The main factors affecting the static spray texture of powder

The main factors affecting the powder electrostectrecturic spray quality are the quality of powder coating, the performance of complete sets of spray equipment and the parameters of the spraying process.
(1) involves the particle size distribution of powder coating quality
(1) powder
powder particle size is too small and easy to fly away, resulting in blockage of the spray gun, however, the load per unit mass is large, easy to deposit on the work piece. The powder particle size suitable for electrostectrulation spraying is 30-40 microns accounting for 60-70% as a good
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the volume resistance of the powder suitable for electrostitectrective spraying should be 14 om-cm of 10 of 10 square-10. Too low, the powder particles that sink on the work piece fall off easily. Too high, particle charge is not easy to release, later powder particles will be rejected, and affect the thickness of the resulting paint film.
(2) involves factors related to the performance of powder electrostectrectrorectroration spraying equipment
(1) electrostectrelectrative voltage
a $60 kV technical parameter for powder spraying. The electrostation voltage increases, the ring effect increases, and the deposition efficiency increases. It is generally advisable to use 80-100 kV.
deposition is closely related to the structure of the charged and diffusion mechanisms of the spray gun. The average electric field of the take-away electrical structure is strong and the deposition rate is relatively high. The diffusion mechanism improves the degree of atomization of powder particles that help to raise the airflow.
the amount of powder is small, the deposition rate can be significantly increased. The uniformity of the powder amount directly affects thecoating. The average degree of powderbasically depends on the average degree ofpowder. That is to say, the powder supply of thethe degree of powder is directly affecting electrostectrecturic spray quality children.
the structural form of the powder room
powder room should have a more reasonable structure, indoor can form the required air flow composition, should be micro-negative pressure, the opening wind speed of 0.3-0.6 meters / second as well. The direction of motion of the air flow, which should be blown from the rear of the spray gun to the area around the coated work piece, can improve the powder deposition rate.
powder chamber should be designed as a separate insulation break. The conveyor chain and other pipelines should be dissoated from the chamber break. Avoid internal static induction to reduce the deposition of powder on the walls of the chamber.
(3) involves factors related to the parameters of the spraying process
1. Spraying distance
an important technical parameter to control the thickness of powder coating. The distance increases and the thickness of the coating decreases. The spray distance is generally 100-250 mm, considering the coating required for formation. If the process lag can be shortened. However, from the spray safety considerations, it is advisable not less than 200 mm. The spray distance is allowed to be reduced to 20 mm with a constant field strong line.
2. Spraying time
spraying time is long, the amount of powder is increased, the deposition rate is reduced, and the thickness of the coating cannot be increased. Therefore, the minimum and possible spray time should be determined by testing.
(3) coverage area is
size of the workware, and the coverage area increases accordingly. However, by the powder electrostectric spray gun spray diameter limit, often in the prescribed spray time can not be covered, but need to increase the number of spray guns, correspondingly to increase the size of the powder chamber. If the application of portable powder electrostectrectriter gun, moving back and forth over a larger coverage area, will make the thickness of the coating is not equal, powder indoor air flow composition is not easy to control. Therefore, the coverage area of the work part is too large, the quality of powder electrostectrectrity spraying is not easy to ensure.
By the above factors can be known, in order to make the powder electrostectrecture paint quality is stable, it is necessary to seek the best process parameters through process testing, determine the performance and conditions of use of complete sets of equipment, and know the characteristics of each batch of powder coatings. In this way, the use of powder electrostectrectrecture spraying is stable, forming a production capacity.
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