Introduction

There are three distinctive characteristics of the "colour period", which are pre-1960 (the black and white years), 1960 to 1990 (colour, colour and more colour!) and post-1990 (an age of sophistication). Powder coating first appeared in the 1960s, with a wide choice of colours offered to the market (by using the RAL colour reference system).

Developed in the early 60s, thermosetting powders are more suitable than water-based paints. Thus, thermosetting powders are being used as an interesting alternative to solvent-based stoving enamels and to thermoplastic coatings. Wet paints, or liquid lacquers, implicate the presence of a solvent or solvent mixture. Generally, such systems are highly flammable and the user of liquid paints is always confronted with very important safety problems: explosion, fire, toxicity, and water/air pollution. Powder coating, a solvent-free, environmentally-friendly coating process, will gain further significance due to the increased severity of environmental regulation as well as the conversion of EU guidelines for the use of solvents into national laws.

There are a few other aspects which have contributed to the tremendous development of powder coatings. The film strength, the ability for the powder to be reclaimed as well as the ease of automatization of the coating lines are among the most important factors influencing the choice of powder instead of liquid enamels.