3D Printing InfoFilament comparison
PA6 vs TPU-CF
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | PA6 (Nylon 6)PA | Carbon-fibre TPUFLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $104.00/kg median; $38.99–$136.00/kg across 3 dated product listings | $107.05/kg median; $107.05–$107.05/kg across 1 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | Polyamide 6, ring-opened from caprolactam — the most hygroscopic of the common nylons[1][2] | Carbon-fibre reinforced thermoplastic polyurethane at the hard end of the range[3] |
| Densityg/cm³ | 1.06 (ISO 1183, 3DXTech iOn PA6 alloy)[4] | 1.22 (Extrudr FLEX HARD CF, ISO 2781)[3] |
| Typical priceUSD/kg | 1 kg-equivalent spools span 39–136; the middle of the market is about 104, though budget unfilled PA6 has now arrived at 39[5][6] | 107 for the only retail listing found (Extrudr 0.5 kg coil, incl. VAT)[7] |
| Price range across brandsUSD/kg | 39–136 across brands; YXPOLYER 39, 3DXTech iOn Nylon 6 Alloy 104, WearX Nylon 6 136. Unfilled PA6 filament stays rare — most PA6 reaches the market glass- or carbon-filled[5][6] | One listing only: EUR 49.56 incl. VAT per 0.5 kg coil, direct from Extrudr; no reseller or second brand found[7] |
| Market availability1–5 | Niche, a handful of specialist brands[5] | Niche, a handful of specialist brands — Extrudr's FLEX HARD CF is the only carbon-filled flexible with a published datasheet found here[3] |
| Spool sizes & diameters | 1.75 and 2.85 mm; 500 g and 750 g spools[5] | 1.75 mm; 0.5 and 2 kg coils[7] |
| Typical applications | Wear parts, bushings and gears where PA6's toughness and abrasion resistance matter more than dimensional stability[1] | Stiffened flexible parts — damping mounts and semi-rigid brackets[3] |
| Printing Parameters | ||
| Nozzle temperature°C | 220–260 (Polymaker); 225–265 (Simplify3D)[1][8] | 230–260 (Extrudr FLEX HARD CF)[3] |
| Bed temperature°C | 70–100 (Polymaker); 70–90 (Simplify3D)[1][8] | 50–90 (Extrudr FLEX HARD CF)[3] |
| Enclosure / chamber requirement1–5 | Enclosure required (passive)[9][1] | Open frame is fine[3] |
| Part cooling fan | Part cooling fan not required (Simplify3D)[8] | Not documented |
| Bed surface & adhesion aid | PEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[8][1] | PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[10][11] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | Not documented | 1.6–8 at the 20–100 mm/s Extrudr specifies on a 0.4 mm nozzle at 0.2 mm layer[3] |
| Bed-adhesion difficulty1–5 | Needs a specific surface plus adhesive[8][1] | Not documented |
| Stringing / oozing tendency1–5 | Moderate — retraction tuning needed[1] | Not documented |
| Overall printing difficulty1–5 | Advanced — enclosure, hardware upgrades, tuning; the filament must be kept dry throughout the print[1][12] | Advanced — enclosure, hardware upgrades, tuning; hardened nozzle needed[3] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass fine indefinitely for unfilled grades[1] | Hardened steel required — Extrudr marks FLEX HARD CF as needing a hardened nozzle where its unfilled FLEX grades do not[3] |
| Abrasiveness1–5 | Non-abrasive when unfilled[1] | Highly abrasive — standard CF composite[3] |
| Nozzle clog risk1–5 | Very high — frequent jams without careful setup; wet nylon pops and cracks in the melt[13][12] | High — jams from moisture, heat creep or particles; a flexible base plus chopped carbon fibre, which Prusa lists as a higher nozzle-clogging risk, and Extrudr requires a hardened nozzle[14][3][10] |
| Heat-creep / jam sensitivity1–5 | Moderate — good heatbreak cooling needed[8] | Not documented |
| Hotend requirement | May require an all-metal hot end (Simplify3D)[8] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[10] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Very high (>2 %) — Polymaker groups nylon with PVA as the most moisture-prone class, and its own PA6-based composites reach 2.35–3.33 % equilibrium[12][15] | Moderate[12] |
| Drying temperature & time | 100 °C for 8 h (Polymaker CoPA); storage below 20 % RH[9][16] | 60 °C for 6 h (Extrudr FLEX HARD CF)[3] |
| Symptoms when wet | Popping and cracking during extrusion, then defects that Polymaker describes as very hard to diagnose[13] | Bubbling and popping at the nozzle, stringing and a rough surface[12] |
| Effect of moisture on strength | Measured dry against wet on printed specimens at 6.16 % moisture (Polymaker CoPA): tensile 78.0 → 34.3 MPa, Young's modulus 2703 → 724 MPa, flexural strength 109.8 → 22.6 MPa, while notched Charpy rises 6.9 → 27.7 kJ/m² and elongation 12.7 → 13.2 %[9][13] | Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[12] |
| Storage requirement | Sealed below 20 % RH with desiccant; Polymaker says nylon often needs to stay in a dryer while printing[16][12] | Sealed with desiccant; often kept in a dryer during the print[12] |
| 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[9][16] | Not documented |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | 62 at break (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned to 20 °C / 50 % RH gives 67.6 ultimate and 49.3 at yield printed XZ (ASTM D638)[4][17] | Not documented |
| Young's modulusMPa | 2110 (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2232 printed XZ and 1817 ZX (ASTM D638)[4][17] | 35 (Extrudr FLEX HARD CF, ISO 527-2/5A/500)[3] |
| Elongation at break% | 9 at break (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 38 printed XZ against 3.2 in ZX (ASTM D638)[4][17] | 380 ultimate elongation (Extrudr FLEX HARD CF, ISO 527-2/5A/500), against 490 for the unfilled FLEX HARD[3] |
| Flexural strengthMPa | 78 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 97.2 printed XZ and 82 ZX (ASTM D790)[4][17] | Not documented |
| Flexural modulusMPa | 2200 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2196 printed XZ and 1879 ZX (ASTM D790)[4][17] | Not documented |
| Other impact data | Izod notched 106 J/m printed XZ against 43 J/m in ZX; unnotched 2873 against 192 J/m (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D256 Method A) — a 15x anisotropy unnotched[17] | Not documented |
| Layer adhesion / Z tensileMPa | 36.5 ultimate and 28.9 at yield printed ZX (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D638)[17] | 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 | Shore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded unfilled PA66 stock (ASTM D2240, D785); no figure is published for a PA6 filament[18] | 70 Shore D (Extrudr FLEX HARD CF, ISO 868), against 58 Shore D for the unfilled FLEX HARD[3] |
| Creep resistance / sustained load1–5 | Moderate[1] | Below average — no CF-grade creep test; the grade is 70 Shore D where a 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[3][19] |
| Fatigue / repeated-flex resistance1–5 | Excellent — living hinges viable[1] | Good — 380 % ultimate elongation and a damping application set (Extrudr cites longboard wheels), below the unfilled grades[3] |
| Elasticity / flexibility1–5 | Semi-flexible[13] | Semi-flexible[3] |
| Z strength as % of XY% | 54 (Stratasys FDM Nylon 6 conditioned, ZX against XZ ultimate tensile, ASTM D638); 59 on the yield figures[17] | Not documented |
| Wear resistance & friction | 3DXTech sells a dedicated wear-resistant PA6 grade; abrasion resistance is the usual reason to choose PA6 over PA12[5] | Abrasion 26 mm³ (Extrudr FLEX HARD CF, ISO 4649-A) — the same as the unfilled FLEX HARD[3] |
| Thermal Properties | ||
| HDT at 1.8 MPa°C | 93 (Stratasys FDM Nylon 6, conditioned, ASTM D648 at 264 psi)[17] | Not documented |
| Glass transition (Tg)°C | 105 (DSC, 3DXTech iOn PA6 alloy)[4] | -24 (Extrudr FLEX HARD CF)[3] |
| Melting point / Vicat°C | Not documented | Vicat A 140 (Extrudr FLEX HARD CF, ISO 306)[3] |
| Thermal expansion (CTE)µm/m·K | 81.0 on extruded unfilled PA66 stock (ASTM D696; source states 4.5e-5 in/in/°F); no figure is published for a PA6 filament, and PA6 and PA66 expand almost identically[18] | Not documented |
| Flammability / UL 94 | Flammable; no UL 94 rating published for the unfilled filament grades surveyed[4] | Not documented |
| Environment & Chemical | ||
| UV resistance1–5 | Months outdoors before embrittlement — unstabilised polyamide yellows and chalks under UV[1] | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[11] |
| Chemical resistance | Withstands oils, fuels and alkalis — the usual reason to choose a polyamide[1] | Withstands industrial solvents and UV exposure (Polymaker)[11] |
| Water / humidity resistance in service1–5 | Absorbs water, properties shift — a conditioned part is measurably softer and larger than the same part dry[13][9] | Not documented |
| Food contact | Polymaker notes medical-grade variants exist, but standard filament is not food-contact certified[1] | Not food safe without specific certification (Polymaker)[11] |
| Biodegradability / compostability | Not biodegradable[1] | Not biodegradable[11] |
| Recyclability | Mechanically recyclable but not accepted in household plastic collection[1] | Not accepted in household plastic collection[11] |
| Health & Safety | ||
| Fume toxicity1–5 | Moderate — measurable VOCs and UFPs, ventilation advised[2] | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[2] |
| 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[2] | Not documented |
| Ultrafine-particle emission rateparticles/min | ≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[2] | 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[2] | Not documented |
| Ventilation / filtration requirement1–5 | Ventilated room or enclosure recommended[2] | Open a window / occasional ventilation[2] |
| Dust & fibre handling hazard | Not documented | Carbon fibre is bound in the matrix; sanding dust should not be inhaled[3] |
| Post-Processing | ||
| Sanding & machining | Sands poorly — the toughness makes it gum rather than powder[8] | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[11] |
| Gluing & solvent welding | Cyanoacrylate; no common solvent welds polyamide[8] | Cyanoacrylate bonds TPU; no common solvent welds it[11] |
| Vapour / chemical smoothing | No practical vapour smoothing[8] | No practical vapour smoothing[11] |
| Support material pairing | PVA dissolves cleanly against nylon; Polymaker sells a break-away PolySupport for PA12[8] | Polymaker warns TPU supports are often very difficult to remove[11] |
| Dimensional accuracy & detail | Parts grow as they absorb moisture after printing; Polymaker declines to publish a standard dimensional allowance because it depends on geometry and infill[13] | Tear strength 165 kN/m (Extrudr FLEX HARD CF, ISO 34-1B)[3] |
| Solvents & Solubility | ||
| Soluble in | Dissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[20] | DMF, DMSO, NMP and THF dissolve the TPU matrix and leave the fibre; ketones are partial solvents. Laboratory reagents.[21] |
| Softened or crazed by | Zinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[20] | Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[21] |
| Solvent welding & smoothing agent | None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[20] | None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[21] |
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
- 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
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- iOn PA6-based Nylon Alloy Technical Data Sheet v2.0 3DXTech · 2026-08 · tds
- 3DXTech product catalogue 3DXTech · 2026-08 · vendor
- YXPOLYER PA6 Black 1 kg — product page YXPOLYER · 2026-08 · vendor
- Extrudr TPU FLEX Hard CF — product page (1.75 mm, 0.5 and 2 kg coils, price) Extrudr (FD3D GmbH) · 2026-08 · vendor
- Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
- Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
- Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
- PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
- FDM Nylon 6 — data sheet (conditioned 20 °C / 50 % RH) Stratasys · 2017-11 · tds
- TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
- BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
- Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
- Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds