Filament comparison
PA12 vs TPU soft
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | PA12 (Nylon 12)PA | Soft TPU (below 85A)FLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $64.33/kg median; $36.00–$170.67/kg across 3 dated product listings | $114.04/kg median; $109.80–$122.27/kg across 4 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | Polyamide 12 — the longest-chain common nylon, with the fewest amide groups per unit mass and so the least moisture uptake[1][2] | Very soft thermoplastic elastomers below 85 Shore A. Fiberlogy's FiberFlex 30D measures 81 Shore A, the softest grade with a published datasheet found here[3] |
| Densityg/cm³ | 1.01 specific gravity (Stratasys FDM Nylon 12, ASTM D792)[4] | 1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[3] |
| Typical priceUSD/kg | 1 kg-equivalent spools span 36–171; the middle of the market is about 64[5][6] | 1 kg-equivalent spools cluster near 115[7][8][9] |
| Price range across brandsUSD/kg | 36–171 across brands; IEMAI 3D 36, Fiberlogy 64 at 3DJake, 3DXTech AmideX Nylon 12 171[5][10][6] | 110–122 at 1 kg-equivalent; Recreus 70A 110 and 60A 116 at 500 g, NinjaTek Edge 83A 112, NinjaTek Chinchilla 75A 122; the Recreus 3 kg spools fall to 70–73[7][9][8] |
| Market availability1–5 | Available from several mainstream brands[5][10] | Niche, a handful of specialist brands[3][11][7] |
| Spool sizes & diameters | 1.75 and 2.85 mm; 750 g and 1 kg spools[10][5] | 1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[3][7][12][8] |
| Typical applications | Dimensionally stable functional parts, ducting and living hinges where PA6 would move too much with humidity[1][13] | Highly compliant seals, soft grips and prosthetic liners[3] |
| Printing Parameters | ||
| Nozzle temperature°C | 260–290 (Extrudr DURAPRO PA12)[14] | Not documented |
| Bed temperature°C | 110 (Extrudr DURAPRO PA12)[14] | 50–70 (Fiberlogy FiberFlex 30D)[3] |
| Enclosure / chamber requirement1–5 | Enclosure required (passive)[1] | Open frame is fine[3] |
| Part cooling fan | Part cooling fan not required (Simplify3D)[15] | Not documented |
| Bed surface & adhesion aid | PEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[15][1] | PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[16][17] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | 12 at Extrudr's 150 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[14][18] | Not documented |
| Bed-adhesion difficulty1–5 | Needs a specific surface plus adhesive[15][1] | Not documented |
| Stringing / oozing tendency1–5 | Moderate — retraction tuning needed[1] | Not documented |
| Overall printing difficulty1–5 | Advanced — enclosure, hardware upgrades, tuning[1] | Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[12][17] |
| Extruder requirement | Not documented | Direct drive only, with a constrained filament path; Bowden is not viable at this hardness[12][11] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass fine indefinitely for unfilled grades[1] | Brass fine indefinitely[14] |
| Abrasiveness1–5 | Non-abrasive when unfilled[1] | Non-abrasive[14] |
| Nozzle clog risk1–5 | High — jams from moisture, heat creep or particles[13][19] | High — jams from moisture, heat creep or particles; below 85 Shore A the filament buckles and compresses, and Simplify3D warns that raised feed rates most likely end in a jam[16][17][19] |
| Heat-creep / jam sensitivity1–5 | Moderate — good heatbreak cooling needed[15] | Very high — softens in the cold zone readily[17] |
| Hotend requirement | May require an all-metal hot end (Simplify3D)[15] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[16] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | High (0.8–2 %) — Polymaker's PA12-CF10 reaches 1.5 % equilibrium against 3.33 % for its PA6-GF25, and Polymaker developed the PA12 grade specifically for lower moisture sensitivity[2][13] | Moderate[19] |
| Drying temperature & time | 60–80 °C for 8–12 h (Extrudr DURAPRO PA12); 100 °C for 8 h (Polymaker CoPA)[14][20] | Not documented |
| Symptoms when wet | Popping and cracking during extrusion, then hard-to-diagnose defects[13] | Bubbling and popping at the nozzle, stringing and a rough surface[19] |
| Effect of moisture on strength | Polymaker states its PA12 grade changes little between wet and dry, unlike its PA6-based materials; the CoPA dry-to-wet reference shows what the PA6-type response looks like[13][20] | Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[19] |
| Storage requirement | Sealed below 20 % RH with desiccant[19] | Sealed with desiccant; often kept in a dryer during the print[19] |
| Hydrolysis at melt temperature | Polymaker requires a 100 °C dry for 8 h and storage below 20 % RH; no molecular-weight loss figure is published, and the published wet data is conditioning rather than melt hydrolysis[20][21] | Not documented |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | 49.3 at yield and 33.4 at break printed XZ (Stratasys FDM Nylon 12, ASTM D638)[4] | Not documented |
| Young's modulusMPa | 1510 printed XZ and 1250 ZX (Stratasys FDM Nylon 12, ASTM D638)[4] | Not documented |
| Elongation at break% | 30 at break printed XZ against 6.5 in ZX (Stratasys FDM Nylon 12, ASTM D638)[4] | 870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[3] |
| Charpy impact, notchedkJ/m² | 11 at +23 °C and 6.0 at -30 °C (Extrudr DuraPro PA12, ISO 179/1eA); unnotched does not break[14] | Not documented |
| Other impact data | Izod notched 138 J/m printed XZ against 71.0 J/m in ZX (Stratasys FDM Nylon 12, ASTM D256)[4] | Not documented |
| Layer adhesion / Z tensileMPa | 41.8 at yield and 41.2 at break printed ZX (Stratasys FDM Nylon 12, ASTM D638) — higher than the XZ break figure, because XZ specimens draw and neck first[4] | Not documented |
| Brittleness1–5 | Tough — absorbs impact, yields before breaking[1] | Very ductile — bends far before failing[3] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Not documented | 81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[3] |
| Creep resistance / sustained load1–5 | Moderate — the long-chain polyamides hold load better than PLA but below PC[1] | Poor — no creep test at this hardness; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[22] |
| Fatigue / repeated-flex resistance1–5 | Excellent — living hinges viable. Stratasys sells FDM Nylon 12 specifically for repetitive-flex parts such as snap-fit clips and press-fit inserts on the strength of its fatigue properties[1][4] | Excellent — living hinges viable[17] |
| Elasticity / flexibility1–5 | Semi-flexible[13] | Rubbery / highly elastic[3] |
| Z strength as % of XY% | 85 (Stratasys FDM Nylon 12, ZX against XZ tensile yield, ASTM D638) — one of the least anisotropic unfilled filaments measured[4] | Not documented |
| Wear resistance & friction | Not documented | Tear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[3] |
| Thermal Properties | ||
| HDT at 0.45 MPa°C | 94.7 printed XY and 91.9 in XZ/ZX (Stratasys FDM Nylon 12, ASTM D648 at 66 psi)[4] | Not documented |
| HDT at 1.8 MPa°C | 84.3 printed XY and 75.3 in XZ/ZX (Stratasys FDM Nylon 12, ASTM D648 at 264 psi)[4] | Not documented |
| Glass transition (Tg)°C | 34.0 (Stratasys FDM Nylon 12, ASTM D7426 inflection point)[4] | Not documented |
| Melting point / Vicat°C | Vicat A 142 (Extrudr DURAPRO PA12, ISO 306)[14] | 170 melting (Fiberlogy FiberFlex 30D, DSC)[3] |
| Continuous service temperature°C | Bounded by a Vicat softening point of 142 °C (Extrudr DURAPRO PA12); no loaded-bar service figure is published[14] | Not documented |
| Thermal expansion (CTE)µm/m·K | 84-103 printed (Stratasys FDM Nylon 12, ASTM E831: 84.4 in XY and 85.6 in XZ/ZX over -50 to 10 °C, 89.1 over 10-45 °C, 98.2 over 45-70 °C); Extrudr quotes 100 for DURAPRO PA12 (ISO 11359-2)[14][4] | Not documented |
| Flammability / UL 94 | Flammable; no UL 94 rating published for the unfilled grades surveyed[14] | Not documented |
| Environment & Chemical | ||
| UV resistance1–5 | Months outdoors before embrittlement[1] | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[17] |
| Chemical resistance | Withstands oils, fuels and alkalis[1] | Withstands industrial solvents and UV exposure (Polymaker)[17] |
| Water / humidity resistance in service1–5 | Good — minor absorption; the least moisture-sensitive of the common nylons[13] | Not documented |
| Food contact | Not food-contact certified as filament[1] | Not food safe without specific certification (Polymaker)[17] |
| Biodegradability / compostability | Not biodegradable[1] | Not biodegradable[17] |
| Recyclability | Mechanically recyclable but not accepted in household plastic collection[1] | Not accepted in household plastic collection[17] |
| Health & Safety | ||
| Fume toxicity1–5 | Moderate — measurable VOCs and UFPs, ventilation advised[23] | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[23] |
| VOC emission rateµg/min | Up to 180 caprolactam, the dominant VOC from nylon; total VOC reached nearly 200 µg/min, the highest of the nine filaments tested[23] | Not documented |
| Ultrafine-particle emission rateparticles/min | ≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[23] | Not documented |
| Hazardous species emitted | Caprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[23] | Not documented |
| Ventilation / filtration requirement1–5 | Ventilated room or enclosure recommended[23] | Open a window / occasional ventilation[23] |
| Post-Processing | ||
| Sanding & machining | Sands poorly — gums rather than powders[15] | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[17] |
| Gluing & solvent welding | Cyanoacrylate; no common solvent welds polyamide[15] | Cyanoacrylate bonds TPU; no common solvent welds it[17] |
| Vapour / chemical smoothing | No practical vapour smoothing[15] | No practical vapour smoothing[17] |
| Support material pairing | Polymaker sells a break-away PolySupport matched to PA12[15] | Polymaker warns TPU supports are often very difficult to remove[17] |
| Dimensional accuracy & detail | Holds dimensions better than PA6 after conditioning — Polymaker singles its PA12 grade out on exactly this point[13] | Not documented |
| Solvents & Solubility | ||
| Soluble in | Dissolved at 23 °C by formic acid, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — all laboratory reagents.[24][25] | DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[26] |
| Softened or crazed by | Not resistant to 10 % formic acid, phenol, chloroform or dichloromethane (Ensinger); zinc chloride stress-cracks nylon.[25][24] | Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[26] |
| Solvent welding & smoothing agent | None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[24] | None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[26] |
Material entries describe families or representative grades, not an interchangeable specification for every spool. Test methods, orientations and conditions may differ. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.
Sources for this comparison
- PA (Nylon) — material basics Polymaker Wiki · 2026-08 · doc
- Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
- FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
- FDM Nylon 12 — Material Data Sheet Stratasys · 2021-09 · tds
- Nylon PA12 — product listing 3DJake International · 2026-08 · vendor
- IEMAI 3D PA12 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
- Recreus product catalogue Recreus · 2026-08 · vendor
- Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
- NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
- 3DXTech product catalogue 3DXTech · 2026-08 · vendor
- Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
- NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
- Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
- PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
- BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
- Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments (Azimi et al.) Environmental Science & Technology 50(3) 1260-1268 · 2016-01 · paper
- Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
- Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
- Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds