A powder coating equipment and a coating method

Abstract

The present application relates to a kind of powder coating equipment, shell (3) bottom (12) top connection coating support (13) and its V-shaped cone cylinder (9), V-shaped cone cylinder upper end is equipped with the screen cage (14) of lamination;Gas delivery device (7) outside the shell is connected with V-shaped cone cylinder lower end;Bottom connection suction pipe (10a), exhaust treatment device (10) and vacuum system (11).Powder coating includes the following steps: single dispersion of powder is spread on the bottom screen layer of each layer of screen cage, first precursor and second precursor are introduced into the powder on screen and react, the above-mentioned reaction is repeated in sequence to form the required film.The beneficial effects of the present application: powder is supported by screen layer, carrier gas enters together with precursor to drive powder to float, powder is completely dispersed and exposed in carrier gas and precursor atmosphere during floating, and then can be adsorbed on the entire surface of powder, form complete film layer, coating effect is good, and efficiency is high.

Description

Background Technology

[0001] Non-metallic mineral powders are commonly used in plastics, rubber, and other polymer materials to form composites with excellent properties. They can also be used as additives in paints, coatings, inks, cosmetics, and other coating materials. Inorganic powder materials, when used as additives in composites, typically require surface treatment and modification to achieve optimal composite performance. Powder modification usually includes organic surface treatment and inorganic surface coating. Inorganic surface coating involves powder surface deposition techniques and methods. However, powders are prone to agglomeration. Therefore, in existing conventional deposition methods, such as atomic layer deposition using magnetron sputtering, uniform and complete coverage of the powder surface cannot be achieved. Other methods, such as high-temperature melting of the deposition material to achieve powder surface coating, are unsuitable for high-melting-point deposition materials.

[0002] For example, Chinese patent CN113564565A discloses a method that uses physical stirring by a rotating impeller combined with the gravity acting on the powder as it falls from above to disperse it, and then introduces a first and a second precursor that are adsorbed onto the powder surface to react and form a thin film. However, despite the impeller stirring, some powder inevitably agglomerates, preventing the introduced first and second precursors from completely coating the powder particle surface, thus failing to form a completely uniform thin film.

[0003] Chinese patent CN110039044A discloses a method of heating a material to be coated into a thin film to a liquid state, while powder, driven by a rotating disc, moves to the molten material and is coated to form a thin film. This process requires high temperatures and can achieve coating for some easily molten metals or ceramics. However, it is difficult to coat most inorganic materials that are difficult to molten.

[0004] Chinese patent CN206157222U uses magnetron sputtering to coat powder, in which the powder is placed in a tray with springs and marbles installed at the bottom. The vibration of the springs and marbles drives the tray to vibrate and achieve the flipping of the powder. However, this process cannot solve the problem of powder agglomeration and still results in the film not being able to completely and uniformly coat the powder.

[0005] Purpose of the invention

[0006] The purpose of this invention is to solve the problem that the thin film cannot achieve uniform and complete coverage of the powder particle surface in the existing powder coating process, and to provide a powder coating equipment and coating method.

[0007] The present invention adopts the following technical solution:

[0008] This invention utilizes an atomic layer deposition method to disperse powder using a layered mesh screen. An airflow carries a coating precursor to sweep the powder surface, causing the powder to float during the airflow sweeping process. This allows the reaction precursor to completely cover the powder surface, and the film is formed under suitable temperature conditions.

[0009] The present invention first provides a powder coating equipment, including a container consisting of a shell and a connected base and a top cover. A heater is provided on the inner wall of the shell. A coating support is connected to the base at the bottom of the shell. A V-shaped cone is connected to the upper end of the coating support. A cylindrical support is provided at the upper end of the V-shaped cone. A heating element is provided inside the cylindrical support. A set of stacked sieves for holding powder is also provided at the upper end of the V-shaped cone. The cylindrical support and its heating element surround the stacked sieves.

[0010] The outer shell is equipped with a carrier gas delivery device, which is connected to the carrier gas and precursor delivery pipelines and is connected to the lower end of the V-shaped cone through the pipelines.

[0011] The base is connected to the exhaust pipe, which is connected to the inner cavity of the housing. The other end of the exhaust pipe is connected to the exhaust gas treatment device, which is connected to the vacuum system through a pipe.

[0012] Based on the above technical solutions, the following further technical solutions are proposed:

[0013] The upper and lower layers and the sides of the sieve cage are surrounded by sieves with a certain aperture. An opening is left on the side of the sieve cage, and the powder to be coated is put into the bottom layer of the corresponding sieve cage through the opening.

[0014] Each of the aforementioned sieve cages is surrounded by a lower sieve mesh with a certain aperture and a side sieve mesh. The sieve cage cover hinged at the top of the cylindrical support cooperates with the uppermost sieve cage cover. The sieve cage cover is flipped open, and the sieve cage cover removes the stacked sieve cages. The powder to be coated is placed into the bottom layer of the corresponding sieve cage through the sieve cage opening.

[0015] The screen cage can be a single-layer screen cage structure or a multi-layer screen cage structure;

[0016] The mesh size of the sieve cage can be the same or different, with a mesh size of 1μm or larger, selected according to the size of the powder particles to be coated.

[0017] The present invention also provides a powder coating method for a powder coating equipment, comprising the following steps:

[0018] 1) First, select sieve cages with different mesh sizes according to the size of the powder, spread the powder of the corresponding size individually on the bottom sieve layer of each sieve cage, and then stack the sieve cages.

[0019] 2) Open the top cover of the shell and place the stacked sieve cages into the powder coating support frame inside the cylindrical bracket; close the top cover and evacuate the vacuum chamber inside the shell. Once the set vacuum level is reached, turn on the temperature control system. The vacuum chamber and the powder coating support frame will be heated to the set temperature and maintained.

[0020] 3) Determine at least one precursor source according to the type of film to be coated, turn on the carrier gas and its carrier gas delivery device, and introduce the corresponding precursor sources in sequence. In order, first introduce the first precursor source. The first precursor source enters the bottom screen layer of each sieve cage through the V-shaped cone in sequence, and then adsorbs the powder on the bottom screen layer of each sieve cage in sequence, so as to coat the powder with the first precursor. After the first precursor source is continuously introduced for a set time, it is stopped. Argon or nitrogen carrier gas is introduced to clean the excess precursor.

[0021] Then, the second precursor is introduced. The second precursor source enters the bottom screen layer of each sieve cage sequentially through the V-shaped cone, and successively adsorbs the powder that wraps the first precursor on the bottom screen layer of each sieve cage, so that the second precursor wraps the first precursor. The second precursor source is continuously introduced for a set time and then stopped. Argon or nitrogen carrier gas is introduced to clean the excess precursor. It is decided whether to introduce a third or more types of precursor sources and carrier gas as needed.

[0022] This process continues until all the precursors required to form the thin film are introduced. After all the precursors are adsorbed, they react with each other to form the film material.

[0023] Repeat the above process until the film thickness reaches the desired thickness.

[0024] The number of times the reaction steps involving the introduction of the first and second precursors are repeated is determined based on the required coating thickness.

[0025] Beneficial effects of the present invention

[0026] The powder is supported by a sieve layer, and the inlets of the carrier gas and precursor are narrow at the bottom and wide at the top. After the carrier gas and precursor enter the inlet, the rising airflow will carry the powder to float. During the floating process, the powder is completely dispersed and exposed to the atmosphere of the carrier gas and precursor. The precursor enters the split sieve with the carrier gas, which will carry the powder particles to suspension and dispersion, and then it can be adsorbed on the entire surface of the powder to form a complete film layer.

[0027] Instruction manual illustrations

[0028] Figure 1 This is a structural diagram of a powder coating device according to the present invention;

[0029] Figure 2 It is a diagram of a stacked screen cage structure;

[0030] Figure 3This is a schematic diagram of the powder coating principle. Implementation

[0031] Example 1, as Figure 1 , Figure 2 As shown, the powder coating equipment provided by the present invention includes:

[0032] The container consists of a shell 3, a connected base 12, and a top cover 2. A heater 4, such as a heat pipe, is installed on the inner wall of the shell 3. A coating support 13 is connected to the base 12 at the bottom of the shell. A V-shaped cone 9 is connected to the upper end of the coating support 13. The larger end of the V-shaped cone 9 is connected to the upper end of the coating support 13, and the smaller end is located on the base 12. A cylindrical support 6 is provided at the upper end of the coating support 13. A heating element 5, such as a heat pipe, is installed inside the cylindrical support. The heating element 5 and the heater 4 are connected to a temperature control device 16 through wires for temperature control.

[0033] The upper end of the V-shaped cone 9 is also equipped with stacked sieve cages 14 for holding powder. The cylindrical support 6 and its heating element 5 surround the stacked sieve cages 14. The sieve cages 14 are not completely closed structures, that is, the upper and lower layers and the sides of the sieve cage are all wrapped with sieves of a certain aperture. An opening 15 is left on the side of the sieve cage. The powder to be coated is put into the bottom layer of the corresponding sieve cage through the opening; or the lower layer and the sides of the sieve cage 14 are all wrapped with sieves of a certain aperture. The upper layer of the sieve cage is hinged to the side. The upper layer of the sieve cage is flipped open, and the powder to be coated is put into the bottom layer of the corresponding sieve cage. The lower sieve cages are all open at the top. The bottom layers of adjacent upper sieve cages are fastened to the openings at the top of the lower sieve cages to form a stacked structure of sieve cages.

[0034] like Figure 2 As shown, this embodiment adopts a three-layer sieve cage stacked structure, with the bottom layer sieve cage having a bottom mesh diameter of 1μm, the middle layer sieve cage having a bottom mesh diameter of 5μm, and the top layer sieve cage having a bottom mesh diameter of 10μm.

[0035] The outer shell 3 is provided with a carrier gas delivery device 7. One end of the carrier gas delivery device is connected to three sets of carrier gas and precursor delivery pipes, and the other end is connected to the lower conical opening of the V-shaped cone 9 through the pipe 8, so that the pipe 8 is connected to the inner cavity of the V-shaped cone 9.

[0036] The base 12 is connected to the exhaust pipe 10a, which is connected to the inner cavity 1 of the housing 3. The other end of the exhaust pipe 10a is connected to the exhaust gas treatment device 10, which is connected to the vacuum system 11 through a pipe.

[0037] Example 2: Surface coating of spherical glass powder with a particle size of 1-10 μm.

[0038] (1) Based on particle size, the powder sieve cage is selected as a three-layer structure sieve cage with a bottom mesh size of 1μm for the upper sieve cage, a bottom mesh size of 5μm for the middle sieve cage, and a bottom mesh size of 10μm for the lower sieve cage.

[0039] (2) Add spherical glass powder with a particle size of 1-10μm to the bottom screen of each powder sieve cage:

[0040] First, add the powder to be coated onto the bottom sieve layer with a mesh size of 10μm through the side or top opening of the bottom sieve cage. Spread the powder until it just covers the sieve layer, and place a container below to catch any smaller powder particles that slip through. Add the remaining powder to the bottom sieve layer of the middle sieve cage with a mesh size of 5μm. Spread the powder until it just covers the sieve layer, and place a container below to catch any smaller powder particles. Finally, add the last remaining powder to the bottom sieve layer of the top sieve cage with a mesh size of 1μm. Spread the powder until it just covers the sieve layer.

[0041] Add an appropriate amount of powder and spread it evenly in a thin layer on the corresponding sieve layer. Shake it appropriately to make the powder spread evenly on each sieve layer.

[0042] (3) Open the top cover, stack the powder sieve cages and place them on the powder coating support frame in the vacuum chamber, close the top cover and turn on the vacuum system 11 to evacuate.

[0043] (4) After the inner cavity of the shell is evacuated to below 0.1 Pa, turn on the temperature control system of the vacuum chamber and the powder support to heat it up to the set temperature between 100°C and 400°C.

[0044] (5) Introduce the precursor source sequentially for coating:

[0045] Introduce Ar carrier gas and turn on the first precursor gas source switch. Set the carrier gas flow rate to 100 sccm and the first precursor gas source introduce time to 1-10 seconds. After introduce the first precursor gas source, wait 15-30 seconds, then introduce carrier gas to flush for 10 seconds. Figure 3 As shown in part a, a first precursor 30 is coated on the surface of powder 20;

[0046] Set the second precursor source inlet time to 1-10 seconds, followed by a waiting time of 15-30 seconds. Figure 3 As shown in section b, a second precursor 40 is coated on the first precursor 30 on the powder surface; then a carrier gas is introduced to rinse for 10 seconds to complete one cycle. The first precursor 30 and the second precursor 40 on the powder surface react tightly to obtain a thin film 50 of a certain thickness.

[0047] (6) Set the number of cycles according to the film thickness requirement. For films with a thickness of 10-100nm, the number of cycles is between 100-1000.

Claims

1. A powder coating equipment, characterized in that... The application relates to a powder film coating device, which comprises a container composed of a shell (3) and a base (12) and an upper cover (2) connected to the shell (3), a heater (4) arranged on the inner wall of the shell (3), a film coating support (13) connected to the top of the base (12) of the shell, a V-shaped conical cylinder (9) connected to the upper end of the film coating support (13), a cylindrical support (6) arranged on the upper end of the V-shaped conical cylinder (9), a heating element (5) arranged in the cylindrical support, a group of stacked powder containing screen cages (14) arranged on the upper end of the V-shaped conical cylinder (9), and the cylindrical support and the heating element surrounding the stacked screen cages (14); a carrier gas conveying device (7) is arranged outside the shell (3) and is connected with carrier gas and precursor conveying pipelines and communicates with the lower end of the V-shaped conical cylinder (9) through a pipeline (8); an air exhaust pipe (10a) is connected to the base (12) and communicates with the inner cavity (1) of the shell (3), and the other end of the air exhaust pipe (10a) is connected with a tail gas treatment device (10), which is connected with a vacuum system (11) through a pipeline. The screen cage is a multi-layer screen cage structure. The mesh size of each layer of the screen cage is different, and the mesh size is larger than 1 mu m, and the mesh size is selected according to the particle size of the powder to be coated. Each screen cage (14) is surrounded by a lower screen mesh with a certain aperture and a side screen mesh, the screen cage mesh cover hinged to the top of the cylindrical support (6) is matched with the upper end cover of the uppermost screen cage, the stacked screen cages (14) are taken out by turning and opening the screen cage cover, and the powder to be coated is put into the corresponding screen cage bottom layer through the screen cage opening.

2. The powder coating method of claim 1, wherein The application further discloses a powder film coating method, which comprises the following steps: 1) according to the size of the powder, screen cages with different mesh sizes are selected, the corresponding size of the powder is single-dispersed and spread on the bottom screen mesh layer of each layer of the screen cage, and then the screen cage layers are stacked; 2) the upper cover of the shell is opened, the stacked screen cages are put into the powder film coating support in the cylindrical support, the upper cover is closed, the vacuum chamber in the shell is vacuumized, the temperature control system is started when the vacuum degree reaches the set value, and the vacuum chamber and the powder film coating support are heated to the set temperature and maintained; 3) at least one precursor source is determined according to the type of the film to be coated, the carrier gas and the carrier gas conveying device are started, the corresponding precursor source is sequentially introduced, the first precursor source is sequentially introduced according to the order, the first precursor source enters the bottom screen mesh layer of each layer of the screen cage through the V-shaped conical cylinder, then sequentially reacts with the powder on the bottom screen mesh layer of each layer of the screen cage, the first precursor is wrapped around the powder, the first precursor source is continuously introduced for a set time and then stopped, and the excess precursor is cleaned by introducing the carrier gas argon or nitrogen; then the second precursor is introduced, the second precursor source enters the bottom screen mesh layer of each layer of the screen cage through the V-shaped conical cylinder, sequentially reacts with the powder wrapped with the first precursor on the bottom screen mesh layer of each layer of the screen cage, and the second precursor is wrapped on the first precursor, the second precursor source is continuously introduced for a set time and then stopped, the excess precursor is cleaned by introducing the carrier gas argon or nitrogen, and whether the third or more types of precursor sources and carrier gases are introduced is determined according to the need; all the precursors are sequentially introduced until all the precursors required for forming the film are introduced, all the precursors are adsorbed, and the film layer material is formed by the reaction between the precursors; The above process is repeated until the thin film thickness reaches the desired thickness.

Images