🧩 PFA+PA – Perfluoroalkoxy + Polyamide
(Technical hybrid material combining the chemical inertness of PFA with the structural toughness of polyamides. Used in multilayer hoses and fittings for aggressive fluids and fuels.)
🔹 What is PFA+PA
PFA+PA is a fluoroplastic-polyamide composite, often obtained through co-extrusion. The primary goal is to combine the non-reactive nature of PFA with the mechanical strength of PA (6, 11, or 12). This results in a material that is easy to process, heat resistant, and highly durable against automotive fluids while maintaining flexibility at low temperatures down to -40 °C.
🔧 Composition & Properties
- Composition: 40–60% PFA, 40–60% PA11 / PA12.
- Density: 1.60–1.75 g/cm³.
- Melting Point: ≈ 250–280 °C.
- Chemical Resistance: Very good (oils, acids, solvents).
- Continuous Heat Resistance: 150–200 °C.
🚗 Where PFA+PA is used in the automotive industry
| Component | Example parts | Observations |
| Fuel / Oil Systems | Multilayer hoses, ducts | Hydrocarbon and pressure resistance |
| EGR / Thermal | Nozzles, gaskets, valves | Thermal stability and perfect seal |
| Chemical Fluids | Pumps, valves, sensors | Inertness and flexibility |
| Mixed Fittings | Connectors, clips, tubes | Excellent interlayer adhesion |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 270 – 290 °C | Controlled, slow, bubble-free weld |
| Heat Plate (Mirror) | 260 – 280 °C | Suitable for PFA-PA12 joints |
| Plastic Extrusion | 270 – 290 °C | PFA or compatible PA rod |
| Heat Fusion | 260 – 280 °C | Used for multilayer tubing |
🔩 Material Compatibility
- ✅ Compatible: PFA, FEP, ETFE, PVDF, PA11, PA12.
- ⚠️ Good Compatibility: PA6, PA66 (partial with treatment).
- ❌ Incompatible: PP, PE, ABS, PC, POM, PVC, PET.
💡 ReplastMD Recommendation: Use FEP or PFA rods for the inner layer and PA12 rods for the outer layer at ≈ 280 °C. Heat gradually. Slow cooling is mandatory to prevent internal stress between the fluorinated and polyamidic phases.
🧠 How to Identify PFA+PA
- Engraved marking: >PFA+PA<, >MULTILAYER<, >PEBAX<, >VESTAMID<.
- Cross-section: Glossy inner layer (PFA), matte outer layer (PA).
- ReplastMD practical test: Very slippery inside but rigid structure. Self-extinguishing flame. Denser than standard PA12.
🛠️ PFA+PA Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PFA+PA multilayer hose repairs, ensuring a perfect seal without delamination.