective reflection area of the full prism retroreflective film, the mold structure of the full prism retroreflective film, such as Chinese Patent Nos. 2015107772604 and 201811202555.9, is very complex, the manufacturing difficulty is very high, and due to the manufacturing error of the mold, the reflective performance is much lower than expected, thus limiting its popularization and application.

[0006] In view of the above deficiencies, the applicant applied for "Retroreflective Microprism Array Structure and Its Manufacturing Method" with publication number CN 117930406 A in March 2024 and "Microprism Reflective Film with Double Triangular Pyramid Composite Structure and Manufacturing Method of Its Mold" with publication number CN118759624B in September 2024 respectively.

[0007] Among them, although "Retroreflective Microprism Array Structure and Its Manufacturing Method" is more convenient for manufacturing compared with patents 2015107772604 and 201811202555.9, it avoids the difficulty of secondary clamping and machining of special-shaped surfaces and ensures the quality of the finished product. However, when making through holes on the second substrate in the processing procedure, it is necessary to drill holes one by one first, and then process them by wire cutting. The processing procedure is still relatively cumbersome. Moreover, each pyramid formed by its processing is a regular triangular pyramid, and the inclination angles of the pyramid surfaces are all the same. There is only one optical design variable for the microprism reflective film obtained, and it is difficult to obtain different incident angles and observation angles. That is, such a microprism reflective film design can meet the performance requirements of Class Ⅳ reflective films. When used for Class Ⅴ reflective films, under the conditions of large observation angles and large incident angles, the retroreflective coefficient cannot meet the standard requirements. Among them, "Microprism Reflective Film with Double Triangular Pyramid Composite Structure and Manufacturing Method of Its Mold" improves the wide-angle retroreflective performance of the reflective film to a certain extent through the regulation of the retroreflective performance of triangular pyramid B and achieves the expected goal. However, since the area ratio of triangular pyramid A to B in the double triangular pyramid composite structure is 75%:25%, the area ratio of pure triangular pyramid B used to optimize the wide-angle performance is only 25%. There are certain limitations in further improving the wide-angle retroreflective performance of the reflective film. Summary of the Invention

[0008] In view of the above existing problems, the purpose of the present invention is to provide a manufacturing method of a microprism reflective film mold integrating two kinds of triangular pyramids and a reflective film. The manufacturing method of the microprism reflective film mold integrating two kinds of triangular pyramids and the reflective film are reasonably designed, can increase the degree of freedom of optical design, obtain better performance indicators under different application conditions, and can reduce the influence of large cone surface angle deviation machining or asymmetric design on optimizing and balancing the retroreflective performance of the 0 / 90 / 180-degree orientation of the reflective film.

[0009] The technical solution of the present invention is as follows: The manufacturing method of the microprism reflective film mold integrating two kinds of triangular pyramids of the present invention is characterized in that: The mold substrate is horizontally installed on the workbench. The workbench can drive the mold substrate to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold substrate to rotate around the normal B-axis of the mold substrate. Above the mold substrate, there is a main shaft parallel to the upper surface of the mold substrate and a fly cutter disk fixedly connected to the main shaft. Replaceable cutters are installed on the fly cutter disk, and the cutters can rotate around the Y-axis driven by the main shaft. The specific manufacturing steps are as follows: S1. Rotate the mold substrate on the B-axis turntable to angles of 0°, 120°, and 60° respectively, and use the first type of cutter array with a cutter angle of α on the fly cutter disk to machine the four side cones and the two diagonal cones of the parallelogram unit body, that is, the first to the third cuts. The first type of cutter is a symmetric cutter with the same inclination angles on both sides, and the inclination angle of the cone surface of the machined mold is α / 2; S2. On the basis of the structure machined in step S1, rotate the mold substrate at positions of 0°, 120°, and 60°, and perform the fourth to the sixth cutter array machining. Among the fourth to the sixth cuts, two cuts use the first type of cutter for machining, and the other cut uses the second type of cutter for machining. The second type of cutter is a symmetric cutter with the same inclination angles on both sides, and the inclination angle of the cone surface of the machined mold is β / 2; So far, a microprism retroreflective film mold integrating two types of triangular pyramids is machined. These two types of triangular pyramids are triangular pyramid A and triangular pyramid B respectively, and the area ratio of triangular pyramid A and triangular pyramid B is 50%:50%. The inclination angles of the three cone surfaces of each triangular pyramid A are all α / 2, the inclination angles of the two cone surfaces of each triangular pyramid B are α / 2, and the inclination angle of one cone surface of each triangular pyramid B is β / 2.

[0010] Preferably, the fourth cut uses the second type of cutter for machining, and the fifth and sixth cuts use the first type of cutter for machining.

[0011] Preferably, the fifth cut uses the second type of cutter for machining, and the fourth and sixth cuts use the first type of cutter for machining.

[0012] Preferably, the sixth cut uses the second type of cutter for machining, and the fourth and fifth cuts use the first type of cutter for machining.

[0013] Preferably, the cutter angle of the first type of cutter is 70.55 degrees, the cutter angle of the second type of cutter is 70.90 degrees. The first to the third cuts use the first type of cutter for machining, and the mold substrate is rotated to angles of 0°, 120°, and 60° respectively, and the array pitch is 0.433 mm; the fourth and fifth cuts use the first type of cutter for machining, and the mold substrate is rotated to angles of 0° and 120° respectively, and the array pitch is 0.433 mm. The sixth cut uses the second type of cutter for machining, and the mold substrate is rotated to an angle of 60°, and the array pitch is 0.433 mm; a microprism retroreflective film mold integrating a combined structure of two types of triangular pyramids is machined: the side length of the triangular pyramid is 250 microns, and the area ratio of triangular pyramid A and triangular pyramid B is 1:1.

[0014] Preferably, the specific processing steps are as follows: Step 1: Rotate the mold substrate on the B-axis turntable by an angle of 0 degrees, and use the first tool array with a tool angle of α installed on the fly cutter head to machine the two tapered surfaces of the parallelogram unit body, and the inclination angles of the tapered surfaces are both α / 2; Step 2: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees, and use the first tool array with a tool angle of α installed on the fly cutter head to machine the other two tapered surfaces of the parallelogram unit body, and the inclination angles of the tapered surfaces are both α / 2; Step 3: Rotate the mold substrate on the B-axis turntable by an angle of 60 degrees, and use the first tool array with a tool angle of α installed on the fly cutter head to machine the tapered surfaces of the two opposite corners of the parallelogram unit body 1, and the inclination angles of the tapered surfaces are both α / 2; Step 4: On the basis of the structure machined in Step 3, rotate the mold substrate to the 0-degree position, and use the second tool array to machine a tapered surface with an inclination angle of β / 2; Step 5: Rotate the mold substrate to 120 degrees in sequence, and use the first tool array for machining, and the inclination angles of the tapered surfaces are both α / 2; Step 6: Rotate the mold substrate to 60 degrees in sequence again, and use the first tool array for machining, and the inclination angles of the tapered surfaces are both α / 2.

[0015] The present invention integrates a microprism retroreflective film with two types of triangular pyramids. The surface of the microprism retroreflective film is formed by an array of identical parallelogram unit bodies. Each parallelogram unit body is composed of four identical triangular pyramids A and four hybrid triangular pyramids B. The bottom surfaces of the triangular pyramids A and the hybrid triangular pyramids B are both the same equilateral triangles. The area ratio of the triangular pyramids A to the hybrid triangular pyramids B is 1:1. The inclination angles of the three tapered surfaces of each triangular pyramid A are all α / 2. The inclination angles of the two tapered surfaces of each triangular pyramid B are α / 2, and the inclination angle of one tapered surface of each triangular pyramid B is β / 2.

[0016] Preferably, α = 70.55 degrees and β = 70.90 degrees as described above.

[0017] Preferably, the array pitch of the above microprism retroreflective film is 0.433 mm.

[0018] The present invention has the following technical advantages.

[0019] 1. Optimized area ratio. The area ratio of the triangular pyramid A to the hybrid triangular pyramid B in the present invention is 50%:50%. Compared with the "Manufacturing Method of Microprism Retroreflective Film with Double Triangular Pyramid Composite Structure and Its Mold" with the publication number CN118759624B, the area ratio of the triangular pyramid B is increased from 25% to 50%, which is beneficial to improving the wide-angle retroreflective performance of the retroreflective film.

[0020] 2. The optimization design is convenient. Only by selecting a conical surface angle β / 2 of the triangular pyramid B can the wide-angle retroreflective performance of the reflective film be optimized and improved.

[0021] 3. The processing technology is simple. The first type of tool α can be used to fly-cut five times, and then the second type of tool β is used to fly-cut once, which is far simpler and lower in cost than the manufacturing of the 3M full prism mold.

[0022] 4. The design verification is simple. First, optimize and verify the pure triangular pyramid A(α / 2, α / 2, α / 2), then optimize and verify the mixed triangular pyramid B(α / 2, α / 2, β / 2), and finally verify the double triangular pyramid combined structure A + B. The verification is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings; Figure 1 is the front view of the traditional triangular pyramid; Figure 2 is the three-dimensional schematic diagram of the mold base placed on the workbench for processing; Figure 3 is the sectional structure schematic diagram of using the first type of tool to process the mold base; Figure 4 is the sectional structure schematic diagram of using the second type of tool to process the mold base; Figure 5 is the front view structure schematic diagram of the microprism reflective film (or mold finished product) of the present invention (only the fourth cut uses the second type of tool for processing, and the others use the first type of tool for processing); Figure 6 is the front view structure schematic diagram of the microprism reflective film (or mold finished product) of the present invention (only the fifth cut uses the second type of tool for processing, and the others use the first type of tool for processing); Figure 7 is the front view structure schematic diagram of the microprism reflective film (or mold finished product) of the present invention (only the sixth cut uses the second type of tool for processing, and the others use the first type of tool for processing); Figure 8 is the three-dimensional structure schematic diagram of the mold base before processing; Figure 9 is Figure 8 the front view of Figure 10 is Figure 8 the front view of the mold base of after being processed through step 1; Figure 11 is Figure 10 the front view of the mold base of after being processed through step 2; Figure 12 is Figure 11 the front view of the mold base of after being processed through step 3; Figure 13 isFigure 12 Stereogram; Figure 14 is Figure 12 The front view of the mold substrate of after being processed by step 4; Figure 15 is Figure 14 Schematic diagram of the three-dimensional structure of ; Figure 16 is Figure 14 The front view of the mold substrate of after being processed by step 5; Figure 17 is Figure 16 Schematic diagram of the three-dimensional structure of ; Figure 18 is Figure 16 The front view of the mold substrate of after being processed by step 6; Figure 19 is Figure 18 Schematic diagram of the three-dimensional structure of , that is, the schematic diagram of the three-dimensional structure of the finished mold of the present application. Specific embodiments

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] The present invention integrates a method for manufacturing molds of two types of triangular pyramid microprism retroreflective films. The mold substrate K1 is horizontally installed on the workbench K2. The workbench can drive the mold substrate to move along the X-axis and Y-axis in the horizontal direction, and the B-axis turntable on the workbench can drive the mold substrate to rotate around the normal B-axis of the mold substrate. Above the mold substrate, there is a main shaft K3 parallel to the upper surface of the mold substrate and a fly cutter head K4 fixedly connected to the main shaft. A replaceable cutter K5 is installed on the fly cutter head. The cutter can rotate around the Y-axis under the drive of the main shaft. The specific manufacturing steps are as follows: S1. Rotate the mold substrate on the B-axis turntable to angles of 0°, 120°, and 60° respectively, and use the first type of cutter array with a cutter angle of α installed on the fly cutter head to machine the four side conical surfaces and the two diagonal conical surfaces of the parallelogram unit 1, that is, the first to the third cuts. The first type of cutter is a symmetric cutter (the cutter has no deflection angle), and the two side inclination angles are the same. The inclination angle of these conical surfaces of the machined mold is α / 2; S2. On the basis of the structure processed in step S1, rotate the mold substrate to the positions of 0°, 120°, and 60°, and perform the fourth to sixth cutter array machining. In the fourth to sixth cuts, two cuts use the first type of cutter for machining, and the other cut uses the second type of cutter (the cutter has no deflection angle). The second type of cutter is a symmetric cutter, and the two side inclination angles are the same. The inclination angle of the conical surface of the machined mold is β / 2; So far, a microprism retroreflective film mold integrating two types of triangular pyramids has been processed. These two types of triangular pyramids are triangular pyramid A and triangular pyramid B respectively, and the area ratio of triangular pyramid A and triangular pyramid B is 50%:50%. The inclination angles of the three conical surfaces of each triangular pyramid A are all α / 2, the inclination angles of two conical surfaces of each triangular pyramid B are α / 2, and the inclination angle of one conical surface of each triangular pyramid B is β / 2.

[0026] In the machining from the 4th cut to the 6th cut, two cuts use the first type of tool for machining, and the other cut uses the second type of tool for machining. For example, if the 4th cut uses the second type of tool for machining, the 5th and 6th cuts use the first type of tool for machining; or if the 5th cut uses the second type of tool for machining, the 4th and 6th cuts use the first type of tool for machining; or the 6th cut uses the second type of tool for machining, and the 4th and 5th cuts use the first type of tool for machining.

[0027] Taking the 4th cut using the second type of tool for machining, and the 5th and 6th cuts using the first type of tool for machining as an example, the specific machining steps are as follows: Step 1 (the 1st cut): Rotate the mold substrate on the B-axis turntable by an angle to 0 degrees (or 180 degrees) (i.e., Figure 9 the state shown), and use the first type of tool array with a tool angle of α installed on the fly cutter head to machine the two conical surfaces on both sides of the parallelogram unit body (i.e., Figure 10 the upper and lower conical surfaces, and during the machining process, the workbench drives the mold substrate to move along the X-axis direction).

[0028] Step 2 (the 2nd cut): Rotate the mold substrate on the B-axis turntable by an angle to 120 degrees (or 300 degrees) (i.e., rotate counterclockwise by 120 degrees (or 300 degrees) around the center of the B-axis in the state shown in Figure 9 ), and use the first type of tool array with a tool angle of α installed on the fly cutter head to machine the other two conical surfaces of the parallelogram unit body (i.e., Figure 11 the left and right conical surfaces, and during the machining process, the workbench drives the mold substrate to move along the X-axis direction).

[0029] Step 3 (the 3rd cut): Rotate the mold substrate on the B-axis turntable by an angle to 60 degrees (or 240 degrees) (i.e., rotate counterclockwise by 60 degrees (or 240 degrees) around the center of the B-axis in the state shown in Figure 9 ), and use the first type of tool array with a tool angle of α installed on the fly cutter head to machine the conical surfaces at two opposite corners of the parallelogram unit body 1, as shown in Figure 12 , 13 shown.

[0030] Step 4 (the 4th cut): On the basis of the structure after the machining in Step 3, rotate the mold substrate to the 0-degree position (i.e., the position shown in Figure 9 ), and during the machining process, the workbench drives the mold substrate to move along the X-axis direction, and use the second type of tool array to machine to form a conical surface with an inclination angle of β / 2; asFigure 14 , 15 as shown

[0031] Step 5 (the 5th cut): Rotate the mold substrate sequentially by 120 degrees (i.e., rotate counterclockwise by 120 degrees around the center at the position shown Figure 9 ), and use the first type of tool array for machining. During the machining process, the workbench drives the mold substrate to move along the X-axis direction, as shown Figure 16 , 17 ; Step 6 (the 6th cut): Rotate the mold substrate sequentially by 60 degrees (i.e., rotate counterclockwise by 60 degrees around the center at the position shown Figure 9 ), and use the first type of tool array for machining. During the machining process, the workbench drives the mold substrate to move along the X-axis direction, as shown Figure 18 , 19 ;

[0032] Figure 18 , 19 That is, the schematic diagram of the structure of the mold finished product of this application, Figure 18 , 19 is the same as Figure 5 . They are both schematic diagrams of the structure of the mold for making the reflective film of this application. The shape and size of the mold obtained by the above method are the same as those of the reflective film formed by the subsequent production of this mold.

[0033] Specific Example 1 of the mold manufacturing method: The tool angle of the first type of tool is 70.55 degrees, and the tool angle of the second type of tool is 70.90 degrees. The first to the third cuts use the first type of tool for machining. The mold substrate rotates to 0 degrees, 120 degrees, and 60 degrees respectively, and the array pitch is 0.433 mm; the fourth and fifth cuts use the first type of tool for machining. The mold substrate rotates to 0 degrees and 120 degrees respectively, and the array pitch is 0.433 mm. The sixth cut uses the second type of tool for machining. The mold substrate rotates to 60 degrees, and the array pitch is 0.433 mm; a microprism reflective film mold integrating two triangular pyramid combination structures is machined and formed: the side length of the triangular pyramid is 250 microns, and the area ratio of triangular pyramid A and triangular pyramid B is 1:1.

[0034] Comparative Example of the mold manufacturing method: The difference between this comparative example and the above example is that a flying tool is used to machine 3 cuts to form a triangular pyramid. The designed tool angle of this flying tool is α = 70.55°, and the rotation axes B of the equipment for the first to the third cuts use 0°, 60°, and 120° respectively, and the array pitch is 0.2165 mm. The sample of the single triangular pyramid structure is machined and formed: the side length of the triangular pyramid is 250 microns, and the inclination angles of the three conical surfaces of the triangular pyramid are α / 2, α / 2, α / 2.

[0035] The comparison test data between the above Example 1 and the comparative example are as follows:

[0036] Compared with the comparative example, Example 1 of the present invention solves the problem that the retroreflective performance cannot meet the Class V standard under the test conditions of (observation angle 0.5°, incident angle 30°), (observation angle 1°, incident angle -4°), (observation angle 1°, incident angle 15°), and (observation angle 1°, incident angle 30°). At the same time, by reducing the interference fit performance at an observation angle of 0.2°, the retroreflective performance at an observation angle of 0.5° is improved.

[0037] A microprismatic retroreflective film integrating two types of triangular pyramids is obtained by using the mold prepared by the above manufacturing method. The surface of the microprismatic retroreflective film is formed by an array of identical parallelogram unit cells 1. Each parallelogram unit cell 1 is composed of four identical triangular pyramids A and four hybrid triangular pyramids B. The bases of the triangular pyramids A and the hybrid triangular pyramids B are all identical equilateral triangles. The area ratio of the triangular pyramids A to the hybrid triangular pyramids B is 1:1. The inclination angles of the three conical surfaces of each triangular pyramid A are all α / 2, the inclination angles of two conical surfaces of each triangular pyramid B are α / 2, and the inclination angle of one conical surface of each triangular pyramid B is β / 2.

[0038] Where α = 70.55 degrees and β = 70.90 degrees; the array pitch of the microprismatic retroreflective film is 0.433 mm.

[0039] The present invention has the following technical advantages.

[0040] 1. Optimized area ratio. The area ratio of the triangular pyramid A to the hybrid triangular pyramid B in the present invention is 50%:50%. Compared with the "Manufacturing Method of Microprismatic Retroreflective Film and Its Mold with Double Triangular Pyramid Composite Structure" with publication number CN118759624B, the area ratio of the triangular pyramid B is increased from 25% to 50%, which is beneficial to improving the wide-angle retroreflective performance of the retroreflective film.

[0041] 2. Convenient optimized design. The wide-angle retroreflective performance of the retroreflective film can be optimized and improved only by selecting one conical angle β / 2 of the triangular pyramid B.

[0042] 3. Simple processing technology. It can be fly-cut five times with the first type of tool α and then fly-cut once with the second type of tool β, which is much simpler and lower in cost than the manufacturing of 3M full prism molds.

[0043] 4. Simple design verification. First, optimize and verify the pure triangular pyramid A (α / 2, α / 2, α / 2), then optimize and verify the hybrid triangular pyramid B (α / 2, α / 2, β / 2), and finally verify the double triangular pyramid composite structure A + B, and the verification is simple.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements on some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A manufacturing method of a micro - prism retro - reflective film mold integrating two triangular pyramids, characterized in that: The mold substrate (K1) is horizontally installed on the workbench (K2). The workbench can drive the mold substrate to move along the X - axis and Y - axis in the horizontal direction, and the B - axis turntable on the workbench can drive the mold substrate to rotate around the normal B - axis of the mold substrate. Above the mold substrate, there is a main shaft (K3) parallel to the upper surface of the mold substrate and a fly - cutter disk (K4) fixedly connected to the main shaft. A replaceable cutter (K5) is installed on the fly - cutter disk. The cutter can rotate around the Y - axis driven by the main shaft. The specific manufacturing steps are as follows: S1. Rotate the mold substrate on the B - axis turntable to angles of 0°, 120°, and 60° respectively. Use the first - type cutter array with a cutter angle of α on the fly - cutter disk to machine the four side - cones and two diagonal - cones of the parallelogram unit 1, that is, the first to the third cuts. The first - type cutter is a symmetric cutter with the same inclination angles on both sides. The inclination angle of the cone surface of the machined mold is α / 2. S2. Based on the structure machined in step S1, rotate the mold substrate to the positions of 0°, 120°, and 60°. Perform the fourth, fifth, and sixth - cutter array machining. In the fourth, fifth, and sixth - cutter machining, two cuts use the first - type cutter for machining, and the other cut uses the second - type cutter for machining. The second - type cutter is a symmetric cutter with the same inclination angles on both sides. The inclination angle of the cone surface of the machined mold is β / 2. So far, a micro - prism retro - reflective film mold integrating two triangular pyramids is machined. These two triangular pyramids are triangular pyramid A and triangular pyramid B respectively. The area ratio of triangular pyramid A and triangular pyramid B is 50%:50%. The inclination angles of the three cone surfaces of each triangular pyramid A are all α / 2, the inclination angles of the two cone surfaces of each triangular pyramid B are α / 2, and the inclination angle of one cone surface of each triangular pyramid B is β / 2.

2. The manufacturing method of the micro prism retroreflective film mold integrating two triangular pyramids according to claim 1, characterized in that: The fourth cut uses the second - type cutter for machining, and the fifth and sixth cuts use the first - type cutter for machining.

3. The manufacturing method of the microprism retroreflective film mold integrating two triangular pyramids according to claim 1, characterized in that: The fifth cut uses the second - type cutter for machining, and the fourth and sixth cuts use the first - type cutter for machining.

4. The manufacturing method of the micro prism retroreflective film mold integrating two triangular pyramids according to claim 1, characterized in that: The sixth cut uses the second - type cutter for machining, and the fourth and fifth cuts use the first - type cutter for machining.

5. The manufacturing method of the microprism retroreflective film mold integrating two triangular pyramids according to claim 1, characterized in that: The cutter angle of the first - type cutter is 70.55 degrees, and the cutter angle of the second - type cutter is 70.90 degrees. The first to the third cuts use the first - type cutter for machining. The mold substrate is rotated to angles of 0°, 120°, and 60° respectively, and the array pitch is 0.433 mm. The fourth and fifth cuts use the first - type cutter for machining. The mold substrate is rotated to angles of 0° and 120° respectively, and the array pitch is 0.433 mm. The sixth cut uses the second - type cutter for machining. The mold substrate is rotated to an angle of 60°, and the array pitch is 0.433 mm. A micro - prism retro - reflective film mold with a combined structure of two triangular pyramids is machined: the side length of the triangular pyramid is 250 microns, and the area ratio of triangular pyramid A and triangular pyramid B is 1:

1.

6. The manufacturing method of the microprism retroreflective film mold integrating two triangular pyramids according to claim 1, characterized in that: The specific processing steps are as follows: Step 1: Rotate the mold substrate on the B - axis turntable to an angle of 0°. Use the first - type cutter array with a cutter angle of α on the fly - cutter disk to machine the two side - cones of the parallelogram unit. The inclination angles of the cone surfaces are both α / 2. Step 2: Rotate the mold substrate on the B-axis turntable by an angle of 120 degrees, and use the first tool array with a tool angle of α installed on the fly cutter head to machine the other two conical surfaces of the parallelogram unit body, and the conical surface inclination angles are both α / 2; Step 3: Rotate the mold substrate on the B-axis turntable by an angle of 60 degrees, and use the first tool array with a tool angle of α installed on the fly cutter head to machine the conical surfaces at two diagonals of the parallelogram unit body 1, and the conical surface inclination angles are both α / 2; Step 4: Based on the structure machined in Step 3, rotate the mold substrate to the 0-degree position, and use the second tool array to machine a conical surface with an inclination angle of β / 2; Step 5: Rotate the mold substrate to 120 degrees in sequence, and use the first tool array to machine, and the conical surface inclination angles are both α / 2; Step 6: Rotate the mold substrate to 60 degrees in sequence again, and use the first tool array to machine, and the conical surface inclination angles are both α / 2.

7. A microprism retroreflective film integrating two triangular pyramids, which is produced by a mold obtained by the production method described in any one of claims 1-6, and is characterized in that: The surface of the microprism retroreflective film is formed by an array of the same parallelogram unit bodies 1. Each parallelogram unit body 1 is composed of four identical triangular pyramids A and four hybrid triangular pyramids B. The bottom surfaces of the triangular pyramids A and the hybrid triangular pyramids B are the same equilateral triangles. The area ratio of the triangular pyramids A and the hybrid triangular pyramids B is 1:

1. The inclination angles of the three conical surfaces of each triangular pyramid A are all α / 2, the inclination angles of the two conical surfaces of each triangular pyramid B are α / 2, and the inclination angle of one conical surface of each triangular pyramid B is β / 2.

8. The integrated microprism retroreflective film integrating two triangular pyramids according to claim 7, characterized in that: The α = 70.55 degrees and β = 70.90 degrees.

9. The integrated microprism retroreflective film integrating two triangular pyramids according to claim 8, wherein: The array intercept of the microprism retroreflective film is 0.433 mm.

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