A Review of Dry Powder Coating: Techniques, Theory, and Applications

Dry powder coating, characterised by the blending of poorly flowing powders with finer coating powders to optimise flowability, represents a sophisticated and evolving approach to powder processing. The optimisation of this method involves precise formulation, carefully combining powders with different particle properties to achieve a desirable blend aimed at enhancing the flow characteristics during the application process. Over the last decade, this field has witnessed increasing activity, focusing on key mixing parameters, such as mixer type and mixing power, as well as understanding the influence of constituent powder characteristics, including size ratio, density, and cohesion. Various techniques have been used to assess the flowability improvement or quantify the degree of coating. This review aims to provide a comprehensive exploration of the literature on powder coating research, highlighting its significance in both academic research and industrial applications. This paper discusses current coating analysis techniques using state-of-the-art equipment and reviews recent findings, particularly the nascent attempts to establish regime maps for dry powder coating.