“There are no lines in nature, only areas of color, one against the other.” – Edouard Manet, French Artist
Human beings are in awe of colors. When a baby is born, it is able to see only black and white. But as it grows, colors become the first thing they see and use it to distinguish different things. Even before they learn to write, they love to doodle with different colors and play with paint. The fascination with colors grows as they grow old. Colors are used to decorate and brighten up almost anything. So without paints, the world would be bland. The early human races used plants and flowers to derive color and use them. But now thanks to the chemical industries and paint factories, there are many ways to create and manufacture paint. And these paints come in all shades, hues, sheen and so many attributes.
Paint Away the Blues
The best way to give one’s home a quick makeover is to paint it. Even a single wall, painted in a new shade and done aesthetically can do wonders to the home décor. But what makes these paints the way they are and how are they manufactured? To understand, let’s break the paint into its components first.
Pigments are the key ingredient or the prime pigments which impart the actual color to the paint. Most of the popular organic pigments are azo-, phthalocyanine and anthraquinone derivatives used in manufacturing. The most common inorganic pigment is the white titanium dioxide which has a high refractive index and gives the paint a glossy finish. Calcium carbonate is another white pigment but has a low refractive index and produces a matte finish. Other pigments for different colors are chrome green oxide, iron oxide (yellow and red), zinc oxide and carbon black.
Resins or Binders hold the paint together. They are polymers derived either naturally from plants like in alkyd resins or manufactured synthetically in chemical industries. Binders provide the required adhesion to the surface or substrate on which paint is being applied. They also provide durability and resistant properties like UV resistance, moisture resistance, stain resistance etc. depending on the material being used.
Solvents or thinners as they are popularly known as are either water or an organic solvent like oil which makes the paint thin, reducing its viscosity and make it easily applicable. Turpentine oil was the most widely used solvent, but now water based ones are becoming more popular due to pollution and allergies that the other solvents create.
Additives constitute a very small part of the paint but have the capability to modify its property. They are added to exhibit properties like modifying surface tension, improved flow, improved finish, controlled foaming etc.
Making True Colors
Paint manufacturing process can be broadly categorized into five stages.
Weighing out the ingredients accurately is very important as a slight change in the number of ingredients can change the eventual color.
Mill base preparation is the next step in which the pigment is prepared. The pigment is milled or broken down further, then wetted in resin and mixed with a solvent. This creates the mill-base which is then dispersed. High-speed mixers combine and disperse the mixture.
Let down is the stage when the additive, solvents, binder, and resin are added to the mill-base produced earlier. All the ingredients are now together and mixed thoroughly in large containers or mixers.
Testing is the next stage where the paint is then tested and checked against the quality parameters. It is quality evaluated for its flow, consistency, color, drying time, the degree of dispersion, gloss and dry film appearance.
Canning is the final stage when the paint is loaded in containers and made ready to dispatch.
When the paint is applied to a surface, the solvent slowly evaporates bringing the resin and pigment particles closer together when they final stick to each other and form the paint film as we know it. There are a number of ways in which paint can be applied using brushes, rollers, spray-painting, airless-spraying etc.
With time and evolving science, there are so many kinds of paint with different properties. Some are stain-resistant, some keep the walls cool, and some are even capable of changing color! Most of the paints manufactured today are safe, lead-free, having no volatile organic compounds harmful for the environment and can be applied in a number of ways. Painting, as it seems, has surely become a child’s play!