Composite microprism reflective film with three triangular pyramid structures and mold manufacturing method thereof

Abstract

The invention relates to a composite microprism reflective film with three triangular pyramid structures and a manufacturing method of a mold of the composite microprism reflective film, and is characterized in that the surface of the microprism reflective film is formed by an array of identical parallelogram unit bodies, and each parallelogram unit body is composed of two identical triangular pyramids A, four 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 the same equilateral triangles, the inclination angles of the three pyramid surfaces of each triangular pyramid A are alpha / 2, the inclination angles of the pyramid surfaces of the mixed triangular pyramids B are alpha / 2, alpha / 2 and beta / 2, and the inclination angles of the three pyramid surfaces of the mixed triangular pyramids C are alpha / 2, beta / 2 and beta / 2 respectively; the area ratio of the triangular pyramid A to the triangular pyramid B to the triangular pyramid C is 1: 2: 1, and the performance under different application conditions can be reasonably optimized, so that the wide-angle performance can be improved, and the optimization and balance of the overall comprehensive performance can be realized.

Description

Technical Field

[0001] The invention relates to a manufacturing method of a composite micro-prismatic reflective film with three triangular pyramid structures 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 The microprismatic reflective film has only one optical design variable (i.e., the three angles of each triangular pyramid are the same), and it is difficult to obtain different incident angles and observation angles (especially wide angles), that is, to improve the retroreflective performance at different azimuth angles at the same time, as well as to balance the retroreflective performance at different incident angles and observation angles (especially wide angles and small incident angles), and balance the retroreflective performance 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; 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.

[0008] Patent application 2025107027357 submitted by the present applicant in May 2025 adopts a specific asymmetric tool γ=0.5(α+β) to achieve the cone angles of three triangular pyramids; and patent application 202510704670X adopts a specific tool deflection angle △=0.5(α-β) (or an equivalent asymmetric tool) to achieve the cone angle design of three triangular pyramids. However, the use of a larger tool deflection angle or a larger asymmetric tool is not conducive to optimizing the retroreflective performance of the balanced reflective film with a 0 / 90 / 180 degree orientation. Summary of the Invention

[0009] In view of the above-mentioned problems, the purpose of the present invention is to provide a method for manufacturing a composite microprismatic reflective sheeting having three triangular pyramid structures and a mold thereof. The method for manufacturing the composite microprismatic reflective sheeting having three triangular pyramid structures and a mold thereof is rationally designed to increase the degree of freedom in optical design, thereby achieving better performance indicators under different application conditions and reducing the impact of large cone angle deviation processing or asymmetric design on the retroreflective performance of the optimized balanced reflective sheeting with 0 / 90 / 180 degree orientation.

[0010] The technical solutions of the present invention are as follows: The composite microprismatic reflective sheeting of three triangular pyramid structures of the present invention is characterized in that: the surface of the microprismatic reflective sheeting is formed by an array of identical parallelogram units, each parallelogram unit being composed of two identical triangular pyramids A, four 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 pyramidal surfaces of each triangular pyramid A are all α / 2, the inclination angles of the pyramidal surfaces of the mixed triangular pyramids B are α / 2, α / 2, and β / 2, and the inclination angles of the three pyramidal surfaces of the mixed triangular pyramid C are α / 2, α / 2, and β / 2, respectively. The mixed triangular pyramids B are triangular pyramids B1, triangular pyramids B2, triangular pyramids B3 and triangular pyramids B4, and the mixed triangular pyramids C are triangular pyramids C1 and triangular pyramids C2. The first row of parallelogram unit bodies is triangular pyramid A1, triangular pyramid B1, triangular pyramid C1 and triangular pyramid B2, and the second row of parallelogram unit bodies is triangular pyramid B3, triangular pyramid C2, triangular pyramid B4 and triangular pyramid A2. The directions of adjacent triangular pyramids are 180 degrees to each other.

[0011] Furthermore, the pyramidal surface B301 of the triangular pyramid B3 is coplanar with the pyramidal surface B401 of the triangular pyramid B4, the pyramidal surface B101 of the triangular pyramid B1 is coplanar with the pyramidal surface B201 of the triangular pyramid B2, the pyramidal surface B302 of the triangular pyramid B3 is coplanar with the pyramidal surface A101 of the triangular pyramid A1, 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 B402 of the triangular pyramid B4 is coplanar with the pyramidal surface A101 of the triangular pyramid A1. 02, the pyramidal surface A202 of triangular pyramid A2 is coplanar with the pyramidal surface B102 of triangular pyramid B1, the pyramidal surface A103 of triangular pyramid A1 is coplanar with the pyramidal surface C101 of triangular pyramid C1, the pyramidal surface C201 of triangular pyramid C2 is coplanar with the pyramidal surface A203 of triangular pyramid A2, the pyramidal surface C202 of triangular pyramid C2 is coplanar with the pyramidal surface B103 of triangular pyramid B1, and the pyramidal surface B403 of triangular pyramid B4 is coplanar with the pyramidal surface C102 of triangular pyramid C1.

[0012] Furthermore, the base areas of the triangular pyramid A, the mixed triangular pyramid B, and the mixed triangular pyramid C account for 25%, 50%, and 25%, respectively.

[0013] Furthermore, the above α=70.55 degrees and β=70.75 degrees.

[0014] Furthermore, the array intercept of the microprismatic reflective film is 0.433 mm.

[0015] The method for manufacturing a mold for a composite microprismatic reflective film having three triangular pyramid structures of the present invention is characterized in that: 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: Step 1: Rotate the mold substrate on the B-axis turntable to 0 degrees, and use the first type of tool array 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 B301 of the triangular pyramid B3, the cone surface B401 of the triangular pyramid B4, the cone surface B101 of the triangular pyramid B1, 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 substrate on the B-axis turntable to 120 degrees, 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 cone surfaces of the parallelogram unit, namely, the cone surface B302 of the triangular pyramid B3, the cone surface A101 of the triangular pyramid A1, 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 substrate on the B-axis turntable to 60 degrees, and use the first type of tool array with a tool angle of α installed on the fly cutter disc to machine the conical surfaces of the two opposite corners of the parallelogram unit, namely, the conical surface B402 of the triangular pyramid B4, the conical surface A102 of the triangular pyramid A1, the conical surface A202 of the triangular pyramid A2, and the conical surface B102 of the triangular pyramid B1, whose inclination angle is also α / 2; Step 4: Based on the structure processed in step 3, the mold substrate is rotated to the 0 degree position, and the first tool array is used to form the pyramid surface C201 of the triangular pyramid C2 and the pyramid surface A203 of the triangular pyramid A2, whose inclination angle is α / 2; at the same time, the pyramid surface A103 of the triangular pyramid A1 and the pyramid surface C101 of the triangular pyramid C1 are formed, whose inclination angle is α / 2; Step 5: Replace the cutter head with a second type of symmetrical tool having a blade angle of β. The left and right blades of the second type of tool have an inclination angle of β / 2. Rotate the mold substrate 120 degrees in sequence and use the second type of tool array to form the pyramidal surface C202 of the triangular pyramid C2 and the pyramidal surface B103 of the triangular pyramid B1. The inclination angles are β / 2. Simultaneously, the pyramidal surface B403 of the triangular pyramid B4 and the pyramidal surface C102 of the triangular pyramid C1 are formed. The inclination angles are β / 2. Step 6: Rotate the mold substrate again by 60 degrees and use the adjusted second tool array to form the pyramid surface C203 of triangular pyramid C2 and the pyramid surface B203 of triangular pyramid B2, with an inclination angle of β / 2. Simultaneously, form the pyramid surface B303 of triangular pyramid B3 and the pyramid surface C103 of triangular pyramid C1, with an inclination angle of β / 2. At this point, the mold for the microprismatic reflective film composed of three different triangular pyramid structures, namely, triangular pyramids A with an inclination angle of α / 2, mixed triangular pyramids B with inclination angles of α / 2, α / 2 and β / 2, and mixed triangular pyramids C with inclination angles of α / 2, β / 2 and β / 2, has been processed and formed.

[0016] Furthermore, the method for manufacturing the mold of the composite microprismatic reflective film having the three triangular pyramid structures is characterized by: The first type of tool is a symmetrical tool with a tool angle α=70.55 degrees; the second type of tool is a symmetrical tool with a tool angle β=70.75 degrees. The first type of tool is used to process the 1st to 3rd cuts, and array processing is performed according to the B-axis rotation angles of 0 degrees, 60 degrees, and 120 degrees, and the intercept is 0.433mm. The first type of tool is used to process the 4th cut, the equipment rotation axis B axis is 0 degrees, and the array spacing is 0.433mm. The second type of tool is used to process the 5th and 6th cuts, the equipment rotation axis B axis is 120° and 60°, and the array spacing is 0.433mm. The molds of the composite microprismatic reflective films with three triangular pyramid structures are processed and formed.

[0017] The present invention has the following technical advantages.

[0018] 1. Area ratio optimization: The area ratio of the three triangular pyramids ABC in the present invention is 25%: 50%: 25%, which is different from the area ratio of the triangular pyramids in the prior patent application mentioned in the background technology, providing a new way to improve the wide-angle retroreflective performance of reflective film.

[0019] 2. Convenient optimization design: By selecting α and β and optimizing the area ratio, the wide-angle retroreflective performance of the reflective film is improved.

[0020] 3. Simple processing technology: The first tool α can be used to fly cut four times, and the second tool β can be used to fly cut two times. It is simpler and lower in cost than the manufacturing of 3M's full prism mold.

[0021] 4. Simple design verification: It can first optimize and verify the pure triangular pyramid A (α / 2, α / 2, α / 2), then optimize and verify the mixed triangular pyramids B (α / 2, α / 2, β / 2) and C (α / 2, β / 2, β / 2), and finally verify the double triangular pyramid combination structure A+B+C, which facilitates verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings; Figure 1 This is the main view of a traditional triangular pyramid; Figure 2 Schematic diagram of the main structure of the microprismatic reflective film of the present invention; Figure 3 yes Figure 2 Schematic diagram of the local structure (i.e. the main structural diagram of the parallelogram unit); Figure 4 It is a three-dimensional schematic diagram of the mold substrate placed on the workbench for processing; Figure 5 This is a schematic diagram of the cross-sectional structure of the mold base material processed using the first type of tool; Figure 6 This is a schematic diagram of the cross-sectional structure of the mold base material processed using the second type of tool; Figure 7 This is a schematic diagram of the main structure of the finished microprismatic reflective film mold of the present invention (for intuitive viewing, the numbers in the figure correspond one to one Figure 2 Marking number of the reflective film); Figure 8 This is a schematic diagram of the three-dimensional structure of the mold base material when it is not processed; Figure 9 yes Figure 8 The main view; Figure 10 yes Figure 8 The front view of the mold substrate after being processed in step 1; Figure 11 yes Figure 10 The front view of the mold substrate after processing in step 2; Figure 12 yes Figure 11 The front view of the mold substrate after processing in step 3; Figure 13 yes Figure 12 Stereoscopic image of Figure 14 yes Figure 12 The front view of the mold substrate after processing in step 4; Figure 15 yes Figure 14 Schematic diagram of the three-dimensional structure; Figure 16 yes Figure 14The front view of the mold substrate after processing in step 5; Figure 17 yes Figure 16 Schematic diagram of the three-dimensional structure; Figure 18 yes Figure 16 The front view of the mold substrate after processing in step 6; 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

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] The surface of the composite microprismatic reflective film with three triangular pyramid structures of the present invention is formed by an array of identical parallelogram units 1. Each parallelogram unit 1 is composed of two identical triangular pyramids A, four 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 the two triangular pyramids A are all α / 2, the inclination angles of the pyramidal surfaces of the mixed triangular pyramids B are all α / 2, α / 2, and β / 2, and the inclination angles of the three pyramidal surfaces of the mixed triangular pyramid C are α / 2, β / 2, and α / 2, respectively. / 2 and β / 2; the triangular pyramids A are triangular pyramid A1 and triangular pyramid A2, the mixed triangular pyramids B are triangular pyramid B1, triangular pyramid B2, triangular pyramid B3 and triangular pyramid B4, 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 A1, triangular pyramid B1, triangular pyramid C1 and triangular pyramid B2, the second row of the parallelogram unit body 1 is triangular pyramid B3, triangular pyramid C2, triangular pyramid B4 and triangular pyramid A2, and the directions of adjacent triangular pyramids are 180 degrees to each other.

[0025] 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, and β=70.75 degrees.

[0026] The pyramidal surface B301 of the triangular pyramid B3 is coplanar with the pyramidal surface B401 of the triangular pyramid B4, the pyramidal surface B101 of the triangular pyramid B1 is coplanar with the pyramidal surface B201 of the triangular pyramid B2, the pyramidal surface B302 of the triangular pyramid B3 is coplanar with the pyramidal surface A101 of the triangular pyramid A1, the pyramidal surface A201 of the triangular pyramid A2 is coplanar with the pyramidal surface B202 of the triangular pyramid B2, the pyramidal surface B402 of the triangular pyramid B4 is coplanar with the pyramidal surface A102 of the triangular pyramid A1. The pyramidal surface A202 of triangular pyramid A2 is coplanar with the pyramidal surface B102 of triangular pyramid B1, the pyramidal surface A103 of triangular pyramid A1 is coplanar with the pyramidal surface C101 of triangular pyramid C1, the pyramidal surface C201 of triangular pyramid C2 is coplanar with the pyramidal surface A203 of triangular pyramid A2, the pyramidal surface C202 of triangular pyramid C2 is coplanar with the pyramidal surface B103 of triangular pyramid B1, and the pyramidal surface B403 of triangular pyramid B4 is coplanar with the pyramidal surface C102 of triangular pyramid C1.

[0027] The specific processing method for the mold used to manufacture the aforementioned three types of triangular pyramid structure composite micro-prismatic reflective films is as follows.

[0028] Example 1, as Figure 4 As 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: 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 tool array with a tool angle of α installed on the fly cutter disc is used to process the two side cone surfaces of the parallelogram unit body (i.e. Figure 10 The upper and lower conical surfaces of the triangular pyramid B3, the workbench drives the mold substrate to move along the X-axis during the processing), that is, the pyramid surface B301 of the triangular pyramid B3, the pyramid surface B401 of the triangular pyramid B4, the pyramid surface B101 of the triangular pyramid B1, 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.

[0029] Step 2: Rotate the mold base material on the B-axis turntable to 120 degrees (or 300 degrees) (i.e. Figure 9In the state shown, rotate 120 degrees (or 300 degrees) counterclockwise around the center of the B axis) and use the first tool array with a tool angle of α installed on the fly cutter disc to machine the other two conical surfaces of the parallelogram unit body (i.e. Figure 11 The left and right cone surfaces of the triangular pyramid B3, the workbench drives the mold substrate to move along the X-axis during the processing), namely the cone surface B302 of the triangular pyramid B3, the cone surface A101 of the triangular pyramid A1, 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.

[0030] 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 of the B axis, and use the first type of tool array 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 B402 of the triangular pyramid B4, the cone surface A102 of the triangular pyramid A1, the cone surface A202 of the triangular pyramid A2, and the cone surface B102 of the triangular pyramid B1, whose inclination angle is also α / 2, as shown in FIG. Figure 12 、 13 shown.

[0031] 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 tool array is used to form the pyramidal surface C201 of the triangular pyramid C2 and the pyramidal surface A203 of the triangular pyramid A2, whose inclination angle is α / 2; at the same time, the pyramidal surface A103 of the triangular pyramid A1 and the pyramidal surface C101 of the triangular pyramid C1 are formed, whose inclination angle is α / 2; Figure 14 、 15 shown.

[0032] Step 5: Replace the second type of tool with a symmetrical structure of blade angle β on the fly cutter disc. The left and right blade angles of the second type of tool are both β / 2. Rotate the mold substrate in sequence at 120 degrees (i.e. Figure 9 The second tool array is used to form the pyramid surface C202 of the triangular pyramid C2 and the pyramid surface B103 of the triangular pyramid B1, with an inclination angle of β / 2. At the same time, the pyramid surface B403 of the triangular pyramid B4 and the pyramid surface C102 of the triangular pyramid C1 are formed, with an inclination angle of β / 2. Figure 16 、 17 As shown; Step 6: Rotate the mold substrate 60 degrees (i.e. Figure 9The second tool array adjusted above is used to form the pyramidal surface C203 of the triangular pyramid C2 and the pyramidal surface B203 of the triangular pyramid B2, with an inclination angle of β / 2; and the pyramidal surface B303 of the triangular pyramid B3 and the pyramidal surface C103 of the triangular pyramid C1 are formed at an inclination angle of β / 2. Figure 18 、 19 shown.

[0033] Figure 18 、 19 That is, the structural diagram of the finished mold of this application, Figure 18 、 19 and Figure 7 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 、 3 The same reference numerals are used to reflect the one-to-one correspondence between the mold and the reflective film.

[0034] At this point, the mold for the microprismatic reflective film composed of three different triangular pyramid structures, namely, triangular pyramids A with an inclination angle of α / 2, mixed triangular pyramids B with inclination angles of α / 2, α / 2 and β / 2, and mixed triangular pyramids C with inclination angles of α / 2, β / 2 and β / 2, has been processed and formed.

[0035] Specific processing example of embodiment 1: The first type of tool has a symmetrical tool with a tool angle α = 70.55 degrees; the second type of tool has a symmetrical tool with a tool angle β = 70.75 degrees (both tools have no deflection angle); when processing, the first type of tool is used first, and array processing is performed according to the B-axis rotation angles of 0 degrees, 60 degrees, 120 degrees and 0 degrees, and the intercept is 0.433 mm (refer to the above steps 1-4 and Figure 9-15 ), replace the second tool, according to the B axis rotation angle of 120 degrees and 60 degrees, respectively, the intercept 0.433mm array processing 5-6 knife; processing the mold of the composite micro-prismatic reflective film composed of a parallelogram unit array (refer to the above steps 5-6 and Figure 14-19 ), each parallelogram unit contains 8 triangular pyramids, among which the reflection surface inclination angles of the two triangular pyramids A are both α / 2, the reflection surface inclination angles of the four triangular pyramids B are α / 2, α / 2 and β / 2 respectively, and the reflection surface inclination angles of the two triangular pyramids C are α / 2, β / 2 and β / 2 respectively. The area ratio of triangular pyramid A (α / 2, α / 2, α / 2), triangular pyramid B (α / 2, α / 2, β / 2) and triangular pyramid C (α / 2, β / 2, β / 2) is 1:2:1.

[0036] In order to improve processing efficiency, the first cut (step 1) and the fourth cut (step 4) in the above processing steps can be performed together (the substrate is at the 0 degree position in both steps, that is, there is no need to rotate the B axis, only the Y axis of the substrate is moved).

[0037] 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).

[0038] 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.

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

[0040] 1. Area ratio optimization: The area ratio of the three triangular pyramids ABC in the present invention is 25%: 50%: 25%, which is different from the area ratio of the triangular pyramids in the prior patent application mentioned in the background technology, providing a new way to improve the wide-angle retroreflective performance of reflective film.

[0041] 2. Convenient optimization design: By selecting α and β and optimizing the area ratio, the wide-angle retroreflective performance of the reflective film is improved.

[0042] 3. Simple processing technology: The first tool α can be used to fly cut four times, and the second tool β can be used to fly cut two times. It is simpler and lower in cost than the manufacturing of 3M's full prism mold.

[0043] 4. Simple design verification: It can first optimize and verify the pure triangular pyramid A (α / 2, α / 2, α / 2), then optimize and verify the mixed triangular pyramids B (α / 2, α / 2, β / 2) and C (α / 2, β / 2, β / 2), and finally verify the double triangular pyramid combination structure A+B+C, which facilitates verification.

[0044] 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 composite microprismatic reflective sheeting having three triangular pyramid structures, 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 two identical triangular pyramids A, four 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 β / 2, and the inclination angles of the three angular pyramid surfaces of the mixed triangular pyramid C are α / 2, β / 2 and β / 2 respectively , the triangular pyramids A are triangular pyramids A1 and triangular pyramids A2, the mixed triangular pyramids B are triangular pyramids B1, triangular pyramids B2, triangular pyramids B3 and triangular pyramids B4, the mixed triangular pyramids C are triangular pyramids C1 and triangular pyramids C2, the first row of the parallelogram unit body (1) is triangular pyramid A1, triangular pyramid B1, triangular pyramid C1 and triangular pyramid B2, the second row of the parallelogram unit body (1) is triangular pyramid B3, triangular pyramid C2, triangular pyramid B4 and triangular pyramid A2, and the directions of adjacent triangular pyramids are 180 degrees to each other.

2. The composite microprismatic reflective sheeting comprising three triangular pyramid structures according to claim 1, wherein: The pyramidal surface B301 of the triangular pyramid B3 is coplanar with the pyramidal surface B401 of the triangular pyramid B4, the pyramidal surface B101 of the triangular pyramid B1 is coplanar with the pyramidal surface B201 of the triangular pyramid B2, the pyramidal surface B302 of the triangular pyramid B3 is coplanar with the pyramidal surface A101 of the triangular pyramid A1, the pyramidal surface A201 of the triangular pyramid A202 of the triangular pyramid B2, the pyramidal surface B402 of the triangular pyramid B4 is coplanar with the pyramidal surface A102 of the triangular pyramid A1. The pyramidal surface A202 of triangular pyramid A2 is coplanar with the pyramidal surface B102 of triangular pyramid B1, the pyramidal surface A103 of triangular pyramid A1 is coplanar with the pyramidal surface C101 of triangular pyramid C1, the pyramidal surface C201 of triangular pyramid C2 is coplanar with the pyramidal surface A203 of triangular pyramid A2, the pyramidal surface C202 of triangular pyramid C2 is coplanar with the pyramidal surface B103 of triangular pyramid B1, and the pyramidal surface B403 of triangular pyramid B4 is coplanar with the pyramidal surface C102 of triangular pyramid C1.

3. The composite microprismatic reflective sheeting comprising three triangular pyramid structures according to claim 2, wherein: The base areas of the triangular pyramid A, the mixed triangular pyramid B and the mixed triangular pyramid C account for 25%, 50% and 25% respectively.

4. The composite microprismatic reflective sheeting comprising three triangular pyramid structures according to claim 3, wherein: The α=70.55 degrees and the β=70.75 degrees.

5. The composite microprismatic reflective sheeting comprising three triangular pyramid structures according to claim 4, wherein: The array intercept of the micro-prismatic reflective film is 0.433 mm.

6. A method for manufacturing a mold for a composite microprismatic reflective sheeting having three triangular pyramid structures, the method being used to manufacture the mold for the composite microprismatic reflective sheeting having three triangular pyramid structures as claimed in any one of claims 1 to 5, 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 array 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 B301 of the triangular pyramid B3, the cone surface B401 of the triangular pyramid B4, the cone surface B101 of the triangular pyramid B1, 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 substrate on the B-axis turntable to 120 degrees, 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 cone surfaces of the parallelogram unit, namely, the cone surface B302 of the triangular pyramid B3, the cone surface A101 of the triangular pyramid A1, 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 array with a tool angle of α installed on the fly cutter disc to process the two diagonal cone surfaces of the parallelogram unit (1), namely, the cone surface B402 of the triangular pyramid B4, the cone surface A102 of the triangular pyramid A1, the cone surface A202 of the triangular pyramid A2, and the cone surface B102 of the triangular pyramid B1, whose inclination angle is also α / 2; Step 4: Based on the structure processed in step 3, the mold substrate is rotated to the 0 degree position, and the first tool array is used to form the pyramid surface C201 of the triangular pyramid C2 and the pyramid surface A203 of the triangular pyramid A2, whose inclination angle is α / 2; at the same time, the pyramid surface A103 of the triangular pyramid A1 and the pyramid surface C101 of the triangular pyramid C1 are formed, whose inclination angle is α / 2; Step 5: Replace the cutter head with a second type of symmetrical tool having a blade angle of β. The left and right blades of the second type of tool have an inclination angle of β / 2. Rotate the mold substrate 120 degrees in sequence and use the second type of tool array to form the pyramidal surface C202 of the triangular pyramid C2 and the pyramidal surface B103 of the triangular pyramid B1. The inclination angles are β / 2. Simultaneously, the pyramidal surface B403 of the triangular pyramid B4 and the pyramidal surface C102 of the triangular pyramid C1 are formed. The inclination angles are β / 2. Step 6: Rotate the mold substrate again by 60 degrees and use the adjusted second tool array to form the pyramid surface C203 of triangular pyramid C2 and the pyramid surface B203 of triangular pyramid B2, with an inclination angle of β / 2. Simultaneously, form the pyramid surface B303 of triangular pyramid B3 and the pyramid surface C103 of triangular pyramid C1, with an inclination angle of β / 2. At this point, the mold for the microprismatic reflective film composed of three different triangular pyramid structures, namely, triangular pyramids A with an inclination angle of α / 2, mixed triangular pyramids B with inclination angles of α / 2, α / 2 and β / 2, and mixed triangular pyramids C with inclination angles of α / 2, β / 2 and β / 2, has been processed and formed.

7. The method for manufacturing a mold for a composite microprismatic reflective film having three triangular pyramid structures according to claim 6, wherein: The first type of tool is a symmetrical tool with a tool angle α=70.55 degrees; the second type of tool is a symmetrical tool with a tool angle β=70.75 degrees. The first type of tool is used to process the 1st to 3rd cuts, and array processing is performed according to the B-axis rotation angles of 0 degrees, 60 degrees, and 120 degrees, and the intercept is 0.433mm. The first type of tool is used to process the 4th cut, the equipment rotation axis B axis is 0 degrees, and the array spacing is 0.433mm. The second type of tool is used to process the 5th and 6th cuts, the equipment rotation axis B axis is 120° and 60°, and the array spacing is 0.433mm. The molds of the composite microprismatic reflective films with three triangular pyramid structures are processed and formed.

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