Hydraulic support component powder spraying process

Abstract

The application discloses a kind of hydraulic support parts powder spraying process, it is related to hydraulic support surface treatment technical field, including using supersaturated water vapor process to remove the oil dirt on the surface of workpiece;Using automatic shot blasting process to remove the scale, rust, welding slag etc. on the surface of workpiece;Using automatic reciprocating machine and manual supplementary spraying process to coat powder coating on the surface of workpiece;Using electric infrared radiation heating process to melt the powder on the surface of workpiece;Using gas catalytic infrared radiation heating process to rapidly increase the temperature of the powder on the surface of workpiece;Using hot air circulation heating process to completely solidify powder coating;Using water atomization and air cooling process to rapidly cool the workpiece;Beneficial effect is in that: realize the application of powder spraying on the non-standard parts of heavy weight, complex structure thick plate type of hydraulic support, the obtained coating has firm binding force, high gloss, high hardness, good corrosion resistance, meets the use demand of different environment mine;Meanwhile, production process does not produce three wastes, realizes the green environmental protection coating of hydraulic support.

Description

Technical Field

[0001] This invention relates to the field of workpiece surface treatment technology, and in particular to a powder coating process for hydraulic support components. Background Technology

[0002] Currently, due to the influence of dark and humid mining environments, corrosion is common on the surface of hydraulic supports. To extend their service life and enhance their performance, surface anti-corrosion treatment is necessary. Coating is traditionally the most widely used anti-corrosion process. Coatings are divided into liquid coatings and powder coatings, so coating processes are divided into spray painting and powder coating.

[0003] A typical spray painting process is as follows: loading the workpiece—shot blasting—cleaning—primer spraying—primer leveling—primer drying—primer forced cooling—topcoat spraying—topcoat leveling—topcoat drying—topcoat forced cooling—workpiece unloading. Characteristics of the spray painting process: numerous steps and long process; low paint utilization rate, approximately 30-60%, resulting in significant waste; poor environmental performance, with VOCs content generally exceeding 250g / L, generating waste gas, wastewater, and waste residue, leading to high treatment costs; high manual labor intensity, difficult to apply, and hard to automate.

[0004] The typical powder coating process is as follows: loading—shot blasting—degreasing—water washing 1—water washing 2—silane treatment—water washing 3—water washing 4—moisture drying—base powder coating—flour coating—powder drying—forced cooling—unloading. Characteristics of powder coating: numerous steps and long process; uses 180℃ room temperature curing powder; only suitable for lightweight, simple thin plates, not suitable for heavy, complex (multiple boxes, many holes) thick plate (25-200mm) non-standard hydraulic support components. The main reasons are: chemicals and water from degreasing, water washing, and silane treatment accumulate in the workpiece and are difficult to remove; the workpiece has a large heat capacity, making it difficult to reach the 180℃ curing temperature on the surface; traditional air cooling methods are insufficient to quickly cool heavy plates to around 40℃ for unloading. These factors affect the application of powder coating on hydraulic support components. Summary of the Invention

[0005] The purpose of this invention is to provide a powder coating process for hydraulic support components in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] A powder coating process for hydraulic support components includes the following steps:

[0008] Step S1: Use supersaturated steam to remove oil stains from the workpiece surface;

[0009] Step S2: Use an automatic shot blasting process to remove oxide scale, loose rust, welding slag, etc. from the surface of the workpiece;

[0010] Step S3: Apply powder coating to the workpiece surface using an automatic reciprocating machine and manual touch-up spraying process;

[0011] Step S4: Melt the powder on the workpiece surface using an electric infrared radiation heating process;

[0012] Step S5: Use gas-fired catalytic infrared radiation heating process to rapidly increase the temperature of the powder on the workpiece surface;

[0013] Step S6: Use hot air circulation heating process to completely cure the powder coating;

[0014] Step S7: Use water atomization and air cooling processes to rapidly cool the workpiece;

[0015] Step S8: The powder coating used is a pure polyester or epoxy-polyester powder that cures at a low temperature of 120-160℃.

[0016] Preferably, the principle of saturated steam degreasing in step S1 is that saturated steam under high temperature and high pressure dissolves the oil stains on the surface being cleaned and vaporizes them, so that the surface cleaned by saturated steam can reach an ultra-clean state. At the same time, supersaturated steam can effectively cut into any tiny holes and cracks, peel off and remove the stains and residues therein.

[0017] Preferably, the surface of the workpiece after shot blasting in step S2 meets the following requirements: rust removal grade Sa2.5; roughness 30-75μm; soluble salts ≤100mg / m 3 Dust cleanliness level ≤ 3.

[0018] Preferably, the powder coating in step S3 is a low-temperature curing base and topcoat combined powder.

[0019] Preferably, in step S4, an electric infrared heating system is used to preheat the powder on the surface of the workpiece to 80°C, causing the coating surface to melt and reducing powder scattering during the conveying process.

[0020] Preferably, in step S5, the surface temperature of the molten powder is heated to 110-130°C using gas-catalyzed infrared radiation.

[0021] Preferably, the temperature of the hot air circulation heating in step S6 is 120-220°C.

[0022] Preferably, the atomization water cooling process in step S7 utilizes the friction between compressed air and liquid to produce a very uniform and fine atomization effect, with an average atomized particle diameter of less than 50μm.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. By adopting methods such as supersaturated steam degreasing, reciprocating automatic spraying, electric infrared radiation + gas catalytic infrared radiation + hot air circulation heating, water atomization cooling + air cooling, and low-temperature curing of pure polyester or epoxy-polyester powder at 120-160℃, powder coating has been applied to non-standard parts of hydraulic supports that are heavy, complex in structure and thick (25-200mm).

[0025] 2. Solved the problem of powder curing and cooling temperature for workpieces of different thicknesses; innovated the powder coating process for heavy-duty plates in the industry, which can meet the coating requirements of hydraulic support parts with a maximum size of 5500mm (length) * 2010mm (width) * 2200mm (height) and a maximum weight of 20T.

[0026] 3. It has enabled automated spraying for the discrete production of non-standard hydraulic support components, reducing the labor intensity of workers;

[0027] 4. A zero-VOC powder coating process for hydraulic supports was developed and applied to the surface coating of hydraulic supports. The resulting coating has strong adhesion (level 0), high gloss (high gloss level), high hardness (≥2H), and good corrosion resistance (720h salt spray resistance), meeting the needs of mines in different environments. At the same time, the production process does not generate any waste, achieving green and environmentally friendly coating for hydraulic supports. Detailed Implementation

[0028] The present invention will be further described below:

[0029] A powder coating process for hydraulic support components includes the following steps:

[0030] Step S1: Use supersaturated steam to remove oil stains from the workpiece surface;

[0031] Step S2: Use an automatic shot blasting process to remove oxide scale, loose rust, welding slag, etc. from the surface of the workpiece;

[0032] Step S3: Apply powder coating to the workpiece surface using an automatic reciprocating machine and manual touch-up spraying process;

[0033] Step S4: Melt the powder on the workpiece surface using an electric infrared radiation heating process;

[0034] Step S5: Use gas-fired catalytic infrared radiation heating process to rapidly increase the temperature of the powder on the workpiece surface;

[0035] Step S6: Use hot air circulation heating process to completely cure the powder coating;

[0036] Step S7: Use water atomization and air cooling processes to rapidly cool the workpiece;

[0037] Step S8: The powder coating used is a pure polyester or epoxy-polyester powder that cures at a low temperature of 120-160℃.

[0038] The principle of saturated steam degreasing in step S1 is that saturated steam under high temperature and pressure dissolves and vaporizes the oil particles on the surface being cleaned, achieving an ultra-clean state. Simultaneously, the supersaturated steam can effectively penetrate any tiny pores and cracks, peeling away and removing stains and residues. To degrease the workpiece surface using a Tyco Steam Box steam cleaner, the specific operation is as follows: turn on the main power switch, wait until the steam pressure on the display panel reaches 10 Bar and the steam temperature reaches 165-180℃, then hold the trigger to spray steam from the nozzle. The nozzle should be kept 200-300mm away from the workpiece, and the moving speed should be 400-500mm. This process has the following advantages: Water saving: Compared with other water-based cleaning methods, steam cleaning consumes very little water; Cleanliness: Under the action of high temperature and high pressure saturated steam, oil stains and dirt are quickly dissolved and removed, rapidly achieving an ultra-clean state; Environmental protection: No wastewater discharge or harmful chemical substances are generated during the cleaning process; Economy: Simple operation, saving time and workload, instant surface drying, eliminating the need for drying steps; Saves wastewater treatment costs.

[0039] In step S2, the workpiece has maximum dimensions of 5500mm (length) × 2200mm (width) × 2100mm (height) and weighs 20 tons. The workpiece is continuously conveyed through the automatic shot blasting chamber by an accumulation and conveying system. The chamber's inlet and outlet are equipped with automatic opening and closing doors, and the front and rear auxiliary chambers have arched shot-blocking sealing curtains. The shot blasting chamber is equipped with 12 shot blasters: eight 22KW and four 30KW Japanese-imported Y-30 shot blasters, offering higher energy efficiency and longer service life. The arrangement of the shot blasters is determined by computer-simulated three-dimensional dynamic modeling, with all angles and positions optimized for the best blasting effect. After being impacted by a shot beam (φ0.8~φ1.0 cast steel shot) with a blasting velocity ≥73m / s, the workpiece surface is rapidly cleaned of oxide scale, dirt, and other attachments. The shot ejected by the shot blasters is collected and processed by a shot recycling system to meet the requirements for reuse. Cleaning and touch-up blasting: Equipped with one shot blasting system, two 75kw power units and one 18.5kw shot suction machine system to meet the needs of touch-up blasting and cleaning of dead corners of workpieces.

[0040] The surface condition of the workpiece after shot blasting should meet the following requirements: rust removal grade Sa2.5; roughness 30-75μm; soluble salts ≤100mg / m 3 Dust cleanliness level ≤ 3.

[0041] The specific solution in step S3 involves using four sets of 3D laser contour scanner systems to dynamically detect the workpiece contour, combining intelligent technology with the main control unit to automatically generate a program, achieving efficient automated spraying. The system controls the movement of five sets of Jinma ZA07, five sets of XT10, and six sets of UA03 reciprocating machine systems, respectively. Combined with adjusting the 30 OptiGun GA03 spray guns configured on the reciprocating machines (eight on the top, eight on the bottom, eight on the sides, and six on the end faces), powder coating coverage can be achieved for 90% of the maximum workpiece size area. The remaining 10% is covered by two handheld OptiFlex-Pro W spray guns, relying on electrostatic adsorption to form a uniform coating on the workpiece surface. The powder coating is a low-temperature curing primer-topcoat integrated powder.

[0042] In step S4, the electric infrared heating system preheats the bottom and sides of the powder-coated workpiece to 60-80°C for 6-8 minutes, causing the surface of the corresponding coating to melt and reducing powder scattering during subsequent transport. This system utilizes Heraeus' mid-wave infrared radiator technology, employing 136 Heraeus mid-wave infrared lamps, each with a power of 3000W and a voltage of 380V, arranged on both sides and the bottom of the infrared furnace. This Heraeus mid-wave infrared radiator features advanced design and powerful performance, generating high-density mid-wave infrared radiation for efficient heating. Heraeus provides high-radiation-density and high-power twin-tube radiators equipped with gold-plated reflective films for comprehensive heating of the object. Compared to metal reflectors, the gold-plated reflective film significantly improves heating efficiency.

[0043] In step S5, Heraeus gas-fired catalytic infrared radiation is used to heat the surface temperature of the molten powder to 110-130℃ for 12-16 minutes. The total effective heating zone length is 6 meters, with 4 heating zones. Each heating zone is equipped with 16 Heraeus HP1660HE catalytic plates, each measuring 1525mm*410mm*131mm, with a gas power of 13.7kW per 1.32m². 3 / h.

[0044] In step S6, a hot air circulation heating process is used to cure the powder coating. The drying temperature is 120–220℃, and the drying time is 60–180 minutes. The curing oven adopts a direct-flow structure with a ternary gas indirect / direct heating system. The drying chamber is automatically controlled using a 3-point temperature measurement method and is equipped with display, over-temperature alarm, and other functions to promptly and comprehensively understand the working status of the drying oven.

[0045] In step S7, the gas and liquid are first mixed and atomized inside the air and liquid cap chambers using an internal mixing atomizing device. Through the impact and friction between compressed air and the liquid, a very uniform and fine atomization effect is produced, with an average atomized particle diameter below 50 μm. Atomization increases the contact area, and water vapor evaporation removes heat from the workpiece, thus achieving rapid cooling. Then, the heat is further removed through a supply and exhaust ventilation system, with airflow reaching 200,000 m³ / h. 3 The total cooling time is 30-60 minutes per hour, which eventually reduces the surface temperature of the workpiece to about 40°C, achieving the purpose of hardening the paint film. This prevents defects such as deformation, dents, and fingerprints from occurring when the workpiece comes into contact with other objects, thus meeting the needs of subsequent transportation.

[0046] The powder coating used in step S8 is a pure polyester or epoxy-polyester powder that cures at a low temperature of 120-160℃.

[0047] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope of the present invention, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A powder coating process for hydraulic support components, characterized in that: Includes the following steps: Step S1: Use supersaturated steam to remove oil stains from the workpiece surface; the principle of supersaturated steam degreasing is to dissolve and vaporize the oil particles on the surface being cleaned by supersaturated steam under high temperature and pressure, so that the surface after cleaning reaches an ultra-clean state. Supersaturated steam can also penetrate into the small holes and cracks of the workpiece, peeling off and removing the stains and residues therein; steam pressure 10 Bar, steam temperature 165-180℃, nozzle distance from workpiece maintained at 200-300mm, moving speed 400-500mm / min; Step S2: Use automatic shot blasting to remove oxide scale, loose rust, and welding slag from the workpiece surface; the shot blasting equipment is equipped with 12 shot blasters with a blasting speed ≥73m / s; after shot blasting, the workpiece surface parameters meet the following requirements: rust removal grade Sa2.5, roughness 30-75μm, soluble salts ≤100mg / m³, and dust cleanliness ≤3 level. Step S3: Apply powder coating to the surface of the workpiece using an automatic reciprocating machine and manual touch-up spraying process; the powder coating is a pure polyester or epoxy-polyester powder that cures at a low temperature of 120~160℃. Step S4: Use an electric infrared radiation heating process to melt the powder on the workpiece surface; use an electric infrared heating system to preheat the powder on the workpiece surface to 80°C for 6-8 minutes to melt the coating surface and reduce powder scattering during the conveying process; Step S5: Use gas-fired catalytic infrared radiation heating process to rapidly raise the temperature of the powder on the workpiece surface; use gas-fired catalytic infrared radiation equipment, including 4 heating zones, each heating zone is equipped with 16 catalytic plates, to heat the surface temperature of the molten powder to 110-130℃, and the heating time is 12-16min; Step S6: Use hot air circulation heating process to completely cure the powder coating; use a direct-flow curing oven, equipped with a ternary gas indirect / direct heating system, the hot air circulation heating temperature is 120-220℃, and the drying time is 60-180min; Step S7: Use water atomization and air cooling processes to rapidly cool the workpiece; first, use an internal mixing atomization device to generate a uniform and fine atomization effect by utilizing the friction between compressed air and liquid, with an average atomized particle diameter ≤50μm; then, use a secondary cooling system through air supply and exhaust circulation to cool the workpiece, with a total cooling time of 30-60 minutes, ultimately reducing the surface temperature of the workpiece to 40℃.

2. The powder coating process for hydraulic support components according to claim 1, characterized in that: When operating the steam cleaner used in step S1, first turn on the main power switch. When the steam pressure value on the display panel reaches 10 Bar and the steam temperature reaches 165~180℃, then hold the trigger to make the nozzle spray steam.

3. The powder coating process for hydraulic support components according to claim 1, characterized in that: In step S2, the automatic shot blasting process is equipped with a shot recycling system, including one shot blasting system, two 75kw shot suction machines, and one 18.5kw shot suction machine, which are used to collect and process the shot thrown out by the shot blaster, so as to achieve recycling and at the same time meet the needs of workpiece dead corners for additional blasting and cleaning.

4. The powder coating process for hydraulic support components according to claim 1, characterized in that: In step S3, the automatic reciprocating machine system is equipped with four 3D laser contour scanner systems to dynamically detect the workpiece contour and combine it with the main control unit to automatically generate the spraying program.

5. The powder coating process for hydraulic support components according to claim 1, characterized in that: In step S4, the electric infrared heating system arranges 136 medium-wave infrared lamps on both sides and the bottom of the infrared furnace; the medium-wave infrared lamps are equipped with gold-plated reflective films.

6. The powder coating process for hydraulic support components according to claim 1, characterized in that: In step S6, the drying chamber of the hot air circulating curing oven uses a 3-point temperature measurement method to automatically control the temperature, and is equipped with temperature display and over-temperature alarm functions.

7. The powder coating process for hydraulic support components according to claim 1, characterized in that: In step S7, the internal mixing atomizing device atomizes gas and liquid by mixing them inside the air cap and liquid cap chambers.