Spraying process for resistance-free high-frequency power supply shell in wire cutting machine

Abstract

The invention discloses a spraying process for a resistance-free high-frequency power supply shell in a wire cutting machine. The spraying process comprises the specific steps that (1) surface pretreatment is conducted, specifically, a part to be sprayed is subjected to cleaning, oil removal and sand blasting roughening treatment; (2) preparing a coating: stirring and mixing epoxy resin, a composite curing agent, a conductive pigment, a conductive filler, an auxiliary agent and a solvent at a high speed, performing melt extrusion through a double-screw extruder, cooling, crushing, and performing micronization treatment to obtain a powder coating; 3) spraying process: spraying by adopting an electrostatic powder spraying method; and (4) curing forming is conducted, specifically, the sprayed to-be-sprayed component is fed into a curing oven after standing in the leveling area, and then the to-be-sprayed component is naturally cooled to the room temperature to form a final coating. In this way, according to the spraying technology for the resistance-free high-frequency power source shell in the wire cutting machine, the self-made functional coating is adopted in the technology, and by adjusting original spraying parameters, the multiple requirements for heat dissipation, electromagnetic shielding, corrosion resistance and mechanical protection can be met at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wire cutting machining equipment manufacturing, in particular to a spraying process for a non-blocking high-frequency power supply shell in a wire cutting machine. BACKGROUND

[0002] The wire cutting machine plays an important role in modern precision machining, and its non-blocking high-frequency power supply, as a core component, plays a decisive role in machining precision and stability. The non-blocking high-frequency power supply generates a large amount of heat during operation and is also affected by the corrosion of the medium (such as deionized water) in the working environment and electromagnetic interference.

[0003] The traditional protection method usually uses ordinary anti-rust paint. The ordinary anti-rust paint coating has a low thermal conductivity, which affects the dissipation of heat inside the power supply, causing electronic components to work in a high-temperature environment, shortening the service life, and also failing to effectively suppress the high-frequency electromagnetic interference generated by the power supply, which may be susceptible to external electromagnetic interference, affecting the stability of wire cutting machining. In the working environment of wire cutting, especially when using water-based working fluid, the power supply shell is easy to be corroded, and it is difficult to ensure the adhesion, impact resistance and wear resistance of the coating under long-term use. SUMMARY

[0004] The technical problem solved by the present application is to provide a spraying process for a non-blocking high-frequency power supply shell in a wire cutting machine, which can balance excellent heat dissipation, electromagnetic shielding, corrosion resistance and mechanical protection performance.

[0005] To solve the above technical problems, one technical solution adopted by the present application is to provide a spraying process for a non-blocking high-frequency power supply shell in a wire cutting machine, comprising the following specific steps: 1) Surface pretreatment: cleaning, degreasing and sandblasting roughening treatment are performed on the to-be-sprayed parts of the non-blocking high-frequency power supply; 2) Preparation of paint: epoxy resin 450-500 parts by weight, composite curing agent 50-100 parts by weight, conductive pigment 50-100 parts by weight, conductive filler 200-250 parts by weight, auxiliary agent 30-50 parts by weight and solvent are mixed by high-speed stirring, melted and extruded by a double-screw extruder at 80-90℃, cooled, broken, and then micronized to a particle size distribution D50 typical value of 15-25μm to obtain a powder coating; 3) Spraying process: electrostatic powder spraying method is used, and the powder coating prepared in step 2) is sprayed on the to-be-sprayed parts treated in step 1), the electrostatic spraying voltage is 60-80kV, and the distance between the spray gun and the to-be-sprayed parts is 150-250mm; 4) curing molding: after the component to be sprayed in step 3) is placed in the leveling area for 5-10 minutes, it is sent into a curing oven, and then naturally cooled to room temperature to form a final coating layer with a dry film thickness of 30-50 μm.

[0006] In a preferred embodiment of the present application, the sand blasting in step 1) uses 100-150 mesh brown corundum with a compressed air pressure of 0.5-0.7 MPa to make the surface roughness reach Ra 6.3-12.5 μm.

[0007] In a preferred embodiment of the present application, the conductive pigment in step 2) is a compound of flaky graphite and ultra-fine silver powder at a ratio of 1:1-1:3.

[0008] In a preferred embodiment of the present application, the conductive filler in step 2) is a compound of silver-plated copper powder and carbon nanotubes at a ratio of 5:1-10:1.

[0009] In a preferred embodiment of the present application, the composite curing agent in step 2) uses a polyamide and imidazole composite curing system with a mixing mass ratio of 6:4-8:2.

[0010] In a preferred embodiment of the present application, the auxiliary agent in step 2) includes a leveling agent, a defoaming agent and an adhesion promoter, wherein the adhesion promoter is a silane coupling agent, which accounts for 1-3% of the total weight of the coating.

[0011] In a preferred embodiment of the present application, the spraying thickness in step 3) is controlled by the spraying time and the moving speed of the spray gun, and the initial single-wet film thickness is controlled at 20-40 μm.

[0012] In a preferred embodiment of the present application, the curing temperature in step 4) uses a stepwise heating method, which is raised from 80℃ to 160-180℃, and the temperature is kept for 15-25 minutes.

[0013] The present application has the following advantages: the spraying process for the non-resistance high-frequency power shell in the wire cutting machine uses self-made functional coating, and by adjusting the original spraying parameters, it can simultaneously solve the multiple requirements of heat dissipation, electromagnetic shielding, corrosion resistance and mechanical protection. DETAILED DESCRIPTION

[0014] The preferred embodiments of the present application are described in detail below to make the advantages and features of the present application more easily understood by those skilled in the art, so as to define the protection scope of the present application more clearly and explicitly.

[0015] Example 1 A spraying process for the non-resistance high-frequency power shell in the wire cutting machine, the specific steps include: 1) Surface pretreatment: clean, degrease, and sandblast the parts to be sprayed of the non-resistance high-frequency power supply, use 100 mesh brown corundum, and the compressed air pressure is 0.5 MPa, so that the surface roughness reaches Ra6.3 μm.

[0016] 2) Coating preparation: mix the epoxy resin 480 parts, composite curing agent 80 parts, conductive pigment 80 parts, conductive filler 220 parts, additive 40 parts, and solvent by weight parts by high-speed stirring, melt extrusion through a 80℃ double screw extruder, cool, crush, and then micronize to a particle size distribution D50 typical value of 15 μm to obtain a powder coating.

[0017] The epoxy resin serves as a coating matrix.

[0018] The conductive pigment is a 1:2 compound of flaky graphite and ultra-fine silver powder.

[0019] The conductive filler in step 2) is a 8:1 compound of silver-plated copper powder and carbon nanotubes.

[0020] The composite curing agent uses a polyamide and imidazole composite curing system, and the mixing mass ratio is 7:3.

[0021] The additive includes a leveling agent, a defoaming agent, and an adhesion promoter, wherein the adhesion promoter is a silane coupling agent, which accounts for 1% of the total weight of the coating.

[0022] An appropriate amount of the solvent is used to adjust the viscosity of the coating.

[0023] 3) Spraying process: use the powder coating prepared in step 2) to spray the parts to be sprayed after step 1) treatment by using an electrostatic powder spraying method, the electrostatic spraying voltage is 70 kV, and the distance between the spray gun and the parts to be sprayed is 200 mm.

[0024] The spraying thickness is controlled by the spraying time and the moving speed of the spray gun, and the initial single-pass wet film thickness is controlled at 35 μm.

[0025] 4) Curing forming: after the parts to be sprayed after step 3) are placed in the leveling area for 5-10 minutes, they are sent to the curing oven, and then naturally cooled to room temperature to form a final coating with a dry film thickness of 40 μm.

[0026] The curing temperature is raised in a stepwise manner from 80℃ to 165℃, and the temperature is kept for 20 minutes.

[0027] Example 2 A spraying process for the shell of a non-resistance high-frequency power supply in a wire cutting machine, the specific steps include: 1) Surface pretreatment: clean, degrease, and sandblast the parts to be sprayed of the non-resistance high-frequency power supply, use 125 mesh brown corundum, and the compressed air pressure is 0.6 MPa, so that the surface roughness reaches Ra 9.2 μm.

[0028] 2) Coating preparation: mix the epoxy resin 460 parts, the composite curing agent 70 parts, the conductive pigment 60 parts, the conductive filler 200 parts, the auxiliary agent 35 parts, and the solvent by weight parts by high-speed stirring, melt extrusion by a double screw extruder at 85℃, cooling, crushing, and then micronizing to a particle size distribution D50 typical value of 20 μm to obtain a powder coating.

[0029] The epoxy resin serves as a coating matrix.

[0030] The conductive pigment is a 1:1 compound of flaky graphite and ultra-fine silver powder.

[0031] The conductive filler in step 2) is a 10:1 compound of silver-plated copper powder and carbon nanotubes.

[0032] The composite curing agent uses a polyamide and imidazole composite curing system, and the mixing mass ratio is 8:2.

[0033] The auxiliary agent includes a leveling agent, a defoaming agent, and an adhesion promoter, wherein the adhesion promoter is a silane coupling agent, which accounts for 2% of the total weight of the coating.

[0034] An appropriate amount of the solvent is used to adjust the viscosity of the coating.

[0035] 3) Spraying process: use the powder coating prepared in step 2) to spray the parts to be sprayed after step 1) treatment by using an electrostatic powder spraying method, the electrostatic spraying voltage is 75 kV, and the distance between the spray gun and the parts to be sprayed is 180 mm.

[0036] The spraying thickness is controlled by the spraying time and the spray gun moving speed, and the initial single-pass wet film thickness is controlled at 30 μm.

[0037] 4) Curing forming: after the parts to be sprayed after step 3) are placed in the leveling area for 5-10 minutes, they are sent into the curing oven, and then naturally cooled to room temperature to form a final coating with a dry film thickness of 35 μm.

[0038] The curing temperature is raised in a stepwise manner from 80℃ to 170℃, and the temperature is kept for 25 minutes.

[0039] Example 3 A spraying process for the shell of a non-resistance high-frequency power supply in a wire cutting machine, the specific steps comprising: 1) Surface pretreatment: clean, degrease, and sandblast the parts to be sprayed of the non-resistance high-frequency power supply, use 150 mesh brown corundum, and the compressed air pressure is 0.7 MPa, so that the surface roughness reaches Ra12.5 μm.

[0040] 2) Coating preparation: mix the epoxy resin 500 parts, the composite curing agent 60 parts, the conductive pigment 70 parts, the conductive filler 240 parts, the auxiliary agent 45 parts, and the solvent by weight parts by high-speed stirring, melt extrusion by a 90℃ double screw extruder, cool, crush, and then micronize to a particle size distribution D50 typical value of 25 μm to obtain a powder coating.

[0041] The epoxy resin serves as a coating matrix.

[0042] The conductive pigment is a compound of flaky graphite and ultra-fine silver powder at a ratio of 1:1.5.

[0043] The conductive filler in step 2) is a compound of silver-plated copper powder and carbon nanotubes at a ratio of 6:1.

[0044] The composite curing agent uses a polyamide and imidazole composite curing system, and the mixing mass ratio is 6:4.

[0045] The auxiliary agent includes a leveling agent, a defoaming agent, and an adhesion promoter, wherein the adhesion promoter is a silane coupling agent, which accounts for 3% of the total weight of the coating.

[0046] An appropriate amount of the solvent is used to adjust the viscosity of the coating.

[0047] 3) Spraying process: use the powder coating prepared in step 2) to spray the parts to be sprayed after step 1) treatment by using the electrostatic powder spraying method, the electrostatic spraying voltage is 65 kV, and the distance between the spray gun and the parts to be sprayed is 220 mm.

[0048] The spraying thickness is controlled by the spraying time and the moving speed of the spray gun, and the initial single-wet film thickness is controlled at 40 μm.

[0049] 4) Curing forming: after the parts to be sprayed after step 3) are placed in the leveling area for 5-10 minutes, they are sent into the curing oven, and then naturally cooled to room temperature to form a final coating with a dry film thickness of 45 μm.

[0050] The curing temperature is raised in a step-by-step manner from 80℃ to 160℃, and the temperature is kept for 18 minutes.

[0051] Performance parameter comparison table The coating for the spraying process of the shell of the non-resistance high-frequency power supply in the wire cutting machine has the following advantages: 1. Excellent heat conduction and dissipation performance: the thermal conductivity of the coating can reach 1.5~2.5W / (m·K), which is conducive to the heat conduction of the internal heat of the power supply.

[0052] 2. Excellent electromagnetic shielding performance: the volume resistivity of the coating can reach 10³~10 5 Ω·cm, and the electromagnetic wave shielding efficiency of 1GHz frequency can reach 35~60dB.

[0053] 3. Strong corrosion resistance: the coating has no blistering and peeling after 500h neutral salt spray test.

[0054] 4. Good mechanical properties and adhesion: the adhesion between the coating and the metal substrate reaches 0 level (crosshatch method).

[0055] Compared with the prior art, the spraying process for the non-blocking high-frequency power supply shell in the wire cutting machine can simultaneously solve the multiple requirements of heat dissipation, electromagnetic shielding, corrosion resistance and mechanical protection by adjusting the original spraying parameters and using the self-made functional coating.

[0056] The above is only an embodiment of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine, characterized in that, The specific steps include: 1) Surface pretreatment: Clean, degrease, and roughen the parts to be coated by the unblocked high-frequency power supply; 2) Coating preparation: 450-500 parts by weight of epoxy resin, 50-100 parts by weight of composite curing agent, 50-100 parts by weight of conductive pigment, 200-250 parts by weight of conductive filler, 30-50 parts by weight of additives and solvent are mixed by high-speed stirring, melt-extruded by twin-screw extruder at 80-90℃, cooled and crushed, and then micronized to a typical particle size distribution D50 value of 15-25μm to obtain powder coating; 3) Spraying process: An electrostatic powder spraying method is used. The powder coating prepared in step 2) is used to spray the part to be sprayed after being treated in step 1). The electrostatic spraying voltage is 60~80kV and the distance between the spray gun and the part to be sprayed is 150~250mm. 4) Curing and molding: After the part to be coated in step 3) is left to stand in the leveling area for 5 to 10 minutes, it is sent into the curing oven and then naturally cooled to room temperature to form a final coating with a dry film thickness of 30 to 50 μm.

2. The spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, In step 1), 100-150 mesh brown corundum is used for sandblasting, and the compressed air pressure is 0.5-0.7 MPa, so that the surface roughness reaches Ra6.3-12.5 μm.

3. The spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, The conductive pigment mentioned in step 2) is a compound of flake graphite and ultrafine silver powder in a ratio of 1:1 to 1:

3.

4. The spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, The conductive filler in step 2) is a compound of silver-plated copper powder and carbon nanotubes in a ratio of 5:1 to 10:

1.

5. The spraying process for the housing of a resistanceless high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, The composite curing agent in step 2) adopts a polyamide and imidazole composite curing system with a mixing mass ratio of 6:4 to 8:

2.

6. The spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, The additives mentioned in step 2) include leveling agents, defoamers, and adhesion promoters, wherein the adhesion promoter is a silane coupling agent, which accounts for 1 to 3% of the total weight of the coating.

7. The spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, In step 3), the coating thickness is controlled by the spraying time and the speed of the spray gun movement, and the initial single-pass wet film thickness is controlled at 20~40μm.

8. The spraying process for the housing of a resistance-free high-frequency power supply inside a wire EDM machine according to claim 1, characterized in that, In step 4), the curing temperature is increased in stages, from 80°C to 160-180°C, and held for 15-25 minutes.

Images