Spraying process suitable for water paint coating line

Abstract

The invention relates to the technical field of energy-saving and new energy automobile paint surface spraying, and discloses a spraying process suitable for a water paint coating line, which comprises the following steps: S1, pretreatment stage: placing a workpiece to be processed on a spraying frame, and then performing degreasing, cleaning, pure water washing, water blowing inspection, drying, cooling and flame treatment on the workpiece; in the spraying stage, after pretreatment, a full-automatic robot and an electrostatic spraying process are used for spraying primer, finish paint and varnish to the to-be-machined part; and in the leveling stage, leveling is conducted after the primer, the finish paint and the varnish are sprayed, the leveling temperature is controlled to be 21-25 DEG C after the primer and the finish paint are sprayed, leveling is conducted for 10 min, and the leveling temperature is controlled to be 26-30 DEG C after the varnish is sprayed. According to the water-based paint spraying device, the full-automatic robot and the electrostatic spraying technology are adopted, and therefore the problem that the existing traditional water-based paint spraying mode is usually adopted in a manual spraying mode, and the coating quality is not high is solved.

Description

Technical Field

[0001] The invention relates to the technical field of paint spraying for energy-saving and new energy vehicles, and specifically to a spraying process suitable for a water-based paint coating line. Background Art

[0002] Water-based paint spraying is a coating process that uses water as a diluent. The principle is to use a spray gun to atomize the water-based paint and spray it evenly on the surface of the object. After the water evaporates, the resin and other film-forming substances in the paint solidify to form a protective film. Compared with traditional oil-based paint spraying, water-based paint spraying has many advantages. First of all, it is extremely environmentally friendly and contains almost no harmful volatile organic compounds (VOCs), which can effectively reduce air pollution and cause less health hazards to construction workers and users. Secondly, water-based paint dries quickly and can improve construction efficiency. Moreover, it has rich colors, smooth paint films, and excellent decorative effects.

[0003] The existing traditional water-based paint spraying is often done by manual spraying. During manual spraying, it is difficult to keep the distance and moving speed between the spray gun and the surface of the object being painted consistent, which will cause the problem of low coating quality. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a spraying process suitable for a water-based paint coating line, which solves the problem that the existing traditional water-based paint spraying often adopts the manual spraying method. During manual spraying, it is difficult to keep the distance and moving speed between the spray gun and the surface of the coated object consistent, which will cause the problem of low coating quality.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A spraying process suitable for a water-based paint coating line, comprising the following steps:

[0006] S1, pre-treatment stage: the workpiece to be processed is placed on the spray rack, and then the workpiece is degreased, cleaned, washed with pure water, blown for inspection, dried, cooled and flame treated;

[0007] S2, spraying stage: after pre-treatment, the workpiece is sprayed with primer, topcoat and varnish using a fully automatic robot plus electrostatic spraying process;

[0008] S3, leveling stage: After the primer, topcoat and clearcoat are sprayed, they are leveled respectively. After the primer and topcoat are sprayed, the leveling temperature is controlled at 21-25℃, and the leveling takes 10 minutes. After the clearcoat is sprayed, the leveling temperature is controlled at 26-30℃, and the leveling takes 10 minutes.

[0009] S4, drying stage: after the primer, topcoat and clearcoat are leveled, they are dried by infrared drying equipment respectively. After the primer and topcoat are leveled, the drying temperature is controlled at 90-95°C and the drying time is controlled at 25 minutes. After the clearcoat is leveled, the drying temperature is controlled at a constant level and the drying time is controlled at 40 minutes.

[0010] S5, cooling stage: after the primer, topcoat and varnish are dried, the workpiece is cooled by centrifugal fans respectively. After the primer and topcoat are dried, the workpiece is cooled for 5 minutes, and the temperature after cooling is controlled at 21-23°C. After the varnish is dried, the workpiece is cooled for 20 minutes;

[0011] S6, unloading stage: remove the cooled workpiece and conduct quality inspection on the workpiece.

[0012] Preferably, the degreasing agent in the degreasing in S1 includes sodium hydroxide, sodium carbonate, and a surfactant. The degreasing agent and pure water are mixed at a ratio of 1:5-1:10 to form a degreasing liquid. The degreasing liquid is sprayed through a spray head. The spray head has a heating device. The heating device can control the temperature of the degreasing liquid sprayed from the spray head to 50-70°C, the spray pressure of the spray head to 2-4 bar, and the spray time of the spray head to 2-5 minutes.

[0013] Preferably, the washing in S1 is performed three times, the first washing lasts for 90 seconds, the second and third washings last for 30 seconds, and there is an interval of 30 seconds between each washing.

[0014] Preferably, the cooling time in S1 is 10 minutes.

[0015] Preferably, the drying in S1 is performed using an infrared dryer, the temperature of the infrared dryer is controlled at 90-95° C., and the drying is performed for 30 minutes.

[0016] Preferably, the water blowing inspection in S1 uses a compressed air spray gun, controls the pressure of the compressed air spray gun to be 0.3-0.5 MPa, controls the angle between the compressed air spray gun and the workpiece surface to be 45-60 degrees, and controls the water blowing time to be 4 minutes.

[0017] Preferably, the gas used for the flame treatment in S1 is propane. After the flame treatment, the workpiece is cooled for 10 minutes by a centrifugal fan to control the temperature of the workpiece at 21-25° C. and the humidity of the workpiece at 60-65%.

[0018] Preferably, when spraying primer in S2, the water-based paint temperature is controlled at 21-25°C and the workpiece humidity is controlled at 60-65%, when spraying topcoat, the water-based paint temperature is controlled at 21-25°C and the workpiece humidity is controlled at 60-70%, and when spraying varnish, the water-based paint temperature is controlled at 21-23°C and the workpiece humidity is controlled at 60-65%.

[0019] Preferably, when controlling the temperature of the water-based paint, the temperature is controlled by a temperature control device, which includes a shell, a leg fixedly connected to the lower surface of the shell, a feed port fixedly connected to the upper inner side of the leg, a discharge port fixedly connected to the lower inner side of the shell, a one-way valve is arranged inside the discharge port, and the one-way valve is used to discharge the paint inside the shell, a water tank is fixedly connected to the upper surface of one side of the shell, the position of the water tank is designed relative to the feed port, a water inlet is fixedly connected to the upper inner side of the water tank, an internal temperature control component is arranged inside the water tank, and the internal temperature control component The temperature of the paint inside the shell is adjusted, and the internal temperature control component is arranged inside the shell; the internal temperature control component includes a water pump, the outer wall of the water pump is fixedly connected to the inside of the water tank, the output end of the water pump is provided with a return pipe, the end of the return pipe close to the water pump is arranged inside one side of the water tank, the outer wall of the return pipe is arranged inside the shell, the end of the return pipe away from the water pump is arranged inside the other side of the water tank, the input end of the water pump is provided with a water pipe, the water pipe is arranged inside the water tank, and the water pipe is used to absorb the water inside the water tank and transport it to the return pipe; the middle upper part of the shell The surface is fixedly connected with a motor, the output end of the motor is connected with a support shaft, the outer wall of the support shaft is rotatably connected to the inside of the shell, and the bottom end of the support shaft is provided with a stirring component, and the stirring component is used to evenly mix the paint inside the shell; the stirring component includes a connecting disk 1, the top end of the connecting disk 1 is fixedly connected to the bottom end of the support shaft, the outer wall of the connecting disk 1 is fixedly connected with a stirring rod 1, and the stirring rod 1 rotates in the middle of the shell, and the bottom end of the connecting disk 1 is provided with an anti-solidification component, and the anti-solidification component is used to prevent the paint at the bottom of the shell from solidifying; the anti-solidification component includes a bevel gear 1, The top end of bevel gear one is fixedly connected to the bottom end of connecting disk one, and the tooth end of bevel gear one is meshedly connected to bevel gear two. A cross shaft is fixedly connected to the interior of connecting disk one, and the upper outer wall of the cross shaft is rotatably connected to the interior of bevel gear one, and the interior of bevel gear two is rotatably connected to the left and right outer walls of the cross shaft. The bottom end of the cross shaft is rotatably connected to connecting disk two, and the top end of connecting disk two is fixedly connected to bevel gear three, and the tooth end of bevel gear three is meshedly connected to the tooth end of bevel gear two. The outer wall of connecting disk two is fixedly connected to stirring rod two, and stirring rod two rotates inside the lower side of the shell.

[0020] Preferably, a one-way valve is provided inside the water inlet, the one-way valve prevents dust from entering the interior of the water tank, and the one-way valve prevents water inside the water tank from spilling out when the outer shell shakes; the one-way valve prevents dust from entering the interior of the outer shell, and the one-way valve prevents paint inside the outer shell from spilling out when the outer shell shakes; the outer wall of the connecting disk one is fixedly connected to the protective shell, and the outer wall of the connecting disk two is rotatably connected to the lower inner side of the protective shell.

[0021] The present invention provides a spraying process suitable for a water-based paint coating line. It has the following beneficial effects:

[0022] 1. In the present invention, by adopting a fully automatic robot plus electrostatic spraying process, the spraying efficiency and uniformity are improved, the spraying amount and spraying range can be accurately controlled, and the waste of paint can be reduced. At the same time, electrostatic spraying can enhance the adhesion between the paint and the workpiece, thereby improving the existing traditional water-based paint spraying which often adopts the manual spraying method. During manual spraying, the distance and moving speed between the spray gun and the surface of the coated object are difficult to keep consistent, which will cause the problem of low coating quality.

[0023] 2. In the present invention, three water washes are used for cleaning, the first water wash is 90 seconds, the second and third water washes are 30 seconds, and the interval between each water wash is 30 seconds. This multiple cleaning method with reasonable time intervals can more thoroughly remove the degreasing liquid and other impurities remaining on the surface of the workpiece, ensuring the cleanliness of the workpiece surface.

[0024] 3. In the present invention, by accurately controlling the temperature of the water-based paint and the humidity of the workpiece when spraying the primer, topcoat and varnish, it is beneficial to ensure the quality and performance of the coating, make the coating adhere better to the surface of the workpiece, and reduce the occurrence of defects such as sagging and bubbling.

[0025] 4. In the present invention, leveling is performed respectively after spraying the primer, topcoat and clearcoat, and different leveling temperatures are set for different paint types, which helps to fully level the paint on the surface of the workpiece, form a uniform coating, and improve the flatness and glossiness of the coating.

[0026] 5. In the present invention, the degreasing liquid only needs to be heated to 50-70°C by the heating device in the spray head during the degreasing process. The relatively low heating temperature reduces energy consumption while ensuring the degreasing effect. In the drying stage, an infrared dryer is used. Infrared drying has the characteristics of fast heating speed and concentrated energy. Compared with traditional hot air drying and other methods, it can transfer heat to the workpiece more efficiently and shorten the drying time, thereby achieving the purpose of reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a process flow chart of the present invention;

[0028] Figure 2 It is a schematic diagram of the three-dimensional structure of the paint temperature control device of the present invention;

[0029] Figure 3 A cross-sectional view of the internal structure of the shell of the paint temperature control device of the present invention;

[0030] Figure 4 A cross-sectional view of the internal structure of a water tank of a paint temperature control device of the present invention;

[0031] Figure 5 It is a schematic diagram of the partial structure of the stirring rod of the paint temperature control device of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Please refer to the attached Figure 1 The embodiment of the present invention provides a spraying process suitable for a water-based paint coating line, which is characterized by comprising the following steps:

[0034] S1, pre-treatment stage: the workpiece to be processed is placed on the spray rack, and then the workpiece is degreased, cleaned, washed with pure water, blown for inspection, dried, cooled and flame treated;

[0035] S2, spraying stage: after pre-treatment, the workpiece is sprayed with primer, topcoat and varnish using a fully automatic robot plus electrostatic spraying process;

[0036] S3, leveling stage: After the primer, topcoat and clearcoat are sprayed, they are leveled respectively. After the primer and topcoat are sprayed, the leveling temperature is controlled at 21-25℃, and the leveling takes 10 minutes. After the clearcoat is sprayed, the leveling temperature is controlled at 26-30℃, and the leveling takes 10 minutes.

[0037] S4, drying stage: after the primer, topcoat and clearcoat are leveled, they are dried by infrared drying equipment respectively. After the primer and topcoat are leveled, the drying temperature is controlled at 90-95°C and the drying time is controlled at 25 minutes. After the clearcoat is leveled, the drying temperature is controlled at a constant level and the drying time is controlled at 40 minutes.

[0038] S5, cooling stage: after the primer, topcoat and varnish are dried, the workpiece is cooled by centrifugal fans respectively. After the primer and topcoat are dried, the workpiece is cooled for 5 minutes, and the temperature after cooling is controlled at 21-23°C. After the varnish is dried, the workpiece is cooled for 20 minutes;

[0039] S6, unloading stage: remove the cooled workpiece and conduct quality inspection on the workpiece.

[0040] Specifically, degreasing can remove oil, grease and other impurities on the surface of the workpiece, providing a good foundation for subsequent cleaning and coating, and ensuring the adhesion between the coating and the workpiece surface. Cleaning after degreasing can remove the degreasing agent and other impurities remaining on the surface of the workpiece, improving the cleanliness of the workpiece surface. Pure water washing after cleaning can further remove the impurity ions that may remain in the cleaning process, so that the surface of the workpiece reaches a higher degree of cleanliness, avoiding these impurities from affecting the quality of the subsequent coating. Water blowing inspection can remove the residual moisture on the surface of the workpiece, and at the same time check whether there are impurities or defects on the surface of the workpiece that have not been cleaned up, so as to timely discover and deal with them. Drying after water blowing inspection can completely remove the moisture on the surface of the workpiece, prevent the residual moisture from causing bubbling, shedding and other problems in the subsequent coating, and at the same time make the surface of the workpiece reach a suitable temperature, which is conducive to the subsequent coating operation. Cooling can avoid the adverse effects of high temperature on subsequent processing, and at the same time release the thermal stress of the workpiece, thereby improving the stability of the workpiece. Flame treatment can improve the activity of the workpiece surface and increase the surface roughness, thereby improving the adhesion between the coating and the workpiece surface, creating good conditions for subsequent coating. Fully automatic robot spraying can accurately control the distance between the spray gun and the surface of the object to be coated, the moving speed, the spraying angle and other parameters, maintain a stable and consistent spraying operation, and avoid the difference in coating quality caused by human factors during manual spraying, thereby ensuring uniform coating thickness, smooth appearance, and improving the overall coating quality. The electrostatic spraying process can use the attraction of the electric charge to make the paint particles more evenly adsorbed on the surface of the workpiece, reducing the splashing and waste of paint; compared with the traditional spraying method, the utilization rate of the paint can be greatly improved, and the electrostatic effect makes the paint particles more densely distributed on the surface of the workpiece, and can better penetrate into the tiny pores on the surface of the workpiece, thereby enhancing the adhesion between the coating and the workpiece, and improving the durability and service life of the coating. The leveling stage allows the solvent in the paint to continue to evaporate, and the paint molecules will flow and redistribute under the action of surface tension, thereby filling in tiny surface defects, making the coating surface smoother and smoother, and improving the appearance quality of the coating; the leveling stage controls the temperature and time to allow the paint to flow and adjust slowly, which helps to release these internal stresses, reduce the possibility of cracking and peeling of the coating during subsequent use, and improve the stability and durability of the coating; leveling can make the coating thickness more uniform, thereby ensuring that the degree of curing of various parts of the coating is consistent in subsequent drying processes, thereby improving the adhesion, hardness and corrosion resistance of the coating.In the S4 drying stage, the heat provided by the infrared dryer causes the film-forming substances in the primer, topcoat and clearcoat to undergo a cross-linking reaction, thereby achieving the curing of the coating. For the primer and topcoat, a drying temperature of 90-95°C and a drying time of 25 minutes can allow them to form a paint film with certain strength and performance, providing a good foundation for subsequent coatings. Due to its special composition and performance requirements, the varnish can be fully cured by drying it at the same temperature for 40 minutes, forming a hard, wear-resistant and glossy surface, thereby achieving the purpose of promoting the curing of the coating; the paint usually contains solvents and water, which will evaporate during the drying process, thereby avoiding problems such as blistering, whitening, and decreased adhesion of the coating, thereby ensuring the quality and performance of the coating. In the S5 cooling stage, the molecular structure of the coating can be gradually stabilized through cooling, which helps to maintain the performance of the coating after drying and prevent performance degradation or deformation, cracking and other problems caused by rapid temperature changes or long-term high temperature; the temperature of the workpiece after cooling is reduced to close to room temperature, which is convenient for workers to carry out subsequent handling, packaging or other processing operations; rapid cooling can shorten the processing cycle of a single workpiece and improve the efficiency of the entire production process. For a continuous production coating line, timely cooling of the workpiece can allow the spray rack to enter the next round of processing cycle faster, improve the utilization rate of the equipment, and thus increase the output per unit time; the varnish is cooled for 20 minutes after drying, which is longer than the cooling time of the primer and topcoat. This is determined according to the characteristics and process requirements of the varnish, which can ensure that the varnish coating is fully cooled and stable, and will not consume too much energy due to excessive cooling.

[0041] The degreasing agent in the degreasing in S1 includes sodium hydroxide, sodium carbonate, and a surfactant. The degreasing agent is mixed with pure water at a ratio of 1:5-1:10 to form a degreasing liquid. The degreasing liquid is sprayed through a spray head. There is a heating device in the spray head. The heating device can control the temperature of the degreasing liquid sprayed from the spray head to 50-70°C, the spray pressure of the spray head to 2-4bar, and the spray time of the spray head to 2-5 minutes.

[0042] Specifically, sodium hydroxide has strong alkalinity and can undergo saponification reaction with oils and fats, decomposing them into water-soluble fatty acid salts and glycerol, thereby effectively removing oil stains such as animal and vegetable oils on the surface of the workpiece; sodium carbonate has an alkaline aqueous solution, and the hydroxide ions produced by hydrolysis can participate in the saponification reaction, further enhancing the ability to remove oil stains, while helping to soften the water quality and improve the degreasing effect; surfactants have emulsifying, dispersing and solubilizing effects, which can reduce the interfacial tension between oil stains and the surface of the workpiece, making the oil stains more easily wetted and emulsified by water, and then dispersed in the degreasing liquid and washed away, and have a significant effect on the removal of non-polar oil stains such as mineral oil. Mixing them into a degreasing liquid in a ratio of 1:5-1:10 can not only ensure that the degreasing agent has sufficient concentration to fully react with the oil stains, but also make the degreasing liquid have good fluidity and permeability, so as to better contact and remove the oil stains on the surface of the workpiece. Controlling the temperature of the degreasing liquid at 50-70℃ can speed up the chemical reaction rate, making the saponification reaction and the action of the surfactant more rapid and effective. At the same time, the appropriate temperature can reduce the viscosity of the oil stains, making it easier to be washed away by the degreasing liquid, thereby improving the degreasing efficiency. The spray head spray pressure is 2-4bar, which can make the degreasing liquid spray on the surface of the workpiece with a certain impact force, enhance the flushing effect on the oil stains, and help remove stubborn oil stains. The spraying time is controlled at 2-5 minutes, which can ensure that the degreasing liquid has enough contact reaction time with the oil stains, but not too long to cause waste of resources and excessive erosion of the workpiece surface.

[0043] The washing in S1 is three times, the first washing is 90 seconds, the second and third washings are 30 seconds, and the interval between each washing is 30 seconds.

[0044] Specifically, the first water washing is for preliminary dirt removal. After degreasing, most of the oil and impurities on the workpiece surface have been decomposed or emulsified by the degreasing agent, but there are still some residual substances attached to the surface. The first water washing time is relatively long, 90 seconds. The purpose is to use the flushing effect of water to initially rinse off the degreasing agent, oil and other water-soluble impurities remaining on the surface of the workpiece after degreasing, laying the foundation for subsequent more thorough cleaning; the second water washing is for further cleaning. The 30-second second water washing can further clean the remaining impurities and make the workpiece surface cleaner; the third water washing is a deep cleaning to ensure that there is almost no residual degreasing agent, impurities or water stains on the workpiece surface. The 30-second interval between each water washing allows the moisture on the workpiece surface to drain naturally, reduce the water accumulation on the workpiece surface, and prepare for the next water washing or subsequent processes.

[0045] The cooling time in S1 is 10 minutes.

[0046] Specifically, 10 minutes of cooling can reduce and stabilize the temperature of the workpiece, avoiding stress inside the workpiece due to rapid temperature changes, thereby preventing deformation, cracking and other problems in the workpiece and ensuring the dimensional accuracy and physical properties of the workpiece.

[0047] In S1, an infrared dryer is used for drying, and the temperature of the infrared dryer is controlled at 90-95°C for 30 minutes.

[0048] Specifically, under the premise of ensuring the drying effect, the processing time of a single workpiece can be shortened as much as possible, thereby improving the efficiency of the entire production process and meeting the needs of large-scale production.

[0049] In S1, a compressed air spray gun is used for water blowing inspection. The pressure of the compressed air spray gun is controlled at 0.3-0.5 MPa, the angle between the compressed air spray gun and the workpiece surface is controlled at 45-60 degrees, and the water blowing time is controlled at 4 minutes.

[0050] Specifically, by controlling the pressure of the compressed air spray gun at 0.3-0.5 MPa, an airflow with a certain impact force can be generated. This pressure intensity is sufficient to effectively blow away the water droplets or water stains remaining on the surface of the workpiece after washing, ensuring that the surface of the workpiece is as dry as possible, reducing the burden on the subsequent drying process, and improving drying efficiency; the spray gun is at an angle of 45-60 degrees to the surface of the workpiece, so that the airflow can act on the surface of the workpiece at a suitable angle. Such an angle can not only use the impact force of the airflow to blow moisture away from the workpiece, but also avoid water splashing or damage to the workpiece surface caused by direct vertical impact of the airflow, ensuring that the moisture is smoothly blown to the edge of the workpiece or other places that are easy to collect; the water blowing time is controlled to 4 minutes, which can ensure that there is enough time to comprehensively blow all parts of the workpiece surface. During this time, the workpiece is carefully blown by a fully automatic robot to ensure that moisture in every corner and gap can be effectively removed, thereby achieving a good drying effect.

[0051] In S1, the flame treatment uses propane as the gas. After the flame treatment, the workpiece is cooled for 10 minutes by a centrifugal fan, and the temperature of the workpiece is controlled at 21-25° C. and the humidity of the workpiece is controlled at 60-65%.

[0052] Specifically, the flame treatment uses a spray gun, the distance between the spray gun and the workpiece surface is controlled at 10-30cm, and the spray gun angle is controlled between 30-90 degrees. Cooling with a centrifugal fan can avoid the internal stress of the workpiece due to rapid temperature changes, prevent deformation, cracking and other problems, and ensure the dimensional accuracy and physical properties of the workpiece. By controlling the humidity of the workpiece at 60-65%, condensation on the workpiece surface due to excessive humidity can be prevented, and moisture can be prevented from affecting the adhesion of the coating. It also helps to maintain the stability of the workpiece performance and prevent problems such as rust during subsequent storage or processing.

[0053] In S2, when spraying primer, the water-based paint temperature is controlled at 21-25°C and the workpiece humidity is controlled at 60-65%. When spraying topcoat, the water-based paint temperature is controlled at 21-25°C and the workpiece humidity is controlled at 60-70%. When spraying varnish, the water-based paint temperature is controlled at 21-23°C and the workpiece humidity is controlled at 60-65%.

[0054] Specifically, by controlling the temperature of water-based paint, the viscosity, surface tension and other properties of the paint can be ensured to be in the best state; the appropriate temperature makes the water-based paint molecules moderately active, and after being sprayed on the surface of the workpiece, it can better interact with the molecules on the surface of the workpiece to form good chemical bonding and physical adsorption, thereby improving the adhesion between the coating and the workpiece. By controlling the humidity of the workpiece, it is possible to avoid defects such as bubbles and pinholes after spraying due to excessive humidity on the surface of the workpiece, and at the same time help maintain the stability of the physical properties of the workpiece itself, and prevent the deformation, expansion or contraction of the workpiece due to humidity changes, thereby affecting the quality and appearance of the coating.

[0055] When controlling the temperature of water-based paint, the temperature is controlled by a temperature control device, such as Figure 2-4 The temperature control device includes a shell 1, a leg 2 is fixedly connected to the lower surface of the shell 1, a feed port 3 is fixedly connected to the upper side of the leg 2, a discharge port 4 is fixedly connected to the lower side of the shell 1, a one-way valve is arranged inside the discharge port 4, and the one-way valve is used to discharge the paint inside the shell 1, a water tank 5 is fixedly connected to the upper surface of one side of the shell 1, the position of the water tank 5 is designed to be opposite to the feed port 3, a water inlet 9 is fixedly connected to the upper side of the water tank 5, an internal temperature control component is arranged inside the water tank 5, the internal temperature control component is used to adjust the temperature of the paint inside the shell 1, and the internal temperature control component is arranged inside the shell 1.

[0056] Specifically, the paint is poured into the interior of the outer shell 1 through the feed port 3, and then hot water or cold water is selectively introduced into the interior of the water tank 5, and then the temperature of the paint inside the outer shell 1 is controlled using the internal temperature control component, thereby achieving the control of the temperature of the paint through the tube-in-tube, preventing heat loss during the transfer process, and improving the energy efficiency of the entire system.

[0057] Reference Figure 3-Figure 4 The internal temperature control component includes a water pump 6, the outer wall of the water pump 6 is fixedly connected to the inside of the water tank 5, a return pipe 7 is arranged at the output end of the water pump 6, the end of the return pipe 7 close to the water pump 6 is arranged inside one side of the water tank 5, the outer wall of the return pipe 7 is arranged inside the shell 1, and the end of the return pipe 7 away from the water pump 6 is arranged inside the other side of the water tank 5, and a water pipe 8 is arranged at the input end of the water pump 6. The water pipe 8 is arranged inside the water tank 5, and the water pipe 8 is used to absorb the water inside the water tank 5 and transport it to the return pipe 7.

[0058] Specifically, the water pump 6 draws the water from the water tank 5 through the water pipe 8 and flows into the return pipe 7. The water flows through the return pipe 7 and the paint inside the shell 1 to heat or cool it, and then flows into the water tank 5 for recycling.

[0059] Reference Figure 2 A one-way valve is arranged inside the water inlet 9 to prevent dust from entering the water tank 5 and prevent water from spilling out of the water tank 5 when the housing 1 is shaken. A one-way valve is also arranged inside the feed port 3 to prevent dust from entering the housing 1 and prevent paint from spilling out of the housing 1 when the housing 1 is shaken.

[0060] Specifically, the one-way valve can prevent dust from entering the inside of the water tank 5 and the inside of the housing 1, thereby preventing water and paint from spilling out, which can effectively prevent external dust, pollutants or impurities from entering the water tank 5 or the inside of the housing 1. This helps to keep the inside of the system clean and reduce equipment failures or paint quality degradation caused by the accumulation of pollutants. By preventing paint from spilling out, the one-way valve can effectively reduce the waste of paint. Paint may overflow or spill out during the transportation process due to pressure changes or inappropriate flow direction. The design of the one-way valve helps to avoid this problem, thereby improving the efficiency of paint use and reducing unnecessary losses.

[0061] Reference Figure 3 The upper surface of the middle part of the housing 1 is fixedly connected with a motor 10, and the output end of the motor 10 is connected with a support shaft 11, and the outer wall of the support shaft 11 is rotatably connected to the inside of the housing 1. The bottom end of the support shaft 11 is provided with a stirring assembly, and the stirring assembly is used to evenly mix the paint inside the housing 1. The stirring assembly includes a connecting plate 12, the top end of the connecting plate 12 is fixedly connected to the bottom end of the support shaft 11, and the outer wall of the connecting plate 12 is fixedly connected with a stirring rod 13, and the stirring rod 13 rotates in the middle of the housing 1. The bottom end of the connecting plate 12 is provided with an anti-solidification assembly, and the anti-solidification assembly is used to prevent the paint at the bottom of the housing 1 from solidifying.

[0062] Specifically, the motor 10 drives the stirring rod 13 to rotate to stir the paint inside the housing 1, so that the paint can be evenly mixed.

[0063] Reference Figure 4The anti-solidification component includes a bevel gear 15, the top of which is fixedly connected to the bottom of a connecting disk 12, the tooth end of the bevel gear 15 is meshedly connected to a bevel gear 2 17, the interior of the connecting disk 12 is fixedly connected to a cross shaft 16, the upper outer wall of the cross shaft 16 is rotatably connected to the interior of the bevel gear 15, the interior of the bevel gear 2 17 is rotatably connected to the left and right outer walls of the cross shaft 16, the bottom end of the cross shaft 16 is rotatably connected to a connecting disk 2 18, the top of the connecting disk 2 18 is fixedly connected to a bevel gear 3 19, the tooth end of the bevel gear 3 19 is meshedly connected to the tooth end of the bevel gear 2 17, the outer wall of the connecting disk 2 18 is fixedly connected to a stirring rod 20, and the stirring rod 20 rotates inside the lower side of the housing 1.

[0064] Specifically, the connection plate 12 rotates and drives the bevel gear 15 to rotate, and the bevel gear 2 17 drives the stirring rod 20 to rotate, thereby preventing the paint on the bottom of the housing 1 from solidifying due to a long time.

[0065] Reference Figure 3 The outer wall of the connecting disk 12 is fixedly connected to the protective shell 14, and the outer wall of the connecting disk 2 18 is rotatably connected to the lower side of the protective shell 14.

[0066] Specifically, the protective shell 14 prevents paint from entering the interior of the bevel gear.

[0067] Working principle: When the device is needed, first open the valve of the feed port 3, then pour the paint into the interior of the shell 1 through the feed port 3, then close the valve of the feed port 3, continue to open the valve of the water inlet 9, choose to introduce hot water or cold water into the interior of the water tank 5, then close the valve of the water inlet 9, and then turn on the water pump 6. The water pump 6 will pump out the water inside the water tank 5 through the water pipe 8 and flow into the interior of the return pipe 7. The water flows through the interior of the return pipe 7 and passes through the paint inside the shell 1 to heat it up or cool it down, and then flows into the interior of the water tank 5 from the tail of the return pipe 7, and then circulates it, so that the temperature of the paint can be controlled through the tube-in-tube structure. Through the tube-in-tube structure, the temperature control medium (such as hot water or cold water, coolant, etc.) flows through the return pipe 7 to control the temperature of the paint in the shell 1. This process can use lower energy consumption to maintain the required temperature, thereby improving the energy efficiency of the entire system. The recycling and reuse of temperature-controlled liquids also reduces energy waste and reduces energy demand;

[0068] Then, the motor 10 is turned on, and the motor 10 drives the support shaft 11 to rotate, and the support shaft 11 drives the connecting plate 12 and the stirring rod 13 to rotate to stir the paint inside the housing 1, so that the paint can be evenly mixed. The stirring device can ensure that all components in the paint (such as pigments, resins, solvents, etc.) are evenly mixed to avoid stratification or agglomeration, thereby ensuring the quality of the paint. Even mixing can improve the gloss, wear resistance, adhesion and other properties of the coating, making the coating effect more stable and consistent;

[0069] When the connecting plate 12 rotates, it will drive the bevel gear 15 to rotate, and the bevel gear 15 will drive the bevel gear 2 17 to rotate, and then the bevel gear 2 17 will drive the connecting plate 2 18, the bevel gear 3 19 and the stirring rod 2 20 to rotate, so as to prevent the paint at the bottom of the housing 1 from solidifying due to a long time. When the paint is stored for a long time, especially water-based paint or solvent-based paint, the pigment or filler may precipitate and form solid blocks or gels. The bottom anti-solid component maintains the uniformity of the paint by continuous stirring and flow, preventing the pigment and other components from settling, thereby maintaining the usability of the paint;

[0070] The paint processed inside the housing 1 can be discharged by opening the discharge port 4, and the liquid inside the water tank 5 can be discharged by pulling the tail of the reflux pipe 7 out from the water tank 5 after use.

[0071] The following is further introduced in conjunction with specific embodiments:

[0072] Embodiment 1:

[0073] A spraying process suitable for a water-based paint coating line, comprising the following steps:

[0074] S1, pre-treatment stage: the workpiece to be processed is placed on the spray rack, and then the workpiece is degreased, cleaned, washed with pure water, blown for inspection, dried, cooled and flame treated;

[0075] S2, spraying stage: after pre-treatment, the workpiece is sprayed with primer, topcoat and varnish using a fully automatic robot plus electrostatic spraying process;

[0076] S3, leveling stage: After the primer, topcoat and clearcoat are sprayed, they are leveled respectively. After the primer and topcoat are sprayed, the leveling temperature is controlled at 21-25℃, and the leveling takes 10 minutes. After the clearcoat is sprayed, the leveling temperature is controlled at 26-30℃, and the leveling takes 10 minutes.

[0077] S4, drying stage: after the primer, topcoat and clearcoat are leveled, they are dried by infrared drying equipment respectively. After the primer and topcoat are leveled, the drying temperature is controlled at 90-95°C and the drying time is controlled at 25 minutes. After the clearcoat is leveled, the drying temperature is controlled at a constant level and the drying time is controlled at 40 minutes.

[0078] S5, cooling stage: after the primer, topcoat and varnish are dried, the workpiece is cooled by centrifugal fans respectively. After the primer and topcoat are dried, the workpiece is cooled for 5 minutes, and the temperature after cooling is controlled at 21-23°C. After the varnish is dried, the workpiece is cooled for 20 minutes;

[0079] S6, unloading stage: remove the cooled workpiece and conduct quality inspection on the workpiece.

[0080] Embodiment 2:

[0081] The difference between this embodiment and the above-mentioned embodiment 1 is that:

[0082] S2, spraying stage: after pre-treatment, workers spray primer, topcoat and varnish on the workpiece.

[0083] Table 1:

[0084] contrast Example 1 Example 2 Average film thickness standard deviation (μm) 5 8 Specular gloss (%) 95 85 Haze value (%) 5 15 △E value (dimensionless) 1.0 1.5 Metamerism index (dimensionless) 1.2 2.0 Pull-off adhesion value (MPa) 15 8

[0085] The comparison in Table 1 is the average film thickness standard deviation, mirror gloss, haze value, ΔE value, metamerism index and pull-off adhesion value. The results in Table 1 are obtained through experiments on workpieces with manual spray painting. By changing the different construction methods of the workpieces in each embodiment, the results of Examples 1-2 in Table 1 are obtained. Table 1 shows that the average film thickness standard deviation, mirror gloss, haze value, ΔE value, metamerism index and pull-off adhesion value of the workpiece can be improved by using a fully automatic robot for standardized construction, thereby improving the quality of the coating.

[0086] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A spraying process suitable for a water-based paint coating line, characterized in that: The following steps are involved: S1, pre-treatment stage: the workpiece to be processed is placed on the spray rack, and then the workpiece is degreased, cleaned, washed with pure water, blown for inspection, dried, cooled and flame treated; S2, spraying stage: after pre-treatment, the workpiece is sprayed with primer, topcoat and varnish using a fully automatic robot plus electrostatic spraying process; S3, leveling stage: After the primer, topcoat and clearcoat are sprayed, they are leveled respectively. After the primer and topcoat are sprayed, the leveling temperature is controlled at 21-25℃, and the leveling takes 10 minutes. After the clearcoat is sprayed, the leveling temperature is controlled at 26-30℃, and the leveling takes 10 minutes. S4, drying stage: after the primer, topcoat and clearcoat are leveled, they are dried by infrared drying equipment respectively. After the primer and topcoat are leveled, the drying temperature is controlled at 90-95°C and the drying time is controlled at 25 minutes. After the clearcoat is leveled, the drying temperature is controlled at a constant level and the drying time is controlled at 40 minutes. S5, cooling stage: after the primer, topcoat and varnish are dried, the workpiece is cooled by centrifugal fans respectively. After the primer and topcoat are dried, the workpiece is cooled for 5 minutes, and the temperature after cooling is controlled at 21-23°C. After the varnish is dried, the workpiece is cooled for 20 minutes; S6, unloading stage: remove the cooled workpiece and conduct quality inspection on the workpiece.

2. The spraying process for a water-based paint coating line according to claim 1, characterized in that: The degreasing agent in the degreasing in S1 includes sodium hydroxide, sodium carbonate, and a surfactant. The degreasing agent and pure water are mixed at a ratio of 1:5-1:10 to form a degreasing liquid. The degreasing liquid is sprayed through a spray head. The spray head has a heating device. The heating device can control the temperature of the degreasing liquid sprayed from the spray head to 50-70°C, control the spray pressure of the spray head to 2-4bar, and control the spray time of the spray head to 2-5 minutes.

3. The spraying process for a water-based paint coating line according to claim 1, characterized in that: The washing in S1 is performed three times, the first washing lasts for 90 seconds, the second and third washings last for 30 seconds, and the interval between each washing is 30 seconds.

4. The spraying process for a water-based paint coating line according to claim 1, characterized in that: The cooling time in S1 is 10 minutes.

5. The spraying process for a water-based paint coating line according to claim 1, characterized in that: In the step S1, an infrared dryer is used for drying, and the temperature of the infrared dryer is controlled at 90-95° C. for 30 minutes.

6. The spraying process for a water-based paint coating line according to claim 1, characterized in that: The water blowing inspection in S1 uses a compressed air spray gun, controls the pressure of the compressed air spray gun to be 0.3-0.5 MPa, controls the angle between the compressed air spray gun and the workpiece surface to be 45-60 degrees, and controls the water blowing time to be 4 minutes.

7. The spraying process for a water-based paint coating line according to claim 1, characterized in that: The flame treatment in S1 uses propane as the gas. After the flame treatment, the workpiece is cooled for 10 minutes by a centrifugal fan to control the temperature of the workpiece at 21-25° C. and the humidity of the workpiece at 60-65%.

8. The spraying process for a water-based paint coating line according to claim 1, characterized in that: In S2, when spraying primer, the water-based paint temperature is controlled at 21-25° C. and the workpiece humidity is controlled at 60-65%. When spraying topcoat, the water-based paint temperature is controlled at 21-25° C. and the workpiece humidity is controlled at 60-70%. When spraying varnish, the water-based paint temperature is controlled at 21-23° C. and the workpiece humidity is controlled at 60-65%.

9. The spraying process for a water-based paint coating line according to claim 8, characterized in that: When controlling the temperature of water-based paint, the temperature is controlled by a temperature control device, the temperature control device comprising a shell (1), a leg (2) fixedly connected to the lower surface of the shell (1), a feed port (3) fixedly connected to the upper interior of the leg (2), a discharge port (4) fixedly connected to the lower interior of the shell (1), a one-way valve provided inside the discharge port (4), the one-way valve used to discharge paint inside the shell (1), a water tank (5) fixedly connected to the upper surface of one side of the shell (1), the position of the water tank (5) being designed relative to the feed port (3), a water inlet (9) fixedly connected to the upper interior of the water tank (5), an internal temperature control component provided inside the water tank (5), the internal temperature control component used to adjust the shell ( 1), the internal temperature control component is arranged inside the housing (1); the internal temperature control component comprises a water pump (6), the outer wall of the water pump (6) is fixedly connected to the inside of the water tank (5), the output end of the water pump (6) is provided with a return pipe (7), the end of the return pipe (7) close to the water pump (6) is arranged inside one side of the water tank (5), the outer wall of the return pipe (7) is arranged inside the housing (1), the end of the return pipe (7) away from the water pump (6) is arranged inside the other side of the water tank (5), the input end of the water pump (6) is provided with a water pipe (8), the water pipe (8) is arranged inside the water tank (5), and the water pipe (8) is used to absorb water inside the water tank (5) and transport it to the return pipe (7); A motor (10) is fixedly connected to the upper surface of the middle portion of the housing (1); the output end of the motor (10) is connected to a support shaft (11); the outer wall of the support shaft (11) is rotatably connected to the inside of the housing (1); a stirring assembly is provided at the bottom end of the support shaft (11); the stirring assembly is used to evenly mix the paint inside the housing (1); The stirring assembly comprises a connecting plate (12), the top end of the connecting plate (12) being fixedly connected to the bottom end of the support shaft (11), the outer wall of the connecting plate (12) being fixedly connected to a stirring rod (13), the stirring rod (13) rotating in the middle of the outer shell (1), and an anti-solidification assembly being provided at the bottom end of the connecting plate (12), the anti-solidification assembly being used to prevent the paint at the bottom of the outer shell (1) from solidifying; The anti-fixing component comprises a bevel gear 1 (15), the top end of the bevel gear 1 (15) is fixedly connected to the bottom end of the connecting disk 1 (12), the tooth end of the bevel gear 1 (15) is meshingly connected to the bevel gear 2 (17), the interior of the connecting disk 1 (12) is fixedly connected to a cross shaft (16), the upper outer wall of the cross shaft (16) is rotatably connected to the interior of the bevel gear 1 (15), the interior of the bevel gear 2 (17) is rotatably connected to the left and right outer walls of the cross shaft (16), the bottom end of the cross shaft (16) is rotatably connected to the connecting disk 2 (18), the top end of the connecting disk 2 (18) is fixedly connected to a bevel gear 3 (19), the tooth end of the bevel gear 3 (19) is meshingly connected to the tooth end of the bevel gear 2 (17), the outer wall of the connecting disk 2 (18) is fixedly connected to a stirring rod 2 (20), and the stirring rod 2 (20) is rotatably connected to the lower interior of the housing (1).

10. The paint temperature control device of the pipe-in-pipe temperature control type for the automobile paint conveying and mixing system according to claim 9, characterized in that: A one-way valve is arranged inside the water inlet (9), and the one-way valve prevents dust from entering the interior of the water tank (5), and the one-way valve prevents water from spilling out of the water tank (5) when the outer shell (1) shakes; a one-way valve is also arranged inside the feed port (3), and the one-way valve prevents dust from entering the interior of the outer shell (1), and the one-way valve prevents paint from spilling out of the outer shell (1) when the outer shell (1) shakes; the outer wall of the connecting plate 1 (12) is fixedly connected to the protective shell (14), and the outer wall of the connecting plate 2 (18) is rotatably connected to the lower side of the protective shell (14).

Images