🧩 PESU – Modified Polyethersulfone
(A new-generation amorphous technical material that blends the clarity and rigidity of PES with the toughness and stability of PPSU. It offers continuous thermal resistance up to 220°C and enhanced mechanical strength.)
🔹 What is PESU
PESU (Modified Polyethersulfone) is a copolymer of PES and PSU/PPSU, designed to improve the balance between rigidity, impact resistance, and thermal stability. It offers a continuous operating temperature of 200–220°C, high dimensional stability, and better processability than pure PES. In the automotive industry, it is used for high-precision OEM components exposed to hot fluids, steam, and oils.
🔧 Composition & Properties
- Base: 70–90% Polyethersulfone (PES).
- Modifiers: 10–30% (PSU / PPSU / Aromatic elastomers).
- Density: 1.33–1.37 g/cm³.
- Vicat Softening Temperature: ≈ 215–225 °C.
- Chemical Resistance: Exceptional (oils, solvents, mild acids).
- Continuous Heat Resistance: 200–220 °C.
🚗 Where PESU is used in the automotive industry
| Component | Example parts | Observations |
| Thermal / Cooling | Fittings, pumps, valves | Resists steam and antifreeze up to 200°C |
| Electrical / Sensors | Housings, covers, insulators | High thermal and dielectric stability |
| Fuel / Braking | Fuel contact parts | Chemically inert, zero shrinkage |
| Technical Structures | Frames, clips, EGR housings | Rigid, glossy, with excellent hardness |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 330–350 °C | Slow melting, dense and controlled flow |
| Plastic Extrusion | 320–340 °C | Use PESU or compatible PES/PPSU rod |
| 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, PPS+PPSU.
- ❌ Incompatible: PP, PE, PS, ABS, PC, PET (completely different melting points).
💡 ReplastMD Recommendation: Use PESU or PES/PPSU rods at 340°C. Heat uniformly while avoiding overheating to maintain clarity and hardness. Slow cooling ensures a perfectly uniform bond without micro-cracks.
🧠 How to Identify PESU
- Engraved marking: >PESU<, >ULTRASON E<, >VERADEL PESU<, >TECASON E<.
- Texture: Glossy or semi-matte, very rigid.
- ReplastMD practical test: If the part is rigid, heat-stable, and amber/semi-transparent, it’s confirmed. Does not deform at 250°C hot air. Burns with a faint sulfone scent.
🛠️ PESU Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PESU / Ultrason E welding for technical fittings and EGR components, ensuring a high-strength, durable, and aesthetic finish.