🧩 PEI+PES – Polyetherimide + Polyethersulfone (Ultem®/Ultrason® blend)
(High-performance technical blend combining the rigidity and thermal resistance of PEI with the chemical stability and clarity of PES. PEI+PES offers an excellent balance between hardness and impact resistance up to 230 °C.)
🔹 What is PEI+PES
PEI+PES is an amorphous blend of Polyetherimide and Polyethersulfone, two structurally compatible aromatic polymers. This mixture leverages the best of both: from PEI, it gains extreme rigidity and flame retardancy; from PES, it inherits superior chemical resistance and dimensional stability. The result is an elite technical material, excellent at resisting steam, fuels, and detergents, making it ideal for automotive components in harsh environments.
🔧 Composition & Properties
- Base: 50–70% PEI, 30–50% PES.
- Density: 1.30–1.35 g/cm³.
- Vicat Softening Temperature: ≈ 220–230 °C.
- Chemical Resistance: Excellent (oils, solvents, fuels).
- Continuous Heat Resistance: 210–230 °C.
🚗 Where PEI+PES is used in the automotive industry
| Component | Example parts | Observations |
| Thermal / Cooling | Pump covers, valves, fittings | Resists antifreeze, hot water, steam |
| Electrical / Sensors | Connectors, housings, ECU covers | High electrical insulation and rigidity |
| Motor / EGR | Pressure parts, supports | Exceptional chemical and thermal resistance |
| Technical Structures | Frames, mounts, clips | Flame retardant, dimensionally stable |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 340 – 360 °C | Slow melting, controlled viscous flow |
| Plastic Extrusion | 330 – 350 °C | PEI or compatible PES rods |
| Heat Plate (Mirror) | 330 – 350 °C | Clean bond, zero oxidation |
🔩 Material Compatibility
- ✅ Compatible: PEI, PES, PSU, PPSU, PPS+PEI, PPS, PEEK.
- ⚠️ Good Compatibility: PPA, PPS+CF, PPS+Valox, PPS+Noryl.
- ❌ Incompatible: PP, PE, PS, ABS, PC, PET (completely different melting points).
💡 ReplastMD Recommendation: Use PEI or PES rods at 350 °C. Uniform heating is essential to avoid oxidation. Slow cooling helps maintain clarity and prevent cracks.
🧠 How to Identify PEI+PES
- Engraved marking: >PEI+PES<, >ULTEM E<, >ULTRASON E<, >TECAPEI<.
- Texture: Glossy or semi-matte, extremely rigid.
- ReplastMD practical test: If the part is rigid, heavy, and does not soften under 250 °C hot air, it is confirmed. Burns with a faint imide/sulfone scent.
🛠️ PEI+PES Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PEI+PES welding for pump housings and technical valves, ensuring a dense, durable, and factory-grade finish.