🧩 PPSU – Polyphenylsulfone
(An amorphous technical material, super heat-resistant and hydro-stable, capable of continuous operation above 180–210°C without degradation. PPSU combines hardness and dimensional stability with excellent resistance to impact, steam, and chemicals.)
🔹 What is PPSU
PPSU (Polyphenylsulfone) is a high-performance thermoplastic polymer from the polysulfone family (PSU, PES, PPSU). It is completely amorphous and offers exceptional heat resistance (up to 220°C Vicat), superior chemical resistance to oils and solvents, and incredible impact toughness—much higher than PSU or PES. This makes it a primary choice for high-end automotive cooling systems, pumps, and valves.
🔧 Composition & Properties
- Base: 100% Polyphenylsulfone.
- Density: 1.29–1.31 g/cm³.
- Vicat Softening Temperature: ≈ 220–225 °C.
- Chemical Resistance: Exceptional.
- Continuous Heat Resistance: 180–210 °C.
🚗 Where PPSU is used in the automotive industry
| Component | Example parts | Observations |
| Thermal / Cooling | Pumps, valves, fittings, joints | Resists boiling water, antifreeze, steam |
| Fuel / Braking | Sensor housings, pressure parts | Chemically inert, no warping |
| Electrical Systems | Connectors, ECU housings | Thermal and electrical stability |
| Technical Structures | Frames, clips, interior housings | Rigid, tough, flame retardant |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 330–350 °C | Slow melting, viscous flow |
| Plastic Extrusion | 320–340 °C | Use PPSU or compatible PES rod |
| Heat Plate (Mirror) | 320–340 °C | Uniform bond, no bubbles |
🔩 Material Compatibility
- ✅ Compatible: PPSU, PES, PSU, PEI, PPS+PEI, PPS+PEEK, PPS+CF.
- ⚠️ Good Compatibility: PPA, PA+PPS, PPS+Noryl.
- ❌ Incompatible: PP, PE, PS, ABS, PC, PET (completely different melting points).
💡 ReplastMD Recommendation: Use PPSU or PES rods at 340°C. Heat slowly and maintain constant temperature to avoid burning. Slow cooling is essential to prevent micro-cracks and ensure a smooth, clear finish.
🧠 How to Identify PPSU
- Engraved marking: >PPSU<, >RADEL R<, >ULTRASON P<, >TECASON P<.
- Texture: Glossy or semi-matte, very dense and rigid.
- ReplastMD practical test: If the part is rigid, heavy, and does not deform under standard hot air (below 300°C), it’s confirmed. Burns with a clean flame and a faint sulfone scent.
🛠️ PPSU Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PPSU / Radel R welding for thermal fittings and pumps, ensuring a dense, technical finish resistant up to 210°C.