Pretreatment powder spraying processing equipment and process thereof

Abstract

The pretreatment powder spraying equipment comprises pretreatment equipment used for degreasing and washing a workpiece, heating equipment connected with the pretreatment equipment through a roller way and used for drying the workpiece, and powder spraying equipment used for spraying powder to the workpiece treated in the heating equipment. The powder spraying equipment comprises a powder supply system for providing powder for a workpiece, a recovery system for collecting residual powder generated after treatment in the powder spraying system and a curing system for performing powder curing on the workpiece after treatment in the powder spraying equipment, and the processing technology of the powder spraying curing processing equipment comprises the following steps of S1, pretreatment; s2, drying treatment is conducted, specifically, the machined workpiece is dried; s3, electrostatic spraying is conducted, specifically, a pressure controller is adopted for compressing air to enable powder to be pre-fluidized, and the atomization pressure of an electrostatic controller is increased to enable the powder to be evenly smeared on the workpiece; and S4, curing treatment is conducted, specifically, the powder attached to the workpiece is cured through a heat supply burner, and heat exchange is conducted on the workpiece through a circulating fan.

Description

Technical Field

[0001] The present invention relates to the technical field of powder spraying and curing, and particularly relates to a pretreatment powder spraying processing device and its process. Background Art

[0002] The high-temperature spraying process is a surface processing method that atomizes molten spraying materials through a high-speed air flow and sprays them on the surface of purified and roughened parts to form a sprayed coating. During the process of spraying alloy particles hitting the substrate surface after being heated and accelerated, when the molten or highly plastic powder particles hit the substrate at a certain flying speed and interact with the substrate, it is an important stage in forming the coating. In the existing spraying layer technology, the spraying effect on workpieces is uneven, the operation steps are cumbersome, and at the same time, a large amount of powder residue is wasted during the spraying process, increasing the cost and wasting the processing cycle of the process. Summary of the Invention

[0003] The present invention provides a powder spraying processing device, which solves the problems in the existing spraying layer technology that the spraying effect on workpieces is uneven, the operation steps are cumbersome, and at the same time, a large amount of powder residue is wasted during the spraying process, increasing the cost and wasting the processing cycle of the process.

[0004] A powder spraying processing device includes: a pretreatment device for degreasing and water washing workpieces, a heating device connected to the pretreatment device through a roller path and used for drying the workpieces, and a powder spraying device for spraying powder on the workpieces processed in the heating device.

[0005] The powder spraying device includes: a powder supply system for supplying powder to the workpieces, a recovery system for collecting residual powder generated after processing in the powder spraying system, and a curing system for curing the powder on the workpieces processed in the powder spraying device.

[0006] The powder supply system includes: a powder supply barrel for installing powder, a powder pump installed on the powder supply barrel, a pressure control machine communicated with the powder supply barrel, a rotary sieve connected to the powder supply barrel through a pipeline, a spray gun connected to the powder supply barrel through a pipeline, an electrostatic controller installed inside the spray gun, and an electrode needle arranged inside the spray gun and electrically connected to the electrostatic controller.

[0007] The recovery system includes: a powder spraying chamber body for placing workpieces, and a cyclone collector installed on the side wall of the powder spraying chamber body.

[0008] The pretreatment device includes: a cavity, a degreaser installed inside the cavity and used for degreasing workpieces, and a spray pipe installed inside the cavity and used for water washing workpieces.

[0009] The curing system includes: a housing communicating with the barrel body, a heating burner installed in the housing, an air duct communicating with the housing, and a circulation fan communicating with the air duct.

[0010] A processing technology of a powder spraying processing device includes the following steps:

[0011] S1. Pretreatment: pre-degreasing, main degreasing, two water washes, silanization treatment, and two more water washes for the processed workpiece.

[0012] S2. Drying treatment: drying the processed workpiece.

[0013] S3. Electrostatic spraying: using a control press to compress air to pre-fluidize the powder, then transporting it to a rotary sieve through a powder pump. The rotary sieve separates powder particles, and then supplies the powder to a spray gun through a powder pump to spray the workpiece. By increasing the atomization pressure of the electrostatic controller, the powder is evenly applied to the workpiece.

[0014] S4. Curing treatment: curing the powder attached to the workpiece through a heating burner, and performing heat exchange on the workpiece through a circulation fan.

[0015] The atomization pressure of the electrostatic controller in S3 is 0.30 - 0.45 MPa.

[0016] The flow velocity pressure of the compressed air by the control press is 0.30 - 0.55 MPa.

[0017] The beneficial effects of the present invention are:

[0018] In the present invention, the atomization effect of the powder is controlled by adjusting the electrostatic controller in the spray gun. In addition to the conservative internal electrode needle, a ring corona is provided outside the spray gun to make the electrostatic field more uniform to keep the thickness of the powder coating uniform. Appropriately increasing the atomization pressure can keep the thickness of the powder coating uniform, and appropriately reducing the atomization pressure can improve the covering ability of the powder. Description of the Drawings

[0019] Figure 1 It is the overall structure diagram of a powder spraying processing device;

[0020] Figure 2 It is the overall structure schematic diagram of the powder spraying device;

[0021] Figure 3 It is the processing technology flow chart of a powder spraying processing device.

[0022] In the figure: 1 - powder supply barrel; 2 - powder pump; 3 - control press; 4 - rotary sieve; 5 - spray gun; 6 - cyclone collector; 7 - oil remover; 8 - spray pipe. Detailed Embodiments

[0023] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0024] As Figure 1-2 shown, a powder spraying processing device includes: a pretreatment device for degreasing and water washing workpieces, a heating device connected to the pretreatment device through a roller path and used for drying the workpieces, and a powder spraying device for spraying powder on the workpieces processed in the heating device.

[0025] The powder spraying device includes: a powder supply system for supplying powder to the workpieces, a recovery system for collecting residual powder generated after processing in the powder spraying system, and a curing system for curing the powder on the workpieces processed in the powder spraying device.

[0026] The powder supply system includes: a powder supply bucket 1 for installing powder, a powder pump 2 installed on the powder supply bucket 1, a pressure control machine 3 communicated with the powder supply bucket 1, a rotary sieve 4 connected to the powder supply bucket 1 through a pipeline, a spray gun 5 connected to the powder supply bucket 1 through a pipeline, an electrostatic controller installed inside the spray gun 5, and an electrode needle arranged inside the spray gun 5 and electrically connected to the electrostatic controller.

[0027] Specifically, an annular corona is also provided outside the spray gun 5 to make the electrostatic field more uniform to keep the thickness of the powder coating uniform. The electrostatic controller generates the required electrostatic high voltage and maintains its stability, with a fluctuation range less than 10%. The powder coating is first added to the powder supply bucket 1, and compressed air pre-fluidizes the powder through the micropores on the fluidizing plate at the bottom of the powder supply bucket 1, and then is transported to the rotary sieve 4 through the powder pump 2. The rotary sieve 4 separates the powder particles with too large particle sizes (above 100 μm), and the remaining powder falls into the powder supply bucket 1. After the powder in the powder supply bucket 1 is fluidized to a specified level, it is supplied to the spray gun 5 through the powder pump 2 and the powder delivery pipe to spray the workpieces.

[0028] In this embodiment, the recovery system includes: a powder spraying chamber body for placing workpieces, and a cyclone collector 6 installed on the side wall of the powder spraying chamber body.

[0029] Specifically, except for a part of the powder sprayed by the spray gun 5 adsorbed on the surface of the workpieces (generally 50% - 70%), the rest naturally settles. During the settlement process, a part of the powder is collected by the cyclone collector 6 on the side wall of the powder spraying shed, and the powder particles with larger particle sizes (above 12 μm) are separated by using the centrifugal separation principle and sent back to the rotary sieve 4 for reuse.

[0030] The pretreatment device includes: a cavity, an oil removal machine 7 installed inside the cavity and used for degreasing workpieces, and a spray pipe 8 installed inside the cavity and used for water washing workpieces.

[0031] The curing system includes: a housing communicating with the barrel body, a heating burner installed in the housing, an air duct communicating with the housing, and a circulation fan communicating with the air duct.

[0032] Specifically, the basic raw material for powder electrostatic spraying uses indoor epoxy polyester powder coating, and the main components are epoxy resin, polyester resin, curing agent, pigment, filler, leveling agent, moisture-proof agent, and edge angle modifier. After the powder is heated and cured, the required coating is formed on the surface of the workpiece.

[0033] As Figure 3 shown, a processing technology of a powder spraying processing device includes the following steps:

[0034] S1. Pretreatment, pre-degreasing, main degreasing, two water washes, silanization treatment, and two more water washes are performed on the processed workpiece;

[0035] S2. Drying treatment, the processed workpiece is dried;

[0036] S3. Electrostatic spraying, the powder is pre-fluidized by using a control press 3 to compress air, and then conveyed to a rotary sieve 4 through a powder pump 2. The rotary sieve 4 separates powder particles, and then supplies the powder to a spray gun 5 through the powder pump 2 to spray the workpiece. By increasing the atomization pressure of the electrostatic controller, the powder is evenly applied to the workpiece;

[0037] S4. Curing treatment, the powder attached to the workpiece is cured by a heating burner, and heat exchange is performed on the workpiece by a circulation fan.

[0038] The atomization pressure of the electrostatic controller in S3 is 0.30 - 0.45 MPa.

[0039] The flow velocity pressure of the compressed air of the control press 3 is 0.30 - 0.55 MPa.

[0040] The workpiece must be degreased and dusted on the surface of the cold-rolled steel plate through pre-treatment before powder spraying. At the same time, a protective film is formed on the surface of the workpiece to enhance the adhesion after powder spraying. The workpiece after pre-treatment must be completely dried of moisture and sufficiently cooled to below 35 °C to ensure the physical and chemical properties and appearance quality of the workpiece after powder spraying.

[0041] Control the electrostatic high voltage of the electrostatic controller at 60 - 90 kV. If the voltage is too high, it is easy to cause powder rebound and edge pitting; if the voltage is too low, the powder coating rate will be low. For the electrostatic current of 10 - 20 μA, if the current is too high, it is easy to cause discharge and breakdown of the powder coating; if the current is too low, the powder coating rate will be low. The flow rate pressure is 0.30 - 0.55 MPa. The higher the flow rate pressure, the faster the powder accumulation speed, which is beneficial to quickly obtain a coating with a predetermined thickness. However, if it is too high, it will increase the powder consumption and the wear rate of the spray gun 5. The atomization pressure is 0.30 - 0.45 MPa. Appropriately increasing the atomization pressure can maintain the thickness uniformity of the powder coating. However, if it is too high, it will cause rapid wear of the powder feeding components. Appropriately reducing the atomization pressure can improve the powder covering ability. If it is too low, it is easy to cause blockage of the powder feeding components. The cleaning gun pressure is 0.5 MPa. If the cleaning gun pressure is too high, it will accelerate the wear of the gun head; if it is too low, it is easy to cause blockage of the gun head. The fluidization pressure of the powder supply bucket 1 is 0.04 - 0.10 MPa. If the fluidization pressure of the powder supply bucket 1 is too high, it will reduce the powder density and decrease the production efficiency. If it is too low, it is easy to show insufficient powder supply or powder agglomeration. The distance from the nozzle of the spray gun 5 to the workpiece is 150 - 300 mm. If the distance from the nozzle of the spray gun 5 to the workpiece is too close, it is easy to cause discharge and breakdown of the powder coating. If it is too far, it will increase the powder consumption and reduce the production efficiency.

[0042] Powder curing: Bake at a constant temperature for 30 min. In actual operation, it is 160 - 220 °C for 15 - 30 min. When the equipment is initially debugged, a furnace temperature tracker needs to be used to measure the surface temperatures and cumulative times at the upper, middle, and lower points of the largest workpiece, and adjust the set temperature of the curing furnace and the speed of the conveyor chain according to the measurement results.

[0043] The above embodiments merely illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A pretreatment powder spraying device, characterized in that, include: Pre-treatment equipment for degreasing and washing workpieces, heating equipment connected to the pre-treatment equipment via rollers and used for drying the workpieces, and powder spraying equipment for spraying powder on the workpieces treated in the heating equipment; The powder spraying equipment comprises: a powder supply system for providing powder to a workpiece, a recovery system for collecting residual powder generated after processing in the powder spraying system, and a curing system for curing powder on the workpiece after processing in the powder spraying equipment.

2. The pretreatment powder spraying device according to claim 1, characterized in that, The powder supply system includes: a powder supply barrel for containing powder, a powder pump installed on the powder supply barrel, a pressure control machine connected to the powder supply barrel, a rotary screen connected to the powder supply barrel through a pipeline, a spray gun connected to the powder supply barrel through a pipeline, an electrostatic controller installed inside the spray gun, and an electrode needle arranged inside the spray gun and electrically connected to the electrostatic controller.

3. The pretreatment powder spraying device according to claim 1, characterized in that, The recovery system comprises: a powder spraying chamber body for placing workpieces, and a cyclone recoverer installed on the side wall of the powder spraying chamber body.

4. A pre-treatment powder spraying device according to claim 1, characterized in that, The pre-treatment equipment comprises: a cavity, an oil remover installed inside the cavity and used for degreasing the workpiece, and a spray pipe installed inside the cavity and used for washing the workpiece.

5. A pre-treatment powder spraying device according to claim 1, characterized in that, The curing system comprises: a shell body communicated with the barrel body, a heat supply burner installed in the shell body, an air duct communicated with the shell body, and a circulation fan communicated with the air duct.

6. A processing technology using the pre-treatment powder spraying equipment described in any one of claims 1-5, characterized in that, It includes the following steps: S1. Pretreatment: pre-degreasing, main degreasing, two water washings, silanization treatment, and two water washings again; S2. Drying treatment: drying the processed workpiece; S3. Electrostatic spraying: Use compressed air from a pressure control machine to pre-fluidize the powder, then transport it to a rotary screen through a powder pump. The rotary screen separates the powder particles, and then supplies them to the spray gun through a powder pump to spray the workpiece. By increasing the atomization pressure of the electrostatic controller, the powder is evenly applied to the workpiece. S4. Curing treatment: the powder attached to the workpiece is cured by a heat supply burner, and the workpiece is heat exchanged by a circulating fan.

7. The processing technology of a powder spraying processing device according to claim 6, characterized in that, The atomization pressure of the electrostatic controller in S3 is 0.30-0.45MPa.

8. The processing technology of a powder spraying processing device according to claim 6, characterized in that, The flow rate pressure of the compressed air of the pressure control machine is 0.30-0.55MPa.

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