Insulation powder film forming defects and solutions

Sources :wenhui  Date:2020-07-24 10:55

Insulation powder film forming defects and solutions


The problems that occur during the use of insulating powder are summarized below for reference.

servo cnc busbar machine

   4. Dimples in the coating film: improper handling, impure oil removal; source contamination, compressed air deoiling, incomplete water removal; uneven workpiece surface; contamination by dust or other impurities.

   5. Bubbles appear on the coating film: after the surface treatment of the workpiece, the moisture is not completely dried, leaving the pretreatment residual liquid; degreasing, rust removal is not complete; the underlying volatiles are not removed; the surface of the workpiece has pores; the powder coating is too thick.

   6. Uneven coating film: uneven powder spraying; the distance between the spray gun and the workpiece is too close; the high-voltage output is unstable.

   7. The coating film has poor impact strength and adhesion: the phosphating film is too thick; the curing temperature is too low, the time is too short, so that the curing is not complete; the bottom metal is not cleaned; the coating will reduce the adhesion after being immersed in water.

8. Pinholes in the coating film: the air contains foreign objects and residual oil; the voltage of the spray gun is too high, causing the coating to break down; the distance between the spray gun and the workpiece is too close, causing the coating to break down; the coating is too thin; the coating film is not sufficiently cured .

   9. A small amount of sand particles appear on the surface of the coating film: the spray is clogged or the air flow is not good; the atomization of the spray gun is not good; there is powder dripping in the powder spraying room; other debris contaminates the surface of the workpiece.

<img alt="servo cnc busbar cut" border=0" title="servo cnc busbar cut" data-original-height="1080" data-original-width="1440" src="" width="781" />

&emsp;&emsp; 10. The coating is off: the surface of the workpiece is not well treated, and the degreasing and rust removal are not complete; the output voltage of the high-voltage electrostatic generator is insufficient; the workpiece is poorly grounded; the air pressure is too high when powdering;

11. Uneven powder supply: the powder supply tube or powder spraying tube is blocked, and the powder adheres and hardens at the nozzle; the air pressure is insufficient and the pressure is unstable; the air compressor is mixed with oil or water; the fluidization of the powder supply is unstable, There is too little powder in the powder feeder; the powder supply tube is too long, and the resistance increases when the powder flows.

&emsp;&emsp;12. Powder flying and poor adsorption: the electrostatic generator does not have insufficient high voltage; the workpiece is not well grounded; the air pressure is too large;

&emsp;&emsp;13. The amount of powder spraying is low: insufficient air pressure, insufficient air volume; too high air pressure, the proportion of air in the mixture of powder and flow is too high; water vapor and oil pollution are mixed in the air space; the spray gun head is partially blocked.

&emsp;&emsp;14. The powder spray tube is blocked: Due to the material of the powder spray tube, the powder is easy to adhere to the wall of the tube; the output tube is heated, causing the powder Lin in the tube to agglomerate; the powder conveying tube is bent and distorted; the powder is mixed with more granular impurities.