🧩 PES – Polyethersulfone
(An amorphous technical material, rigid and stable at high temperatures (up to 200–220°C), with excellent chemical and dimensional resistance. PES combines the hardness and clarity of polysulfones with superior thermal stability.)
🔹 What is PES
PES (Polyethersulfone) is a high-performance polymer from the polysulfone family, alongside PSU and PPSU. It is completely amorphous with a rigid aromatic structure, providing continuous thermal resistance up to 200°C. It is more heat-resistant than PSU but slightly more brittle than PPSU. PES is inert to solvents, fuels, and oils, making it a staple for precision automotive and medical components.
🔧 Composition & Properties
- Base: 100% Polyethersulfone.
- Density: 1.36–1.38 g/cm³.
- Vicat Softening Temperature: ≈ 220 °C.
- Chemical Resistance: Exceptional.
- Continuous Heat Resistance: 190–210 °C.
🚗 Where PES is used in the automotive industry
| Component | Example parts | Observations |
| Thermal / Cooling | Pumps, valves, technical fittings | Resists boiling water and antifreeze |
| Electrical / Sensors | Housings, covers, connectors | Excellent insulation and stability |
| Fuel / Braking | Pressure parts, valves, joints | Chemically inert, rigid, flame retardant |
| Technical Structures | Clips, frames, tech covers | Glossy finish, dimensionally stable |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 330–350 °C | Slow melting, dense and viscous flow |
| Plastic Extrusion | 320–340 °C | Compatible with PES or PSU/PPSU rods |
| Heat Plate (Mirror) | 320–340 °C | Clean bond, no oxidation |
🔩 Material Compatibility
- ✅ Compatible: PES, PSU, PPSU, PEI, PPS, PEEK.
- ⚠️ Good Compatibility: PPA, PPS+CF, PPS+Noryl.
- ❌ Incompatible: PP, PE, PS, ABS, PC, PET (completely different melting points).
💡 ReplastMD Recommendation: Use PES or PSU/PPSU rods at 340°C. Slow and uniform heating is essential for a clear weld without oxidation. Controlled cooling ensures a transparent or uniform matte finish.
🧠 How to Identify PES
- Engraved marking: >PES<, >ULTRASON E<, >VERADEL<, >TECASON E<.
- Texture: Glossy or semi-transparent, amber-colored surface.
- ReplastMD practical test: If the part is rigid, amber-colored, and does not warp at 250°C, it’s confirmed. Burns with a faint sulfone scent.
🛠️ PES Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PES welding for pump housings and technical valves, ensuring a clear, high-strength finish resistant up to 210°C.