What Is Paint?
Paint is a material used in the decoration process to improve the appearance and add functions such as waterproofing, insulation, and impact resistance.
Paint is sold as a product in several forms based on factors such as ease of manufacture, ease of application, and environmental friendliness. Paint is generally applied in liquid form, although some powder paints are available, because solid paints are difficult to handle when applied to the surface of a material.
Liquid paint with a certain viscosity can be applied with a brush or roller. If the area to be painted is large, for example, spraying is more efficient, and the viscosity must be low enough to allow the paint to pass smoothly through the nozzle.
Types of Paint
There are four main components of paint:
1. Resin
Resin is the main component of paint. Types of resins include acrylic, urethane, alkyd, vinyl chloride, polyester, epoxy, silicone, fluorine, etc.
2. Solvents
Solvents are liquid solvents that dissolve resins and other materials to be mixed. A solvent is called a water-based paint when it is partially or completely replaced by water instead of an organic solvent.
3. Additives
Additives are used to increase productivity, improve product quality, or provide additional functions. They include dispersants, leveling agents, anti-precipitants, preservatives, rust and mildew inhibitors, emulsifiers, matting agents, and antifoam agents.
4. Pigments
The main purpose of pigments is coloring. Specifically, materials such as titanium dioxide for white and carbon black for black are used.
Types by Shape
1. Water-Based Paint
Water-based paint is a typical form of paint. It has been gaining attention in recent years as a substitute for conventional organic solvent-based paint due to environmental and health concerns.
Because they do not contain organic solvents, they can significantly reduce the generation of volatile organic compounds (VOCs) and are safe to work with. However, because it is water-based, it is susceptible to rainfall and condensation, and requires pretreatment to remove oil from the surface to be painted.
2. Powder-Based Paint
Paint powder does not contain any organic solvents and, like water-based paints, is safe for the environment and the health of the user. Compared to liquid-based paint, powder-based paint has the advantage that the quality of the coating film is more stable because it is easier to automate the coating machine.
It is also less susceptible to weather conditions such as temperature and humidity, and can improve the resistance of objects (impact resistance, chemical resistance, corrosion resistance, etc.).
Types by Resin Content
1. Epoxy Resin Paint
Epoxy resin paints are available in two types: room temperature curing type used for large steel structures, ships, concrete structures, etc., which require a high level of corrosion and chemical resistance, and heat curing type used as powder coatings.
2. Polyurethane Paint
Polyurethane resin paints are a combination of a base resin (polyol) and a hardener (polyisocyanate), and the characteristics can be changed by changing the combination of the base resin and hardener. Paint is mainly used for buildings and large structures as a topcoat that requires weather resistance.
3. Acrylic Resin Paint
Acrylic resin paint has a very high degree of freedom in design, and its hardness, polarity, etc. can be freely changed. They have excellent resistance to weather, water, oil, and alkalis, and are mainly used as coatings for floors and concrete surfaces.
Painting Process
Paint is applied in several coats to ensure consistent quality. For example, in the case of a three-layer system, the appropriate paint is used for the base coat, middle coat, and top coat, respectively.