Electrostatic lens focused aerosol printing system

Abstract

The application discloses a kind of electrostatic lens focusing aerosol printing systems, it is related to 3D printing equipment technical field, including: printing platform, printing platform includes fixed plate, heating table and fixed bottom electrode of plate shape that are laid on the top surface of heating table are set on fixed plate;Print head, print head includes sequentially communicating atomizing device, aerosol charging device and electrostatic focusing nozzle;Electrostatic focusing nozzle includes first shell, top in first shell is provided with upper electrode, the side wall of first shell is provided with side wall electrode, the bottom end of first shell is detachably connected with lens aperture plate electrode, and through hole is provided on lens aperture plate electrode as lens aperture;Bottom electrode is located below lens aperture plate;Drive mechanism is used to drive print head to move in three-dimensional space.The application realizes printing by using liquid material through electrostatic lens focusing aerosol printing technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing equipment, in particular to an electrostatic lens focusing aerosol printing system. BACKGROUND

[0002] The existing electrostatic lens focusing printing method forms a nanometer metal particle aerosol through electric spark discharge ablation. Since electric spark discharge ablation can only discharge and ablate solid conductive metal materials, it cannot atomize liquid materials, so there is a problem of single printing material, which leads to the inability to print organic functional materials and the inability to realize true multi-material printing, greatly limiting the application scenarios of the printing method. SUMMARY

[0003] The purpose of the present application is to provide an electrostatic lens focusing aerosol printing system to solve the problems existing in the prior art and realize printing with liquid materials by electrostatic lens focusing aerosol printing technology.

[0004] To achieve the above purpose, the present application provides the following solutions:

[0005] The present application provides an electrostatic lens focusing aerosol printing system, comprising:

[0006] A printing platform, comprising a fixed plate, a heating table arranged on the fixed plate, and a bottom electrode in the form of a plate arranged on the top surface of the heating table;

[0007] A print head, comprising an atomization device, an aerosol charging device and an electrostatic focusing nozzle in sequence; the atomization device is used to atomize the printing material, and the aerosol charging device is used to charge the atomized printing material; the electrostatic focusing nozzle comprises a first shell, an upper electrode arranged at the top of the first shell, a side wall electrode arranged on the side wall of the first shell, and a lens aperture plate electrode detachably connected to the bottom end of the first shell, wherein the side wall electrode is electrically connected to the upper electrode, the lens aperture plate electrode is provided with through holes as lens apertures, the printing material sprayed through all the lens apertures can form a planar pattern on the projection surface of the lens aperture plate electrode, and an insulating isolation layer is arranged on the outer circle of the lens aperture plate; the bottom electrode is located below the lens aperture plate;

[0008] A driving mechanism for driving the print head to move in a three-dimensional space;

[0009] The power supply unit comprises a negative high-voltage direct current power supply, a first positive high-voltage direct current power supply and a second positive high-voltage direct current power supply, the negative high-voltage direct current power supply is used for supplying power to the corona charging device; the positive pole of the first positive high-voltage direct current power supply is electrically connected with the lens aperture plate electrode, the negative pole of the first positive high-voltage direct current power supply is electrically connected with the upper electrode and the side wall electrode and grounded; the positive pole of the second positive high-voltage direct current power supply is electrically connected with the bottom electrode, and the negative pole of the second positive high-voltage direct current power supply is grounded.

[0010] Preferably, the atomization device adopts an ultrasonic atomizer or a pneumatic atomizer; the ultrasonic atomizer comprises a bottle body, a shielding cover and an ultrasonic atomizing sheet are arranged in the bottle body, the shielding cover is located above the ultrasonic atomizing sheet, the feeding port and the discharging port of the bottle body are located above the shielding cover, a plurality of holes are formed in the shielding cover, and the edge of the shielding cover is sealingly connected with the inner wall of the bottle body.

[0011] Preferably, the aerosol charging device adopts a corona charging device, the corona charging device comprises a second shell, a cylindrical electrode and a needle electrode, the cylindrical electrode and the needle electrode are fixedly arranged at the top of the second shell, the cylindrical electrode is coaxial with the needle electrode, the top of the second shell is provided with a charging feeding port and the bottom of the second shell is provided with a charging discharging port, and the charging feeding port and the charging discharging port are eccentric to the second shell; the positive pole of the negative high-voltage direct current power supply is electrically connected with the needle electrode, and the negative pole of the negative high-voltage direct current power supply is electrically connected with the cylindrical electrode.

[0012] Preferably, the printing head further comprises an aerosol particle size selector, the aerosol particle size selector comprises a third shell and a U-shaped channel vertically arranged in the third shell, the discharging port of the atomization device is in communication with one end of the U-shaped channel, and the charging feeding port is in communication with the other end of the U-shaped channel; a pre-heater is fixedly arranged on the outer wall of the third shell, and the pre-heater is used for heating the third shell.

[0013] Preferably, the surface of the second shell is sprayed with a conductive layer, and the material of the conductive layer is conductive copper paint.

[0014] Preferably, the feeding port of the electrostatic focusing nozzle passes through the center of the upper electrode.

[0015] Preferably, the lens aperture plate has a plurality of lens aperture plates, each of the lens aperture plates is detachably connected with the bottom of the first shell; the layout and the number of the lens apertures on different lens aperture plates are different.

[0016] Preferably, the heating table is fixedly arranged on a connecting plate, and at least three leveling mechanisms are arranged on the connecting plate.

[0017] The leveling mechanism comprises a fixed pressing plate, a leveling bolt and two leveling nuts respectively threaded with the leveling bolt, the leveling bolt passes through the connecting plate, the bottom end of the leveling bolt is fixedly connected with the fixed pressing plate, the fixed pressing plate is fixedly connected with the fixed plate, and the two leveling nuts are used for clamping the connecting plate.

[0018] Preferably, the control unit comprises a controller or a control circuit, and the control unit is used for controlling the heating table, the driving mechanism, the atomization device, the aerosol charging device and the pre-heater.

[0019] Preferably, the driving mechanism adopts an X-Y-Z motion system.

[0020] The present application has the following technical effects relative to the prior art:

[0021] The electrostatic lens focusing aerosol printing system realizes printing by using liquid materials to perform printing through the electrostatic lens focusing aerosol printing technology.

[0022] The electrostatic lens focusing aerosol printing system realizes atomization and charging of various liquid materials including organic functional materials through the atomization device and the aerosol charging device, and designs an electrostatic focusing printing nozzle with an array hole, realizes precise focusing and high-efficiency printing of multiple materials by using the electrostatic lens, and greatly expands the application prospect of the printing method. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0024] Fig. 1 It is a structural schematic diagram of the electrostatic lens focusing aerosol printing system of the present application;

[0025] Fig. 2 It is a partial structural schematic diagram of the electrostatic lens focusing aerosol printing system of the present application;

[0026] Fig. 3 It is a structural schematic diagram of the lens hole plate electrode in the electrostatic lens focusing aerosol printing system of the present application;

[0027] The components include: 1. Drive mechanism; 2. Mounting plate; 3. Ultrasonic atomizing device; 4. Aerosol particle size filter; 5. Corona charging device; 6. Preheater; 7. Electrostatic focusing nozzle; 8. Bottom electrode; 9. Heating platform; 10. Leveling mechanism; 11. Fixing plate; 12. Control unit; 13. Negative high voltage DC power supply; 14. First positive high voltage DC power supply; 15. Second positive high voltage DC power supply; 16. Connecting plate; 17. Leveling nut; 18. Leveling bolt; 19. Fixing pressure plate; 20. Bottle body; 21. Shielding cover; 22. Ultrasonic atomizing plate; 23. Lower fixing plate; 24. Upper fixing plate; 25. Sealing plug; 26. Needle electrode; 27. Charging upper end cover; 28. Cylindrical electrode; 29. ​​Second outer shell; 30. Nozzle upper end cover; 31. Upper electrode; 32. First outer shell; 33. Side wall electrode; 34. Lens aperture plate electrode; 35. Lens aperture; 36. Insulating layer. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide an electrostatic lens focusing aerosol printing system to solve the problems existing in the prior art and realize the printing of liquid materials using electrostatic lens focusing aerosol printing technology.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figs. 1-3 As shown, this embodiment provides an electrostatic lens focusing aerosol printing system, including a drive mechanism 1, a print head, a printing platform, a power supply unit, and a control unit 12.

[0032] The drive mechanism 1 employs an XYZ motion system, which is an existing component in current 3D printing devices and will not be described in detail in this embodiment. The function of the drive mechanism 1 is to drive the print head to move in three-dimensional space.

[0033] The printhead includes an atomizing device 3, an aerosol particle size filter 4, an aerosol charging device, and an electrostatic focusing nozzle 7, which are connected in sequence. The printhead is fixed on the mounting plate 2, and the drive mechanism 1 drives the mounting plate 2 to move, thereby moving the printhead.

[0034] The atomization device 3 is used for atomizing the printing material; for ink materials with low viscosity, atomization is performed by an ultrasonic atomizer, when the viscosity of the ink material used is large, it is difficult to atomize by ultrasonic atomization, and a pneumatic atomization device 3 is used for atomization, so the atomization device 3 uses an ultrasonic atomizer or a pneumatic atomizer.

[0035] In this embodiment, the ultrasonic atomizer includes a bottle body 20, the bottle body 20 is provided with a shielding cover 21 and an ultrasonic atomization sheet 22, the shielding cover 21 is located above the ultrasonic atomization sheet 22, the inlet and outlet of the bottle body 20 are located above the shielding cover 21, a plurality of holes are formed in the shielding cover 21, and the edge of the shielding cover 21 is sealingly connected with the inner wall of the bottle body 20. The shielding cover 21 prevents large-size aerosol droplets generated by atomization from splashing into the subsequent focusing print head from above, thereby affecting the printing precision. The holes in the shielding cover 21 are used to ensure the smooth entry of the raw material and the smooth discharge of the aerosol generated after atomization of the raw material. A sealing plug 25 is arranged on the bottle mouth of the bottle body 20, two O-shaped sealing rings are fixed on the sealing plug 25, and the sealing plug 25 ensures good sealing of the ultrasonic atomizer. The ultrasonic atomization sheet 22 is compressed by the upper fixing sheet 24 and the lower fixing sheet 23, and is connected with the bottle body 20 by bolts and nuts. In order to ensure good sealing, an O-shaped sealing ring is arranged between the upper fixing sheet 24 and the bottle body. A circulating heat dissipation passage is formed in the lower fixing sheet 23 to ensure heat dissipation of the ultrasonic atomization sheet 22 during atomization.

[0036] The aerosol particle size selector 4 includes a third shell and a U-shaped channel vertically arranged in the third shell, the outlet of the atomization device 3 is in communication with one end of the U-shaped channel, and the charging inlet is in communication with the other end of the U-shaped channel; a pre-heater 6 is fixed on the outer wall of the third shell, and the pre-heater 6 is used for heating the third shell. The aerosol particle size selector 4 increases the flow path of the aerosol generated by the atomization device through the U-shaped channel, so that the large-size droplets generated by atomization naturally settle to achieve the function of particle size sorting.

[0037] After the ink material is atomized by the atomization device 3, the generated aerosol is transported to the aerosol particle size selector 4 by the conveying gas flow, the pipe distance is increased by the aerosol particle size selector 4, and further settlement and sorting of large-size aerosol droplets are realized. At the same time, the pre-heater is installed outside the aerosol particle size selector 4, the temperature of the pre-heater 6 is controlled by adjusting the heating power, the solvent is preliminarily volatilized during the process of the aerosol droplet passing through the high-temperature aerosol particle size selector 4, the particle size is reduced, which is helpful to improve the subsequent printing precision, and at the same time, the initial temperature of the aerosol droplet is increased, which improves the forming ability and forming speed in the process of realizing three-dimensional structure printing.

[0038] The aerosol charging device is used to charge the atomized printing material, that is, to charge the aerosol droplets generated by atomization, so that the aerosol droplets are charged, which is a prerequisite for subsequent focusing of the aerosol droplets in an electric field; in the embodiment, the aerosol charging device adopts a corona charging device 5.

[0039] The corona charging device 5 includes a second housing 29, a cylindrical electrode 28 and a needle electrode 26, the cylindrical electrode 28 and the needle electrode 26 are both fixedly arranged at the top of the second housing 29, and the cylindrical electrode 28 is coaxial with the needle electrode 26, the top of the second housing 29 is provided with a charging inlet, and the bottom is provided with a charging outlet, and the charging inlet and the charging outlet are both eccentric to the second housing 29.

[0040] The basic principle of the corona charging device 5 is to apply a direct-current high voltage exceeding the corona voltage to the needle electrode 26, so that a very strong electric field is generated at the tip of the needle electrode 26 with a very small curvature radius, causing local gas ionization to generate free electrons, which accelerate away from the needle electrode 26 region under the action of electric field force, and in the process of flying away, the free electrons collide with other gas molecules, causing gas molecules to ionize and continue to generate free electrons, so that the number of free electrons grows exponentially, thereby forming an electron avalanche effect. A large number of free electrons adhere to the aerosol droplets to charge the aerosol droplets. The charging upper end cover 27 is connected with the second housing 29 through a bolt and a nut, and an o-ring is additionally installed to ensure the air tightness of the device. The upper end cover is provided with a needle electrode 26 fixing device and an aerosol inlet, and the tail of the needle electrode 26 fixing device has an opening to facilitate the hot melt adhesive to enter the inside of the fixing device to stably fix the needle electrode 26 after the needle electrode 26 is inserted. The cylindrical electrode 28 is fixed by interference fit. The second housing 29 is provided with an opening to facilitate subsequent welding of the cylindrical electrode 28 wire, and the charging outlet and the charging inlet are arranged on the same side of the central axis of the second housing 29, not on the same axis. The reason is that after the aerosol is charged in the charging device, it will deflect to the side of the cylinder wall under the action of the electric field line, so the outlet is designed in the shape shown in the figure to reduce the loss of aerosol droplets in the charging device. At the same time, a layer of conductive copper paint is sprayed on the outer surface of the second housing 29 as a conductive layer to achieve the purpose of electrostatic shielding and prevent the deposition of aerosol droplets caused by the interference of the nearby electric field.

[0041] The electrostatic focusing nozzle 7 comprises a first shell 32, a top of the first shell 32 is provided with an upper electrode 31, a side wall of the first shell 32 is provided with a side wall electrode 33, the side wall electrode 33 is electrically connected with the upper electrode 31, a bottom end of the first shell 32 is detachably connected with a lens aperture plate electrode 34, the lens aperture plate electrode 34 is provided with through holes as lens apertures 35, an outer circle of the lens aperture plate electrode 34 is provided with an insulating isolation layer 36; it should be noted that the lens apertures 35 on the lens aperture plate electrode 34 are distributed in a pattern, so that the printing material sprayed through all the lens apertures 35 can form a plane pattern on the projection surface of the lens aperture plate electrode 34.

[0042] The nozzle upper end cover 30 is connected with the shell through a bolt and a nut, and a sealing washer is additionally installed to ensure the sealing performance. The electrostatic focusing side wall electrode 33 is made of a copper pipe and is matched with the shell through interference, and the upper electrode 31 is pressed tightly through the nozzle upper end cover 30, so as to ensure that the upper electrode 31 and the side wall electrode 33 are tightly attached and interconnected. The nozzle upper end cover 30 is provided with a through hole for lead welding of the upper electrode 31. The lens aperture plate electrode 34 is made of a PCB plate and is provided with through holes as lens apertures 35, so as to form a focusing electric field, and an aerosol beam is deposited on the bottom electrode 8 from the lens apertures 35. The outer circle of the lens aperture plate electrode 34 is provided with an insulating isolation layer 36 to prevent electrical breakdown of the lens aperture plate electrode 34 and the bottom electrode 8, and the edge of the lens aperture plate electrode 34 and the bottom edge of the first shell 32 are provided with two positioning pin holes to ensure positioning and alignment during installation. The lens aperture plate electrode 34 and the first shell 32 are fixed by means of liquid glue. It should be noted that the above-mentioned bonding is not a firm connection, but the lens aperture plate electrode 34 can be easily separated from the first shell 32 by manual operation. The feeding port of the electrostatic focusing nozzle 7 passes through the center of the upper electrode 31.

[0043] The lens aperture plate electrode 34 has a plurality of lens aperture plate electrodes 34, each of which can be detachably connected with the bottom of the first shell 32; the layout and number of the lens apertures 35 on different lens aperture plate electrodes 34 are different. For different printing patterns and structures, the lens aperture plate electrode 34 can be quickly replaced to achieve the purpose.

[0044] The printing platform comprises a fixed plate 11, a heating table 9 arranged on the fixed plate 11, and a plate-shaped bottom electrode 8 fixedly laid on the top surface of the heating table 9; the bottom electrode 8 is located below the lens aperture plate electrode 34;

[0045] The electrostatic focusing nozzle 7 and the bottom electrode 8 jointly form an electrostatic focusing electric field to realize focusing printing of the charged aerosol.

[0046] The power supply unit comprises a negative high-voltage direct current power supply 13, a first positive high-voltage direct current power supply 14 and a second positive high-voltage direct current power supply 15, the negative high-voltage direct current power supply 13 is used for charging the corona charging device 5, the positive pole of the negative high-voltage direct current power supply 13 is electrically connected with the needle electrode 26, and the negative pole of the negative high-voltage direct current power supply 13 is electrically connected with the cylindrical electrode 28; the positive pole of the first positive high-voltage direct current power supply 14 is electrically connected with the lens aperture plate electrode 34, the negative pole of the first positive high-voltage direct current power supply 14 is electrically connected with the upper electrode 31 and the side wall electrode 33 and grounded; the positive pole of the second positive high-voltage direct current power supply 15 is electrically connected with the bottom electrode 8, and the negative pole of the second positive high-voltage direct current power supply 15 is grounded.

[0047] The heating table 9 is fixedly arranged on the connecting plate 16, and the connecting plate 16 is provided with at least three leveling mechanisms 10; the leveling mechanism 10 comprises a fixed pressing plate 19, a leveling bolt 18 and two leveling nuts 17 which are respectively threadedly connected with the leveling bolt 18, the leveling bolt 18 penetrates through the connecting plate 16, the bottom end of the leveling bolt 18 is fixedly connected with the fixed pressing plate 19, the fixed pressing plate 19 is fixedly connected with the fixed plate 11, and the two leveling nuts 17 are used for clamping the connecting plate 16.

[0048] The control unit 12 adopts a controller or a control circuit, and is used for controlling the heating table 9, the driving mechanism 1, the atomization device 3, the aerosol charging device and the pre-heater 6.

[0049] In the description of the present application, it should be noted that the terms “first” and “second” are only used for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0050] In the present application, specific examples are applied to describe the principles and implementation modes of the present application, and the above embodiment descriptions are only used to help understand the method and core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range can be changed. In conclusion, the content of the present application should not be understood as a limitation of the present application.

Claims

1. An electrostatic lens focusing aerosol printing system, characterized in that, include: A printing platform, comprising a fixed plate, a heating stage disposed on the fixed plate, and a plate-shaped bottom electrode fixedly laid on the top surface of the heating stage; A printhead includes an atomizing device, an aerosol charging device, and an electrostatic focusing nozzle connected in sequence. The atomizing device atomizes the printing material, and the aerosol charging device charges the atomized printing material. The electrostatic focusing nozzle includes a first housing, with an upper electrode at the top and sidewall electrodes on the sidewalls of the first housing, electrically connected to the upper electrode. A lens aperture plate electrode is detachably connected to the bottom of the first housing. The lens aperture plate electrode has through holes serving as lens holes, allowing printing material ejected through all the lens holes to form a planar pattern on the projection surface of the lens aperture plate electrode. An insulating layer is provided around the outer ring of the lens aperture plate. The bottom electrode is located below the lens aperture plate. A drive mechanism, used to drive the print head to move in three-dimensional space; The power supply unit includes a negative high-voltage DC power supply, a first positive high-voltage DC power supply, and a second positive high-voltage DC power supply. The negative high-voltage DC power supply is used to power the corona charging device. The positive terminal of the first positive high-voltage DC power supply is electrically connected to the lens aperture plate electrode, and the negative terminal of the first positive high-voltage DC power supply is electrically connected to the upper electrode and the side wall electrode and grounded. The positive terminal of the second positive high-voltage DC power supply is electrically connected to the bottom electrode, and the negative terminal of the second positive high-voltage DC power supply is grounded. The aerosol charging device employs a corona charging mechanism, which includes a second housing, a cylindrical electrode, and a needle electrode. Both the cylindrical electrode and the needle electrode are fixed to the top of the second housing, and are coaxial. The second housing has a charging inlet at the top and a charging outlet at the bottom, both eccentrically positioned relative to the second housing. The positive terminal of the negative high-voltage DC power supply is electrically connected to the needle electrode, and the negative terminal is electrically connected to the cylindrical electrode. The printhead also includes an aerosol particle size filter, comprising a third housing and a U-shaped channel vertically disposed within the third housing. The outlet of the atomizing device is connected to one end of the U-shaped channel, and the charging inlet is connected to the other end of the U-shaped channel. A preheater is fixed to the outer wall of the third housing for heating the third housing.

2. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: The atomizing device employs an ultrasonic atomizer or a pneumatic atomizer; the ultrasonic atomizer includes a bottle body, in which a shield and an ultrasonic atomizing plate are disposed, the shield being located above the ultrasonic atomizing plate, the inlet and outlet of the bottle body being located above the shield, the shield having multiple holes, and the edge of the shield being sealed to the inner wall of the bottle body.

3. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: The surface of the second outer casing is coated with a conductive layer, and the material of the conductive layer is conductive copper paint.

4. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: The feed inlet of the electrostatic focusing nozzle passes through the center of the upper electrode.

5. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: The lens aperture plate is multiple, and each lens aperture plate can be detachably connected to the bottom of the first housing; The layout and number of lens holes on different lens aperture plates are different.

6. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: The heating platform is fixed on the connecting plate, and the connecting plate is provided with at least three leveling mechanisms; The leveling mechanism includes a fixed pressure plate, a leveling bolt, and two leveling nuts that are threadedly connected to the leveling bolt. The leveling bolt passes through the connecting plate, and the bottom end of the leveling bolt is fixedly connected to the fixed pressure plate. The fixed pressure plate is fixedly connected to the fixed plate, and the two leveling nuts are used to clamp the connecting plate.

7. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: It also includes a control unit, which is a controller or control circuit, and is used to control the heating platform, the drive mechanism, the atomizing device, the aerosol charging device and the preheater.

8. The electrostatic lens focusing aerosol printing system according to claim 1, characterized in that: The drive mechanism adopts an XYZ motion system.

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