Manufacturing method of micro-prismatic reflective film integrating three triangular pyramid combinations and mold thereof

Abstract

The present invention relates to a microprismatic reflective film integrating a combination of three triangular pyramids and a method for manufacturing the mold thereof. The present invention is characterized in that the surface of the microprismatic reflective film is formed by an array of identical parallelogram units, each of which is composed of four identical triangular pyramids A, two mixed triangular pyramids B, and two mixed triangular pyramids C. The bases of the triangular pyramids A, the mixed triangular pyramids B, and the mixed triangular pyramids C are all identical equilateral triangles. The inclination angles of the three pyramidal surfaces of each triangular pyramid A are α / 2, the inclination angles of the pyramidal surfaces of the mixed triangular pyramids B are α / 2, α / 2, and βL, and the inclination angles of the three pyramidal surfaces of the mixed triangular pyramids C are α / 2, α / 2, and βR, respectively. The present invention can reasonably optimize the performance under different application conditions, thereby achieving improved wide-angle performance and optimization and balance of overall comprehensive performance.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a micro-prismatic reflective film integrating three triangular pyramid combinations and a mold thereof. Background Art

[0002] Design of micro-prismatic reflective film based on triangular pyramid unit structure: use one tool to process the three pyramidal surfaces of the triangular pyramid, and the inclination angles (angles with the vertical plane) of the three pyramidal reflective surfaces are the same, such as Figure 1 As shown. This type of micro-prismatic reflective film design is mainly used for Class III and IV reflective films with low performance requirements. When used for Class V reflective film, the retroreflection coefficient cannot meet the standard requirements under conditions of large observation angles and large incident angles. In order to achieve the performance requirements of Class V reflective film, different design or manufacturing solutions have been proposed at home and abroad. 3M Company of the United States proposed a reflective film optical design using a full prism structure. However, this design has a complex structure and requires very high mold manufacturing precision. In addition, the manufacturing error has a great impact on the performance of the reflective film, which has limited its promotion and application in China.

[0003] Specifically, the above Figure 1 There is only one optical design variable for the microprismatic reflective film, and it is difficult to obtain a balance between the retroreflective performance at different incident angles and observation angles (especially wide angles), that is, at different azimuth angles, as well as a balance between the retroreflective performance at different incident angles and observation angles (especially wide angles and small incident angles), and at different azimuth angles (such as 0 degrees, 90 degrees, and 180 degrees).

[0004] In the prior art, to achieve isotropic uniformity in the retroreflective performance of reflective sheeting at different azimuth angles, four types of reflective sheeting nickel molds are typically manufactured by mechanically interlocking and splicing two reflective sheeting nickel molds with different orientations, one at 0 degrees and the other at 90 degrees, to create a roller master mold. This method achieves control of the retroreflective performance of the reflective sheeting (e.g., improving wide-angle performance) by slightly adjusting an angle to deviate from the standard corner cone reflector structure. However, this method is very cumbersome to manufacture and is subject to mechanical splicing errors, making it difficult to achieve the desired effect.

[0005] Although the retroreflective performance of the microprismatic reflective film using full prisms (US 3M) is 50% higher than that of the microprismatic reflective film using triangular pyramids (or the effective reflection area of ​​the triangular pyramid reflective film is 66.67% of the effective reflection area of ​​the full pyramid reflective film), the mold structure of the full pyramid reflective film (such as Chinese patent No. 2015107772604 and 201811202555.9) is very complex and difficult to manufacture. In addition, the reflective performance is much lower than expected due to mold manufacturing errors, which limits its promotion and application.

[0006] In response to the above-mentioned shortcomings, the applicant applied for "Retro-reflective microprism array structure and its manufacturing method" (Announcement No. CN 117930406 A) in March 2024 and "Manufacturing method of microprismatic reflective film with double triangular pyramid combination structure and its mold" (Announcement No. CN118759624B) in September 2024.

[0007] Among them, although the "retro-reflective micro-prism array structure and its manufacturing method" is more convenient to manufacture than patents 2015107772604 and 201811202555.9, avoids the difficulty of secondary clamping and special-shaped surface processing, and ensures the quality of the finished product, when making through holes on the second substrate in the processing process, it is necessary to drill holes one by one and then process them by wire cutting. The processing process is still relatively cumbersome, and the corner cones formed by the processing are all regular triangular pyramids with the same inclination angle of the corner cone surface. The optical design variable of the micro-prismatic reflective film produced therefrom is only one, and it is difficult to obtain different incident angles and observation angles. That is, such a micro-prismatic reflective film design can meet the performance requirements of Class IV reflective film. When used for Class V reflective film, the retroreflection coefficient cannot meet the standard requirements under the conditions of large observation angles and large incident angles;

[0008] Among them, the "Manufacturing method of micro-prismatic reflective film with a double triangular pyramid combination structure and its mold" proposes using two tools with tool design angles of α and β to process two micro-prismatic reflective films with a triangular pyramid combination structure on the same mold substrate. After using the first tool with a tool angle of α to process the large triangular pyramid, the second tool with a tool angle of β is used for processing. According to the design requirements, the tool orientation is adjusted so that the inclination angles of the three corner cone surfaces of the central triangular pyramid are all β / 2. At this time, the inclination angles of the two corner cone surfaces of the corner triangular pyramid are α / 2, and the inclination angle of the third corner cone surface in the middle is β / 2. Although the wide-angle performance of the reflective film can be optimized to a certain extent by adjusting the angle variables of the triangular pyramid located in the center, or the performance of the reflective film at 0 degrees and 90 degrees can be optimized to a certain extent, the micro-prismatic reflective film obtained therefrom still has the disadvantage of insufficient freedom in optical design optimization. Summary of the Invention

[0009] In view of the above-mentioned problems, the purpose of the present invention is to propose a method for manufacturing a microprismatic reflective film and a mold thereof that integrates a combination of three triangular pyramids. The method for manufacturing a microprismatic reflective film and a mold thereof that integrates a combination of three triangular pyramids is rationally designed, can further increase the freedom of optical design, is conducive to optimizing the design, and obtains better performance indicators under different application conditions.

[0010] The technical solutions of the present invention are as follows:

[0011] The present invention integrates a microprismatic reflective film with three triangular pyramid combination structures, characterized in that: the surface of the microprismatic reflective film is formed by an array of identical parallelogram units, each parallelogram unit is composed of four identical triangular pyramids A, two mixed triangular pyramids B and two mixed triangular pyramids C, the bottom surfaces of the triangular pyramids A, the mixed triangular pyramids B and the mixed triangular pyramids C are all identical equilateral triangles, the inclination angles of the three corner cone surfaces of each triangular pyramid A are all α / 2, the inclination angles of the corner cone surfaces of the mixed triangular pyramid B are α / 2, α / 2 and βL, and the inclination angles of the three corner cone surfaces of the mixed triangular pyramid C are α / 2, α / 2 and βL. are α / 2, α / 2 and βR respectively; the triangular pyramids A are triangular pyramid A1, triangular pyramid A2, triangular pyramid A3 and triangular pyramid A4, the mixed triangular pyramids B are triangular pyramid B1 and triangular pyramid B2, the mixed triangular pyramids C are triangular pyramid C1 and triangular pyramid C2, the first row of parallelogram unit bodies are triangular pyramid A3, triangular pyramid A4, triangular pyramid C2 and triangular pyramid B2, the second row of parallelogram unit bodies are triangular pyramid C1, triangular pyramid B1, triangular pyramid A1 and triangular pyramid A2, and the directions of adjacent triangular pyramids are 180 degrees to each other.

[0012] Preferably, the pyramidal surface C101 of the triangular pyramid C1 is coplanar with the pyramidal surface A101 of the triangular pyramid A1, the pyramidal surface A401 of the triangular pyramid A4 is coplanar with the pyramidal surface B201 of the triangular pyramid B2, the pyramidal surface C102 of the triangular pyramid C1 is coplanar with the pyramidal surface A301 of the triangular pyramid A3, the pyramidal surface A201 of the triangular pyramid A2 is coplanar with the pyramidal surface B202 of the triangular pyramid B2, and the pyramidal surface A102 of the triangular pyramid A1 is coplanar with the pyramidal surface A301 of the triangular pyramid A3. 2 are coplanar, the pyramidal surface A202 of triangular pyramid A2 is coplanar with the pyramidal surface A402 of triangular pyramid A4, the pyramidal surface A303 of triangular pyramid A3 is coplanar with the pyramidal surface C201 of triangular pyramid C2, the pyramidal surface B101 of triangular pyramid B1 is coplanar with the pyramidal surface A203 of triangular pyramid A2, the pyramidal surface B102 of triangular pyramid B1 is coplanar with the pyramidal surface A403 of triangular pyramid A4, and the pyramidal surface A103 of triangular pyramid A1 is coplanar with the pyramidal surface C202 of triangular pyramid C2.

[0013] Preferably, the above-mentioned α=70.55 degrees, β=70.15 degrees, βL=35.15°, and βR=35.00°.

[0014] Preferably, the array intercept of the microprismatic reflective film is 0.433 mm, and each parallelogram unit in the microprismatic reflective film contains 8 triangular pyramids with a base length of 250 μm.

[0015] The present invention provides a method for manufacturing a mold for a microprismatic reflective film having an integrated structure of three triangular pyramid combinations, and is used to manufacture the mold for the microprismatic reflective film having an integrated structure of three triangular pyramid combinations.

[0016] The mold base is installed horizontally on a workbench. The workbench can drive the mold base to move along the horizontal X-axis and Y-axis. The B-axis turntable on the workbench can drive the mold base to rotate around the normal B-axis of the mold base. Above the mold base is a spindle parallel to the upper surface of the mold base and a flying cutter disk fixedly connected to the spindle. The flying cutter disk is equipped with a tool that can rotate around the Y-axis driven by the spindle. The specific steps of manufacturing are as follows:

[0017] Step 1: Rotate the mold substrate on the B-axis turntable to 0 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter disc to machine the two side cone surfaces of the parallelogram unit, namely, the cone surface C101 of the triangular pyramid C1, the cone surface A101 of the triangular pyramid A1, the cone surface A401 of the triangular pyramid A4, and the cone surface B201 of the triangular pyramid B2. The inclination angle is α / 2. The first type of tool is a symmetrical tool with the same inclination angle on both sides.

[0018] Step 2: Rotate the mold base on the B-axis turntable to 120 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the other two cone surfaces of the parallelogram unit, namely, the cone surface C102 of the triangular pyramid C1, the cone surface A301 of the triangular pyramid A3, the cone surface A201 of the triangular pyramid A2, and the cone surface B202 of the triangular pyramid B2, with their inclination angles also being α / 2;

[0019] Step 3: Rotate the mold base material on the B-axis turntable to 60 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the conical surfaces of the two opposite corners of the parallelogram unit body, namely, the conical surface A102 of the triangular pyramid A1, the conical surface A302 of the triangular pyramid A3, the conical surface A202 of the triangular pyramid A2, and the conical surface A402 of the triangular pyramid A4, whose inclination angle is also α / 2;

[0020] Step 4: Based on the structure processed in step 3, rotate the mold substrate to the 0 degree position, and use the first tool to machine the pyramidal surface B101 of the triangular pyramid B1 and the pyramidal surface A203 of the triangular pyramid A2, with an inclination angle of α / 2; at the same time, machine the pyramidal surface A303 of the triangular pyramid A3 and the pyramidal surface C201 of the triangular pyramid C2, with an inclination angle of α / 2;

[0021] Step 5: Rotate the mold substrate 120 degrees and use the first tool to machine the pyramidal surface B102 of the triangular pyramid B1 and the pyramidal surface A403 of the triangular pyramid A4, with an inclination angle of α / 2. Simultaneously, machine the pyramidal surface A103 of the triangular pyramid A1 and the pyramidal surface C202 of the triangular pyramid C2, with an inclination angle of α / 2.

[0022] Step 6: Replace and install a second type of asymmetric tool with a blade angle of β on the fly cutter disc. The left blade of the second type of tool has an inclination angle of βL, and the right blade has an inclination angle of βR. βL is not equal to βR. The inclination angle of the triangular pyramid reflective surface processed by the left blade is βL, and the inclination angle of the triangular pyramid reflective surface processed by the right blade is βR. Rotate the mold substrate again at 60 degrees in this order, and use the adjusted second type of tool to process and form the pyramid surface B103 of the triangular pyramid B1 and the pyramid surface B203 of the triangular pyramid B2, whose inclination angle is βL; at the same time, form the pyramid surface C103 of the triangular pyramid C1 and the pyramid surface C203 of the triangular pyramid C2, whose inclination angle is βR.

[0023] At this point, the mold for the microprismatic reflective film composed of three different triangular pyramid structures, namely, triangular pyramids A with inclination angles of α / 2, mixed triangular pyramids B with inclination angles of α / 2, α / 2 and βL, and mixed triangular pyramids C with inclination angles of α / 2, α / 2 and βR, has been processed and formed.

[0024] Preferably, the first tool has a blade angle α of 70.55 degrees; the second tool has an asymmetric blade angle of β = 70.15 degrees, the left blade angle is βL = 35.15 degrees, and the right blade angle is βR = 35.00 degrees; when processing, the first tool is used first, and the array processing is performed according to the B-axis rotation angle of 0 degrees, 60 degrees, and 120 degrees, and the intercept is 0.433 mm. The 1st to 3rd tools are formed into a large triangular pyramid, and then the B-axis rotation angles are 60 degrees, 120 degrees, and the intercept is 0.433 mm along the center of the edge of the large triangular pyramid. The 4th and 5th cuts were processed in an array along the connecting lines; finally, the second tool was replaced, and the 6th cut was processed in an array along the center connecting lines of adjacent edges of the large triangular pyramid with an intercept of 0.433 mm according to the B-axis rotation angle of 60° to form a composite microprismatic reflective film composed of a parallelogram unit array. Each parallelogram unit contains 8 triangular pyramids with a side length of 250 μm, of which the inclination angles of the reflection surfaces of 4 triangular pyramids are α / 2, the inclination angles of the reflection surfaces of 2 triangular pyramids are α / 2, α / 2 and βL respectively, and the inclination angles of the reflection surfaces of 2 triangular pyramids are α / 2, α / 2 and βR respectively.

[0025] The present invention has the following technical advantages.

[0026] From the perspective of optical design, the increase in the degree of freedom of optical design means that the optical system is expected to simultaneously meet the performance indicators of more different application conditions. For Class V reflective sheeting with high performance requirements, improving its wide-angle performance at large observation angles and large incident angles, and the performance of 90-degree and 0-degree azimuth orientations as well as their optimization and balance have always been the focus of research and development of Class V reflective sheeting technology. The reflective sheeting of the present invention comprises a triangular pyramid A with a pyramidal surface inclination angle of α / 2, a mixed triangular pyramid B with pyramidal surface inclination angles of α / 2, α / 2 and βL, and three pyramidal surfaces with inclination angles of α / 2, α / 2 and βL, respectively. The three triangular pyramids of the mixed triangular pyramid C of α / 2 and βR achieve design freedom of the three triangular pyramids. The base area of ​​the three triangular pyramids A, B and C accounts for 50%, 25% and 25% respectively, which can reasonably optimize the performance under different application conditions, thereby obtaining wide-angle performance improvement that cannot be achieved by micro-prismatic reflective sheeting with traditional triangular pyramid unit structure and double triangular pyramid combination structure, as well as optimization and balance of overall comprehensive performance. It can further improve the performance of the reflective sheeting while maintaining the simplicity of the reflective sheeting structure and effectively controlling the complexity of the reflective sheeting mold manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings;

[0028] Figure 1 This is the main view of a traditional triangular pyramid;

[0029] Figure 2 It is a schematic diagram of the three-dimensional structure of the parallelogram unit body of the present invention;

[0030] Figure 3 yes Figure 2 The main view;

[0031] Figure 4 It is a three-dimensional schematic diagram of the mold substrate placed on the workbench for processing;

[0032] Figure 5 It is a schematic diagram of the cross-sectional structure of the die substrate processed by the flying cutter tool;

[0033] Figure 6 3D schematic diagram of the finished mold of the microprismatic reflective film of the present invention;

[0034] Figure 7 yes Figure 6 The main view (for intuitive viewing, the numbers in the figure correspond to each other) Figure 3 the number of the reflective film);

[0035] Figure 8 This is a schematic diagram of the three-dimensional structure of the mold base material when it is not processed;

[0036] Figure 9 yes Figure 8 The main view;

[0037] Figure 10 yes Figure 8 The front view of the mold substrate after being processed in step 1;

[0038] Figure 11 yes Figure 10 The front view of the mold substrate after processing in step 2;

[0039] Figure 12 yes Figure 11 The front view of the mold substrate after processing in step 3;

[0040] Figure 13 yes Figure 12 Stereoscopic image of

[0041] Figure 14 yes Figure 12 The front view of the mold substrate after processing in step 4;

[0042] Figure 15 yes Figure 14 Schematic diagram of the three-dimensional structure;

[0043] Figure 16 yes Figure 14 The front view of the mold substrate after processing in step 5;

[0044] Figure 17 yes Figure 16 Schematic diagram of the three-dimensional structure;

[0045] Figure 18 yes Figure 16 The front view of the mold substrate after processing in step 6;

[0046] Figure 19 yes Figure 18 A schematic diagram of the three-dimensional structure of the mold product of the present application (i.e., a schematic diagram of the three-dimensional structure of the mold product of the present application). DETAILED DESCRIPTION

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0048] The surface of the microprismatic reflective film integrating three triangular pyramid combinations of the present invention is formed by an array of identical parallelogram units 1, each parallelogram unit 1 being composed of four identical triangular pyramids A, two mixed triangular pyramids B, and two mixed triangular pyramids C. The bottom surfaces of the triangular pyramids A, the mixed triangular pyramids B, and the mixed triangular pyramids C are all identical equilateral triangles. The inclination angles of the three corner pyramid surfaces of each triangular pyramid A are all α / 2, the inclination angles of the corner pyramid surfaces of the mixed triangular pyramid B are α / 2, α / 2, and βL, and the inclination angles of the three corner pyramid surfaces of the mixed triangular pyramid C are α / 2, α / 2, and βL, respectively. 2 and βR; the triangular pyramids A are triangular pyramid A1, triangular pyramid A2, triangular pyramid A3 and triangular pyramid A4, the mixed triangular pyramids B are triangular pyramid B1 and triangular pyramid B2, the mixed triangular pyramids C are triangular pyramid C1 and triangular pyramid C2, the first row of the parallelogram unit body 1 is triangular pyramid A3, triangular pyramid A4, triangular pyramid C2 and triangular pyramid B2, the second row of the parallelogram unit body 1 is triangular pyramid C1, triangular pyramid B1, triangular pyramid A1 and triangular pyramid A2, and the directions of adjacent triangular pyramids are 180 degrees to each other.

[0049] In one embodiment, the array intercept of the microprismatic reflective film is 0.433 mm, and each parallelogram unit 1 in the microprismatic reflective film contains 8 triangular pyramids with a base length of 250 μm; α=70.55 degrees, β=70.15 degrees, βL=35.15°, and βR=35.00°.

[0050] The pyramidal surface C101 of the triangular pyramid C1 is coplanar with the pyramidal surface A101 of the triangular pyramid A1, the pyramidal surface A401 of the triangular pyramid A4 is coplanar with the pyramidal surface B201 of the triangular pyramid B2, the pyramidal surface C102 of the triangular pyramid C1 is coplanar with the pyramidal surface A301 of the triangular pyramid A3, the pyramidal surface A201 of the triangular pyramid A2 is coplanar with the pyramidal surface B202 of the triangular pyramid B2, the pyramidal surface A102 of the triangular pyramid A1 is coplanar with the pyramidal surface A302 of the triangular pyramid A3 Coplanar, the pyramidal surface A202 of the triangular pyramid A2 is coplanar with the pyramidal surface A402 of the triangular pyramid A4, the pyramidal surface A303 of the triangular pyramid A3 is coplanar with the pyramidal surface C201 of the triangular pyramid C2, the pyramidal surface B101 of the triangular pyramid B1 is coplanar with the pyramidal surface A203 of the triangular pyramid A2, the pyramidal surface B102 of the triangular pyramid B1 is coplanar with the pyramidal surface A403 of the triangular pyramid A4, and the pyramidal surface A103 of the triangular pyramid A1 is coplanar with the pyramidal surface C202 of the triangular pyramid C2.

[0051] The specific processing method for the mold used to manufacture the aforementioned micro-prismatic reflective film integrating the three triangular pyramid combinations is as follows.

[0052] Example 1, as Figure 4 、 5As shown, the mold base K1 is horizontally mounted on a workbench K2. The workbench can drive the mold base to move along the horizontal X-axis and Y-axis, and the B-axis turntable on the workbench can drive the mold base to rotate around the normal B-axis of the mold base. Above the mold base is a spindle K3 parallel to the upper surface of the mold base and a flying cutter disk K4 fixedly connected to the spindle. The spindle K3 can be driven by an existing machine tool. The flying cutter disk is equipped with a tool K5, which can rotate around the Y-axis driven by the spindle. The specific steps of manufacturing are as follows:

[0053] Step 1: Rotate the mold base on the B-axis turntable to 0 degrees (or 180 degrees) (i.e. Figure 9 As shown in the figure), the first type of tool with a tool angle α installed on the fly cutter disc is used to machine the two side cone surfaces of the parallelogram unit body (i.e. Figure 10 The upper and lower conical surfaces of the triangular pyramid C1, the workbench drives the mold substrate to move along the X-axis during the processing), that is, the pyramid surface C101 of the triangular pyramid C1, the pyramid surface A101 of the triangular pyramid A1, the pyramid surface A401 of the triangular pyramid A4, and the pyramid surface B201 of the triangular pyramid B2, whose inclination angle is α / 2. The first type of tool is a symmetrical tool with the same inclination angle on both sides. In one embodiment, α=70.55 degrees, and the inclination angle on both sides is 35.275 degrees. Figure 10 shown.

[0054] Step 2: Rotate the mold base material on the B-axis turntable to 120 degrees (or 300 degrees) (i.e. Figure 9 In the state shown, rotate 120 degrees (or 300 degrees) counterclockwise around the center), and use the first type of tool with a tool angle of α installed on the fly cutter disc to machine the other two sides of the parallelogram unit (i.e. Figure 11 The left and right cone surfaces of the triangular pyramid C1, the workbench drives the mold substrate to move along the X-axis during the processing), namely the cone surface C102 of the triangular pyramid C1, the cone surface A301 of the triangular pyramid A3, the cone surface A201 of the triangular pyramid A2 and the cone surface B202 of the triangular pyramid B2, whose inclination angles are also α / 2, as shown in FIG. Figure 11 shown.

[0055] Step 3: Rotate the mold base material on the B-axis turntable to 60 degrees (or 240 degrees) (i.e. Figure 9 In the state shown, rotate 60 degrees (or 240 degrees) counterclockwise around the center, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the two diagonal cone surfaces of the parallelogram unit 1, namely the cone surface A102 of the triangular pyramid A1, the cone surface A302 of the triangular pyramid A3, the cone surface A202 of the triangular pyramid A2, and the cone surface A402 of the triangular pyramid A4, whose inclination angle is also α / 2, as shown in FIG. Figure 12 、 13 shown.

[0056] Step 4: Based on the structure after step 3, rotate the mold substrate to the 0 degree position (that is, Figure 9 As shown in the figure), the first type of tool is used to form the pyramidal surface B101 of the triangular pyramid B1 and the pyramidal surface A203 of the triangular pyramid A2, whose inclination angle is α / 2; at the same time, the pyramidal surface A303 of the triangular pyramid A3 and the pyramidal surface C201 of the triangular pyramid C2 are formed, whose inclination angle is α / 2; Figure 14 、 15 shown.

[0057] Step 5: Rotate the mold substrate 120 degrees (i.e. Figure 9 The first tool is used to form the pyramidal surface B102 of the triangular pyramid B1 and the pyramidal surface A403 of the triangular pyramid A4, whose inclination angle is α / 2. At the same time, the pyramidal surface A103 of the triangular pyramid A1 and the pyramidal surface C202 of the triangular pyramid C2 are formed, whose inclination angle is α / 2. Figure 16 、 17 As shown;

[0058] Step 6: Replace the second type of tool with an asymmetric structure with a blade angle of β on the fly cutter disc. The left blade angle of the second type of tool is βL, and the right blade angle is βR. βL is not equal to βR. The inclination angle of the triangular pyramid reflective surface processed by the left blade is βL, and the inclination angle of the triangular pyramid reflective surface processed by the right blade is βR. Rotate the mold substrate in sequence to 60 degrees (i.e. Figure 9 The second tool adjusted above is used to form the pyramidal surface B103 of the triangular pyramid B1 and the pyramidal surface B203 of the triangular pyramid B2, with an inclination angle of βL; and the pyramidal surface C103 of the triangular pyramid C1 and the pyramidal surface C203 of the triangular pyramid C2 are formed at the same time, with an inclination angle of βR; Figure 18 、 19 shown.

[0059] Figure 18 、 19 That is, the structural diagram of the finished mold of this application, Figure 18 、 19 and Figure 7 、 8 They are all schematic diagrams of the structure of the mold used to make the reflective film of this application. The shape and size of the mold obtained by the above method are the same as the reflective film formed by the subsequent production of the mold. In order to facilitate intuitive viewing, Figure 7 The labels and Figure 2 The same reference numerals are used to reflect the one-to-one correspondence between the mold and the reflective film.

[0060] At this point, the mold for the microprismatic reflective film composed of three different triangular pyramid structures, namely, triangular pyramids A with inclination angles of α / 2, mixed triangular pyramids B with inclination angles of α / 2, α / 2 and βL, and mixed triangular pyramids C with inclination angles of α / 2, α / 2 and βR, has been processed and formed.

[0061] A specific processing example of Example 1: The first tool has a cutting angle α of 70.55 degrees; the second tool is an asymmetric tool with a cutting angle β of 70.15 degrees, a left blade angle βL of 35.15 degrees, and a right blade angle βR of 35.00 degrees; during processing, the first tool is first used, and array processing is performed according to the B-axis rotation angles of 0 degrees, 60 degrees, and 120 degrees, with an intercept of 0.433 mm. The first to third tools are processed to form a large triangular pyramid (side length 500 microns, refer to the above steps 1-3 and Figure 9-13 ), then rotate the B axis at 60° and 120° respectively, and process the 4th and 5th cuts along the center line of the large triangular pyramid edge with an intercept of 0.433mm; finally, replace the second tool, rotate the B axis at 60° and 0.433mm respectively, and process the 6th cut along the center line of the adjacent edge of the large triangular pyramid to form a composite microprismatic reflective film composed of a parallelogram unit array (refer to the above steps 4-6 and Figure 14-19 ), each parallelogram unit contains 8 triangular pyramids with a side length of 250 μm, of which the inclination angles of the reflection surfaces of 4 triangular pyramids are α / 2, the inclination angles of the reflection surfaces of 2 triangular pyramids are α / 2, α / 2 and βL respectively, and the inclination angles of the reflection surfaces of 2 triangular pyramids are α / 2, α / 2 and βR respectively.

[0062] In order to verify the significant advantages of the above embodiments of the present application, a comparative example is provided below:

[0063] The tool angle α = 70.55 degrees, the side length of the triangular pyramid is 250μm, the rotation angles along the B axis are 0 degrees (or 180 degrees), 60 degrees (or 240 degrees), and 120 degrees (or 300 degrees), and the intercept is 216.5μm. The array is processed to form a conventional triangular pyramid microprismatic reflective film composed of an array of identical parallelogram units. Each parallelogram unit is composed of two identical triangular pyramids, and the inclination angle of the reflecting surface of the triangular pyramid is α / 2.

[0064] Technical Advantages: The comparative example is a conventional triangular pyramid microprismatic reflective sheeting, whose retroreflective performance is mainly distributed at a small observation angle of 0.2 degrees. It cannot meet the requirements of the Class V standard under the test conditions of an incident angle of 30 degrees, an observation angle of 0.5 degrees and 1 degree, and an observation angle of 1 degree, an incident angle of -4 degrees and 15 degrees. The microprismatic reflective sheeting prepared by the present invention is composed of three different triangular pyramids, which optimizes and improves the retroreflective performance under large observation angle and large incident angle test conditions, so that the retroreflective performance under all test conditions meets the Class V standard requirements.

[0065] In order to improve processing efficiency, the first knife (step 1) and the fourth knife (step 4) in the above processing steps can be performed together (the substrate is at the 0 degree position in both steps, that is, the B axis does not need to be rotated, only the Y axis of the substrate needs to be moved), and the second knife (step 2) and the fifth knife (step 5) can be performed together (the substrate is at the 120 degree position in both steps, that is, the B axis does not need to be rotated, only the Y axis of the substrate needs to be moved).

[0066] The mold obtained by the above processing is then processed by conventional technical means to obtain a reflective film (which is existing technology and will not be described here).

[0067] The "Method for Manufacturing Microprismatic Reflective Sheeting with a Double Triangular Pyramid Combination Structure and Its Mold" (Publication No. CN118759624B) uses a first tool with a knife angle of α to machine the large triangular pyramid, and then uses a second tool with a knife angle of β to machine the large triangular pyramid (a total of six cuts, six steps). Although adjusting the angle variables of the triangular pyramid at the center can optimize the wide-angle performance of the reflective sheeting to a certain extent, or achieve a certain degree of optimization of the 0-degree and 90-degree performance of the reflective sheeting, under the same processing steps (this application also uses six cuts, six steps), the microprismatic reflective sheeting produced by this patent still lacks the design freedom of the two triangular pyramids and lacks the freedom of optical design optimization.

[0068] The present application has three triangular pyramids, namely, a triangular pyramid A with a pyramidal surface inclination angle of α / 2, a mixed triangular pyramid B with a pyramidal surface inclination angle of α / 2, α / 2 and βL, and a mixed triangular pyramid C with three pyramidal surface inclination angles of α / 2, α / 2 and βR; it achieves the design freedom of the three triangular pyramids, and the base area of ​​the three triangular pyramids A, triangular pyramid B and triangular pyramid C accounts for 50%, 25% and 25% respectively, which can further reasonably optimize the performance under different application conditions, thereby obtaining wide-angle performance improvement that cannot be achieved by the micro-prismatic reflective film of the traditional triangular pyramid unit structure and the double triangular pyramid combination structure, as well as optimization and balance of the overall comprehensive performance.

[0069] As a special case, when βL=βR=β / 2, it becomes a conventional symmetrical structure pyramid surface. Another special case is that the pyramid surface is a symmetrical structure but its orientation has a deviation angle △,

[0070] 1. The included angle β of the asymmetric cone is composed of the sum of the inclination angle βL of the left cone and the inclination angle βR of the right cone, that is, β=βL+βR.

[0071] 2. The inclination angles βL and βR of a pyramid with a deflection angle △ are equivalent to a specific asymmetric pyramid inclination angle: βL=β / 2+△, βR=β / 2-△.

[0072] 3. When △ = 0, βL = βR = β / 2. The left and right sides of the pyramid are symmetrical.

[0073] In this embodiment, during the mold forming process of the reflective film, the second type of tool with a tool angle β is a symmetrical structure tool. By adjusting the specific tool deflection angle Δ value, βL=β / 2+Δ and βR=β / 2-Δ. The selection of the tool deflection angle △ during the forming process is equivalent to using a specific asymmetric tool βL=β / 2+Δ and βR=β / 2-Δ. When the tool deflection angle △ changes, the angle β between two adjacent cone surfaces formed by the second type of tool remains unchanged. For a given tool angle β, once the deflection angle △ is selected, βL and βR are also determined accordingly. βL and βR are not two completely independent cone angle design variables, but are both dependent on the tool angle β and its deflection angle △.

[0074] In summary, the present invention has the following technical advantages.

[0075] From an optical design perspective, increased optical design freedom means that optical systems can potentially meet performance indicators for a wider range of different application conditions. For high-performance Class V reflective sheeting, improving its wide-angle performance at large observation angles, wide angles of incidence, and performance at both 90-degree and 0-degree azimuth orientations, as well as their optimization and balance, has always been a focus of research and development in Class V reflective sheeting technology. The reflective sheeting of the present invention comprises three triangular pyramids: a triangular pyramid A with a pyramidal surface inclination angle of α / 2, a hybrid triangular pyramid B with pyramidal surface inclination angles of α / 2, α / 2, and βL, and a hybrid triangular pyramid C with pyramidal surface inclination angles of α / 2, α / 2, and βR. This achieves design freedom for the three triangular pyramids, with the base area of ​​the three triangular pyramids A, B, and C accounting for 50%, 25%, and 25%, respectively. This allows for optimal performance optimization for different application conditions, thereby achieving wide-angle performance improvements unattainable with conventional microprismatic reflective sheeting with triangular pyramid unit structures or dual triangular pyramid combination structures, as well as overall optimization and balance of comprehensive performance.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention. They should all be included in the scope of the technical solution for protection of the present invention.

Claims

1. A microprismatic reflective sheeting integrating three triangular pyramid combinations, characterized by: The surface of the microprismatic reflective film is formed by an array of identical parallelogram units (1), each parallelogram unit (1) is composed of four identical triangular pyramids A, two mixed triangular pyramids B and two mixed triangular pyramids C, the bottom surfaces of the triangular pyramids A, the mixed triangular pyramids B and the mixed triangular pyramids C are all identical equilateral triangles, the inclination angles of the three angular pyramid surfaces of each triangular pyramid A are all α / 2, the inclination angles of the angular pyramid surfaces of the mixed triangular pyramid B are α / 2, α / 2 and βL, and the inclination angles of the three angular pyramid surfaces of the mixed triangular pyramid C are α / 2, α / 2 and βR respectively , βL is not equal to βR; the triangular pyramids A are triangular pyramids A1, A2, A3 and A4, the mixed triangular pyramids B are triangular pyramids B1 and B2, the mixed triangular pyramids C are triangular pyramids C1 and C2, the first row of the parallelogram unit body (1) is triangular pyramid A3, triangular pyramid A4, triangular pyramid C2 and triangular pyramid B2, the second row of the parallelogram unit body (1) is triangular pyramid C1, triangular pyramid B1, triangular pyramid A1 and triangular pyramid A2, the adjacent triangular pyramids are arranged in a circle. The directions of the cones are 180 degrees to each other; the pyramid surface C101 of the triangular pyramid C1 is coplanar with the pyramid surface A101 of the triangular pyramid A1, the pyramid surface A401 of the triangular pyramid A4 is coplanar with the pyramid surface B201 of the triangular pyramid B2, the pyramid surface C102 of the triangular pyramid C1 is coplanar with the pyramid surface A301 of the triangular pyramid A3, the pyramid surface A201 of the triangular pyramid A2 is coplanar with the pyramid surface B202 of the triangular pyramid B2, the pyramid surface A102 of the triangular pyramid A1 is coplanar with the pyramid surface A302 of the triangular pyramid A3, and the pyramid surface A202 of the triangular pyramid A2 is coplanar with the pyramid surface A301 of the triangular pyramid A3. The pyramidal surface A103 of the triangular pyramid A1 is coplanar with the pyramidal surface A402 of the triangular pyramid A4, the pyramidal surface A303 of the triangular pyramid A3 is coplanar with the pyramidal surface C201 of the triangular pyramid C2, the pyramidal surface B101 of the triangular pyramid B1 is coplanar with the pyramidal surface A203 of the triangular pyramid A2, the pyramidal surface B102 of the triangular pyramid B1 is coplanar with the pyramidal surface A403 of the triangular pyramid A4, and the pyramidal surface A103 of the triangular pyramid A1 is coplanar with the pyramidal surface C202 of the triangular pyramid C2; the base area of ​​the triangular pyramid A, the mixed triangular pyramid B and the mixed triangular pyramid C accounts for 50%, 25% and 25% respectively.

2. The microprismatic reflective sheeting integrating three triangular pyramid combinations according to claim 1, characterized in that: The α=70.55 degrees, β=70.15 degrees, βL=35.15 degrees, and βR=35.00 degrees.

3. The microprismatic reflective sheeting integrating three triangular pyramid combinations according to claim 2, characterized in that: The array intercept of the micro-prismatic reflective film is 0.433 mm, and each parallelogram unit (1) in the micro-prismatic reflective film contains 8 triangular pyramids with a base length of 250 μm.

4. A method for manufacturing a mold for a microprismatic reflective film having an integrated combination of three triangular pyramids, the method being used to manufacture the mold for the microprismatic reflective film having an integrated combination of three triangular pyramids as claimed in any one of claims 1 to 3, characterized in that: The mold base (K1) is horizontally mounted on a workbench (K2). The workbench can drive the mold base to move along the horizontal X-axis and Y-axis, and the B-axis turntable on the workbench can drive the mold base to rotate around the normal B-axis of the mold base. A spindle (K3) parallel to the upper surface of the mold base and a flying cutter disc (K4) fixedly connected to the spindle are provided above the mold base. A tool (K5) is mounted on the flying cutter disc. The tool can rotate around the Y-axis driven by the spindle. The specific steps of manufacturing are as follows: Step 1: Rotate the mold substrate on the B-axis turntable to 0 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter disc to machine the two side cone surfaces of the parallelogram unit, namely, the cone surface C101 of the triangular pyramid C1, the cone surface A101 of the triangular pyramid A1, the cone surface A401 of the triangular pyramid A4, and the cone surface B201 of the triangular pyramid B2. The inclination angle is α / 2. The first type of tool is a symmetrical tool with the same inclination angle on both sides. Step 2: Rotate the mold base on the B-axis turntable to 120 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter head to machine the other two cone surfaces of the parallelogram unit, namely, the cone surface C102 of the triangular pyramid C1, the cone surface A301 of the triangular pyramid A3, the cone surface A201 of the triangular pyramid A2, and the cone surface B202 of the triangular pyramid B2, with their inclination angles also being α / 2; Step 3: Rotate the mold base material on the B-axis turntable to 60 degrees, and use the first type of tool with a tool angle of α installed on the fly cutter disc to machine the two diagonal cone surfaces of the parallelogram unit (1), namely, the cone surface A102 of the triangular pyramid A1, the cone surface A302 of the triangular pyramid A3, the cone surface A202 of the triangular pyramid A2, and the cone surface A402 of the triangular pyramid A4, whose inclination angle is also α / 2; Step 4: Based on the structure processed in step 3, rotate the mold substrate to the 0 degree position, and use the first tool to machine the pyramidal surface B101 of the triangular pyramid B1 and the pyramidal surface A203 of the triangular pyramid A2, with an inclination angle of α / 2; at the same time, machine the pyramidal surface A303 of the triangular pyramid A3 and the pyramidal surface C201 of the triangular pyramid C2, with an inclination angle of α / 2; Step 5: Rotate the mold substrate 120 degrees and use the first tool to machine the pyramidal surface B102 of the triangular pyramid B1 and the pyramidal surface A403 of the triangular pyramid A4, with an inclination angle of α / 2. Simultaneously, machine the pyramidal surface A103 of the triangular pyramid A1 and the pyramidal surface C202 of the triangular pyramid C2, with an inclination angle of α / 2. Step 6: Replace and install a second type of asymmetric tool with a blade angle of β on the fly cutter disc. The left blade of the second type of tool has an inclination angle of βL, and the right blade has an inclination angle of βR. βL is not equal to βR. The inclination angle of the triangular pyramid reflective surface processed by the left blade is βL, and the inclination angle of the triangular pyramid reflective surface processed by the right blade is βR. Rotate the mold substrate again at 60 degrees in this order, and use the adjusted second type of tool to process and form the pyramid surface B103 of the triangular pyramid B1 and the pyramid surface B203 of the triangular pyramid B2, whose inclination angle is βL; at the same time, form the pyramid surface C103 of the triangular pyramid C1 and the pyramid surface C203 of the triangular pyramid C2, whose inclination angle is βR. At this point, the mold for the microprismatic reflective film composed of three different triangular pyramid structures, namely, triangular pyramids A with inclination angles of α / 2, mixed triangular pyramids B with inclination angles of α / 2, α / 2 and βL, and mixed triangular pyramids C with inclination angles of α / 2, α / 2 and βR, has been processed and formed.

5. The method for manufacturing a mold for a microprismatic reflective film integrating three triangular pyramid combinations according to claim 4, characterized in that: The first type of tool has a cutting angle of α=70.55 degrees; the second type of tool has an asymmetric cutting angle of β=70.15 degrees, and its left blade inclination angle is βL=35.15 degrees, and the right blade inclination angle is βR=35.00 degrees. During processing, the first type of tool is used first, and the array processing is performed according to the B-axis rotation angle of 0 degrees, 60 degrees, and 120 degrees, and the intercept is 0.433mm. The 1st to 3rd tools are formed into a large triangular pyramid, and then the B-axis rotation angles are 0 degrees, 120 degrees, and the intercept is 0.433mm along the center line of the edge of the large triangular pyramid. The 4th and 5th cuts were processed in an array respectively; finally, the second cutter was replaced, and the 6th cut was processed in an array along the center line connecting the adjacent edges of the large triangular pyramid with an intercept of 0.433 mm according to the B-axis rotation angle of 60° to form a composite microprismatic reflective film composed of a parallelogram unit array. Each parallelogram unit contains 8 triangular pyramids with a side length of 250 μm, of which the inclination angles of the reflection surfaces of 4 triangular pyramids are α / 2, the inclination angles of the reflection surfaces of 2 triangular pyramids are α / 2, α / 2 and βL respectively, and the inclination angles of the reflection surfaces of 2 triangular pyramids are α / 2, α / 2 and βR respectively.

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