Filmvormers

Filmvormers are substances that form a continuous, coherent film on a surface after application and drying. They function as binders in coatings, inks, adhesives, and many cosmetic products, supplying adhesion to the substrate and cohesion within the film, along with mechanical and barrier properties such as hardness, flexibility, gloss, and water resistance.

Film formation typically occurs when a solvent or water evaporates and the film-forming phase transitions from dispersed particles or dissolved polymers into a unified layer. In latex paints, polymer particles coalesce as drying proceeds; in solvent-borne systems, a polymer dissolved in solvent forms a film upon evaporation. Some filmvormers also rely on chemical cross-linking after application to increase stiffness or chemical resistance.

Common types include natural film-formers such as shellac or certain gums, and synthetic binders such as polyvinyl acetate, acrylics, vinyl polymers, cellulose derivatives (like ethyl cellulose and hydroxyethyl cellulose), nitrocellulose, and polyurethane dispersions. In cosmetics, film-formers such as certain vinylpyrrolidone polymers and acrylates create a flexible, adherent film on skin or hair.

Applications span paints and varnishes (wood finishes, automotive coatings), inks and packaging coatings, adhesives, textiles, and cosmetic products (mascaras, nail polishes, hair sprays). Key properties of a filmformer include its drying behavior, glass transition temperature, tensile properties, adhesion to substrates, flexibility, and resistance to water or chemicals. Formulation considerations involve compatibility with pigments and solvents, plasticizers, and potential for cracking or blush under temperature changes.

See also: binders, coatings, polymers, film formation.