Dandy roll manufacturing method and dandy roll

Abstract

A dandy roll manufacturing method and a dandy roll (10). The manufacturing method comprises: machining a steel roll to obtain a steel roll body (110), and arranging a plurality of coating areas on the steel roll body; performing mechanical or laser machining on a steel pipe to obtain a mask having a plurality of holes, the diameter of the steel pipe being greater than the diameter of the steel roll body; clamping and positioning the mask, and inserting the steel roll body into the mask, each hole being corresponding to one coating area; and performing sandblasting and spraying operations on the mask to form coating blocks (120) on the coating areas; engraving watermark patterns on the coating blocks to obtain a dandy roll. The manufacturing method achieves a local fixed-point coating by means of masking, and manufactures the dandy roll by means of sandblasting and spraying, thereby simplifying the manufacturing process.

Description

Preparation method of watermark plate roller and watermark plate roller

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on October 24, 2023, with application number "202311384016.2" and application name "A method for preparing a watermark plate roller and a watermark plate roller", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of printing plate rollers, and in particular to a preparation method of a watermark plate roller and a watermark plate roller. Background Art

[0003] Watermarks are formed during the papermaking process. They are embedded in the paper rather than on its surface. When viewed against the light, they clearly reveal patterns, images, or text with light and dark textures. Watermarks are not only aesthetically pleasing but also a key method for banknote anti-counterfeiting. Specifically, a watermark roller presses against the paper, transferring the pattern created on the roller to the paper. This can be simply understood as the process of stamping paper. Currently, the roller material is primarily formed through electroforming and electroplating processes. The electroplating industry is not only strictly regulated due to environmental concerns and carries risks and uncertainties, but also requires complex and cumbersome auxiliary processes. The watermark roller features a partially raised structure, so creating the watermark block requires removing material from the roller except for the raised areas. This extensive material removal on a large-scale roller presents significant challenges in implementing the processing equipment and process, and does not improve processing efficiency.

[0004] Summary of the Invention

[0005] This application aims to solve or improve the above technical problems.

[0006] To this end, the first purpose of the present application is to provide a method for preparing a watermark plate roller.

[0007] The second purpose of this application is to provide a watermark plate roller.

[0008] The third purpose of this application is to provide a watermark plate roller.

[0009] To achieve the first purpose of the present application, the technical solution of the first aspect of the present application provides a method for preparing a watermark plate roller, comprising: processing a steel roller to obtain a steel roller base, and setting a plurality of coating areas on the steel roller base; mechanically or laser processing a steel pipe to obtain a mask with a plurality of holes, the diameter of the steel pipe being larger than the diameter of the steel roller base; clamping and positioning the mask, and inserting the steel roller base into the mask, each hole corresponding to a coating area; sandblasting and spraying the mask to form a coating block on the coating area; engraving a watermark pattern on the coating block to obtain a watermark plate roller.

[0010] According to the method for preparing a watermark roller provided in this application, a steel roller is first processed to obtain a steel roller base. The steel roller base surface is then ground to the required roughness and roundness, and multiple coating areas are formed on the surface of the steel roller base. A steel tube of a certain thickness and a diameter greater than the diameter of the steel roller base is then mechanically or laser-processed into a mask with localized holes. The mask is clamped and positioned, and the steel roller base is placed within the mask. The locations of the holes correspond to the locations on the steel roller base where the coating is to be applied. The mask is then sandblasted and sprayed to form coating blocks on the coating areas. Finally, a watermark pattern is engraved on the coating blocks to obtain the watermark roller. By using a mask to block the localized coating, and by sandblasting and spraying to manufacture the watermark roller, the roller production process is simplified and environmentally sustainable. Powder material is directly sprayed onto the prepared steel roller, completing the localized coating blocks in a single step. This not only eliminates the need for repeated electroplating steps but also effectively solves the problem of large-scale removal of roller surface material, improving processing efficiency. Due to the inherent performance characteristics of the spraying material, it can meet the service requirements of directly serving as a coating block, so the produced coating block does not require surface treatment such as chrome plating for strengthening. The technical solution of this application has flexible control and is also widely applicable to the size of the workpiece and the type of substrate material.

[0011] In addition, the technical solution provided by this application may also have the following additional technical features:

[0012] In some technical solutions, optionally, the mask is sandblasted and sprayed to form coating blocks on the coating area, specifically including: sandblasting the mask by sandblasting equipment to form a sand layer on the coating area; spraying the mask by spraying equipment to form coating blocks on the sand layer; wherein the spraying includes thermal spraying or cold spraying, and the thermal spraying includes supersonic flame spraying.

[0013] In this technical solution, the mask is sandblasted and sprayed to form coating blocks on the coating area. Specifically, sandblasting equipment is first used to perform sandblasting to improve the adhesion of the coated metal particles. At this time, a sand layer has been formed on the surface of the steel roller through the mask. The mask is thermally sprayed or cold sprayed with nearly spherical nickel-containing tungsten carbide powder. Thermal spraying includes supersonic flame spraying. At this time, coating blocks are formed in the area where the sand layer has been formed through the mask. The deposition rate of the material by supersonic flame spraying can reach 11.3kg / h, which improves the production efficiency of the plate roller and the timeliness of production response. Supersonic flame spraying is environmentally sustainable. The use of supersonic flame spraying local fixed-point spraying process to manufacture watermark plate rollers simplifies the plate roller production process, not only effectively exerts the advantages of additive manufacturing technology, but also achieves the processing purpose of one-piece molding of materials.

[0014] In some technical solutions, optionally, a watermark pattern is engraved on the coating block to obtain a watermark plate roller, which specifically includes: grinding and polishing the coating block; and engraving a watermark pattern on the coating block by a laser engraving device to obtain a watermark plate roller.

[0015] In this technical solution, a watermark pattern is engraved on a coating block to obtain a watermark plate roller. Specifically, the coating block is ground and polished, and then a watermark pattern is engraved on the coating using a laser engraving device to complete the watermark plate roller.

[0016] In some technical solutions, optionally, the angle between the edge of the coating block and the surface of the steel roller substrate is in the range of 60° to 90°.

[0017] In this technical solution, the angle between the edge of the coating block and the surface of the steel roller substrate is in the range of 60° to 90°, and can be 65°, 70° or 80°.

[0018] In some technical solutions, optionally, the thickness of the mask is in the range of 5 mm to 8 mm; the angle between the slope of the mask and the surface of the steel roller base is in the range of 60° to 90°; the distance between the inner wall of the mask and the surface of the steel roller base is in the range of 3 mm to 5 mm; the distance between the spray gun of the spraying equipment and the mask is in the range of 300 mm to 500 mm.

[0019] In this technical solution, the mask thickness ranges from 5mm to 8mm, and the angle between the mask's slope and the surface of the steel roller base is between 60° and 90°. This means the mask has a sloped or vertical surface. The distance between the mask's inner wall and the surface of the steel roller base is between 3mm and 5mm, and the spraying distance is between 300mm and 500mm. These parameters ensure that the angle between the edge of the coating and the surface of the steel roller base is between 60° and 90°.

[0020] In some technical solutions, optionally, the spray material of the spraying equipment is nearly spherical nickel-containing tungsten carbide powder, and the particle size of the nearly spherical nickel-containing tungsten carbide powder is in the range of 15μm to 50μm; the powder feeding amount of the spraying equipment is in the range of 70g / min to 100g / min; and the movement speed of the spray gun of the spraying equipment is in the range of 30mm / s to 40mm / s.

[0021] In this technical solution, the spraying material of the spraying equipment is nearly spherical nickel-containing tungsten carbide powder, and the particle size of the nearly spherical nickel-containing tungsten carbide powder is in the range of 15μm to 50μm, and can be 20μm, 25μm or 35μm. The powder feeding rate of the spraying equipment is in the range of 70g / min to 100g / min, and can be 75g / min, 80g / min or 90g / min. The movement speed of the spray gun of the spraying equipment is in the range of 30mm / s to 40mm / s, and can be 31mm / s, 35mm / s or 39mm / s.

[0022] In some embodiments, the steel rollers optionally comprise seamless carbon steel or stainless steel tubes.

[0023] In this technical solution, the steel roller can be a seamless carbon steel or stainless steel tube.

[0024] In some technical solutions, optionally, the Vickers hardness of the coating block is in the range of 700 HV to 1200 HV.

[0025] In this technical solution, the Vickers hardness of the coating block is in the range of 700 HV to 1200 HV.

[0026] In some technical solutions, optionally, the coating porosity of the coating block is less than 1%.

[0027] In this technical solution, the coating porosity of the coating block is less than 1%.

[0028] In some technical solutions, optionally, shaft heads are provided at both ends of the steel roller base.

[0029] In this technical solution, shaft heads are provided at both ends of the steel roller base.

[0030] In some technical solutions, optionally, the nickel content of the nearly spherical nickel-containing tungsten carbide powder is in the range of 10% to 30%.

[0031] In this technical solution, the nickel content of the nearly spherical nickel-containing tungsten carbide powder is in the range of 10% to 30%.

[0032] In some technical solutions, optionally, the mask has a sloped surface and / or a vertical surface.

[0033] In this technical solution, the mask has a sloped surface or a vertical surface.

[0034] In some technical solutions, optionally, the propane pressure of the spray equipment is in the range of 60 PSI to 120 PSI.

[0035] In this technical solution, the propane pressure of the spraying equipment is in the range of 60 PSI to 120 PSI.

[0036] In order to achieve the second purpose of the present application, the technical solution of the second aspect of the present application provides a watermark plate roller, which is prepared using the preparation method of the watermark plate roller of any technical solution in the first aspect above.

[0037] According to the watermark plate roller provided in the present application, the watermark plate roller is prepared by using the preparation method of the watermark plate roller of any technical solution in the first aspect mentioned above.

[0038] In order to achieve the third purpose of this application, the technical solution of the third aspect of this application provides a watermark plate roller, including: a steel roller base; multiple coating blocks, the multiple coating blocks are arranged on the surface of the steel roller base, and the coating blocks are engraved with watermark patterns.

[0039] The watermark roller provided herein comprises a steel roller base and multiple coating blocks. The coating blocks are disposed on the surface of the steel roller base and are engraved with a watermark pattern. The metal-ceramic coating on the watermark roller is applied using a thermal spray process. The watermark roller is used to transfer the pattern applied to the paper by pressing the paper, forming a watermark.

[0040] In some technical solutions, optionally, the angle between the edge of the coating block and the surface of the steel roller substrate is in the range of 60° to 90°.

[0041] In this technical solution, the watermark plate roller includes a steel roller base and a coating block on the steel roller base, and the angle between the edge of the coating block and the surface of the steel roller base is an angle between 60° and 90°.

[0042] In some technical solutions, optionally, shaft heads are provided at both ends of the steel roller base.

[0043] In this technical solution, shaft heads are provided at both ends of the steel roller base.

[0044] In some technical solutions, optionally, the coating porosity of the coating block is less than 1%; and the Vickers hardness of the coating block is in the range of 700 HV to 1200 HV.

[0045] In this technical solution, the coating porosity of the coating block is less than 1%, and the Vickers hardness of the coating block is in the range of 700 HV to 1200 HV.

[0046] Additional aspects and advantages of the present application will become apparent in the following description or may be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0048] FIG1 is a flow chart of the steps of a method for preparing a watermark plate roller according to an embodiment of the present application;

[0049] FIG2 is a flow chart of the steps of a method for preparing a watermark plate roller according to an embodiment of the present application;

[0050] FIG3 is a flow chart of the steps of a method for preparing a watermark plate roller according to an embodiment of the present application;

[0051] FIG4 is a schematic diagram of the three-dimensional structure of a watermark plate roller according to an embodiment of the present application;

[0052] FIG5 is a schematic block diagram of the structure of a system for preparing a watermark plate roller according to an embodiment of the present application;

[0053] FIG6 is a schematic block diagram of the structure of a preparation system for a watermark plate roller according to an embodiment of the present application.

[0054] The corresponding relationship between the reference numerals and component names in FIG. 4 to FIG. 6 is as follows:

[0055] 10: Watermark plate roller; 110: Steel roller base; 112: Shaft head; 120: Coating block; 20: Watermark plate roller preparation system; 210: Steel roller processing module; 220: Steel pipe processing module; 230; Clamping and positioning module; 240: Spraying module; 250; Engraving module; 30: Watermark plate roller preparation system; 300: Memory; 400: Processor. DETAILED DESCRIPTION

[0056] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0057] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0058] The following describes the preparation method of the watermark plate roller and the watermark plate roller of some embodiments of the present application with reference to Figures 1 to 6.

[0059] As shown in FIG1 , a method for preparing a watermark plate roller according to an embodiment of the present application includes:

[0060] Step S102: processing the steel roller to obtain a steel roller base, and setting a plurality of coating areas on the steel roller base;

[0061] Step S104: The steel pipe is processed mechanically or by laser to obtain a mask having a plurality of holes, wherein the diameter of the steel pipe is larger than the diameter of the steel roller base;

[0062] Step S106: Clamp and position the mask, and insert the steel roller substrate into the mask, with each hole corresponding to a coating area;

[0063] Step S108: sandblasting and spraying the mask to form a coating block on the coating area;

[0064] Step S110: Carving a watermark pattern on the coating block to obtain a watermark plate roller.

[0065] In this embodiment, a steel roller is first processed to obtain a steel roller base. The surface of the steel roller base is then ground to the required roughness and roundness, and multiple coating areas are formed on the surface of the steel roller base. A steel tube of a certain thickness and a diameter larger than the diameter of the steel roller base is then mechanically or laser-processed into a mask with localized holes. The mask is clamped and positioned, and the steel roller base is placed within the mask. The locations of the holes correspond to the locations on the steel roller base where the coating is to be applied. The mask is then sandblasted and sprayed, forming coating blocks on the coating areas. Finally, a watermark pattern is engraved on the coating block to obtain a watermarked roller. Powdered material is directly sprayed onto the fabricated steel roller, completing the production of the localized coating blocks in a single step. This not only eliminates the need for repeated electroplating steps but also effectively solves the problem of large-scale removal of roller surface material, thereby improving processing efficiency. Due to the inherent performance characteristics of the sprayed material, it can be used directly as a coating block, and the resulting coating block does not require surface treatment such as chrome plating for strengthening. The technical solution of this embodiment has control flexibility and is also widely applicable to the specifications and sizes of workpieces and the types of substrate materials.

[0066] It can be understood that holes are machined into the mask at the locations on the steel roller substrate where coating is desired. Due to the characteristics of thermal spraying, spraying is generally performed continuously. When the steel roller substrate is placed in the mask, powder particles pass through the holes in the mask to form a coating on the steel roller substrate. Where there are no holes, powder particles will form a coating on the mask and will not reach the surface of the steel roller substrate. This is the principle of forming a localized, targeted coating on the steel roller substrate.

[0067] As shown in FIG2 , according to a method for preparing a watermark plate roller according to an embodiment of the present application, a mask is sandblasted and sprayed to form a coating block on the coating area, specifically comprising:

[0068] Step S202: sandblasting the mask using a sandblasting device to form a sand layer on the coating area;

[0069] Step S204: spraying the mask with a spraying device to form a coating block on the sand layer;

[0070] Among them, spraying includes thermal spraying or cold spraying, and thermal spraying includes supersonic flame spraying.

[0071] In this embodiment, the mask is sandblasted and sprayed to form a coating block on the coating area. Specifically, sandblasting equipment is first used to perform sandblasting to improve the adhesion of the coated metal particles. At this time, a sand layer has been formed on the surface of the steel roller through the mask. The mask is thermally sprayed or cold sprayed with nearly spherical nickel-containing tungsten carbide powder. Thermal spraying includes supersonic flame spraying. At this time, a coating block is formed in the area where the sand layer has been formed through the mask. The deposition rate of the material by supersonic flame spraying can reach 11.3kg / h, which improves the production efficiency of the plate roller and the timeliness of the production response. Supersonic flame spraying is environmentally sustainable. The use of supersonic flame spraying local fixed-point spraying process to manufacture watermark plate rollers simplifies the plate roller production process, not only effectively exerts the advantages of additive manufacturing technology, but also achieves the processing purpose of one-piece molding of materials.

[0072] As shown in FIG3 , according to a method for preparing a watermark plate roller according to an embodiment of the present application, a watermark pattern is engraved on a coating block to obtain a watermark plate roller, which specifically includes:

[0073] Step S302: grinding and polishing the coating block;

[0074] Step S304: engraving a watermark pattern on the coating block by laser engraving equipment to obtain a watermark plate roller;

[0075] In this embodiment, a watermark pattern is engraved on a coating block to obtain a watermark plate roller. Specifically, the coating block is ground and polished, and then a watermark pattern is engraved on the coating using a laser engraving device to complete the watermark plate roller.

[0076] In some embodiments, the mask thickness is optionally within a range of 5 mm to 8 mm, and the angle between the slope of the mask and the surface of the steel roller substrate is within a range of 60° to 90°. This means that the processed mask has a certain slope or is vertical. The distance between the inner wall of the mask and the surface of the steel roller substrate is within a range of 3 mm to 5 mm, and the spraying distance is within a range of 300 mm to 500 mm. These appropriate parameters ensure that the angle between the edge of the coating block and the surface of the steel roller substrate is within a range of 60° to 90°.

[0077] In some embodiments, optionally, the spray material of the spraying equipment is a nearly spherical nickel-containing tungsten carbide powder, and the particle size of the nearly spherical nickel-containing tungsten carbide powder is in the range of 15 μm to 50 μm, and can be 20 μm, 25 μm or 35 μm. The powder feeding rate of the spraying equipment is in the range of 70 g / min to 100 g / min, and can be 75 g / min, 80 g / min or 90 g / min. The movement speed of the spray gun of the spraying equipment is in the range of 30 mm / s to 40 mm / s, and can be 31 mm / s, 35 mm / s or 39 mm / s.

[0078] In some embodiments, the steel roller may comprise a seamless carbon steel or stainless steel tube. The steel roller base is obtained by processing the seamless carbon steel or stainless steel tube, or by processing a carbon steel or stainless steel plate of a certain thickness into a steel roller to meet the required specifications. Shaft heads 112 are provided at both ends of the steel roller base.

[0079] In some embodiments, optionally, after the coating block is ground and polished, the Vickers hardness of the coating block is in the range of 700 HV to 1200 HV, and the coating porosity of the coating block is less than 1%.

[0080] In some embodiments, the nickel content of the nearly spherical nickel-containing tungsten carbide powder is optionally in the range of 10% to 30%. The propane pressure of the spraying equipment is in the range of 60 PSI to 120 PSI. The compressed air pressure of the spraying equipment is in the range of 80 PSI to 150 PSI.

[0081] An embodiment of the second aspect of the present application provides a watermark plate roller, which is prepared using the preparation method of the watermark plate roller as described in any embodiment of the first aspect above.

[0082] In this embodiment, the watermark plate roller is prepared by the preparation method of the watermark plate roller according to any one of the embodiments of the first aspect.

[0083] As shown in Figure 4, an embodiment of the third aspect of the present application provides a watermark plate roller 10, including: a steel roller base 110; a plurality of coating blocks 120, the plurality of coating blocks 120 are arranged on the surface of the steel roller base 110, and a watermark pattern is engraved on the coating blocks 120.

[0084] The watermark roller 10 provided in this embodiment comprises a steel roller base 110 and a plurality of coating blocks 120. The coating blocks 120 are disposed on the surface of the steel roller base 110 and are engraved with a watermark pattern. The metal-ceramic coating on the watermark roller 10 is applied using a thermal spraying process. The watermark roller 10 is used to transfer the pattern applied to the paper by pressing the paper, forming a watermark.

[0085] The angle between the edge of the coating block 120 and the surface of the steel roller base 110 is between 60° and 90°. The steel roller base 110 is provided with shaft heads 112 at both ends. The coating block 120 has a coating porosity of less than 1%. The Vickers hardness of the coating block 120 is within the range of 700 HV to 1200 HV.

[0086] As shown in Figure 5, an embodiment of the fourth aspect of the present application provides a preparation system 20 for a watermark plate roller, including: a steel roller processing module 210, used to process the steel roller to obtain a steel roller substrate, and a plurality of coating areas are provided on the steel roller substrate; a steel pipe processing module 220, used to obtain a mask with a plurality of holes by mechanical or laser processing of the steel pipe, and the diameter of the steel pipe is larger than the diameter of the steel roller substrate; a clamping and positioning module 230, used to clamp and position the mask, and insert the steel roller substrate into the mask, each hole corresponding to a coating area; a spraying module 240, used to sandblast and spray the mask to form a coating block on the coating area; an engraving module 250, used to engrave a watermark pattern on the coating block to obtain a watermark plate roller.

[0087] The watermark roller preparation system 20 provided in this embodiment includes a steel roller processing module 210, a steel pipe processing module 220, a clamping and positioning module 230, a spraying module 240, and an engraving module 250. The steel roller processing module 210 is used to process the steel roller to obtain a steel roller base, which is provided with multiple coating areas. The steel pipe processing module 220 is used to mechanically or laser process the steel pipe to obtain a mask with multiple holes, where the diameter of the steel pipe is larger than that of the steel roller base. The clamping and positioning module 230 is used to clamp and position the mask and insert the steel roller base into the mask, with each hole corresponding to a coating area. The spraying module 240 is used to sandblast and spray the mask, forming coating blocks on the coating areas. The engraving module 250 is used to engrave a watermark pattern on the coating blocks to produce the watermark roller. Directly spraying the powdered material onto the pre-fabricated steel roller creates a localized coating block in a single step. This not only eliminates repeated electroplating steps but also effectively solves the challenge of removing large areas of roller surface material, improving processing efficiency. Due to the inherent performance characteristics of the sprayed material, it can be used directly as a coating block, eliminating the need for surface treatments such as chrome plating. This embodiment offers flexible control and is widely applicable to workpiece sizes and substrate types.

[0088] As shown in Figure 6, an embodiment of the fifth aspect of the present application provides a watermark plate roller preparation system 30, including: a memory 300 and a processor 400, wherein the memory 300 stores a program or instruction that can be run on the processor 400, and when the processor 400 executes the program or instruction, it implements the steps of the watermark plate roller preparation method of any one of the embodiments of the first aspect, and thus has the technical effect of any one of the embodiments of the first aspect mentioned above, which will not be repeated here.

[0089] An embodiment of the sixth aspect of the present application provides a readable storage medium on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method for preparing a watermark plate roller of any one of the embodiments of the first aspect are implemented, and thus the technical effects of any one of the embodiments of the first aspect are achieved, which will not be repeated here.

[0090] As shown in Figures 1 to 6 , according to a specific embodiment of the present invention's method for preparing a watermark roller, a thermal spraying process is used to create a metal-ceramic coating. The coating serves as the carrier of the watermark pattern. A mask is used to achieve localized, targeted coating. Parameters are controlled to maintain an angle between the edge of the coating and the steel roller surface between 60° and 90°.

[0091] Specifically, the main process flow of thermal spraying watermark plate roller is: making steel roller, making coating block, grinding and polishing coating block, and engraving watermark pattern.

[0092] First, use seamless carbon steel or stainless steel pipes, or carbon steel or stainless steel plates of a certain thickness to make steel rollers that meet the specifications. Add shaft heads at both ends and grind the surface to achieve the required roughness and roundness.

[0093] A steel pipe with a certain thickness and a diameter greater than the diameter of a medium steel roller is processed mechanically or by laser to form a mask with local holes. Specifically: 1) holes are formed on the mask at the locations on the steel roller where coating is required. According to the characteristics of thermal spraying, the spraying operation is generally continuous and uninterrupted. When a medium steel roller is placed in the mask, the powder particles will form a coating on the steel roller through the holes in the mask at locations where there are holes. The powder particles will form a coating on the mask at locations where there are no holes and will not be able to reach the surface of the steel roller. This is also the principle of forming a local fixed-point coating on the steel roller. 2) The thickness of the mask is in the range of 5mm-8mm. The angle between the slope of the mask and the surface of the steel roller is in the range of 60°-90°, that is, the processed mask has a certain slope or is a vertical surface. The distance between the inner wall of the mask and the surface of the steel roller is in the range of 3mm-5mm, and the spraying distance is 300mm-500mm. By selecting appropriate parameters above, it is possible to ensure that the angle between the edge of the coating block and the surface of the steel roller is an angle between 60° and 90°.

[0094] The mask is then clamped and positioned, and the steel roller is placed in the mask. Sandblasting equipment is used to improve the adhesion of the coated metal particles. At this time, a local coating block has been formed on the surface of the steel roller through the mask.

[0095] Then, flame spraying was performed using nearly spherical nickel-containing tungsten carbide powder (nickel content 10%-30%) with a particle size between 15μm and 50μm, with propane pressure of 60-120 PSI, compressed air pressure of 80-150 PSI, powder feed rate of 70g / min-100g / min, spraying distance of 300mm-500mm, and spray gun movement speed of 30mm / s-40mm / s. This is to form a coating block in the area where the sand layer has been formed through the mask.

[0096] Finally, the coating block is ground and polished to a Vickers hardness of 700HV-1200HV and a coating porosity of less than 1%. The watermark pattern is then engraved on the coating using laser engraving equipment to complete the watermark plate roller.

[0097] In summary, the beneficial effects of the embodiments of the present application are:

[0098] 1. Spray powder material directly onto the prepared steel roller substrate, and complete the production of local coating blocks in one step. This not only saves the production steps of repeated electroplating, but also effectively solves the problem of removing large areas of roller surface material.

[0099] 2. Due to the performance characteristics of the spraying material itself, it can meet the service requirements of being directly used as a coating block, so the produced coating block will not require surface treatment such as chrome plating for strengthening.

[0100] 3. The technical solution of this embodiment has control flexibility and is also widely applicable to the specifications and sizes of workpieces and the types of substrate materials.

[0101] 4. Supersonic flame spraying can deposit materials at a rate of up to 11.3 kg / h, significantly improving the efficiency of plate roller production and the timeliness of production response. Supersonic flame spraying is environmentally sustainable. Using a localized, fixed-point spraying process with supersonic flame spraying to manufacture watermark plate rollers simplifies the plate roller production process, effectively leveraging the advantages of additive manufacturing technology while achieving the goal of one-piece material production. Compared to electroplated plate roller production, the supersonic flame spraying material forming process does not use water as a production raw material, thus generating no industrial wastewater and reducing the hexavalent chromium generated in the electroplating chromium process at the source.

[0102] In this application, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless expressly limited otherwise. Terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; "connected" can mean a direct connection or an indirect connection through an intermediary. Those skilled in the art can understand the specific meanings of the above terms in this application based on the specific circumstances.

[0103] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0104] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0105] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing a watermark plate roller, wherein: include: Processing a steel roller to obtain a steel roller substrate, and arranging a plurality of coating areas on the steel roller substrate; Processing a steel pipe mechanically or by laser to obtain a mask having a plurality of holes, wherein the diameter of the steel pipe is greater than the diameter of the steel roller substrate; Clamping and positioning the mask, and inserting the steel roller substrate into the mask, each of the holes corresponding to one of the coating areas; performing sandblasting and spraying operations on the mask to form coating blocks on the coating area; A watermark pattern is engraved on the coating block to obtain the watermark plate roller.

2. The method for preparing a watermark plate roller according to claim 1, wherein: The sandblasting and spraying operations are performed on the mask to form a coating block on the coating area, specifically including: sandblasting the mask by using a sandblasting device to form a sand layer on the coating area; The mask is sprayed by a spraying device to form a coating block on the sand layer; Wherein, the spraying includes thermal spraying or cold spraying, and the thermal spraying includes supersonic flame spraying.

3. The method for preparing a watermark plate roller according to claim 1, wherein: The step of engraving a watermark pattern on the coating block to obtain the watermark plate roller specifically comprises: Grinding and polishing the coating block; The watermark pattern is engraved on the coating block by laser engraving equipment to obtain the watermark plate roller.

4. The method for preparing a watermark plate roller according to claim 1, wherein: The angle between the edge of the coating block and the surface of the steel roller substrate is in the range of 60° to 90°.

5. The method for preparing a watermark plate roller according to claim 2, wherein: The thickness of the mask is in the range of 5 mm to 8 mm; The angle between the slope of the mask and the surface of the steel roller substrate is in the range of 60° to 90°; The distance between the inner wall of the mask and the surface of the steel roller substrate is in the range of 3 mm to 5 mm; The distance between the spray gun of the spraying equipment and the mask is in the range of 300 mm to 500 mm.

6. The method for preparing a watermark plate roller according to claim 2, wherein: The spraying material of the spraying equipment is a nearly spherical nickel-containing tungsten carbide powder, and the particle size of the nearly spherical nickel-containing tungsten carbide powder is in the range of 15 μm to 50 μm; The powder feeding amount of the spraying equipment is in the range of 70 g / min to 100 g / min; The movement speed of the spray gun of the spraying equipment is in the range of 30 mm / s to 40 mm / s.

7. The method for preparing a watermark plate roller according to claim 1, wherein: The steel rolls comprise seamless carbon steel or stainless steel tubes.

8. The method for preparing a watermark plate roller according to claim 1, wherein: The Vickers hardness of the coating block is in the range of 700 HV to 1200 HV.

9. The method for preparing a watermark plate roller according to claim 1, wherein: The coating porosity of the coating block is less than 1%.

10. The method for preparing a watermark plate roller according to claim 1, wherein: Both ends of the steel roller base are provided with shaft heads.

11. The method for preparing a watermark plate roller according to claim 6, wherein: The nickel content of the nearly spherical nickel-containing tungsten carbide powder is in the range of 10% to 30%.

12. The method for preparing a watermark plate roller according to any one of claims 1 to 11, wherein: The mask has a sloped surface and / or a vertical surface.

13. The method for preparing a watermark plate roller according to claim 2, wherein: The propane pressure of the spray equipment is in the range of 60 PSI to 120 PSI.

14. The method for preparing a watermark plate roller according to claim 2, wherein: The compressed air pressure of the spray equipment is in the range of 80PSI to 150PSI.

15. A watermark plate roller, wherein: The watermark plate roller is prepared by the preparation method of any one of claims 1 to 14.

16. A watermark plate roller, wherein: include: Steel roller base (110); A plurality of coating blocks (120) are provided on the surface of the steel roller substrate (110), and a watermark pattern is engraved on the coating block (120).

17. The watermarking plate roller according to claim 16, wherein: The angle between the edge of the coating block (120) and the surface of the steel roller substrate (110) is in the range of 60° to 90°.

18. The watermarking plate roller according to claim 16, wherein: Both ends of the steel roller base (110) are provided with shaft heads (112).

19. The watermarking plate roller according to claim 16, wherein: The coating porosity of the coating block (120) is less than 1%; The Vickers hardness of the coating block (120) is in the range of 700 HV to 1200 HV.

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