Before manufacture something we must know about the element used in it. Some of the elements used in paints are:
- Binder or Vehicle
Pigments are excellently grounded powders that are dispersed in paints, providing color and hiding. There are two primary types of pigments prime and extenders. Prime pigment provides whiteness and color and is the main source of hiding capability. Titanium dioxide (TiO2) is a predominant white pigment, provide exceptional whiteness by scattering light; delivers whiteness and hiding in flat and glossy paints. Extenders are used to ensure proper spacing of particles to avoid crowding and loss of hiding and provide greater chalking tendency to paints. In contrast color pigments, (either organic or inorganic) provide color by selective absorption of light. Color pigments are compounded into liquid dispersions called colorants. In factories color pigments are use as dry powder and in liquid colorant form to make pre-packed color paint. Usually used extenders are clay, silica, silicate, calcium carbonate, talc and zinc oxide.
It provides adhesion, integrity and toughness to the dry paints by binding the pigment together. The binder effect properties like flow leveling and gloss development. Oil based binder are generally refer to both oil and alkyd coatings and some coatings mainly exterior primers are completed with the combination of both oil and alkyd to achieve appropriate flexibility. The most commonly used binder are cold pressed linseed oil, however, it can be made with walnut oil, poppy seed oil, safflower oil or other less general oils.
The liquid portion of the paint (also referred to as Carrier) provide wanted consistency and it possible to apply the pigment and binder to the surface being painted. For most oil based and alkyd paints, the liquid component is paint thinner and water is primarily used in latex paint.
When we apply paint to any surface the liquid portion (generally thinner) is evaporate and what remain on the wall is pigment and binder. Together they are called the solid portion of the paint (pigment + binder = solid).While the coating is a combination of liquid and solid.
The manufacturing of paint include following steps
The paints are prepare by pigments and fillers, binders (oil or resins), solvent, plasticizers, driers other raw material. In Industries paints are manufacture by using water ring type vacuum pumps to suck the raw material into a chemical reactor which can decrease physical work.
Now raw material is put into a high speed dispersing kettle which combines all the raw materials and form mixture and you get a semi-finished paint.
Now semi-finished paint is put into the horizontal sand miller to grind the granule (residue from the semi-finished paint) into smaller particles, for the better stirring.
After grinding process add the semi-finished paint into the color mixing tank, add some pigment or extra additives into it to make other color for the paint. If the paint need to be diluted, it can be finished in this tank.
After all these process of mixing, grinding, coloring it is essential to filter it to remove all impurities from the paint to obtain high-quality paint.
After filtering process paint is ready to pack and proceed to the machines that automatically fill and pack it in barrels, boxes etc.
Today, with the exception of a few pigments that are too delicate to be made other than by hand, oil paints are generally made by machine. For packaged paints, the machine process is far more effective than the techniques used in making paints by hand, and the range of available colors is much greater.