Film formation from latex dispersions

A trend to replace conventional solvent-based coatings with waterborne ones is apparent. In general, those waterborne coatings consist of pigment (e.g., TiO2), polymer particles (binder), water (solvent), and additives (thickeners, dispersants, anti-foam agents, etc.). The film formation proceeds while the water evaporates. When the temperature is sufficiently high, the film formation will be successful. A considerable number of authors have described this process theoretically. These studies have been reviewed by Visschers et al.(1) In this paper we discuss which of the operative forces in film formation are the dominant ones. The prevailing forces are evaluated in more detail. We briefly indicate the evolution of theories over the years. Also, the influence of material parameters (particle size, wetting properties, etc.) and drying conditions (temperature, humidity, etc.) are discussed. Then, an experimental him-drying cell as well as the results obtained are presented. Other potential applications to investigate the performance of waterborne paints are discussed.