🧩 PEEK+Ultem – Polyether Ether Ketone + Ultem® (Technical PEI)
(Industrial-grade hybrid material combining the rigidity and heat resistance of PEEK with the dimensional stability and flame retardancy of Ultem® (PEI). Designed for precision components operating at 240–260 °C.)
🔹 What is PEEK+Ultem
PEEK+Ultem is a semi-crystalline–amorphous blend resulting from the fusion of PEEK and PEI (Ultem®). The goal is to provide the structural integrity of PEEK with the superior processability and fire safety of PEI. This results in a dimensionally stable, non-flammable composite with a smooth technical finish, perfect for high-precision OEM parts.
🔧 Composition & Properties
- Base: 60–70% PEEK, 30–40% PEI (Ultem®).
- Density: 1.35–1.38 g/cm³.
- Melting Point: ≈ 340 °C.
- Flammability: UL94 V-0 (self-extinguishing).
- Continuous Heat Resistance: 240–260 °C.
🚗 Where PEEK+Ultem is used in the automotive industry
| Component | Example parts | Observations |
| Electrical / Sensors | ECU covers, connectors, mounts | Fire resistance and electrical insulation |
| Engine / Thermal | EGR covers, pumps, valves | Stable at 250 °C, rigid and inert |
| Transmission | Structural parts, spacers | High pressure and wear resistance |
| Fuel / Air Systems | Fittings, clips, gaskets | Chemical resistance and stability |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 380 – 400 °C | Slow melting, controlled flow |
| Plastic Extrusion | 370 – 400 °C | PEEK or compatible PEEK+PEI rod |
| Heat Plate (Mirror) | 370 – 390 °C | Clean bond, zero oxidation |
🔩 Material Compatibility
- ✅ Compatible: PEEK, PEI, PPS, PPSU, PES, PSU, PEEK+GF.
- ⚠️ Good Compatibility: PEEK+PEI, PPA, PPS+CF.
- ❌ Incompatible: PP, PE, PS, ABS, PC, PET (completely different melting points).
💡 ReplastMD Recommendation: Use PEEK or PEEK+PEI rods at 390 °C. Uniform heating is essential for a homogeneous bond between the semi-crystalline and amorphous matrices. Allow the part to cool naturally to avoid internal stresses.
🧠 How to Identify PEEK+Ultem
- Engraved marking: >PEEK+PEI<, >PEEK+ULTEM<, >VICTREX<, >EXTEM<.
- Texture: Semi-glossy, gray or technical black, very rigid.
- ReplastMD practical test: Heavy part that self-extinguishes when exposed to flame, with no toxic smoke. Softens only above 300 °C.
🛠️ PEEK+Ultem Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PEEK+Ultem welding for ECU covers and technical sensors, ensuring a clean, high-strength, and flame-retardant finish.