🧩 PEI+PA – Polyetherimide + Polyamide
(High-performance technical material combining the thermal stability of PEI with the toughness and elasticity of polyamides. Used in automotive components requiring mechanical strength and dimensional precision.)
🔹 What is PEI+PA
PEI+PA is an engineering blend that joins two advanced polymer families: PEI (rigid, thermally stable, flame retardant) and PA (tough, impact and abrasion resistant). The result is a versatile material with a balance of mechanical strength, dimensional stability, and controlled flexibility, maintaining high thermal resistance up to 200 °C.
🔧 Composition & Properties
- Composition: 60–70% Polyetherimide (PEI), 30–40% Polyamide (PA6 / PA66).
- Density: 1.25–1.35 g/cm³.
- Vicat Softening Temperature: ≈ 200–210 °C.
- Chemical Resistance: Very good (oils, greases, fuels).
- Continuous Heat Resistance: 190–210 °C.
🚗 Where PEI+PA is used in the automotive industry
| Component | Example parts | Observations |
| Electrical / ECU | Sensor covers, mounts | Good electrical and mechanical insulator |
| Engine / Thermal | Pumps, valves, fittings | Oil and heat resistant |
| Structural Parts | Clips, frames, rigid covers | Low shrinkage, high stability |
| Interior / OEM | Technical covers, aesthetic parts | Matte finish, thermal shock resistant |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 330 – 350 °C | Uniform flow, clean melting |
| Plastic Extrusion | 320 – 340 °C | PEI+PA or pure PEI rod |
| Heat Plate (Mirror) | 320 – 340 °C | Dense bond, no oxidation |
🔩 Material Compatibility
- ✅ Compatible: PEI, PA6, PA66, PPSU, PES, PSU, PPS+PEI.
- ⚠️ Good Compatibility: PPS, PEEK, PPA, PEI+PC.
- ❌ Incompatible: PP, PE, PS, ABS, PVC, PMMA (different melting points).
💡 ReplastMD Recommendation: Use PEI+PA or pure PEI rods at 340 °C. Heat uniformly without direct flame and allow the part to cool slowly to avoid internal stresses. Clean the area thoroughly from oils for maximum adhesion.
🧠 How to Identify PEI+PA
- Engraved marking: >PEI+PA<, >ULTRASON PA<, >TECAPEI PA<.
- Texture: Matte or semi-glossy, dense, slightly flexible.
- ReplastMD practical test: If the part shows medium rigidity with slight elasticity and a PEI+PA mark, it is confirmed. Burns with a faint imide and amide scent.
🛠️ PEI+PA Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PEI+PA welding for engine components and sensor housings, ensuring a dense, durable finish resistant up to 200 °C.