Modern automotive paint must withstand rain, hail, ice and snow, heat and cold as well as years of cleaning with car-wash brushes. It is also exposed to gravel and crushed stones on unpaved roads, desert sand, salt on icy roads or the UV rays of the sun. The paint has to stand up reliably to all of these factors and stresses.
After the CDP primer coat (cathodic dip), 3 or 4-layer paint superstructures, consisting of filler, base coat and clear coat, are applied. These are very complex and must be very finely adapted to one another and coalesce a multitude of different properties. A layer of paint that is one-tenth of a millimeter thick has the same requirements for mechanical and chemical robustness as for excellent color stability or special gloss effects.
New tendencies toward aqueous systems, powder coating, radiation curing systems or "nano-paints" also provide for very active research and development.
Mixing and De-Aerating