🧩 PA12 – Polyamide 12 (Grilamid®, Vestamid®)

(High-performance technical polyamide, valued for its extremely low water absorption, flexibility at low temperatures, chemical resistance, and dimensional stability. One of the most widely used polyamides for hoses, connectors, and parts exposed to fuels.)

🔹 What is PA12

PA12 (Polyamide 12) is an aliphatic polyamide obtained from laurolactam (C12). It features long molecular chains, which provide minimal water absorption (<0.5%), excellent flexibility at cold temperatures, dimensional stability, and high resistance to fuels and oils. Due to these properties, PA12 is a primary choice for fuel systems, connectors, hoses, and flexible elements in automobiles.

🔧 Composition

Polyamide 12 (PA12): 100%
Additives: UV stabilizers, lubricants, glass fibers (optional).
Density: 1.01–1.03 g/cm³ (very low density).
Melting Point: ≈ 175–180 °C.
Water Absorption: <0.5% (extremely low).
Chemical Resistance: Excellent (oils, fuels, solvents, antifreeze).
Continuous Heat Resistance: 90–110 °C.

🚗 Where PA12 is used in the automotive industry

Component	Example parts	Observations
Fluid Systems	Fuel hoses, brake pipes, nozzles	Excellent chemical stability and flexibility
Connectors / Sensors	Caps, plugs, gaskets	Insulation and resistance to antifreeze/oils
Engine Bay	Clips, supports, housings	No deformation under heat and vibration
Tech / Structural	Small, elastic, functional parts	Resists shocks and cold down to -40 °C

🔧 Welding Temperature and Methods

Method	Optimal Temperature	Observations
Hot Air	230 – 250 °C	Easy melting, clean and flexible weld
Heat Plate (Mirror)	220 – 240 °C	Uniform joint without deformations
Manual Extrusion	220 – 240 °C	Suitable for long cracks or pipes

🔩 What to Weld PA12 With (Material Compatibility)

PA12 has excellent compatibility within the polyamide family, being closely related to PA11 and PA610.

✅ Compatible with:

PA12 ↔ PA11 / PA610 / PA612 / PA66 / PA6 / PC+PA – ideal.
PA12 ↔ PBT / PET / PC+PBT – partially compatible.

❌ Incompatible with:

PP, PE, PVC, PS, ABS, ASA, pure PMMA – completely different melting points.

💡 ReplastMD Recommendation:

Use PA12 rods (Grilamid® or Vestamid®) at 240–250 °C. Preheat the part to avoid internal stress. For pipes and hoses, maintain a moderate airflow to preserve original elasticity.

🏭 Manufacturers and Trade Names

EMS-GRIVORY: Grilamid®
Evonik: Vestamid® L
Arkema: Rilsan® D / Rilsamid®
DuPont: Zytel® 12

🧠 How to Identify PA12

Engraved marking: >PA12<, >Grilamid<, >Vestamid<, >Rilsan D<.
Semi-matte surface, smooth, slightly elastic.
Very light, low density.
Blue flame, nylon smell, burns without bubbling.
Remains flexible even at low temperatures (-40 °C).
ReplastMD practical test: If the part is matte, slightly elastic, very light, doesn’t absorb water, and is marked >PA12< – it’s a confirmed Polyamide 12.

🛠️ PA12 Welding at ReplastMD:

At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PA12 welding for fuel hoses, technical pipes, and engine bay clips, ensuring a clean, elastic, and fuel-resistant finish.