Polyester coatings originated in Italy in the 1930s and is now the main lacquer used for wood products in industrially developed countries.
Polyester coating has superior physical and chemical properties, which are unmatched by polyurethane paints and nitrocellulose paints. It is an ideal paint for decorating high-end furniture.
This article specifically introduces what polyester coatings is, as well as the details of its application and chemical composition. Hope it can help you.
Definition
The polyester coating generally refers to the polyester formed by the polycondensation reaction of polybasic acid and polyol (including partially unsaturated polybasic acid) and then mixed with a comonomer, which is crosslinked and cured under the action of initiator and accelerator to form a coating film. Coatings are customarily called polyester coatings.
Properties
The paint film of polyester paint is hard, wear-resistant, water-resistant, heat-resistant, resistant to dilute acids, alkalis, solvents, oils, and other chemicals, and has good insulation.
The appearance of the paint film is plump and thick, with an extremely high gloss.
The varnish has a light color, high transparency, good gloss, and color retention, and is highly decorative.
Features
The paint film is plump and bright. It is a solvent-free paint with a high paint conversion rate, thicker coating film, and the fullness of the coating film is far beyond what other paints can.
High solute content and strong hiding power.
The paint film is hard and wear-resistant, heat-resistant, acid and alkali resistant, and its liquid resistance exceeds that of polyurethane and nitro paint films.
Convenient construction and fast drying. The construction can be applied by brushing, spraying, showering, and other techniques, but relatively speaking, spraying is convenient to use and the quality of the coating film is relatively high. Drying is also faster than polyurethane paint and nitrocellulose paint.
There is no harmful gas volatilization, it has little pollution to the environment, and can reduce the ventilation energy consumption of the workshop.
Applications
Polyester paint is mainly used for furniture, wooden floors, metal anti-corrosion, and other purposes.
Furniture: wooden sofas, wooden tables, and chairs, wooden floors, etc.
Metal: automobile industry, sports equipment manufacturing, bicycles, power tools, garden, and household appliances parts, etc.
In addition, polyester paint can also be used on guitars, wooden pianos, and other places.
How to paint polyester?
It is particularly important to pay attention to changes in climate and temperature before applying polyester coatings.
The construction of polyester paint should pay great attention to the preparatory work, which mainly includes the following contents:
- Check the air path of the air compressor to ensure that no moisture in the air is mixed into the paint.
- The furniture to be constructed must be thoroughly cleaned, paying special attention to the dead corners.
- Wet the spray booth with water as needed to reduce flying dust.
- Prepare tools such as filter cloth, paint mixing utensils, cleaning thinner, paint mixing thinner, curing agent, etc., so as to avoid temporary hasty mixing.
- Avoid construction on rainy days. The curing agent will react with moisture and cause many coating defects. Therefore, construction should be avoided in rainy or humid weather.
Construction technology
1. Wood floor coating: sanding and brushing the floor blank 1-2 times with the bottom Depot (or primer) sanding and brushing the floor paint 2-3 times.
The wood floor material is high-grade, you can also directly brush the floor paint 2-3 times without using the primer; the wood floor material is ordinary, with wooden eyes and wood seams, you can also scrape the transparent putty 1-2 times on the white blank, and polish it smoothly Then apply the primer again.
2. Application of transparent top coat: white body sanding and scraping transparent putty 1-2 times, sanding and brushing 1-2 times for the bottom of Depot or transparent base polyester paint application lacquer sanding and clearing paint for 2 times, for deep color and light wood eyes The putty is not scratched when the high-quality board is painted.
3. Sticker furniture painting: white blank sanding and brushing transparent lacquer 1 time, sanding the wood-grain paper and then brushing the bottom of Depot (or special clear primer) 1-2 times, sanding and brushing the clear lacquer 1-2 times.
Issues that need special attention:
- Pay attention to the paint ratio and reasonable paint mixing
- Sufficiently skilled in the use of spray guns
- Improve the conditions of the construction site
- Use appropriate thinners to tune the paint
The isocyanate monomer and its adducts in the polyester paint have a strong irritating effect on the human body. If the free monomer content exceeds the specified standard, it will cause serious irritation to the human eyes, skin, and respiratory system during construction.
If you are exposed to polyurethane paint and polyester paint for a long time, the human body may also be infected with bronchitis, asthma, or emphysema. In addition, most of the solvents and thinners in polyurethane paints and polyester paints are very toxic benzene-based substances, and air circulation must be ensured when painting.
Polyester vs. Polyurethane Coatings
Meaning
Polyester coating is a kind of thick paint with polyester resin as the main film-forming material. The film-formed material has the high-quality properties of full paint film and hard and thick paint film.
Polyurethane coating is also called polyurethane paint, and its corresponding varnish product is called polyurethane varnish. It has bright paint film, strong adhesion, high-quality water resistance and abrasion resistance, high-end corrosion resistance, and so on.
Application
Polyester coating is commonly known as “piano paint” inside and outside the industry. It is very common in furniture factories and is usually used on high-end furniture and speaker enclosures.
Polyurethane coating is commonly used in industrial and agricultural machinery, steel furniture, metal pre-coating, automotive, and other industrial coatings.
Polyester vs. Epoxy Powder Coat
Polyester paint and epoxy paint are both industrial paints. But there is a big difference between the two. Following is a detailed explanation of the differences between them.
Product ingredients
Polyester coating is a thick paint made with polyester resin as the main film-forming material.
Epoxy paint is composed of epoxy resin, extender pigment, and curing agent.
Product appearance
Polyester paint: The paint film is full, the color is gorgeous, and the decoration is good.
Epoxy paint: Although the color is various and adjustable, it is slightly less decorative than polyurethane paint compared to polyurethane paint.
Product use
Polyurethane paint is mainly used for wooden objects. In addition, it can also be used as a coating paint for prepainted steel coils.
Epoxy paint: Since epoxy paint has poor weather resistance and is easy to chalk, it is mostly used as a primer.
Corrosion resistance
Polyester paint: Polyurethane topcoat has strong acid resistance
Epoxy paint: Epoxy paint has strong alkali resistance, and the moisture and heat resistance of epoxy paint is slightly better than that of polyurethane paint.
Respective defects
Polyurethane paint: Polyester topcoat is prone to yellowing.
Epoxy paint: Epoxy paint is prone to chalking when used outdoors.
Polyester vs. Nylon Coating
Heat resistance
Nylon is thermoplastic. Thermoplastic compounds will also melt at high temperatures, but no chemical reaction is involved. The process is reversible.
Polyester is a thermosetting plastic. When subjected to a sufficiently high temperature, these polymers react to form strong chemical bonds. This process is irreversible.
Polyester coatings have higher heat resistance than nylon coatings.
Durability
Polyester coatings are often flexible, with strong impact and chemical resistance.
Once the nylon coating is applied to the part, it forms a continuous protective bond on the surface. A strong barrier is formed, which can resist UV lamp wear.
Polyester vs. Nitro lacquer vs. Water-based paint
Ingredients
Polyester coating, also called unsaturated polyester coating, is a thick paint made of polyester resin as the main film-forming material.
The main film-forming material of nitrocellulose lacquer is mainly nitrocellulose.
Water-based paint is paint that uses water as a diluent. It is mainly divided into three types: water-dispersible paint (latex paint), water-soluble paint, and water-reducible paint.
Features
The paint film of polyester paint is plump, with thick layers and hard surfaces.
Nitro lacquer has a good decorative effect, simple construction, good hardness and brightness, and easy repair.
Water-based paint is harmless to the human body, has good rust and corrosion resistance, and is not easy to be infiltrated and oxidized by water.
Types of Powder Coatings
According to the characteristics of the resin, it can be divided into thermoplastic powder coating and thermosetting powder coating.
According to the coating method and existing state, it can be divided into electrostatic powder spraying powder coating, fluidized bed dip coating powder coating, electrophoretic powder coating, ultraviolet curing powder coating, and water dispersion powder coating.
According to the appearance of the coating film, it can be divided into high-gloss powder coatings, bright powder coatings, semi-gloss powder coatings, matte powder coatings, matte powder coatings, and wrinkle powder coatings.
According to special functions and uses, it can be classified into decorative powder coatings, anticorrosive powder coatings, weather-resistant powder coatings, insulating powder coatings, antibacterial powder coatings, and high-temperature resistant powder coatings.
Conclusion
In recent years, the variety and series of polyester coating have increased and the scope of application has been expanded with each passing day.
Polyester coating is an indispensable material in modern decoration. It is environmentally friendly and safe. It is not only bright in color, but also not easy to wrinkle and fall off. It is a decorative paint that everyone loves very much.
