Table of Contents
What is Polyester Coating?
Polyester coatings are a form of protective treatment applied to a material to improve its aesthetics and durability. They are renowned for their durability, including their resistance to UV rays, moisture, corrosion, impact, and abrasion. Polyester coatings are generally applied to any material that is not heat-sensitive. Some common applications include: fences, windows, doors, car parts, white goods, and furniture. The advantage of applying polyester coatings to these products is the increased longevity the coating brings. By using polyester coatings, products look better for longer and last longer, which reduces life cycle costs.
This article will discuss what polyester coating is, its properties, applications, and advantages.
What Is Polyester Coating?
Polyester coating is a form of finishing, whereby a coat is sprayed directly onto the metal from a spray gun in the form of a dried powder to give it a stronger coating in comparison to conventional paint. Polyester coating provides the same desired look as a painted finish but will provide a more inherently robust finish that is long-lasting, durable, and applicable on many surfaces.
What Are the Uses of Polyester Coating?
Polyester coating has a wide range of uses. It is commonly used for outdoor products and is often a replacement for traditional paint for various applications, such as:
Outdoor furniture, such as tables and chairs.
Window frames.
Fencing.
Guardrails.
External door surfaces, coated frames, and surfaces of electronic devices.
Car parts.
Microwave ovens.
Refrigerators.
What Is Polyester Coating Made Of?
Polyester coatings are made of a mix of different ingredients including: resins, pigments, flow agents, matting agents, curing agents, and waxes. The type of additives that make up the polyester coating will determine its properties, behavior, color, and finish. The composition percentages and exact chemicals will vary depending on the specific polyester coating. However, an example of a polyester coating composition is 40% polyester, 26% melamine cross-linker, 16% cellulose acetate butyrate, and 18% binder solids.
How Does Polyester Coating Differ From Other Types of Coating?
Polyester coatings differ from epoxy coatings because epoxy coatings are much better at adhering to metals than polyesters, however they are more adversely affected by the weather. For this reason, epoxy coatings are used as an undercoat, and polyesters are used as a final coat. Urethanes are very similar to polyester coatings as they are chemically similar; the main difference is the curing agent they use. Urethanes are more chemically resistant but also more expensive than polyester. Urethanes also give off gas a lot during curing and can become brittle when applied in thick layers.
Is Polyester Coating Better Than Latex Coating?
No, one is not necessarily better than the other. Polyester and latex have their benefits. Both coatings have good corrosion resistance and UV resistance and come in a range of colors. Latex coatings have a higher level of shrinkage and handle high temperatures less well than polyester coatings.
What Are the Properties of Polyester Coating?
Polyester coatings are widely used for their desirable properties over traditional painting methods. An important property of polyester coating is its hardness, which increases its resistance to wear and abrasion. Polyester coatings also produce a high-gloss finish. In addition to wear resistance, polyester coatings are highly chemical resistant. Finally, polyester coatings have a more even finish than is achievable with traditional paint.
What Are the Different Types of Polyester Coating?
There are only two types of polyester powder coatings which are listed below:
TGIC (tri glycidyl isocyanurate): Chemical used for cross-linking in the coating.
Non-TGIC: Uses alternative chemicals to induce cross-linking in the powder coating.
How To Choose a Polyester Coating
To choose a polyester coating, first choose between using a TGIC or TGIC-free coating. TGIC coatings can cure at lower temperatures, are less sensitive to excess film thickness, and provide more resistance to over-baking than TGIC-free coatings. After choosing between TGIC or TGIC-free coatings you need to choose from a range of colors and finish types. The finish types of polyester coatings are generally a form of high-gloss finish, and there is a wide range of colors to choose from.
What Is Polyester Coating for Steel?
The polyester coating used for steel adds a layer of corrosion resistance which is important for the longevity of the steel. The polyester coating can either be colored or clear, which can add to the aesthetic of the steel for a cost-effective price. Polyester coatings can be used in conjunction with galvanization for steel.
What Is Polyester Coating for Plastic?
Plastics use a low-baked polyester coating to reduce the thermal impact of the polyester curing on the plastic. The low curing temperature of under 100 ºC for under a minute of cure time allows polyester to be used on plastics. The high cross-linking of the polyester results in a hardened polyester coating that is resistant to wear.
What Is Polyester Coating for Wood?
Polyester coatings are commonly used for wood furniture and fittings in interior and exterior settings. For wood applications, a low-bake polyester powder coating is used. Both wax and wax-free versions of polyester coatings are ideal for making a high-gloss finish. Polyester coatings used for top coats achieve a high chemical resistance which is easy to sand and is less susceptible to shrinkage when compared to traditional paint.
What Are the Advantages of Polyester Coating?
There are several advantages of using polyester coating over traditional painting methods, these advantages include:
No solvents or toxic chemicals are used in the application of polyester coatings.
Do not melt when exposed to elevated temperatures.
Can be applied at low curing temperatures for materials that are not heat tolerant.
Is resistant to chipping, abrasion, and impact damage.
Is very smooth.
Is highly resistant to UV degradation.
What Are the Disadvantages of Polyester Coating?
While polyester powder systems do bring many advantages over traditional paint systems there are still some disadvantages, as listed below:
Have an average thickness between 40 and 60 microns; for coating which is required to be thinner than this, traditional paint is better.
Polyester powder application machines take longer to clean when changing between colors.
While polyester coating comes in many colors, new colors cannot be mixed to create a new color. However, this is largely overcome by having a large selection of colors to begin with.
Polyester has less impact, chemical, and corrosion resistance than polyurethane and epoxy coatings.
What Is the Process of Polyester Coating?
The application of polyester coating is achieved by using a spray gun. After spraying the part with the coating the part must be heated to ensure the polyester coating properly cures and bonds to the surface and itself. If the coating is not properly bonded, then the polyester coating may peel away from the surface, leaving it exposed to the environment. The application of a polyester coating using this method should leave a uniform and smooth finish. However, if it does not, sandblasting can be used to improve the surface finish.
What Are the Most Common Applications of Polyester Coatings?
Polyester coating is used across a wide range of products and industries, the most common of which are listed below:
Automotive: For example, coating on external door surfaces, under-the-hood finishing, and intermediate finish on wheel finishing.
Home Appliance: For example, fridges, microwaves, washing machines, and food utensils.
Electronics: For example, surfaces and external frames for appliances such as blenders or pumps.
Furniture: For example, metal benches, and other outdoor furniture such as tables and chairs.
Architectural: For example, fencing, window frames, and stadium seating.
Can Polyester Coatings Be Used on Outdoor Surfaces?
Yes, polyester coatings are suitable for outdoor surfaces. It can be argued that they are better than using traditional surface coatings. This is because polyester coatings are more corrosion-resistant and UV-resistant, which means they can survive use in harsh outdoor environments.
Are Polyester Coatings Suitable for Use in Automotive Applications?
Yes, polyester coatings are widely used in automotive applications for interior and exterior trim, suspensions, and wheels. It is not however used for bodywork panels. Reasons for the use of polyester powder coatings are that they do not produce volatile organic compounds (VOC), are highly corrosion-resistant, and overspray areas are nearly always recoverable.
What Are the Surfaces That Can Be Polyester Coated?
There are a range of material surfaces that can be coated in polyester. The most important aspect of applying a polyester coating is that the surface is prepared, which means all dust and grease is removed and the surface is even and fairly smooth. Polyester coating can be used on wood and metal.
Is It Possible To Apply Polyester Coatings on Rubber Surfaces?
No, as a rule, polyester coatings are not applied to rubber surfaces. This is because the curing temperatures of polyester coatings can exceed 300 degrees, which is not good for the rubber. There are also low-cure-temperature polyester coatings that may be used, but it would be necessary to consult a specialist depending on the application.
Can Polyester Coatings Be Used on Electronic Components’ Surfaces?
Yes, polyester coatings can be used on electronic components’ surfaces. It is most commonly applied to metal surfaces such as steel and aluminum and used across various industries, including electronic components. Polyester coating is designed to provide insulation and protection for electronic devices while allowing full functionality of the equipment. Most commonly, electronic components employ the use of polyester powder coating for surfaces and external frames of appliances such as blenders and pumps for additional protection. Other examples include: microwave ovens, washing machines, and refrigerators.
Is Polyester Coating Toxic?
No, polyester coating does not contain any toxic chemicals or solvents. This is one of the significant benefits of polyester coating. Polyester coating remains highly resistant to hydrocarbons, oils, and fuels as well as having a high degree of UV tolerance while not being carcinogenic or toxic.
How Can XTJ Help You With Your Polyester Coating Needs?
XTJ can help you with your polyester coating needs by connecting you with a reliable supplier. By using the XTJ discovery platform here, you can find a supplier that can fulfill your polyester powder coating needs. The filters provided by the XTJ discovery platform can help you find a supplier by: location, certification, business type, or registration. Using the XTJ discovery platform can also give you peace of mind by using the XTJ registration or verification filter. XTJ registration assures that the company details are correct and the primary products and services offered are legitimate. XTJ verification goes one step further and ensures that all products and services offered by a company are valid and that the company is set up and ready to quote for your needs.
How Much Does Polyester Coating Cost?
Polyester coatings will vary in price in the $44–$70 per m² range. The price of polyester will vary depending on: the composition of the polyester powder used for coating, the color, method of application, the pretreatment, and the size of the project. Projects that use larger amounts of powder will generally be able to source polyester coating for a lower price as it is more cost-effective to buy larger amounts of the coating. Generally, powder coating is more expensive than using traditional painting methods. However, it is also more durable and so better protects the surface beneath it. This can in turn save money.
What Is the Quality of Polyester Coating?
Polyester coatings are a high-quality surface treatment compared to more traditional painting methods. Polyester coatings are renowned for their resistance to wear and environmental conditions, which leads to a long service life. However, to properly gain all the benefits of a polyester coating the surface of the material needs to be properly prepared, which means sanding out any imperfections and removing all contaminants from the surface before spraying.
How Durable Are Polyester Coatings?
Polyester coatings are known for their durability. Polyester coatings are highly UV, corrosion, and chemically resistant. Not only does it perform better for longer, but it also retains its aesthetic qualities for longer. The durability of polyester coatings will save money in the long run.
How Long Does Polyester Coating Last?
Polyester coatings are extremely durable when compared to non-powder coatings, as polyester can last for up to 40 years. Polyester is known for being resistant to chemicals, corrosion, and UV, which is why it can last so long. The abrasion and impact resistance of the cross-linked polymer chains also add to the longevity of this coating. That being said, the longevity of polyester coating can vary depending on several factors including: the surface preparation, the material being coated, the environmental condition, inclusion and void rates, and the specific composition of the polyester coating.
What Is the Difference Between Polyester Coating and Nylon Coating?
Nylon and polyester coatings are quite different as nylon is a thermoplastic and polyester is a thermosetting plastic. This significantly changes the way each coating reacts to high temperatures; thermoplastics (nylon) melt in response to heat, whereas thermoset plastics (polyester) have lots of molecular cross-linking which makes it impossible for the plastic to be melted and reformed. Nylon is also very low in coefficient of friction which gives it the ability to reduce noise and vibration passing through the parts that it coats. Nylon is also more sustainable as it can be stripped off of the product and reused.
What Is the Difference Between Polyester Coating and Epoxy Coating?
Polyester is impact-resistant, flexible, has a low curing temperature, and has long-lasting, durable UV resistance. Epoxy is best at chemical and corrosion resistance, and is better at adhering to metal. Epoxy is not very good at UV resistance and experiences fading. This can be overcome with the use of epoxy in conjunction with other coatings or used as a primer (which is coated on top but with a different coating).
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