Emulsions are a mixture of two substances that do not mix. One of the substances is dispersed in the other. Emulsions have a clouded look due to the various substance boundaries that scatter light rays passing through them. Emulsions are not formed naturally and are generally unstable. Paints are a kind of emulsion. The paint pigments are suspended in a solvent that is also used to control the viscosity of the emulsion paint.
Properties of Emulsion Paints
Emulsion paints have fillers to thicken the film, support the paint structure and increase the volume of the emulsion paint. Emulsion paints also contain catalysts, stabilizers, emulsifiers, adhesion enhancers, texturizers and flatteners . Once the paint is applied, the emulsion paint becomes tack free on solidifying. The hardening of the paint may result because of curing, evaporation or even phase change, depending on the type of binder. Emulsion paints also contain a lot of additives to impart various properties like antifreeze, foam control, skinning control, bacterial-growth control and pigment stability .
Application of Emulsion Paints
Emulsion paints can be applied as a gas (aerosol) or as liquids . Direct applications of emulsion paints are possible by means of brushes, paint rollers, blades and other instruments. Once emulsion paint is applied, it can be blended with other painted regions within a certain interval of time. This time interval period is known as “open time”. The open time of emulsion paints can be pulled out by addition of white spirit or similar glycols.
Modern Emulsion Paints
Modern emulsion paints have water as base along with vinyl or acrylic resins added to make them hard wearing. Emulsion paints give various degrees of sheen. The paint becomes harder wearing as the shine increases. Emulsion paints are available in matt, egg shell, silk, satin and full gloss ranges. Special water based emulsion paints are available for wood works.