Clariant Polyamide 12 3D Printer Filament is supplied as an unfilled, natural-colour semicrystalline nylon 12 feedstock for fused filament fabrication and direct extrusion additive manufacturing. The material designation appears on supplier documentation as Clariant Polyamide 12 3D Printer Filament; regional order codes differ by diameter, spool weight, and packaging date. The product is available in 1.75 mm and 2.85 mm diameters on vacuum-sealed spools with desiccant, typically in 500 g, 750 g, or 1 kg net weights depending on the distribution SKU. The base polymer is poly(ω-laurolactam), with a differential scanning calorimetry melting peak at 178–180 °C under ISO 11357-3. Compounding is performed on twin-screw extruders with length-to-diameter ratios of 44:1 and melt temperatures 240–260 °C, followed by melt filtration and diameter-controlled winding. This feedstock is not a low-temperature filament; it requires an all-metal hot end, a heated build plate, and active moisture management.

Incoming diameter tolerance is maintained at ±0.03 mm for 1.75 mm stock and ±0.05 mm for 2.85 mm stock, with ovality below 0.03 mm under dual-axis laser gauge. Vacuum-sealed spools are dried to below 0.1 wt% moisture before packaging. Once the sealed barrier is opened, exposure to 23 °C and 50 % RH for more than 24 h shifts the moisture equilibrium toward 0.3–0.6 wt%; processing in that state produces steam-related porosity at the nozzle and reduces interlayer weld strength. If ambient relative humidity exceeds 60 % RH, or if the spool has been open for longer than 24 h, drying at 80 °C in a desiccant dry-air or vacuum dryer with a dew point below -30 °C for 4–6 h is mandatory before printing. Dried spools should be fed from a sealed dry box maintained below 10 % RH to prevent re-adsorption during long build jobs.

What separates Clariant PA12 filament from PLA, ABS, and PA6 in serial part fabrication?

The principal differences are moisture equilibrium, failure strain, and chemical response. Compared with unreinforced PA6 filament, polyamide 12 has a lower amide group density and therefore reaches a lower saturated water uptake under ISO 62: 1.4–1.6 wt% for PA12 versus 9–10 wt% for PA6. That distinction stabilises printed part dimensions in humid environments and reduces steam-driven outgassing during melt deposition. Compared with PLA filament, PA12 has a lower tensile modulus—1200–1400 MPa versus 3000–3500 MPa under ISO 527-2—and higher elongation at break, typically 20–40 % for dry conditioned PA12 against 3–8 % for PLA. Compared with ABS, PA12 has higher resistance to aliphatic hydrocarbon stress cracking and no styrene monomer in the polymer backbone; ABS exhibits lower moisture uptake and lower cost, but may have lower solvent resistance and a more brittle failure mode at similar elongation levels. Table 2 provides representative literature values for unfilled unmodified grades; these are not lot-specific supplier certificates.

On production fused filament fabrication systems, a hardened steel or ruby nozzle with bore 0.4 mm to 0.6 mm is specified; brass nozzles wear rapidly with semicrystalline nylon filaments, particularly at sustained nozzle temperatures above 250 °C. A heated build plate set to 80–110 °C is required, with polyamide-targeted adhesion media or a structured polyamide build sheet. A passively heated chamber at 45–60 °C is recommended for parts with continuous lengths above 150 mm; chamber temperatures below 40 °C increase warp and reduce Z-direction tensile strength because the interlayer weld solidifies before chain interdiffusion can reach the required depth. Part-cooling fans are disabled or limited to 20 % duty cycle for cross-sections above 50 mm to prevent delamination. Print speed is typically 30–80 mm/s on a 0.4 mm nozzle; above 100 mm/s, melt throughput approaches the heat capacity limit of standard 40 W hot ends, producing irregular extrusion and lower layer adhesion. Direct-drive retraction settings of 0.5–2 mm at 20–30 mm/s are used to prevent nozzle clogging; Bowden systems require longer retraction values tied to tube length and should be established by machine-specific tuning.

Support removal is a constraint in serial production. Unfilled PA12 forms strong self-welds, so breakaway supports are difficult to separate cleanly; dual-extrusion soluble supports must withstand PA12 nozzle temperatures, because PVA support material decomposes below 200 °C and is not compatible. A maleic-anhydride-compatible copolyamide or dedicated PA12 support grade with a lower melt viscosity is preferred when the geometry requires soluble supports. In continuous extrusion or pellet-fed additive manufacturing conversion, the material should be dried to below 0.1 wt% moisture and processed at a melt temperature not exceeding 270 °C. Residence time above 280 °C should remain below 5 min to limit thermo-oxidative chain scission and yellowing. Batch-to-batch variation is monitored by melt volume-flow rate under ISO 1133-1:2022 at 235 °C with a 2.16 kg piston load; typical unfilled PA12 lot values fall in the 8–12 cm³/10 min range. A certificate of analysis should list this value together with moisture and diameter measurements for the exact lot.

Printed PA12 parts usually require scale-factor compensation for semicrystalline shrinkage. Representative shrinkages for plate-printed unfilled PA12 in an actively heated chamber are 0.3–0.8 % in the XY plane and 1.0–1.5 % in the Z direction, depending on infill density and chamber setting. For close-tolerance features, a validation print with at least 3 replicate parts and coordinate measuring machine inspection is necessary before production release.

Moisture equilibration, drying thresholds, and interlayer fusion limits

Polyamide 12 absorbs water primarily through hydrogen bonding at amide sites, but the C12 aliphatic chain dilutes the amide concentration and limits equilibrium uptake. Under ISO 62 immersion at 23 °C, unfilled PA12 reaches saturation at roughly 1.4–1.6 wt%; at 23 °C and 50 % RH, equilibrium uptake is near 0.6–0.8 wt%. Moisture above 0.1 wt% in the melt phase hydrolyses amide bonds during extrusion, reducing molecular weight and interlayer weld strength. The practical failure signature is a milky, steam-voided surface and a loss of Z-axis tensile strength below 30 % of XY-plane strength. Drying at 80 °C for 4–6 h in a dry-air dryer with a dew point below -30 °C is adequate for spools exposed to 60 % RH for up to 24 h. If spools have been exposed for longer than 48 h, drying should be extended to 8–12 h and confirmed by Karl Fischer titration or weight loss until moisture is below 0.1 wt%. Drying above 90 °C is not recommended because the filament can locally deform on the spool and lose diameter tolerance.

Interlayer fusion in PA12 is controlled by intimate contact development and chain diffusion across the weld plane. The processing window is narrow: below 250 °C, melt viscosity is too high to wet the previous layer; above 270 °C, oxidative yellowing and outgassing increase. At a chamber temperature of 60 °C, isothermal crystallisation is sufficiently retarded to maintain a molten interface. Reported Z-axis tensile strength retention for unfilled PA12 fused filament parts in peer-reviewed studies falls in the 50–60 % range relative to XY-plane strength. At chamber temperatures below 40 °C, retention can drop below 30 %, particularly when cooling fans are used. Published data for the exact Clariant stabilised filament configuration is limited; therefore, machine-specific printed tensile bars under ISO 527-2 are required for critical load-bearing parts.

When end-use parts must survive fuel contact, hydrolysis, or repeated mechanical cycling

PA12 is specified for fluid-contact brackets, automotive under-hood clips, hydraulic line guides, and medical device mock-ups because the long aliphatic chain provides a balance of low-temperature ductility and resistance to aliphatic hydrocarbons. Chemical resistance is not inferred from polymer class alone; each fluid class should be validated under ASTM D543-14. In straight-run diesel and non-oxygenated gasoline at 23 °C, unfilled PA12 typically shows weight change below 2 % after 7 days, but methanol- or ethanol-blended fuels can increase uptake and extraction of low-molecular weight species. Concentrated mineral acids, phenols, and chlorinated solvents should be avoided because they degrade the amide bond or plasticise the matrix. Repeated autoclave sterilisation at 121 °C is not recommended because saturated steam accelerates hydrolytic degradation and produces dimensional change. Low-temperature hydrogen peroxide gas plasma and gamma irradiation up to 25 kGy are more compatible when validated under ISO 11135 and ISO 11137. If the part contacts skin or tissue, application-specific biocompatibility review under ISO 10993-5 and ISO 10993-10 is required; the base feedstock should not be assumed to be medical-grade without lot-level documentation.

Compared with glass-filled PA12, this unfilled filament has lower tensile modulus—usually 2500–4500 MPa at 15–30 % glass loading versus 1200–1400 MPa for unfilled—but retains much higher elongation at break and lower nozzle abrasion. Compared with polyamide 11, PA12 has a slightly lower melting peak and a more tightly controlled melt-volume-flow range in standard filament grades, while PA11 may offer higher impact at cryogenic temperatures but varies more between suppliers. Unfilled PA12 is therefore selected where repeated snap-fit cycling and low-temperature ductility dominate; it is not recommended for continuous service above 120 °C under load because oxidative embrittlement becomes measurable after extended exposure, and a high-temperature polymer should be substituted.

Thermal and mechanical properties measured under ISO test conditions

The values in Table 1 are representative for unfilled, dry polyamide 12 filament of the same base resin family; they are not batch-specific minima. All mechanical values are influenced by moisture state, print orientation, interlayer time, and specimen conditioning. For design calculations, printed test coupons should be conditioned for at least 40 h at 23 °C and 50 % RH according to ISO 291 before testing.

The material is supplied with a REACH SVHC content below 0.1 % w/w per supplier statement and is evaluated for RoHS Directive 2011/65/EU when the finished electrical or electronic article is within scope. No UL Yellow Card flame classification is available for the feedstock itself unless specified on the finished part by the end user. The filament is not food-contact certified unless a specific lot-level migration study under Regulation (EU) 10/2011 or FDA 21 CFR 177.1500 has been executed and documented.

For quality control, printed tensile specimens oriented in the XY plane are prepared to ISO 527-2 Type 1BA geometry, and Z-axis adhesion is evaluated with the same standard using an extensometer. Without conditioning, as-printed PA12 can show apparent tensile modulus 10–15 % higher because of residual crystallinity anisotropy; moisture uptake later reduces this value. Design calculations should use conditioned values rather than dry as-printed values.

Unopened spools should be stored at 20–25 °C in a low-humidity environment below 10 % RH; shelf life is typically 12 months from the packaging date when the moisture-barrier pouch remains intact. After opening, the spool should be consumed within 48 h or re-dried before use. Humidity indicators should be inspected before printing; if the indicator shows exposure above 20 % RH, the drying cycle should be repeated. These storage limits are operational boundaries intended to prevent hydrolysis and diameter drift; lot-specific packaging slips may impose tighter restrictions.