🧩 PA66 – Polyamide 66 (Nylon 66)
(High-performance technical material with high mechanical and thermal resistance. Widely used in automotive parts subject to high stress, such as structural components, housings, and engine bay parts.)
🔹 What is PA66
PA66 (Polyamide 66) is a semi-crystalline polymer with a dense molecular structure, which provides superior hardness, rigidity, and dimensional stability. It resists oils, fuels, and high temperatures exceptionally well. PA66 is the go-to material for technical automotive parts exposed to vibration, abrasion, and thermal shock.
🔧 Composition
- Polyamide 66 (PA66): 100% (base resin).
- Possible Additives: glass fibers (GF), lubricants, heat stabilizers.
- Density: 1.13–1.16 g/cm³.
- Melting Point: ≈ 255–265 °C.
- Chemical Resistance: Excellent (oils, fuels, mild solvents).
- Continuous Heat Resistance: up to 130–150 °C.
🚗 Where PA66 is used in the automotive industry
| Component | Example parts | Observations |
| Engine / Technical | Covers, mounts, clips, housings | High thermal and mechanical resistance |
| Fixings and Consoles | Clips, fasteners, small arms | Excellent dimensional stability |
| Electrical Systems | Connector housings, guides | Electrical insulation and toughness |
| Technical / Struct. | Parts exposed to vibration | High wear and friction resistance |
🔧 Welding Temperature and Methods
| Method | Optimal Temperature | Observations |
| Hot Air | 270 – 290 °C | Strong, controlled weld |
| Heat Plate (Mirror) | 260 – 280 °C | Stable joint for thick parts |
| Manual Extrusion | 260 – 280 °C | Ideal for reinforcements and long cracks |
🔩 What to Weld PA66 With (Material Compatibility)
PA66 welds effectively only with similar materials from the polyamide family.
✅ Compatible with:
- PA66 ↔ PA66 / PA6 / PA-GF / PA+CF – excellent.
- PA66 ↔ PBT / PC+PBT / PET – partially compatible.
❌ Incompatible with:
- PP, PE, PVC, PS, ABS, ASA, PMMA – completely different melting and adhesion.
💡 ReplastMD Recommendation:
Use original PA66 rods at 270–290 °C. Preheat the part to avoid moisture issues (PA is hygroscopic). Allow for slow cooling after welding to prevent internal stresses.
🏭 Manufacturers and Trade Names
- DuPont: Zytel® 66
- BASF: Ultramid® A
- DSM: Akulon® 66
- Solvay: Technyl® 66
🧠 How to Identify PA66
- Engraved marking: >PA66<, >Nylon 66<, >Zytel<, >Ultramid<.
- Semi-matte surface, rigid, slightly rough.
- Blue flame with yellow tip, smells of amines (nylon).
- Softens at ≈ 260 °C without bubbling.
- ReplastMD practical test: If the part is matte, rigid, bends slightly without cracking, and smells like nylon when melted – it is confirmed PA66.
🛠️ PA66 Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PA66 welding for technical housings and engine components, ensuring a tough, heat-resistant, like-new result.