This unit discusses the most commonly used binders followed by the pigments. Amounts ranging up to 40 000 dm 3 of paint may be made in a single batch.įigure 1 Contents of a white gloss (alkyd) paint and a white matt emulsion (acrylic) paint. Each batch of ingredients is thoroughly mixed in large, stirred containers with the required additives (Figure 1). Solvent is then added to give the required consistency. The pigment powder is broken down into individual particles which are coated by and dispersed in the binder (resin) - known as 'wetting out'.
Paints are formulated according to their proposed use - primer, undercoat, special finishes (matt, gloss, heat resistance, anti-corrosion, abrasion resistance). fungicides and algaecides - to protect exterior paint films against disfigurement from moulds, algae and lichen.bactericides - to preserve water based paints in the can.anti-settling agents - to prevent pigment settling.thixotropic agents - to give paints a jelly-like consistency that breaks down to a liquid when stirred or when a brush is dipped into it.silicones - to improve weather resistance.dispersants - to separate and stabilise pigment particles.The binder may be dissolved as a solution or carried as a dispersion of microscopically small particles in a liquid.ĭepending on the type of paint and intended use, additives may include: The binder (resin) and solvent together are sometimes known as the vehicle. additives - used to modify the properties of the liquid paint or dry film.Water-borne paints are replacing some paints that use volatile organic compounds such as the hydrocarbons which are harmful to the atmosphere. solvent (sometimes called a thinner) - either an organic solvent or water is used to reduce the viscosity of the paint for better application.extender - larger pigment particles added to improve adhesion, strengthen the film and save binder.binder (resin) - a polymer, often referred to as resin, forming a matrix to hold the pigment in place.pigment(s) - prime pigments to impart colour and opacity.Paints may be broadly classified into Decorative paints, applied on site to decorate and protect buildings and other objects, and Industrial coatings which are applied in factories to finish manufactured goods such as cars. Paint is used to decorate, protect and prolong the life of natural and synthetic materials, and acts as a barrier against environmental conditions.
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