The emulsion paint is a mixture of two liquids that do not blend well with each other i.e. the mixture of two different non-blending liquids.
In the emulsion paint, 50 to 60% volume of water is present and the remaining portion consists of the oily or solid portion in the pigment form. The oily particles have a higher density than water.
Mostly, two types of emulsion are formed by oil and water which are as follows:
a. Oil in Water Emulsion:
In this emulsion, the oil is dispersed in water i.e. water is the dispersion medium and oil is in the dispersed phase.
b. Water in Oil Emulsion:
In this emulsion, water is dispersed in oil i.e. oil is in the dispersion medium and the water is in the dispersed phase.
Composition of Emulsion Paint
This paint is composed of the following:
The base used can be titanium oxide, zinc oxide or iron oxide.
The selection of the base is mostly done based on the shade or colour of the paint. For example: in white-coloured emulsion paint, titanium white is used as the base.
Mostly Linseed oil, or alkyd resins, or acrylic resin, or epoxy resins are used as the vehicle.
c. Solvent/ Thinner:
Water or white spirit is commonly used as the solvent.
d. Inert Filler/ Extender:
Calcium carbonate powder or calcined kaolin clay is used as the extender.
e. Colouring Pigment:
The calcium carbonate powder is used as the colouring pigment in emulsion paint.
Calgon is used as an additive.
Uses of Emulsion Paint
The uses of emulsion paint can be listed as follows:
a. It is used both for the external walls and internal walls of the building as the surface coat. This is because it dries very quickly.
b. It is one of the most desired exterior paint.
c. It can be used both for new and old plastered surfaces.
d. It is suitable for painting even wooden and metallic surfaces.
Application of Emulsion Paint
The application of emulsion paint is comparatively easy. The emulsion paint can be applied easily using the rollers and brushes. The manufacturer’s instruction must be thoroughly read before the application of the paint. The emulsion paint is mostly not manufactured in a ready to use the form and thus a small amount of thinner must be added to it before the application. The thinner used is water.
Some of the benefits offered by the emulsion paint can be listed as follows:
a. It is less toxic in comparison to other types of paint. This paint causes lesser reaction or irritation on the skin.
b. It is easy to apply and also dries quickly.
c. This type of paint is non-inflammable and thus prevents the risk of fire hazard.
d. The surface painted with emulsion paint is hard and can be easily cleaned utilizing water or mild detergent.
e. It is suitable for metal surfaces, wooden surfaces, walls, glasses and concrete.
f. It is not affected even when exposed to water.
g. It offers good resistance to humidity and thus can be used even in the kitchen and bathrooms where sufficient steam can be generated.
h. It also offers good resistance to sunlight and does not crack or fade out upon the exposure to sunlight.
i. Since it can bond well with any type of surface, it can be applied directly i.e. without any pre-treatment.
Some of the disadvantages of emulsion paint can be listed as follows:
a. The drying rate of this paint in the high humid atmosphere is relatively low.
b. It is more expensive than oil-based paints.