Paint is needed to form a coating film. Though the details of paints will be introduced later, paints in general are in flowable liquids, and surfaces to be painted (hereafter called painted surface) are coated using this fluid nature. There are many coating procedures,
In order to form coating films that have performance to fulfill the expectations, as the same as other surface treatments, foreign substances such as oil, dusts, and rust must not exist in between the paint film and the panted surface, thus preconditioning processes are required. Additionally, if order for the paint film to firmly bond to the base material surface, the paint element polymers must be oriented depending on the nature of the base material surface. To achieve this, it is advantageous for the paint to be in liquid forms where molecular motion is free. Therefore, most paints in use today are in liquids.

Painting process outline is as follows.

(1) Pretreatment Process

Surface to be painted is cleaned by removing foreign substances such as oil, dusts, and rust. Degreasing and Acid Washing correspond to this process. In addition as requested, mechanical polishing such as buff polishing and sand blasting, and chemical conversion treatments to improve the film adhesion and corrosion resistance such as phosphating and etc. are applied.

(2) Preparation of paints

Fluidity of the paints are adjusted to suit the painting method. Also, color adjustments are applied to obtain intended finished colors. For multi-liquid type paints, main component, hardener, and accelerator are prepared according to the best ratio for the purpose.

(3) Applying paint on painted surface

Brush, spraying, airless spraying, hot spraying, electrostatic painting, electrodeposition painting procedures are used.

(4) Drying of paint coating film

　Paint is cured into coating film. The change of fluid paint film into viscoelastic solids is called Drying. It is a transformation of Sol to Gel. The mechanisms of paint drying differ depending on the types and compositions of the paint. There are cooling solidification, evaporative drying, oxidation drying, polymerization drying, and combinations of these.

(5) Post-processing

If required, as the dried paint coating film post-processing, Surfacer (undercoating) surface is polished.

(6) Recoating

Depending on the purpose, recoatings are applied several times on this. Primer, intermediate, and overcoat.