Learn about powder coating in paint coating work.

10 June 2024

In the world of industrial coatings, powder coating has emerged as a popular and preferred method. If you're wondering what powder coating is and why it's so advantageous, this article will provide you with a comprehensive overview.

Powder coating is a process that applies a dry powder coating to a metal surface. This powder is then cured under heat, resulting in a durable, smooth, and environmentally friendly finish. Unlike traditional liquid paint, powder coating doesn't require solvents, making it a more sustainable option.

What is Powder Coat?

Powder Coating is a type of coating applied as a free-flowing dry powder. The powder is made from finely ground particles of resin, curing agent, and pigments. When applied to a metal surface, the powder is heated, causing it to melt and form a smooth coating. This process is often used to apply a decorative and protective finish to metals such as steel, aluminum, and stainless steel, as well as other materials like wood and plastics.

The benefits of powder coating that you may not know

Many people wonder about the advantages of powder coating and why it's more popular than other painting methods. Here are the four main benefits of powder coating:

1. Enhanced Aesthetics:
The most immediate benefit is the superior aesthetic appeal. Powder coating provides a smoother finish than traditional liquid paint, even with a single coat. Additionally, it can be applied in multiple layers to achieve a deeper, more lustrous finish.

2. Cost-Effective:
Powder coating material can be recycled almost entirely, significantly reducing overall painting costs. The more you use, the lower the cost per unit, making it an economical choice for large or thick coatings.

3. Safe for Operators:
Powder coating is environmentally friendly and safe for workers. Unlike liquid paints, it contain no volatile organic compounds (VOCs), fumes, or strong odors. This ensures a healthier working environment, even during prolonged exposure. Moreover, powder coating is highly resistant to ignition.

4. Durable and Long-lasting Finish:
Powder coatings adhere exceptionally well to surfaces, providing superior adhesion compared to liquid paints. They are resistant to scratches, impact, bending, moisture, chemicals, and UV radiation. As a result, powder-coated finishes maintain their appearance and functionality for extended periods.

How many types of powder coating are there? What are they?

Types of Powder Coatings
Powder coatings can be primarily categorized into two main types, each with distinct properties:

  1. Thermosetting Powder Coatings
    Thermosetting powder coatings undergo a cross-linking reaction when exposed to heat during the curing process. This reaction bonds the coating particles together, creating a durable and chemically resistant film. Importantly, this cross-linking reaction is irreversible, meaning the coating will not melt or soften upon reapplication of heat. Common resin systems used in thermosetting powder coatings include epoxy, polyester, and acrylic.
  2. Thermoplastic Powder Coatings
    Unlike thermosetting coatings, thermoplastic powder coatings do not undergo a cross-linking reaction. Instead, they melt when exposed to heat in an oven, forming a continuous film. Upon cooling, the coating solidifies. However, if reheated to a sufficient temperature, the coating can be remelted and reformed. Common resin systems used in thermoplastic powder coatings include polyethylene, polypropylene, nylon, polyvinyl chloride, polyester, and polyvinylidene fluoride (PVDF) or fluorocarbons.

Classification Based on Resin Type
In addition to the thermosetting and thermoplastic classification, powder coatings can also be categorized based on the primary resin system used. The three main types are:

  • Epoxy (EP) Powder Coatings: Known for their excellent corrosion resistance and scratch resistance, epoxy coatings are commonly used for indoor applications and components exposed to harsh environments, such as appliances and household items.
  • Polyester (PE) Powder Coatings: Polyester coatings offer exceptional resistance to UV radiation, making them ideal for outdoor applications like satellite dishes, fences, and automotive parts.
  • Hybrid Powder Coatings: Combining the best properties of both epoxy and polyester coatings, hybrid coatings provide excellent heat resistance and high gloss. They are often used for furniture applications.

Note: The specific properties and applications of powder coatings can vary depending on the exact formulation and curing conditions.

What are the steps involved in powder coating?

Powder Coating Process, while the detailed process of powder coating can be quite complex, the basic principle is straightforward. The powder coating equipment is connected to a power source to generate an electrostatic charge, which is then transferred to the workpiece. Meanwhile, the powder coating gun is adjusted to a specific pressure, allowing the powder to adhere firmly to the object and prevent peeling. Subsequently, the coated workpiece is cured in an oven at a temperature of approximately 180-200 degrees Celsius, causing the powder to melt and form a uniform coating.

Furthermore, pretreatment processes such as chemical conversion coating or phosphating, including Phosphate for steel or Chrome/Non-Chrome for aluminum, significantly enhance the adhesion of the powder coating. These processes provide superior corrosion and wear resistance. Thai Parkerizing offers a range of pretreatment services, including phosphating, to improve the quality of the coating. Additionally, we supply pretreatment chemicals to enhance adhesion and corrosion protection, as well as chemicals for powder coating booths, such as stripping agents, color precipitants, and mesh coating chemicals. Our products are manufactured to the highest quality standards.

How to choose the right powder paint for your application

"Choosing the right powder coat finish is a crucial aspect of powder coating. Selecting a finish that complements your workpiece will enhance the overall outcome.

  • Smooth finish: The most common type, ideal for applications requiring a sleek aesthetic, such as furniture. It doesn't require a perfectly smooth surface prior to coating.
  • Textured finish: This finish can mask imperfections like wrinkles or orange peel, making it suitable for surfaces with a similar texture, like electrical cabinets or metal doors.
  • Hammered finish: This finish provides a textured appearance that can hide surface irregularities. The grainy feel is reminiscent of a hammered surface and is commonly used on items like amplifier cabinets or certain types of furniture."

Powder coating is a superior surface finish that provides exceptional resistance to scratches, UV rays, and corrosion. It offers a sleek and durable appearance, making it ideal for a wide range of applications. Thai Parker Rising is excited to introduce our new powder coating services, building upon our long-standing commitment to quality. Our standard coatings include epoxy and polyester (hybrid) options, but we are flexible to meet your specific requirements. In addition to our powder coating services, we also provide a comprehensive line of high-performance chemical products. Contact us today to discuss your project and explore our extensive range of solutions.