Electrophoretic coating lines with small capacity

Electrophoretic Coating/Painting Plant and Equipment

What is the Electrophoretic Coating Process?
 The Electrophoretic coating process is a method of depositing water based paint or clear coatings on to metal or conductive parts. The biggest use for this process is as a first coat primer for automotive cars, truck bodies, parts and components. 99% of mass produced cars, trucks and component parts are Electrophoretic primer coated. The most common resin types used are epoxy, acrylic, hybrid and polyurethane technologies. Epoxy type chemistry give excellent corrosion resistance whereas acrylic and polyurethane offer high UV resistance. Polyurethane type offer very good UV properties combined with excellent chemical resistance. Another big market is for decorative or protective finishes on electroplated door hardware, light fitting, jewellery and electronic devices such as mobile phones.

Process Method
 
The Electrophoretic Process uses a stable emulsion of suspended organic resins in purified water (deionised). The Electrophoretic Process solution normally comprises of organic solvents, water, acid or alkali stabilisers, ionic components, wetting agents and if coloured pigments or dyes.
 
When a D.C. voltage is applied across two immersed electrodes, the passage of current is accompanied by electrolysis of water. This results in oxygen gas being liberated at the anode (positive electrode) and hydrogen gas liberated at the cathode (negative electrode). The liberation of these gases disturbs the hydrogen ion balance in the water nearby the electrodes. This results in a subsequent pH change and this in turn de-stabilises the resin emulsion components of the solution and they coagulate onto the appropriate electrode. It is often referred to as controlled precipitation of the paint or resin particles on to the electrode.
 
Electrolysis of water causes the cathode to become alkaline and the anodes to become acid. Cathodic Electrophoretic systems are stable except at high (alkaline) pH. Anodic are stable except at low (acid) pH.
It is very common to refer to Electropaint as "Electrophoretic"