8, film pin-hole: air containing foreign bodies, residual oil; spray voltage is too high, the resulting coating breakdown; spray gun and the workpiece are too close, causing the coating breakdown; coating too thin; not fully cured coating film.
In 9, the film surface of small grains of sand: the spray plug or airflow is not bad; the spray atomization spray chamber; powder dropping; other debris pollution workpiece surface.
10, coating : surface treatment is not good, degreasing derusting not complete; a high voltage electrostatic generator output voltage is insufficient; the workpiece grounding; powder when the air pressure is too high;
In 11, the powder supply quantity is not uniform: powder feeding tube or dusting pipe plug, powder in the nozzle adhesion hardening; insufficient air pressure, pressure is not stable; air mixed with oil or water; powder supply device of unstable fluidization powder, powder supply device for powder tube is too long, too little; powder flow resistance increase.
12, powder dust, adsorption difference: electrostatic generator without high pressure is insufficient; the workpiece grounding; pressure is too large; recovery device in air duct obstruction. |
