What Does Film Formation Mean?
Film formation refers to a process of forming a thin film on surfaces when film-forming materials, such as surface coatings, are applied on that surface. In the film formation process, a low-viscosity liquid surface coating is applied to a solid substrate. After curing this surface, it produces a solid, high molecular weight, polymer-based adherent film. This film protects a substrate from the attack of corrosive substances as well as corrosion.
Corrosionpedia Explains Film Formation
Coatings are mostly liquid and possess a suitable viscosity to apply on a substrate. The liquid coating is transformed into a dry or solid film after application on materials. Powder coatings are also liquefied after application and transformed into a solid film. Both physical and chemical changes occur in the process, which is known as "film formation." The film formation process is critical to the final appearance and functionality of the coating.
Surface coatings are applied by spraying, brushing or through various industrial processes. This application gives a solid film after the evaporation of solvents from coatings. Surface coatings like paints, drying oils and varnishes, synthetic clear coatings, and other products are used to protect the surface of a material from the environment.
Films can be formed in a few different ways. The simplest way is to dissolve a polymer in solvents with necessary concentrations required for an application. After the application of a coating, solvents are allowed to evaporate and leave a dry film. Since the viscosity of coatings increases with the evaporation of solvents, the film will be dry to the touch soon after application.
In the case of lower-MW thermosetting resins coatings, less solvent is needed and many combinations of chemical reactions occur, which ultimately initiate polymerization and cross-linking to impart good film properties during the evaporation of solvents.