Powder Coating Types
Powder coatings based on their applications and purposes:
EPOXY
EPOXY powder coating is a thermoset polymer coating known for its hardness, chemical resistance, flexibility, and strong adhesion. This distinctive blend of thermal, physical, chemical, and mechanical properties positions Epoxy as an excellent functional coating for safeguarding substrates across diverse applications. Examples of its application include industrial equipment, automotive under-body components, metal furniture, and household appliances.
Important to note that Epoxy-based powder coating is not advisable for use in exposed, open-air environments or situations where exposure to ultraviolet radiation may lead to chalking.
- Formulated with epoxy resin and a suitable hardener.
- Ideal for applications requiring chemical resistance, such as fuel tanks.
- Exhibits lower resistance to heat and light, often used as a primer for high corrosion resistance.
EPOXY POLYESTER (HYBRID)
Epoxy-polyester (Hybrid) coatings, considered general-purpose solutions, are widely utilized in powder coating with widespread applications. Renowned for their outstanding hardness, these coatings boast the highest levels of chemical and corrosion resistance among available powders. An additional advantage lies in their user-friendly nature and a diverse range of cure schedules. Epoxy-polyester coatings form strong bonds with metals, exhibiting excellent adhesion facilitated by various metal pre-treatments, including phosphate and sandblasting.
However, it’s important to note a limitation of Epoxy-polyester (Hybrid) powders— they lack robust UV resistance. Prolonged exposure to exterior elements, particularly sunlight, may result in fading and chalking, with surface degradation often observed after a few months. Consequently, Epoxy-polyester coatings are better suited for indoor applications where UV exposure is limited.
- Contains both epoxy and polyester resin for combined physical and chemical resistance.
- Indoor usage, particularly prevalent in the white appliances industry.
- Suitable for coating metal furniture, lighting fixtures, hospital equipment, and more.
- Offers greater heat and light resistance compared to epoxy types.
POLYESTER
Polyester powder coating based on polyester resin stands out as a resilient coating, offering a robust alternative to traditional paint by withstanding elemental challenges. This type of coating serves as a protective shield against detrimental factors such as ultraviolet rays, abrasion, and corrosion, maintaining its color integrity. Beyond its color-preserving capabilities, polyester powder coating boasts chemical resistance, low surface friction, and significant impact protection, enhancing overall product durability.
Recommended for both indoor and outdoor applications, corrosion-resistant polyester coatings find common usage in various contexts. Examples include the coating of outdoor furniture, automobile components, as well as residential and commercial building exteriors.
There are 2 types of Polyester powder coatings, as follows:
POLYESTER/TGIC
- Includes Polyester resin and TGIC hardener, recommended for exterior walls.
- Suitable for aluminum window and door profiles, enduring climatic conditions for up to 10 years.
- Widely used in the aluminum profile industry, agricultural machinery, bicycles, rims, and lighting fixtures.
POLYESTER/TGIC FREE or PRIMID
- Comprises Polyester resin and Primid hardener, suitable for exterior walls.
- Recommended for architectural applications, capable of withstanding up to 10-15 years based on climatic conditions.
- Primid, a strong competitor to TGIC, does not require specific labeling marks according to European Union norms.
Key advantages of powder coatings
Solvent-Free Processing
- Powder coatings remain solvent-free throughout all processing stages, from application to curing, making them widely recognized as low or zero VOC (Volatile Organic Compounds) systems.
High Dry Film Thickness
- The application of very high dry film thicknesses is achievable in a single pass, and any overspray not adhering to the substrate can be collected and reused.
Exceptional Coating Characteristics
- Corresponding coatings are acknowledged for their high flexibility, strong adhesion, and resistance to chemicals, humidity, and corrosion
Durability in Aggressive Environments
- The careful selection of coating ingredients allows the formulation of coatings that exhibit outstanding durability when exposed to challenging environmental conditions.
Versatility in Appearance
- Powder coatings offer unlimited options in terms of color, gloss level, and special effects, providing flexibility for diverse aesthetic preferences.