Circular screen squeegee device

Abstract

The application discloses a rotary screen printing device, which comprises a rotary screen, a doctor blade assembly, and a feeding pipe. The rotary screen is provided with printing holes. The doctor blade assembly is arranged in a space surrounded by the rotary screen and comprises a doctor blade holder, a doctor blade arranged on the doctor blade holder, and a squeegee blade arranged on the doctor blade holder. The end of the doctor blade acts on the inner surface of the rotary screen. The end of the squeegee blade and the inner surface of the rotary screen form a gap. The doctor blade and the squeegee blade surround an ink accumulation area in the circumferential direction of the rotary screen. The feeding pipe is arranged in the space surrounded by the rotary screen and is provided with an ink outlet hole facing the ink accumulation area. The technical scheme of the application can print electronic paste on a film substrate uniformly and fully, and improves the printing quality and efficiency of the electronic paste.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printed electronics, in particular to a rotary screen printing device. BACKGROUND

[0002] With the development of modern electronic technology, flexibility and thinness have become the pursuit goal of electronic products, and flexible electronics has become an important direction of future electronic technology. The flexible electronic devices prepared by printed electronics technology have become a hot spot of scientific research and industrial application. Not only in functional materials, but also in process technology, device structure and other aspects have been developed rapidly and made great progress.

[0003] Printed electronics technology is an additive manufacturing technology that uses solutionized functional materials to manufacture functional lines or functional films. And it can use various patterning manufacturing technologies such as screen brush, inkjet, intaglio, offset, transfer printing and aerosol printing. At present, the most commonly used is screen printing technology to manufacture various flexible electrode circuits, such as thin film switch circuit, notebook keyboard circuit, sensor electrode and the like. However, the current screen printing technology is still in the transition stage from the first generation single machine to the second generation roll-to-roll flat screen printing technology, and its overall production efficiency is low, the use range of printing materials is small, the production cost is high, and the degree of equipment integration is low.

[0004] Rotary screen printing technology is a kind of rapid patterning manufacturing technology using a circular screen. The difference is that the squeegee is fixed in the metal rotary screen and does not move, while the metal rotary screen rotates and moves synchronously with the substrate. This technology can realize high-speed patterning printing, but it is still used for traditional ink patterning preparation. With the development of printed electronics technology and the higher requirement for production efficiency, rotary screen printing technology has also been applied to the preparation of electronic devices. However, the existing rotary screen equipment has problems such as low viscosity requirement of electronic paste, poor web passing property and poor printing quality.

[0005] The information disclosed in this BACKGROUND section is only intended to increase an understanding of the general background of the application and is not intended to be a recognition or any form of suggestion that this information forms prior art. SUMMARY

[0006] The purpose of the present application is to provide a rotary screen printing device which can overcome the technical problems of low viscosity requirement of electronic paste, poor web passing property and poor printing quality in the prior art.

[0007] To achieve the above-mentioned purpose, the embodiment of the present application provides a rotary screen printing device, comprising:

[0008] A circular screen having printing holes distributed thereon;

[0009] The doctor assembly is arranged in the space surrounded by the round screen, and comprises a doctor holder, a doctor blade and a flood bar arranged on the doctor holder, the end of the doctor blade acts on the inner surface of the round screen, the end of the flood bar and the inner surface of the round screen form a coating gap, and the doctor blade and the flood bar surround an ink accumulation area in the circumferential direction of the round screen.

[0010] The ink feeding pipe is arranged in the space surrounded by the round screen, and the ink feeding pipe has an ink outlet hole facing the ink accumulation area.

[0011] In one or more embodiments of the present application, a guide groove is formed on the surface of the flood bar opposite to the round screen, and the guide groove has a guide surface which can vertically guide the ink to the inner surface of the round screen.

[0012] In one or more embodiments of the present application, the end of the side of the flood bar opposite to the doctor blade is recessed to form a slope connected to the guide groove.

[0013] In one or more embodiments of the present application, the guide groove has a circular arc-shaped bottom surface.

[0014] In one or more embodiments of the present application, an adjusting bolt is arranged on the doctor holder, the adjusting bolt acts on the flood bar and can make the end of the flood bar approach or move away from the inner surface of the round screen.

[0015] In one or more embodiments of the present application, the doctor holder is fixed on the ink feeding pipe.

[0016] In one or more embodiments of the present application, the doctor holder comprises a first V-shaped arm and a second V-shaped arm, and the doctor blade and the flood bar are arranged on the first arm and the second arm respectively.

[0017] In one or more embodiments of the present application, the ink feeding pipe is supported between the first arm and the second arm.

[0018] In one or more embodiments of the present application, a first insertion slot is formed on the first arm, and the end of the doctor blade away from the round screen is inserted into the first insertion slot, and / or a second insertion slot is formed on the second arm, and the end of the flood bar away from the round screen is inserted into the second insertion slot.

[0019] In one or more embodiments of the present application, a supporting roller is further included, a gap for the substrate to pass through is formed between the supporting roller and the outer surface of the round screen, and the doctor blade acts on the position of the round screen close to the supporting roller.

[0020] Compared with the prior art, the present application adopts a double-knife structure (a squeegee knife and a floodbar) to limit the electronic paste in a flood area, and through the special-shaped structure of the floodbar, the electronic paste shows good printing effect. The present application has the following advantages:

[0021] 1) The electronic paste is limited in the flood area between the squeegee knife and the floodbar, which is beneficial to reducing the volatilization of the paste and maintaining the stability of the paste; at the same time, it is beneficial to the neatness of the squeegee holder and the recovery of the electronic paste;

[0022] 2) The electronic paste can be uniformly covered on the screen under the action of the floodbar, and the dampening time is long; in the process of rotation of the rotary screen, the centrifugal force further promotes the electronic paste to enter the rotary screen holes;

[0023] 3) The floodbar is designed as a special-shaped structure, so that the electronic paste forms a flow perpendicular to the metal rotary screen after passing through the neck area of the floodbar, which is beneficial to the dampening of the electronic paste. At the same time, it is beneficial to the use range of the viscosity of the electronic paste and the control of the quality of the printed functional line or film. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic view of a rotary screen squeegee printing device according to an embodiment of the present application;

[0025] Figure 2 is a schematic view of the movement of the electronic paste at the floodbar according to an embodiment of the present application;

[0026] Figure 3 is an enlarged schematic view of the special-shaped structure of the floodbar according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0028] Unless otherwise explicitly stated, in the entire specification and claims, the term "comprise" or its variants such as "contain" or "include" and the like will be understood to include the stated element or component without excluding the presence of other elements or components.

[0029] As shown in Figure 1 Fig. 1, a rotary screen squeegee printing device 10 according to a preferred embodiment of the present application comprises a circular screen 11, a squeegee knife assembly 12, a paste feeding pipe 13 and a supporting roller 14, and the squeegee knife assembly 12 and the paste feeding pipe 13 are arranged in the space surrounded by the circular screen 11.

[0030] A gap is formed between the outer surface of the roller 14 and the circular screen 11 for the substrate 20 to pass through. In operation, the substrate 20 is pressed between the roller 14 and the circular screen 11, the roller 14 acts as a driving wheel, and the roller 14 rotates in the clockwise direction, for example, to drive the substrate 20 to move forward, and at the same time, the circular screen 11 is driven to move in the counterclockwise direction. The circular screen 11 transfers the paste to the surface of the substrate 20 during rotation.

[0031] The circular screen 11 is made of a metal screen, for example, by nickel metal plating, and has printing holes 111 penetrating the metal screen, the shape of the printing holes 111 corresponds to the pattern to be printed on the substrate 20, and the shape can be designed according to the specific application scenario.

[0032] The circular screen 11 surrounds a cylindrical space 112, which can rotate along its axial direction, and the paste is printed on the surface of the substrate 20 during rotation. For example, Figure 1 The circular screen 11 rotates in the counterclockwise direction.

[0033] The doctor assembly 12 is arranged in the space 112 surrounded by the circular screen 11, and includes a doctor holder 121, and a squeegee blade 122 and a flood bar 123 arranged on the doctor holder 121. The end of the squeegee blade 122 acts on the inner surface of the circular screen 11, and the end of the flood bar 123 and the inner surface of the circular screen 11 form a squeegee gap. The squeegee blade 122 and the flood bar 123 surround an ink accumulation area 124 in the circumferential direction of the circular screen 11, and the ink accumulation area 124 is a region with a sector-shaped cross section.

[0034] The doctor holder 121 includes a first branch arm 1211 and a second branch arm 1212, and the squeegee blade 122 and the flood bar 123 are arranged on the first branch arm 1211 and the second branch arm 1212, respectively, and extend towards the inner surface of the circular screen along the direction of the first branch arm 1211 and the second branch arm 1212, respectively.

[0035] In a preferred embodiment, the doctor holder 121 is integrally formed of a metal or a plastic material.

[0036] A first insertion slot 12111 is formed at the end of the first branch arm 1211 of the doctor holder 121, and one end of the squeegee blade 122 is inserted into the first insertion slot 12111.

[0037] In this embodiment, the squeegee blade 122 and the doctor holder 121 can be quickly assembled by insertion, and when the squeegee blade 122 is damaged, it is convenient to replace, and the operation is convenient and the cost is low.

[0038] It is easy to think that the welding or screw fastening can also be used between the doctor blade 122 and the doctor blade holder 121.

[0039] The second slot 12121 is formed on the second arm 1212 of the doctor blade holder 121, and the end of the flood bar 123 away from the round screen 11 is inserted into the second slot 12121.

[0040] In the preferred embodiment, the second slot 12121 away from the end of the flood bar 123 is also provided with an adjusting bolt 125, which acts on the flood bar 123 and can drive the end thereof to approach or away from the inner surface of the round screen 11.

[0041] Specifically, the adjusting bolt 125 is rotationally connected between the doctor blade holder 121, the end of the adjusting bolt 125 is threadedly connected with the flood bar 123, and when the adjusting bolt 125 rotates, it can drive the flood bar 123 to approach or away from the inner surface of the round screen 11 along the second slot 12121.

[0042] In this technical solution, the second slot 12121 can realize the rapid positioning of the flood bar 123 on the one hand, and can be used as a guide slot when the flood bar 123 moves.

[0043] In an embodiment, in order to avoid the self-rotation of the flood bar 123 (the cross section is circular), at least one side of the cross section of the second slot 12121 is a straight side, such as a square or triangular cross section.

[0044] The ink inlet pipe 13 is arranged in the space 112 surrounded by the round screen 11, and the ink inlet pipe 13 has an ink outlet hole 131 facing the ink accumulation area 124. After the ink enters the ink accumulation area 124 through the ink outlet hole 131, it is limited in this area.

[0045] In an embodiment, the doctor blade holder 121 is fixed on the ink inlet pipe 13. Further, the ink inlet pipe 13 is supported between the first arm 1211 and the second arm 1212.

[0046] The fixing mode of the ink inlet pipe 13 and the doctor blade holder 121 can adopt welding, screw fastening, clamping, binding and the like. For example, in an embodiment, the inner walls of the first arm 1211 and the second arm 1212 respectively protrude inwardly with elastic clamping members, the clamping members form a hoop shape and have an opening for the ink inlet pipe 13 to enter. During assembly, the doctor blade holder 121 is directly hung on the ink inlet pipe 13, and then pressed down to realize quick assembly.

[0047] In this embodiment, the feeding pipe 13 is provided at the inner angle of the V-shaped area of the scraper holder 121, which can make full use of the space surrounded by the scraper holder 121, and the scraper holder 121 is supported on the feeding pipe 13 in a suspended manner, which is convenient for installation and positioning and has high stability.

[0048] The doctor blade 122 is preferably made of elastic metal sheet, and the material can be stainless steel, aluminum, nickel and their alloy materials.

[0049] The end of the doctor blade 122 is in linear contact with the inner surface of the circular screen 11, and the contact point is located at the contact position of the supporting roller 14 and the circular screen 11. Under the action of the doctor blade 122, the printing paste on the inner surface of the circular screen 11 can be printed onto the surface of the substrate 20.

[0050] The flood bar 123 is preferably made of metal material, such as stainless steel, aluminum, copper, nickel and their alloy materials. The end of the flood bar 123 forms a gap with the circular screen 11, and the electronic paste can be uniformly covered on the circular screen 11 under the action of the flood bar 123.

[0051] In combination with Figure 2 and Figure 3 As shown in the figures, the opposite surface of the flood bar 123 to the circular screen 11 is concavely formed with a guide groove 1231, which has a guide surface 12311 that can vertically guide the paste to the inner surface of the circular screen.

[0052] In an embodiment, the guide groove 1231 is a concavely formed circular arc groove (R angle structure). When the paste enters and exits the guide groove 1231 from the ink accumulation area 124, it can flow vertically on the surface of the circular screen 11.

[0053] In an embodiment, the end of the opposite side of the flood bar 123 to the doctor blade 122 is concavely formed with a slope 1232 connected to the guide groove. The opening of the slope 1232 gradually decreases in the direction of the paste entering the guide groove 1231, forming a narrow neck area.

[0054] In this embodiment, when the circular screen 11 rotates, the paste in the ink accumulation area 124 is extruded into the guide groove 1231 from the narrow neck area. During printing, the electronic paste flows under the special structure and finally forms a downward pressure perpendicular to the circular screen 11, so that the electronic paste can better infiltrate into the pores of the metal circular screen.

[0055] The working principle of the rotary screen printing device 10 in this embodiment is as follows: the electronic paste 30 is pumped into the paste inlet pipe 13 by a pump, and then flows into the ink accumulation area 124 through the paste outlet hole 131 at the lower part of the paste inlet pipe 13. The electronic paste 30 rolls and moistens the screen in this area as the rotary screen 11 rotates. After passing through the flood bar 123, the electronic paste 30 uniformly covers the rotary screen 11 and penetrates into the holes of the rotary screen 11. Since the part of the flood bar 123 close to the rotary screen 11 is designed as a special-shaped structure, when the electronic paste 30 passes through the narrow area of the neck of the flood bar 123, an extrusion force is generated, and then the electronic paste 30 forms a flow perpendicular to the rotary screen 11 after entering the R-angle area, so that the electronic paste 30 generates a downward pressure to penetrate the holes of the rotary screen 11, thereby making the electronic paste 30 better penetrate into the holes of the rotary screen 11. In addition, after the electronic paste 30 is flooded by the flood bar 123, it will have a rotating movement process to the position of the squeegee 122 for printing; in this process, on the one hand, the electronic paste 30 has a time for moistening the screen, and on the other hand, the centrifugal force generated by the rotation also helps the electronic paste 30 to penetrate the screen. When the electronic paste 30 rotates to the position of the squeegee 122, it is transferred to the substrate 20 under the action of the squeegee 122, thereby realizing the rapid patterning printing of the electronic paste 30.

[0056] The foregoing description of specific exemplary embodiments of the application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the application. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application and to allow others skilled in the art to understand the application for various exemplary embodiments with various modifications being suited to the particular use contemplated. The scope of the application is to be defined by the claims and their equivalents.

Claims

1. An engravine applicator, characterized by, The invention relates to a printing device comprising: a circular screen having printing holes distributed thereon; a squeegee assembly arranged in a space surrounded by the circular screen, comprising a squeegee frame, and a squeegeeing blade and a flood bar arranged on the squeegee frame, the squeegeeing blade having an end acting on an inner surface of the circular screen, the flood bar having an end forming a squeegee gap with the inner surface of the circular screen, and the flood bar having a guide groove recessed on a surface opposite to the circular screen, the guide groove having a circular arc-shaped bottom surface, the guide groove having a guide surface vertically guiding the paste to the inner surface of the circular screen, the end of the flood bar opposite to the squeegeeing blade being recessed to form a slope connecting the guide groove, the slope gradually reducing the opening between the flood bar and the circular screen in the direction of the paste entering the guide groove, forming a narrow neck region, the squeegeeing blade and the flood bar forming a paste accumulation area in a circumferential direction of the circular screen; a paste feeding pipe arranged in the space surrounded by the circular screen, the paste feeding pipe having a paste outlet hole facing the paste accumulation area.

2. An apparatus as claimed in claim 1, wherein the blade is mounted on a shaft which is mounted on a bearing which is mounted on the frame. The squeegee frame is provided with an adjusting bolt acting on the flood bar and capable of moving the end of the flood bar close to or away from the inner surface of the circular screen.

3. An apparatus as claimed in claim 1, wherein the blade is mounted on a shaft which is mounted on a bearing which is mounted on the frame. The squeegee frame is fixed on the paste feeding pipe.

4. An apparatus as claimed in claim 3, wherein the blade is mounted on a shaft which is mounted on a bearing which is mounted on the frame. The squeegee frame comprises a first V-shaped arm and a second V-shaped arm, and the squeegeeing blade and the flood bar are arranged on the first arm and the second arm respectively.

5. An apparatus as claimed in claim 4, wherein the blade is mounted on a shaft which is mounted on a bearing which is mounted on the frame. The paste feeding pipe is supported between the first arm and the second arm.

6. An apparatus as claimed in claim 4, wherein the blade is mounted on a shaft which is mounted on a bearing which is mounted on the frame. The first arm is provided with a first insertion slot, and an end of the squeegeeing blade away from the circular screen is inserted into the first insertion slot, and / or The second arm is provided with a second insertion slot, and an end of the flood bar away from the circular screen is inserted into the second insertion slot.

7. The rotary screen squeegee apparatus of claim 1, wherein, The device further comprises a supporting roller, and a gap is formed between the supporting roller and an outer surface of the circular screen for the substrate to pass through, and the squeegeeing blade acts on a position of the circular screen close to the supporting roller.

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