In addition to painting houses, paints are used to give color to automobiles, underground storage vessels, road markings, ships and many more items.
The element in paints that is responsible for lending color to several applications is pigments. Pigments hold a place of great importance in the paint industry with huge quantities of the several varieties being used for different purposes. Pigments in paints act as colorants in commercial, industrial and decorative applications. The different type of pigments for paints can be listed as below:
Earth Colour Pigments: These are obtained from natural sources and are classified as inorganic pigments. They are weather resistant, light fast and chemical fast. Some examples under this category are Umber, Ocher, Swedish red, Bolus etc.
Mineral Pigments: These are classified as synthetic inorganic pigments. A few of the pigments included in this category are Chrome oxide green, Titanium dioxide, Ultramarine variety of pigment blue, Iron oxide yellow, Nickel titanium yellow etc.
Plant Colour Pigments: These are obtained from natural organic pigments available in plants. Some examples that come in this category are Saffron, Indigo, Alizarin red, Reseda, Woad etc.
Synthetic Pigments: Some synthetic pigments also find their way into the paint industry. Phthalocyanine, Azo, Dioxazine are just to name a few of them.
The pigment in paints not only acts as a colorant but also offers the underneath surface protection from weathering and corrosion. It is in fact responsible for holding the paint together. Special pigments are used in specific applications such as providing metallic finishes to automobile bodies or offering long lasting feature for road markings. In addition to pigments, paints contain binders and solvent.
The binder helps in holding the coating of paint to the substrate. Solvents also called as thinners act as a medium in which the binder, additives and pigments are dispersed as true solutions or as colloidal dispersion. The pigment, binder and the solvent have to be mixed in the right proportions so that the final finished output is a smooth, continuous and attractive coat of paint. The paint technologist and the paint technician work in conjunction to achieve the desired final product.
With industrial applications of paints ranging from aerospace, coil, automotive to architectural and decorative, paint formulations have to fulfill varied technical criteria besides offering durability, opacity and ease of application. It is the job of the paint technologist to formulate the paint as per pre-determined standards and the paint technician who is responsible for its manufacture to ensure the achievement of the features set down by the paint technologist. The equipment that is commonly used in the manufacture of paint includes ball or pebble mills, vertical and horizontal bead mills and top speed intensive stirrers. The paint manufacturer can make use of several other machinery that is available for the purpose. The efforts of all are however, directed towards obtaining top quality paints!