Development of polyester powder coating systems for outdoor architectural application in Europe

Over the last few years, the share of powder coatings used for the protection of aluminium extrusions and claddings for architectural uses in competition with conventional liquid paints and as an alternative to anodising has sharply increased. In 1987, about 47 million m2 or 135 thousand tons of aluminium used in outdoor architecture have been powder coated in France, Germany, Italy and United Kingdom. This paper gives a thorough description of the latest developments of the polyester powder coating systems used for aluminium extrusions and claddings in Europe, underlining the criteria of the choice of the weathering resistant powders, the importance of metal pretreatment and of the coating process itself as well as of the quality control in this industry. A comparison with competitive coating technologies is also given.