A method for connecting reflective film mold at room temperature

Abstract

The invention discloses a room-temperature connection method for reflective film molds, comprising the following steps: S1, electroforming with a cleaned reflective film template as a cathode and a nickel plate as an anode, and electroforming a mother plate having a pattern structure opposite to that of the reflective film template on the reflective film template; S2, fixing the mother plate with its pattern structure facing upward on a support plate in an electroforming tank, fixing two reflective film templates to be connected side by side on the mother plate with their pattern structures facing downward, and coating an electrical insulating layer on the upper end surfaces of the two reflective film templates to be connected; S3, electroforming deposition with a strip nickel plate as an anode and the mother plate as a cathode, and accumulating the deposited metal in a space formed by a slit between the two reflective film templates to be connected and the mother plate; and S4, polishing and trimming the connection position of the two reflective film molds to complete the processing operation.

Description

Technical Field

[0001] The invention relates to the field of reflective film production, in particular to a method for connecting a reflective film mold at room temperature. Background Art

[0002] Reflective film, with its excellent reflective properties and good wide-angle performance, is widely used in various road traffic safety signs, vehicle passive safety protection devices and personal safety protection products, and can play a significant role in safety warnings. Among commonly used reflective films, reflective films with a micro-prismatic surface structure are usually processed by using a mold with a micro-prism array structure to roll out a precise micro-prism structure on the surface of the material. During the processing process, the larger the size of the mold, the higher the reflective film production efficiency and the lower the production cost. However, in actual production, the diamond fly-cutting technology for processing micro-prismatic reflective film molds can only produce flat reflective film templates with small-area micro-prism structures due to processing efficiency and cost limitations, and cannot be well applied to the continuous production of large-area reflective film.

[0003] In actual production, laser welding is often used to splice small-area reflective film templates into large-size and large-area molds (the invention patent with patent number CN201310012424.5 also discloses a method for manufacturing seamless nickel sheets with microprism arrays). This is a connection method with high production efficiency. However, the use of laser welding to melt the metal at the mold connection at high temperature will cause the weld pattern to be blurred, deformed, and discontinuous. After welding, there is large deformation and residual internal stress at the weld. In subsequent production and processing, the mold is very likely to crack and break at the weld, causing mold failure. This is also a major problem faced in actual production.

[0004] The invention patent (CN200910099167.7) discloses a method for producing a large-scale microprismatic reflective film metal mold. After using precision machining to process a small-scale mold, this mold is used as the cathode to electroform a small-area nickel thin film mold. The pattern is then transferred to a polycarbonate substrate using step-by-step pressing to form a large-scale template, which is then electroformed onto the substrate to produce the large-scale metal mold. While this method allows for a single-step mold formation, it involves multiple pressing, coating, and electroforming steps, resulting in a complex process. To achieve the transition from a small-area template to a large-area mold, the pattern must be pressed in a step-by-step manner, requiring very high alignment accuracy. Furthermore, the pressing process requires heating and pressurizing, which can easily cause pattern deformation and reduce mold precision, hindering market adoption.

[0005] The invention patent (ZL201711001879.1) also discloses a method for manufacturing a metal mold for large-scale microprismatic reflective film. It proposes an electroforming method for connecting two small metal molds to form a large-area metal mold. To increase the strength of the electroformed joint, a groove is created on the back of the two small metal molds at the joint, similar to the groove created during welding. This room-temperature connection method provides low stress and avoids stress concentration at the joint. However, due to the presence of a certain gap between the two unit molds, the microprismatic array pattern at the original gap location becomes interrupted or discontinuous after connection, seriously affecting the production quality of large-scale microprismatic reflective film. Therefore, improvements are necessary. Summary of the Invention

[0006] The purpose of the present invention is to address the above-mentioned problems and provide a room temperature connection method for reflective film molds. The method has low production cost, can maintain the complete pattern of the connection, and has no residual stress and deformation. It can effectively improve the quality and performance of the connection of the reflective film mold and ensure the service life of the reflective film mold.

[0007] In order to achieve the above object, the technical solution of the present invention is:

[0008] A method for connecting a reflective film mold at room temperature, characterized in that it comprises the following steps:

[0009] S1. Electroforming is performed using the cleaned reflective film template as a cathode and the nickel plate as an anode to electroform a master having a pattern structure opposite to that of the reflective film template on the reflective film template, and the master is cleaned and dried;

[0010] S2. Fix the dried master template with its pattern structure facing upward on a support plate in an electroforming tank. Fix two reflective sheeting templates to be connected side by side on the master template with their pattern structures facing downward, so that the pattern structures of the reflective sheeting templates match the pattern structures of the master templates in convex and concave directions. Then, apply an electrically insulating layer to the upper end surfaces of the two reflective sheeting templates to be connected.

[0011] S3, performing electroforming deposition with the strip nickel plate as the anode and the master plate as the cathode, wherein the deposited metal accumulates in the space formed by the slit between the two reflective film templates to be connected and the master plate, and stopping the electroforming deposition when the height of the deposited metal exceeds the height of the top end surface of the reflective film template;

[0012] S4. Grind the upper end surface of the connection position of the two reflective film molds to make it completely flush with the reflective film molds, clean and dry the connected reflective film molds, and then complete the processing.

[0013] Furthermore, in step S1, the reflective film template is ultrasonically cleaned with acetone and secondary deionized water in sequence to obtain a clean reflective film template.

[0014] Furthermore, in step S2, the height of the support plate is higher than the liquid level of the electroplating solution in the electroforming tank.

[0015] Furthermore, in step S2, the electrical insulation layer is an electrical insulation layer resistant to acid and alkali corrosion.

[0016] Furthermore, in step S3, the width of the slit between the two reflective film templates to be connected is the width of 1 to 5 unit patterns in the pattern structure of the reflective film template.

[0017] Furthermore, in step S3, the width of the strip nickel plate is not less than the width of the slit between the two reflective film templates to be connected, and the length of the strip nickel plate is not less than the length of the reflective film template.

[0018] Furthermore, in step S3, current limiting plates are set on both sides of the strip nickel plate (the function of the current limiting plates is to limit the current, and they cannot contact the strip nickel plate, but can contact the electrical insulation layer). A space for the electroforming liquid to flow through is set between the current limiting plates and the strip nickel plate, and the bottom end of the current limiting plates is higher than the electrical insulation layer on the surface of the reflective film template to be connected.

[0019] Furthermore, during electroforming deposition, the electroforming liquid in the electroforming liquid circulation system flows down from the top of the strip nickel plate, passes through the current limiting plate, enters the narrow gap between the two reflective film templates to be connected, and then flows into the electroforming tank.

[0020] Compared with the prior art, the present invention has the following advantages and positive effects:

[0021] 1. The method adopted by the present invention is to directly assemble the reflective film template with its patterned surface facing downward onto the patterned surface of the master. The patterned structure of the reflective film template matches the patterned structure of the master surface in a convex-concave manner. During electroforming, metal atoms grow with the patterned master as the base and fill the space between the reflective film templates to be connected. The generated electroformed layer completely replicates the pattern on the master. Therefore, the connection point and the reflective film templates connected on both sides can form a continuous pattern structure, which can achieve seamless connection of the reflective film templates and high replication accuracy.

[0022] 2. The room temperature connection adopted by the present invention is to achieve the connection of the reflective film template through the growth of metal atoms. The metal layer at the connection has no residual thermal stress and deformation, dense structure, and is filled with no gaps. Its strength is the same as that of the reflective film template, and it has good reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is an operational effect diagram of the present invention;

[0025] Figure 2 for Figure 1 A magnified view of the local structure;

[0026] Figure 3 This is the connection structure diagram of the reflective film template and the master;

[0027] Figure 4 Schematic diagram of the structure of the rear reflective film template. Implementation Method

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts, any modifications, equivalent replacements, improvements, etc., shall be included in the scope of protection of the present invention.

[0029] like Figures 1 to 4 As shown, the present invention provides a method for connecting a large-area reflective film mold at room temperature, which includes the following steps:

[0030] (1) Cleaning the reflective film template 5; ultrasonically cleaning the reflective film template 5 to be connected with acetone and secondary deionized water in sequence to remove the residual oil on the reflective film template 5 and impurities generated during the processing;

[0031] (2) Electroforming a master 4; electroforming is performed using a clean reflective film template 5 as a cathode and a nickel plate as an anode, and a master 4 having a pattern structure opposite to that of the reflective film template is electroformed on the reflective film template 5, and the master 4 is cleaned and dried;

[0032] (3) Preparation of cathode for room temperature connection; fix the reproduced master 4 with the pattern facing upward on the support plate 3 in the electroforming tank, and fix the two reflective film templates 5 to be connected with the pattern facing downward on the master 4, so that the convex and concave patterns on the surfaces of the reflective film templates 5 and the master 4 fit together and are fixed on the master 4; align the edges of the reflective film templates 5 to be connected, and the width of the slit between the edges to be connected of the two reflective film templates 5 is not less than the size of a unit pattern on the reflective film template; then apply an electrical insulating layer 6 on the back surface of the two reflective film templates 5;

[0033] (4) Electroforming at room temperature to connect the reflective film template 5; Electroforming deposition is performed with the strip nickel plate 9 as the anode and the assembled master plate 4 as the cathode. The electroformed metal 7 grows on the master plate 4 and in the narrow gap between the two reflective film templates 5. When the height of the electroformed metal 7 is consistent with the thickness of the reflective film template 5, the connection is completed;

[0034] (5) Finishing: Grind the back of the reflective film mold connection after electroforming to make it flat, clean and dry it, and complete the processing.

[0035] During the room-temperature electroforming connection process, to ensure that the electroformed metal 7 grows only on the master plate 4 and in the narrow gap between the connected reflective film template 5, the support plate 3 in the electroforming tank 1 must be higher than the plane of the electroforming liquid 2, and current limiting plates 8 are provided on both sides of the anode strip nickel plate 9. The electroforming liquid 2 conveyed by the electroforming liquid circulation system 10 flows from the upper end of the anode strip nickel plate 9 and the current limiting plates 8 to the narrow gap on the surface of the cathode master plate 4 to be connected, and then flows into the electroforming tank 1 for filtering and circulation.

[0036] The width of the slit between the two reflective film templates 5 to be connected can be selected to be 1 to 5 unit pattern sizes.

[0037] When assembling the cathode for electroforming room temperature connection, the electrical insulating layer 6 coated on the back of the reflective film template 5 is an insulating layer resistant to acid and alkali corrosion, which can be photoresist, adhesive film and non-porous cloth.

[0038] The width of the strip nickel plate 9 used in the electroforming room temperature connection is not less than the width of the slit between the two reflective film templates 5 fixed on the mother plate 4, and its length is not less than the length of the two micro-prismatic reflective film templates 5.

[0039] The present invention has the following beneficial effects:

[0040] 1. The method adopted by the present invention is to directly assemble the reflective film template on the master. During electroforming, metal atoms grow with the master as the base and fill in the space between the reflective film templates to be connected. The generated electroformed layer completely replicates the pattern on the master. Therefore, the connection point together with the reflective film templates connected on both sides can form a continuous pattern structure, which can achieve seamless connection of the reflective film templates and high replication accuracy.

[0041] 2. The room temperature connection adopted by the present invention is to achieve the connection of the reflective film template through the growth of metal atoms. The metal layer at the connection has no residual thermal stress and deformation, dense structure, and is filled with no gaps. Its strength is the same as that of the reflective film template, and it has good reliability.

Claims

1. A room temperature connection method for reflective film molds, characterized by: The following steps are involved: S1. Electroforming is performed using the cleaned reflective film template as a cathode and the nickel plate as an anode to electroform a master having a pattern structure opposite to that of the reflective film template on the reflective film template, and the master is cleaned and dried; S2. Fix the dried master template with its pattern structure facing upward on a support plate in an electroforming tank. Fix two reflective sheeting templates to be connected side by side on the master template with their pattern structures facing downward, so that the pattern structures of the reflective sheeting templates match the pattern structures of the master templates in convex and concave directions. Then, apply an electrically insulating layer to the upper end surfaces of the two reflective sheeting templates to be connected. S3. Perform electroforming deposition using a strip nickel plate as an anode and a master plate as a cathode. The deposited metal accumulates in the space formed by the slit between the two reflective film templates to be connected and the master plate. The width of the slit between the two reflective film templates to be connected is not less than the size of one unit pattern on the reflective film template. Stop electroforming deposition when the height of the deposited metal exceeds the height of the top end face of the reflective film template. S4. Grind the upper end surface of the connection position of the two reflective film molds to make it completely flush with the back of the reflective film molds, and clean and dry the connected reflective film molds to complete the processing.

2. The method for connecting a reflective film mold at room temperature according to claim 1, wherein: In the step S1, the reflective film template is ultrasonically cleaned with acetone and secondary deionized water in sequence to obtain a clean reflective film template.

3. The method for connecting a reflective film mold at room temperature according to claim 2, wherein: In step S2, the height of the support plate is higher than the level of the electroplating solution in the electroforming tank.

4. The method for connecting a reflective film mold at room temperature according to claim 3, wherein: In step S2, the electrical insulation layer is an electrical insulation layer resistant to acid and alkali corrosion.

5. The method for connecting reflective film molds at room temperature according to claim 4, wherein: In the step S3, the width of the slit between the two reflective film templates to be connected is the width of 1 to 5 unit patterns in the pattern structure of the reflective film template.

6. The method for connecting reflective film molds at room temperature according to claim 5, wherein: In step S3, the width of the strip nickel plate is not less than the width of the slit between the two reflective film templates to be connected, and the length of the strip nickel plate is not less than the length of the reflective film template.

7. The method for connecting reflective film molds at room temperature according to claim 6, wherein: In step S3, current limiting plates are provided on both sides of the strip nickel plate, a space for the electroforming liquid to flow through is provided between the current limiting plates and the strip nickel plate, and the bottom end of the current limiting plates is higher than the electrical insulation layer on the surface of the reflective film template to be connected.

8. The method for connecting reflective film molds at room temperature according to claim 7, wherein: During electroforming deposition, the electroforming liquid in the electroforming liquid circulation system flows down from the top of the strip nickel plate, passes through the current limiting plate, enters the narrow gap between the two reflective film templates to be connected, and then flows into the electroforming tank.

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