Polyester Powder Coating: Features, Benefits, Applications and Complete Selection Guide
News 2026-06-29
Polyester powder coating has become the largest-volume and most widely used type of thermosetting powder coating due to its excellent overall performance, outstanding weather resistance, and relatively low cost.
It is widely applied in various indoor and outdoor applications where high requirements for durability and decorative performance are required.
This article systematically introduces the concept, characteristics, functions, application fields, selection considerations, and common problem-solving measures of polyester powder coating. It focuses on the role of polyester powder coating, helping readers better understand what polyester powder coating is, its characteristics, and its main application fields.
What Is Polyester Powder Coating
Polyester powder coating is a solid powder coating composed of polyester resin, curing agents, pigments, fillers, and various additives.
Polyester resin is the key component that determines coating performance. It is produced through a high-temperature polymerization reaction between polyols and polyacids.
It contains no organic solvents and is applied through electrostatic spraying, making it an environmentally friendly coating.
Characteristics of Polyester Powder Coating
The main characteristics of polyester powder coating are as follows.
- Excellent Weather Resistance
Polyester powder coating has extremely strong UV resistance.
During long-term outdoor use, it can maintain excellent gloss and color retention and is not prone to chalking, fading, or yellowing.
Therefore, it is the preferred choice for outdoor powder coatings and is widely used in applications requiring long-term exposure to sunlight and rain, such as architectural aluminum profiles and guardrails.
- Excellent Decorative and Physical Properties
Good Decorative Performance
It can provide high-gloss, smooth leveling surfaces with bright colors and various textures, including:
Sand texture
Metallic effects
Other decorative finishes
Balanced Mechanical Properties
The coating provides good adhesion, flexibility, and impact resistance.
Its balanced overall performance can meet the protection requirements of most industrial products.
- Economy and Environmental Performance
High Cost Performance
Compared with acrylic powder coating, polyester powder coating has lower raw material costs.
Compared with epoxy powder coating, it has a wider range of applications.
Overall, it is one of the powder coatings that achieves the best balance between performance and cost.
Environmental Advantages
Like all powder coatings, it contains no organic solvents, has extremely low VOC emissions, and oversprayed powder can be recycled and reused.
Functions of Polyester Powder Coating
The main functions of polyester powder coating are reflected in the following aspects.
- Long-Term Outdoor Protection Function
This is its most important and irreplaceable function.
The coating formed after polyester powder coating curing can effectively resist harsh environmental factors such as:
UV radiation
Acid rain
Temperature changes
It provides excellent gloss and color retention and is not easily affected by chalking, fading, or yellowing.
It can provide reliable protection for outdoor metal facilities (such as architectural aluminum profiles, guardrails, and transportation facilities) for more than 10 years, significantly extending service life.
- Surface Decoration and Appearance Enhancement
It can provide various gloss levels, colors, and texture effects, including:
High gloss
Matte
Sand texture
Metallic texture
This decorative performance not only meets different product design requirements but also effectively covers minor substrate defects.
It is an important method for improving product appearance quality and brand recognition.
- Balanced Physical Protection Function
The coating has good adhesion, flexibility, and impact resistance.
It can effectively protect products from bumps and scratches during transportation, installation, and daily use.
This balanced physical performance enables it to meet the protection requirements of most general industrial products, such as appliance housings and mechanical equipment.
Application Fields of Polyester Powder Coating
Polyester powder coating is mainly applied in the following fields.
- Architecture and Building Materials
This is the most mature and largest application field of polyester powder coating.
It is widely used for:
Architectural aluminum profiles (doors and windows)
Curtain walls
Steel structures
Outdoor guardrails
Highway guardrails
Street light poles
These applications require coating weather resistance of more than 10 years, allowing long-term protection against sunlight and rain.
- Home Appliances and Electronic Equipment
It is widely used in:
Outdoor air conditioner units
Refrigerator side panels
Washing machine panels
Microwave ovens
Electric water heaters
Computer cases
Server cabinets
Due to its balanced performance and cost-effectiveness, it has become one of the mainstream choices for appliance coating.
- Transportation and Vehicle Equipment
Applications include:
Automotive components (wheels, chassis parts, seat frames)
Commercial vehicles
Agricultural machinery
Construction machinery
It provides strong protection against:
Stone impact
Chemical corrosion
Weather exposure
- General Industrial and Emerging Fields
Applications cover:
Agricultural equipment
Construction machinery
Storage racks
Hardware tools
With technological development, polyester powder coating is gradually expanding into new fields such as:
New energy vehicle battery housings
Energy storage equipment
Communication base stations
How to Choose Polyester Powder Coating
When selecting polyester powder coating, users may encounter difficulties in choosing the right product.
Based on our industry experience, we recommend focusing on the following factors.
- Consider Application Environment
Indoor Applications (such as appliances and furniture)
Weather resistance requirements are relatively low.
Focus mainly on hardness and leveling performance.
Epoxy-polyester hybrid powder coating can be selected due to its high cost-effectiveness.
However, it is not suitable for outdoor exposure.
Outdoor Applications (such as aluminum profiles and guardrails)
Pure polyester powder coating must be selected due to its UV resistance.
There are mainly two common systems:
TGIC System
Stable performance
Widely used in China
Contains certain toxicity concerns
HAA System
More environmentally friendly
Suitable for lower-temperature curing
More prone to pinholes when applying thick coatings
- Consider Appearance Requirements
Select according to product positioning:
Gloss level: high gloss / matte
Texture: smooth / sand texture / hammer texture
Color requirements
Sand and hammer textures can effectively hide minor substrate defects.
- Consider Coating Process
Confirm Curing Conditions
Normally requires baking at 180–200℃.
If the workpiece is sensitive to high temperature or energy saving is required, low-temperature curing powder coating (such as 160℃ curing type) can be selected.
Coating System
High-standard products (such as automotive components) require a:
Primer powder + top powder double-layer system
For ordinary protection requirements, a single spraying process is sufficient.
Common Problems and Solutions of Polyester Powder Coating
During the use of polyester powder coating, common problems mainly include the following.
Based on our industry experience, we provide targeted solutions to help effectively solve powder coating problems.
- Crater Problem
Problem:
Circular depressions appear on the coating surface.
Main Causes:
Incomplete degreasing during pretreatment
Oil contamination on the workpiece
Oil or water contamination in compressed air
Solutions:
Strengthen pretreatment
Regularly check degreasing tank conditions
Wipe workpieces with solvent before spraying
Install oil-water separators to ensure clean air supply
- Orange Peel Problem
Problem:
The coating surface becomes rough and uneven like an orange peel.
Main Causes:
Poor powder atomization (incorrect air pressure)
Rapid heating during curing causing insufficient leveling time
Solutions:
Adjust spray gun atomizing air pressure
Reduce curing oven heating rate appropriately
Extend leveling time in the low-temperature zone
- Pinholes and Bubble Problems
Problem:
Small needle-like holes appear on the coating surface.
Main Causes:
Excessive coating thickness (especially HAA systems)
Volatile substances remaining after substrate pretreatment are released during baking
Solutions:
Control coating thickness within recommended limits
Strengthen pretreatment
Ensure the workpiece is fully dried
- Poor Adhesion Problem
Problem:
The coating peels off easily or fails impact tests.
Main Causes:
Poor pretreatment quality (phosphating/silanization)
Insufficient curing temperature or curing time
Solutions:
Strictly control pretreatment processes
Regularly check oven temperature curves
Ensure sufficient curing conditions (such as 180℃ × 15 min)
- Outdoor Weather Resistance Failure Problem
Problem:
After several months outdoors, the coating loses gloss, becomes chalky, or color fades significantly.
Main Causes:
Indoor powder coating (hybrid type) mistakenly used outdoors
Pigments with poor UV resistance
Solutions:
Outdoor products must use pure polyester powder coating.
Suppliers should provide weather resistance test reports (such as Florida exposure testing or QUV testing).
- HAA System Pinhole Problem
Problem:
Dense pinholes appear when applying thick coatings.
Main Causes:
During the HAA (Primid) curing reaction, water molecules are released.
When the coating is too thick, moisture cannot escape effectively.
Solutions:
Control film thickness (recommended below 80–100 μm)
Use a degassing agent specially designed for HAA systems
Or switch to a TGIC system
If you encounter difficult problems during the use of polyester powder coating, please feel free to contact us at any time.
We will provide professional technical support, discuss solutions together, and promote the development of the powder coating industry.
We hope this article provides you with a professional and reliable reference for the powder coating industry.
We sincerely welcome your inquiries regarding powder coating product performance, industry standards, application methods, precautions, or any related questions.
Please feel free to leave a message or contact us directly. We will provide more detailed product information, demonstration videos, or customized solutions to help you fully understand the functions and advantages of our products.
