Electrostatic Spraying Method for Fluoropolymer and Thermoplastic-Based Industrial Components

Performance Polymers and Coatings utilizes Advanced Electrostatic Spray Gun System processing for applying a variety of fine powdered Polymers in applications of functional coatings to a broad range of chemical processing, medical, scientific, automotive and industrial parts and fasteners.

Electrostatic spraying is a highly efficient coating method that uses electrostatic charge to attract and bond powdered or liquid coatings to industrial components. It is commonly used for fluoropolymer (PTFE, PFA, FEP) and thermoplastic (polyethylene, nylon, polyester, etc.) coatings, providing excellent corrosion resistance, chemical resistance, low friction, and wear resistance. This method is widely applied in automotive, aerospace, medical, chemical, and food processing industries for coating metal and non-metal substrates.

1. Electrostatic Spraying Process Steps

Step 1: Surface Preparation

Proper surface treatment is essential for strong adhesion and coating performance:

Cleaning & Degreasing:
- Remove oils, dirt, and contaminants using solvent cleaning (IPA, acetone) or alkaline cleaners.
Abrasive Blasting (for metal components):
- Aluminium oxide or sandblasting (50-100 mesh) creates a rough surface for better adhesion.
Priming (for certain coatings):
- Some fluoropolymers require a PTFE-compatible primer to enhance adhesion.

Step 2: Electrostatic Powder Coating Application

Electrostatic Charge Generation:
- The coating powder is charged using a corona discharge or triboelectric process.
- The component is grounded, creating an attraction between the charged particles and the surface.
Spray Gun Selection:
✅ Corona Electrostatic Spray Gun: Most common, uses high voltage to charge particles.
✅ Triboelectric Spray Gun: Uses friction charging, ideal for thermoplastic powders.

Application Technique:

Maintain a 6-12 inch distance from the surface.
Apply in thin, even layers for uniform coverage.
Ensure proper powder cloud formation to maximize efficiency.
Multiple coats may be applied for desired thickness.

Step 3: Curing & Fusion Process

Fluoropolymer Curing (PTFE, PFA, FEP):
- Parts are baked at 360-425°C (680-800°F) to fully sinter the coating.
Thermoplastic Powder Coating Curing (Nylon, Polyethylene, Polyester):
- Cured at 180-230°C (350-450°F) depending on the polymer type.
- The powder melts and bonds to the substrate, forming a durable finish.

Step 4: Cooling & Post-Processing

The coated component is gradually cooled in air or water.
Additional polishing, masking, or quality inspections may be conducted.

2. Coating Material Selection

Fluoropolymer Coatings (High Performance, Non-Stick, Chemical Resistant)

✅ PTFE (Teflon®): Excellent non-stick properties, heat resistance up to 260°C (500°F).
✅ PFA (Perfluoroalkoxy): High purity, superior chemical and heat resistance.
✅ FEP (Fluorinated Ethylene Propylene): Excellent dielectric properties, low friction.

Thermoplastic Coatings (Durable, Corrosion-Resistant, Cost-Effective):

✅ Nylon: High impact resistance, wear-resistant, good adhesion.
✅ Polyethylene: Chemical-resistant, UV-stable, used in outdoor applications.
✅ Polyester: Durable, scratch-resistant, and available in various colours.

3. Key Advantages of Electrostatic Spraying

High transfer efficiency (up to 95%) → Reduces material waste.
✅ Uniform, smooth finish → Suitable for complex geometries.
✅ Excellent adhesion and durability → Works well on metal, aluminium, and composite substrates.
✅ Corrosion and chemical resistance → Ideal for harsh industrial environments.
✅ Non-stick, low-friction properties → Used in food, medical, and automotive applications.

4. Common Industrial Applications

Aerospace: Fasteners, aircraft engine components, landing gear parts.
Automotive: Fuel system parts, suspension components, chassis protection.
Medical Equipment: Surgical instruments, implants, anti-microbial coatings.
Chemical Processing: Pipe linings, pumps, tanks, valve coatings.
Food & Beverage Industry: Non-stick coatings for bakery trays, conveyor belts.

At PPC, we can coat most solid substrates with custom fluoropolymer and thermoplastic electrostatic coating powders, including metals, ceramics, glass, composites, plastics, and rubber products. Fluoropolymers can be applied with custom-engineered formulations of wet spray, electrostatic powder, fluidized bed powder, and dip-spin coating.