Resin Data
PA12
Poliamida 12 (Nylon)
PA12·Polyamides·Semi-crystalline
PA12 (Nylon 12) is the "premium" of the polyamide family: minimum moisture absorption (~1.5% vs 3% for PA6), excellent chemical resistance to fuels and hydrocarbons, and the foundation of virtually every automotive fuel and brake line in the world. Every brake line you drive at 200 km/h with, every fuel hose, every quick-connect in a gasoline or ethanol line — almost certainly PA12. You also know it by its brand names: Rilsamid/Rilsan (Arkema, which also brands bio-based PA11), Vestamid (Evonik), Grilamid (EMS-Grivory).
It is also the king of industrial 3D printing (SLS and HP MJF) — PA12 powder is the most-used material for additive functional parts. Chemistry distinguishes it: 12 carbons between amide groups (vs 6 in PA6, 6+6 in PA66) → more hydrophobic chains, more flexible, more hydrolysis-resistant. Here we have compiled the reference ranges from the PDS, plus the questions that come up over and over on the shop floor: when PA12 vs PA66 makes sense (3× cost vs stability), use in fluid lines, bio-based from castor oil, mold temperature, and SLS vs injection.
Share your experience in the comments — ranges vary by manufacturer and grade, and collective discussion is what gets us out of trouble on the floor.
The ranges shown in these data tables were compiled by the MVPS team from various parameter sheets and literature, integrating the lower and upper limits for each material type.
This information must be carefully reviewed when developing injection molding processes. Final ranges and processing tolerances are the responsibility of the engineer in charge.
These ranges are not recommended for developing specific process tolerances. MVPS always recommends requesting and consulting the supplier's data sheet.
General Properties
| Chemical Structure | Semi-crystalline |
| Specific Gravity (Density) | 1.01:1 |
| L/D Ratio | 18 – 22 |
| Compression Ratio | 2 – 2.5 |
| Tonnage Factor | 4.63 – 7.72kN/cm² |
| Thermal Diffusivity | 0.165mm²/s |
| Max Shear Rate | 60,0001/s |
| Shrinkage | 0.7 – 2% |
| Regrind | 25% |
| Heat Deflection (HDT) @ 1.82 MPa | 157°C |
| Glass Transition (Tg) @ 10°C/min | 50°C |
| Vicat Softening @ 50N | 170°C |
Drying
| Drying Temperature | 74 – 79°C |
| Drying Time | 3 – 6h |
| Recommended Moisture | 0.2% |
| Recommended Dryer Type | Desiccant |
| Dew Point | -40°C |
Temperatures
| Melt | 241 – 260°C |
| Nozzle | 221 – 260°C |
| Front | 221 – 260°C |
| Middle | 221 – 260°C |
| Rear | 216 – 260°C |
| Demolding | 46 – 102°C |
| Mold (Cooling) | 29 – 91°C |
| Feed Throat | 10 – 49°C |
Processing
| Back Pressure | 3.4 – 6.9bar |
| Screw Speed | 20 – 50RPM |
| Injection Speed | High |
| Barrel Occupancy | 20 – 70% |
| Injection Pressure | 1,000 – 2,000Pbar |
| Holding Pressure | 250 – 1,600Pbar |
| Cushion | 6.4 – 12.7mm |
Mold
| Runner Diameter | 3.05 – 6.1mm |
| Gate Diameter | 0.76 – 1.52mm |
| Gate Area | 0.46 – 1.82mm² |
| Wall Thickness | 0.51 – 3.05mm |
Venting
| Depth (Vent Depth) | 0.0203 – 0.0406mm |
| Land (Vent Land) | 0.508 – 1.02mm |
| Width (Vent / Clearance) | 3.05 – 12.7mm |
| Relief (Relief Channel) | 0.127 – 0.254mm |
Frequently asked questions
PA12 is a semi-crystalline engineering thermoplastic in the polyamide family, synthesized by ring-opening polymerization of laurolactam (a cyclic 12-carbon monomer, vs PA6's 6). That longer chain between amide groups (–CO–NH–) means hydrogen bonds are more spaced out → lower moisture absorption (0.25–1.5% at equilibrium, vs 3% for PA6) and higher flexibility. Density ~1.01 g/cm³ (the lowest among polyamides), melting point 178°C, HDT 50–60°C unfilled.
Moisture absorption: PA12 0.25–1.5%, PA66 2.5%, PA6 3% — this is the most important difference. HDT: PA66 255°C >> PA6 220°C >> PA12 175°C (PA12 loses stiffness sooner). Cost: PA12 ~3× PA66 ~1.15× PA6. Hydrocarbon chemical resistance: PA12 >> PA66 > PA6. Flexibility: PA12 > PA6 > PA66. Rule of thumb: if the part sees water/fuel/oil + needs dimensional stability → PA12. If you need high temperature + stiffness and humidity doesn't matter → PA66. If it's generic mechanical at room temperature → PA6.
Three reasons: (1) Excellent chemical resistance to gasoline, diesel, E85/E100 ethanol blends, B20 biodiesel, DOT 3/4/5.1 brake fluids, road de-icer brine. (2) Low moisture absorption → flexible tubing that doesn't change dimensions with climate. (3) Superior fatigue resistance to cyclic pressures hydraulic lines see. Combined with PA11 (more bio-based) and PA1010, they dominate: fuel lines, brake lines, AC refrigerant lines, urea/AdBlue lines, construction hydraulic lines. Standards: SAE J844 for pneumatics, SAE J2260 for fuel, ISO 7628 for brakes. The switch to EVs doesn't reduce demand — also used in battery pack coolant lines.
Selective Laser Sintering (SLS) and Multi Jet Fusion (HP MJF) are the two dominant industrial additive technologies for functional parts. Both use PA12 powder as the main material. Reasons: (1) wide process window (180–200°C melting, doesn't burn easily), (2) excellent surface finish vs other powders, (3) very low moisture absorption (no drying required in storage), (4) isotropic mechanical properties (no layer orientation), (5) unsintered powder recyclability (40–60% refresh per build). Brands: EOS PA2200 (PA12), HP HR PA12, Sinterit PA12, Stratasys PA12 GB (glass beads). Applications: functional prototypes, low-volume end parts, custom medical (orthopedics), aerospace.
Neat PA12 (Vestamid L, Grilamid L1, Rilsamid AESNO): for flexible fuel lines, connectors, elastic parts requiring chemical resistance. PA12-GF30 (with 30% glass fiber): much higher rigidity, HDT 160°C, for structural under-hood parts with low-absorption requirement. PA12-plasticized (Vestamid LX): even more flexible, almost rubbery, for coiled hoses. PA12 trans (transparent): clear as glass when cooled fast (stays amorphous), for goggles, lenses, optical-flexible signage. PA612, PA610, PA1010, PA1012: similar chemical siblings, all long-chain with similar properties.
PA11: 100% bio-based, derived from castor oil (African drought-resistant plant). It's the original green plastic, commercialized since 1947 by Arkema. Carbon footprint significantly lower than petrochemical polyamides. PA12: currently not bio-based — its monomer (laurolactam) comes from petrochemical butadiene. But there is an active industrial project (Evonik, Arkema) to produce laurolactam from castor oil — commercially available at small scale. PA1010 (Grilamid 1S): 100% bio-based from castor oil, properties intermediate between PA11 and PA12. If your application demands premium sustainability + low absorption, PA11 or PA1010 is the choice.
PA12 absorbs 0.25–0.4% at equilibrium — low, but that same level at injection temperature (220–240°C) can generate bubbles, silver streaks and localized degradation via catalytic hydrolysis. The PDS marks desiccant at 80°C for 3–6 h, dew point ≤ –30°C, target ≤0.1% moisture. In temperate climates with sealed-bag material, you can skip if you use it right after opening. In tropical climate, drying is mandatory even for PA12. Good news: if you forget to dry PA12 once, the damage is much smaller than with PA6 or PA66 — the longer chain is more hydrolysis-resistant.
The PDS marks 38–82°C unfilled. PA12 crystallizes slower than PA6 (longer chain, larger crystallites), so mold temperature matters a lot for final crystallinity. Cold (40–55°C) = more amorphous parts, more flexible, better transparency (PA12 transparent grades require cold mold + fast cooling to stay clear). Hot (70–85°C) = more crystallinity, more rigidity, better chemical resistance, but worse transparency. For fuel lines and mechanical: 70–80°C. For optical transparent PA12 (goggles, signage): 40–50°C + fast cooling. For PA12-GF: 80°C minimum.
Three factors: (1) expensive monomer — laurolactam is manufactured in few global plants and butadiene (its petrochemical precursor) prices are volatile, (2) smaller production scale — global PA12 capacity ~150 kt/year vs ~3000 kt/year for PA6, which keeps margins high, (3) premium specs — most PA12 goes to critical applications (automotive safety, medical, aerospace) that justify price. Result: PA12 costs ~3× what PA66 costs and ~3.5× what PA6 costs. For parts where low moisture absorption or fuel resistance is NOT critical, modified PA6 or PA66 with HR (hydrolysis resistant) is almost always more cost-effective.
Good question — these are border materials. Plasticized PA12 or copolymers: flexible but retains polyamide chemical/thermal resistance. Good shape memory, good elastic recovery. TPE-A (Thermoplastic polyamide elastomer): even more flexible, almost rubbery (Shore 70A to 60D), but lower chemical and thermal resistance. Rule of thumb: for pressurized fuel hoses, quick-disconnect connectors that need moderate rigidity + compression sealing → PA12. For bellows joints, brake boots, decorative hoses that need repeated flexing without fatigue → TPE-A. Many automotive applications use PA12 + TPE-A coextruded: PA12 as barrier/structure, TPE-A as sealing/flexibility layer.