Everything You Need to Know About General Powder Coating

General powder coating is widely used in construction materials (such as aluminum doors and windows), household appliances, general industrial products (such as metal furniture), and transportation industries due to its environmental friendliness (zero VOC emissions), high coating efficiency, and excellent overall protective performance.
This article systematically introduces the concept, types, characteristics, functions, application fields, selection considerations, and common issues of general powder coatings. Special emphasis is placed on their applications in various industries to help readers gain a comprehensive understanding of what general powder coating is, its key features, and where it is primarily used.

What Is General Powder Coating?

General powder coating is a solvent-free, environmentally friendly coating material composed of 100% solid powder. It consists of solid resins, pigments, fillers, and additives blended into a powder mixture.
After electrostatic spraying, the powder is heated, melted, leveled, and cured to form a dense and durable coating film.

Types of General Powder Coatings

General powder coatings can be classified according to the nature of the film-forming material as follows:
1. Thermoplastic Powder Coatings
Thermoplastic powder coatings soften when heated and solidify upon cooling through a physical process. The coating can be repeatedly melted and reformed.
Common types include:
Polyethylene (PE)
Polyvinyl Chloride (PVC)
Polyamide (Nylon)
These coatings are mainly used for corrosion protection and electrical insulation applications.
2. Thermosetting Powder Coatings (Mainstream Market Type)
Thermosetting powder coatings undergo a chemical cross-linking reaction when heated, forming an infusible network structure.
They offer superior overall performance compared with thermoplastic coatings and dominate the current powder coating market.

Characteristics of General Powder Coatings

The main characteristics of general powder coatings include:
1. Environmentally Friendly
Solvent-free formulation
Zero VOC emissions
Oversprayed powder can be recycled and reused almost completely
2. Cost-Effective
Minimal material waste
Lower coating cost per unit area compared with liquid paints
3. High Application Efficiency
A single application can achieve a thick coating film (50–100 μm)
Suitable for automated production lines
4. Excellent Performance
The coating film provides:
Strong adhesion
High impact resistance
Excellent wear resistance
Good chemical corrosion resistance
5. Diverse Appearance Options
Available in:
High gloss
Matte finishes
Textured finishes
Metallic effects
6. Limitations
Requires heat curing
Not suitable for on-site coating applications
Color changes require cleaning and equipment adjustment, making them relatively time-consuming

Functions of General Powder Coatings

The primary functions of general powder coatings include:
1. Substrate Protection
Protects metal surfaces from:
Rust
Corrosion
Wear and abrasion
Thereby extending the service life of the product.
2. Decorative Appearance
Provides a wide variety of:
Colors
Gloss levels
Surface textures
Including high gloss, matte, and textured finishes.
3. Functional Performance
Can be formulated to provide specific properties such as:
Electrical insulation
Electrical conductivity
High-temperature resistance
UV resistance (for outdoor applications)

Application Fields of General Powder Coatings

General powder coatings are primarily used for corrosion protection and decoration of metal surfaces.
1. Construction and Building Materials
Applications include:
Aluminum doors and windows
Curtain walls
Guardrails
Steel structures
2. Household Appliances
Used on:
Refrigerators
Washing machines
Air conditioners
Ovens
and other appliance housings.
3. General Industrial Products
Applications include:
Metal furniture
Filing cabinets
Storage racks
Industrial machinery
Automotive components
4. Functional and Heavy-Duty Corrosion Protection
Used for:
Buried gas pipelines
Oil pipelines
Fire protection water pipes
Internal ship components
5. Other Applications
Including:
Hardware tools
Sports equipment
Electrical cabinets
Lighting fixtures

How to Choose General Powder Coatings

When selecting general powder coatings, users often find it difficult to determine the most suitable option. Based on our industry experience, we recommend paying attention to the following factors:
1. Consider the Service Environment
For outdoor use, choose Pure Polyester Powder Coatings for superior weather and UV resistance.
For indoor use, choose Epoxy-Polyester Hybrid Powder Coatings for balanced performance.
For heavy-duty corrosion protection, choose Pure Epoxy Powder Coatings, which offer excellent adhesion but are suitable only for indoor applications.
2. Evaluate Performance Requirements
For highly corrosive environments, require a salt spray resistance of at least 500 hours.
Select gloss levels and textures according to appearance requirements.
Standard coating thickness is typically 60–80 μm.
3. Compare Actual Coating Cost
Do not focus solely on powder price.
Instead, compare:
Coverage rate
Coating area per kilogram
A powder with higher volume and better coverage may provide lower overall coating costs.
4. Quick Quality Assessment
High-quality powder coatings generally exhibit:
Smooth and fluffy powder texture
Good hiding power after only 1–2 spray passes
Minimal smoke generation during curing

Common Problems and Solutions for General Powder Coatings

1. Cratering
Causes
Oil contamination
Moisture or oil in compressed air
Cross-contamination from other powders
Solutions
Thoroughly clean workpieces and air supply systems
Clean spray booths to prevent contamination
2. Orange Peel Effect
Causes
Poor flow and leveling
Excessive curing temperature
Coating film too thin
Solutions
Lower curing temperature or extend curing time
Maintain proper film thickness (typically 60–80 μm)
3. Poor Adhesion or Powder Peeling
Causes
Inadequate surface pretreatment
Oil or rust contamination
Insufficient curing temperature or curing time
Solutions
Perform thorough degreasing and rust removal (Sa2.5 standard)
Use a furnace temperature data logger to verify curing conditions
4. Brittle Impact Cracking
Causes
Over-curing
Excessively thick phosphate conversion coating
Solutions
Precisely control curing temperature
Maintain proper phosphate coating thickness
5. Color Difference
Causes
Temperature fluctuations during curing
Uneven film thickness
Mixing powders from different production batches
Solutions
Maintain stable oven temperatures
Ensure uniform coating thickness
Use the same production batch for the entire order
6. Low Powder Transfer Efficiency
Causes
Insufficient electrostatic output
Moisture absorption by powder
Unstable air pressure
Solutions
Adjust electrostatic settings to 60–90 kV
Store powder in a cool, dry environment
Inspect and stabilize the compressed air supply
Professional Technical Support
If you encounter powder coating issues that are difficult to resolve, please feel free to contact us. We are committed to providing professional technical support and working together with customers to solve coating challenges and promote the development of the powder coating industry.
 
We hope this article provides a professional and reliable reference for understanding general powder coatings.
We sincerely welcome inquiries regarding powder coating performance, industry standards, application methods, precautions, or any related questions. Please feel free to contact us or leave a message at any time. We would be pleased to provide detailed product information, demonstration videos, technical documentation, and customized coating solutions to help you fully understand the functions and advantages of our powder coating products.