How to choose the electrophoretic coating equipment

Electrophoretic coating is the workpiece and the corresponding electrode into the water soluble paint, after the power is switched on, rely on the physical and chemical effects of electric field produced by the resin, paint, pigment and filleron the object to be coated as a method of coating on the surface of the electrode uniform deposition forming water-insoluble film. Electrophoretic coating is an extremely complex process of electrochemical reaction, whichincludes at least the electrophoresis, electroosmosis, electrolysis,electrodeposition of four processes. Electrophoretic coating by deposition performance can be divided into the anode electrophoresis (workpiece isanode, coating is anionic) and cathode electrophoresis (workpiece cathode,paint is a cationic); press the power can be divided into DC and ACelectrophoresis electrophoresis; according to the process of method andconstant voltage and constant current method. At present widely in industry is used in anodic electrophoretic DC power supply constant voltage method.

1- after the workpiece surface processing; 2- power; 3- workpiece; 4- water for washing bath; 5- filter; 6- sedimentation tank; 7- circulation pump

Comparison of electrophoretic coating and other coating method, with the following characteristics:

(1) the water soluble paint, with water as the dissolution medium, saves a large amount of organic solvent, greatly reducing air pollution and harmful to environment, health and safety, and avoids the hidden trouble of fire;

(2) coating with high efficiency, small loss of paint, paint utilization rate of up to90% ~ 95%;

(3) film thickness, strong adhesion, good coating quality, various parts such as inner layer, depression, workpiece welding joint can obtain uniform, smoothfilm, solves the problem of complex shape workpiece coating other coating method;

(4) the construction of high production efficiency, can realize the automation ofcontinuous production, improve labour efficiency;

(5) complex equipment, high investment cost, large power consumption, hightemperature drying and curing requirements, coating, coating managementcomplex, construction condition strictly, and the need for wastewater treatment;

(6) only use water soluble paint, does not change color in the coating process,coating is not easy to control long storage stability.

Electrophoresis painting equipment:

Electrophoretic coating equipment is composed of electrophoresis tank, a stirring device, a filtering device, coating, coating temperature adjusting devicemanagement device, DC power supply device, electrophoresis coating after washing device, ultrafiltration equipment, baking device, a spare tank etc..

The size and shape of the electrophoresis tank should be determinedaccording to the workpiece size, shape and construction technology. In a certain distance between the poles of the guarantee conditions, should as far as possible to design smaller. Slot is provided with a filtering device and a temperature adjusting device, so as to ensure the temperature of liquid paintcertain and remove impurities and air bubbles in the liquid circulating paint.The stirring device can make the liquid paint work kept uniform, multi usecirculating pump, liquid paint cycle per hour on average 4 to 6 times, when the circulation pump is started, the liquid paint liquid tank should be uniformturning. Coating management device is added to adjust the coatingcomposition, control of bath pH, removal of neutralizing agent and using ultrafiltration device eliminate low molecular weight with ingredients such asmembrane electrode. Electrophoresis power choice, usually adopts DC power supply. Rectifier equipment can use silicon or silicon controlled rectifier. The current size and coating properties, temperature, work area, electricity is related to the mode, generally 30 ~ 50A/m2. Washing device used for washingthe workpiece electrophoretic coating before and after, generally with thedeionized water, but need to pressure equipment, commonly used is a washingnozzle with a spiral body. Baking device used to facilitate drying film-formingelectrophoretic coating, using resistance furnace, induction heating furnaceand the infrared curing equipment. Drying room designed to heat three section of preheating, heating and, should be based on the formulation of coatingsand the workpiece situation.