Early spraying equipment had reciprocating machines and automatic spray guns for simple spraying. With the rapid development of technology and product diversification, simple reciprocating machines can no longer meet the requirements of different shapes and complex spraying processes. Industrial flexible robot spraying technology has irreversibly become an indispensable link in the coating production line.

(1) Painting robot painting efficiency, painting efficiency and painting efficiency.

Painting efficiency is the efficiency of spraying operations, including the spraying area per unit time, the effective utilization of paint and spraying area. The coating efficiency is the ratio of the amount of paint applied to the coating object and the total amount of sprayed paint during the spraying process, or the ratio of the measured thick film on the surface of the coated object to the thickness of the coating film calculated from the amount of sprayed paint. , Which is the paint transfer efficiency (TE) or paint utilization.

The coating efficiency refers to the ratio of the actual surface area of the object to be sprayed to the area covered by the spray gun. In order to complete the coating film at the edge of the object, the coverage area of the general spray gun should be larger than the area of the object to be coated.

(2) Spray track of spraying robot.

The spraying trajectory of the spraying robot refers to the sequence and stroke of the spray gun during the spraying process. The spraying trajectory of the skilled painter can be simulated by the spraying robot.

(3) Coating flow rate of spraying robot.

The spraying robot coating flow rate is the amount of coating material that is delivered to each rotating cup per unit time, also known as the spraying flow rate and the rate of paint output.

In addition to the rotating cup speed, paint flow rate is the second factor affecting the fineness of atomized particles. When other parameters are unchanged, the lower the paint flow rate, the finer the atomized particles, but it will also cause the solvent volatilization in the paint mist to increase.

The coating robot spray coating has a high flow rate, which will form a corrugated coating film. When the paint flow is overloaded by the Ambassador Rotary Cup, the coating on the edge of the Rotary Cup will thicken to a certain extent, resulting in the groove pattern on the Rotary Cup that cannot divert the paint. And the layer of patent leather appears, which will produce air bubbles or the uneven phenomenon of paint droplets.

The maximum paint flow rate of each spray gun of the spraying robot is related to the diameter of the high-speed spin cup and the density of the rotating speed paint. The upper limit is determined by the fineness of the atomization and the effect of electrostatic coating. Practical experience shows that the coating should be input at a constant speed, and fluctuations in a small range will not affect the quality of the coating film. The metal processing WeChat content is good and worthy of attention.

In the actual spraying process of the spraying robot, the area sprayed by each rotating cup is different, and the flow rate of the coating material is also different. In addition, the coating flow rate of the rotating cup must be changed due to the change of the shape of the coating object. Take spraying the car body as an example. When spraying large areas such as door panels, the amount of sprayed material should be large. When spraying door posts and window pillars, the amount of sprayed material should be small, and the sprayed material will be automatically and accurately controlled during the spraying process. Quantity can ensure uniform coating quality and coating film thickness, which is also one of the important measures to improve the utilization rate of coatings.

(4) Rotating speed of the rotating cup of the spraying robot.

The speed of the spraying robot's rotating cup is the factor that has the greatest influence on the atomization fineness of the high-speed rotating cup. When the other process parameters are unchanged, the larger the rotation speed of the spin cup, the smaller the diameter of the coating droplet. In the slightly lower speed range, the influence of the rotational speed on the atomization fineness is significantly increased than in the high speed range.

The rotation speed of the spraying robot's rotating cup will have an effect on the film thickness. When the rotation speed is too low, the coating film will be rough; if the spraying robot is too fine, the paint mist will be lost (causing overspray), which will cause the thickness of the coating film to fluctuate; when the atomization is ultra fine, the airflow in the painting room will be very sensitive. In addition to the excessive rotation speed of the spin cup, it will cause excessive wear of the turbine bearings, which will increase the consumption of compressed air for clear use and reduce the amount of solvent contained in the coating film. The optimal rotation speed of the spraying robot of the spraying robot can be determined according to the flow rate characteristics of the coating used. Therefore, the rotation speed of the rotating cup for water-based coatings with high surface tension and high-viscosity two-component coatings is higher than that of ordinary solvent-based coatings.

Generally, the speed of the no-load rotating cup is 6X10 ＾ 4r / min, and the speed range set under load is (1.0 ～ 4.2) X10 ＾ 4r / min error ± 500r / min.

Electrostatic spraying technology has become the mainstream spraying technology in the automotive industry today, and the application of electrostatic automatic spraying equipment has made the automotive middle and top coatings enter the automation era. The following briefly describes the main spraying parameters of the spraying robot.

1.Spraying flow

The electrostatic spraying robot's flow rate is the amount of coating material that is fed to the rotating cup per unit time, which is also called the discharge amount. The amount of flow affects the thickness of the paint film. Different colors of paint have different hiding powers and different thicknesses. During the spraying process, each robot has a different spraying area and different flow settings. At the same time, the flow is also related to the shape of the object being sprayed. For cars, the regular five-door one-cover profile generally has a larger flow, while the pillar, ridge, and corner flow are small.

2.Forming air

The gas is sprayed from the uniformly distributed small holes on the back side of the spin cup, which is used to limit the amplitude (fan width) of the paint mist, and push the atomized paint mist toward the coating object, and place the paint mist to diffuse and rebound to pollute the spin cup and Atomizer. For metallic paint, the spray width affects the final color effect, and the spray width is not suitable and it is easy to appear zebra pattern or flowering. The setting of the spray width is related to the distance between the two guns, and the paint is superimposed three times. If the distance between the two guns is 100mm, the spray width should be controlled to 300mm, so that the same point of paint can be superimposed 3 times.

3, rotating cup speed

The rotation speed of the spin cup is the key parameter of paint atomization. The centrifugal force generated when the spin cup rotates at high speed makes the paint atomize very fine (50-100μm). The smaller the paint droplet diameter, the better the smoothness of the paint film, the smaller the orange peel effect and the higher the gloss. The setting of the rotation speed is also related to the type of paint. The rotation speed of the colored paint is relatively small, and the rotation speed of the middle paint and varnish is relatively high. Rotational speed and flow rate are also related. If the flow rate is large, the rotation speed must be increased to achieve a better atomization effect. However, if the rotation speed is too high, the paint sprayed onto the coated object will be dry, which will cause orange peel problems.

4.High voltage

In electrostatic spraying, the object to be coated is the positive electrode, and the rotating cup is the negative electrode. After applying a high voltage between the two electrodes, a strong electrical attraction force is generated, so that the atomized paint mist particles are transmitted to the surface of the object to be coated. The high voltage affects the electrostatic effect of electrostatic spraying, paint rate, and uniformity of the paint film.

Flow, speed, molding air, and high pressure directly affect film formation quality, but also affect paint utilization. In the production, it is necessary to adjust the characteristics of the paint and the parameters of the atomizer, and the parameters of the quadruple must be comprehensively considered and continuously optimized to achieve the ideal spraying effect.