🧩 PA6 – Polyamide 6 (Nylon 6)
(Durable semi-crystalline technical plastic, used in structural and technical parts in the automotive industry.)
🔹 What is PA6
PA6 (Polyamide 6, also known as Nylon 6) is a high-performance semi-crystalline thermoplastic, valued for its mechanical strength, thermal stability, and wear durability. It is widely used in parts that withstand mechanical stress, high temperatures, and friction.
🔧 Composition
- Polyamide chain (caprolactam) — semi-crystalline structure with amide bonds.
- Technical additives — can include UV stabilizers, glass fibers, lubricants.
- Common variants: PA6-GF30 (30% Glass Fiber), PA6.6 (Nylon 6.6).
🚗 Where PA6 is used in the automotive industry
| Component | Example parts | Observations |
| Engine / Technical | Timing covers, sensor supports, gears | Resists high temperatures |
| Interior Mechanics | Fasteners, pedal housings, tech clips | Elastic and vibration resistant |
| Exterior / Struct. | Headlight supports, fan housings | Rigid, stable, impact resistant |
| Tech Applications | Industrial parts | Weld only with original PA6 rod |
🔧 Welding Temperature and Methods
| Method | Optimal Temperature | Observations |
| Hot Air | 320 – 340 °C | Requires precise control; risk of oxidation |
| Heat Plate (Mirror) | 300 – 320 °C | Clean, uniform joint |
| Manual Extrusion | 290 – 310 °C | Only for technical repairs |
🔩 What to Weld PA6 With (Material Compatibility)
The question “what to weld PA6 with” is very important, as this material behaves completely differently from polyolefins (PP, PE). PA6 adheres only to materials with a similar polyamide structure.
✅ Compatible with:
- PA6 ↔ PA6 — ideal combination; welds perfectly.
- PA6 ↔ PA6.6 — partially compatible (small melting point difference).
- PA6 ↔ PA6-GF30 — possible with high thermal control.
❌ Incompatible with:
- PP, PE, ABS, ASA, PC — no adhesion; different chemistry and melting.
- PVC, PBT — carbonize or decompose at temperature.
💡 ReplastMD Recommendation:
PA6 easily absorbs moisture, which affects weld quality. Before welding, preheat the part and the rod at 80–100 °C to dry and use original PA6 rods at a controlled temperature of 320 °C. Cooling must be slow to avoid tension and micro-cracks.
🏭 Manufacturers and Trade Names
- BASF: Ultramid®
- DuPont: Zytel®
- DSM: Akulon®
- Lanxess: Durethan®
🧠 How to Identify PA6
- Engraved marking: >PA6<, >PA66<, >PA-GF30<.
- Blue flame, smells of burnt hair (protein) when burning.
- Hard surface, slightly glossy, “oily” feel when cut.
- Density > 1 g/cm³ (sinks in water).
- ReplastMD practical test: if the part softens slowly, emits a burnt hair smell, and returns slowly to shape → PA6 or PA66.
🛠️ PA6 Welding at ReplastMD:
At our service center in Chisinau (Ciocana sector), ReplastMD performs professional PA6 welding for technical housings, mounts, and engine covers, ensuring restored structural strength and durability.