3D Printing Info

Filament comparison

PA6-GF vs TPU soft

Compare printing settings, strength, heat resistance, dated prices and sources.

Glass-fibre PA6 (PA6-GF) guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6-GF comparisonsMore TPU soft comparisons
PA6-GF vs TPU soft — documented properties and sources
PropertyGlass-fibre PA6 (PA6-GF)PASoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$59.98/kg median; $39.99–$130.00/kg across 6 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPA6 reinforced with chopped glass fibre — Polymaker's grade is 25 wt%[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/cm³1.14 (Bambu Lab) and 1.20 (Polymaker Fiberon), ISO 1183[2][1]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[3]
Typical priceUSD/kg1 kg-equivalent spools span 40–130; the middle of the market is about 60[2][4][5]1 kg-equivalent spools cluster near 115[6][7][8]
Price range across brandsUSD/kg40–130 across brands; SUNLU 40, YXPOLYER 45, Polymaker Fiberon and Bambu Lab 60, 3DXTech FibreX 87, Obsidian Nylon 6+GF 130[4][2][9][5][10]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[6][8][7]
Market availability1–5Stocked by most mainstream brands[2][4][9][5][10]Niche, a handful of specialist brands[3][11][6]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75 and 1 kg spools[4][9][2]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[3][6][12][7]
Typical applicationsStiff, heat-resistant structural parts where a matte finish and lower cost beat carbon fibre[2][1]Highly compliant seals, soft grips and prosthetic liners[3]
Printing Parameters
Nozzle temperature°C260–290 (Bambu Lab)[2]Not documented
Bed temperature°CNot documented50–70 (Fiberlogy FiberFlex 30D)[3]
Enclosure / chamber requirement1–5Enclosure required (passive) — Bambu Lab specifies a 45–60 °C chamber[2]Open frame is fine[3]
Recommended chamber temperature°C45–60 (Bambu Lab)[2]Not documented
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[13][14]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[15][16]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s10 at Bambu Lab's 130 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[2][17]Not documented
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[13]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed[14]Not documented
Overall printing difficulty1–5Expert / industrial hardware only[2][18]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][16]
Extruder requirement0.6 mm nozzle recommended by Bambu Lab; 0.4 and 0.8 also supported[2]Direct drive only, with a constrained filament path; Bowden is not viable at this hardness[12][11]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required — Polymaker measures brass nozzle life at about 9 h on PA6-GF25 and recommends hardened steel or ruby[1]Brass fine indefinitely[19]
Abrasiveness1–5Highly abrasive — standard GF composite; Polymaker puts brass nozzle life at roughly 9 h on PA6-GF25[1]Non-abrasive[19]
Nozzle clog risk1–5Very high — frequent jams without careful setup[18]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[15][16][18]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[13]Very high — softens in the cold zone readily[16]
Hotend requirementMay require an all-metal hot end (Simplify3D)[13]No special hot-end required, but a direct-drive extruder is (Simplify3D)[15]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %) — 2.56 % saturated at 25 °C / 55 % RH (Bambu Lab) and 3.33 % equilibrium (Polymaker Fiberon), the highest in the dataset[2][1]Moderate[18]
Equilibrium moisture content at ~50 % RH%2.56 saturated at 25 °C / 55 % RH (Bambu Lab); 3.33 equilibrium (Polymaker Fiberon PA6-GF25)[2][1]Not documented
Drying temperature & time80 °C for 8–12 h (Bambu Lab)[2]Not documented
Symptoms when wetPopping and cracking during extrusion, then hard-to-diagnose defects[20]Bubbling and popping at the nozzle, stringing and a rough surface[18]
Effect of moisture on strengthPolymaker publishes dry and wet printed blocks for PA6-GF25 itself: at 4.57 % moisture tensile falls 80.1 → 40.2 MPa and modulus 5357 → 1794 MPa, while notched Charpy rises 10.0 → 28.0 kJ/m²[1][20]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[18]
Storage requirementSealed below 20 % RH with desiccant[18]Sealed with desiccant; often kept in a dryer during the print[18]
Hydrolysis at melt temperaturePolymaker specifies an 80–100 °C dry and storage below 20 % RH; no molecular-weight loss figure is published, and the wet data it does publish is conditioning rather than melt hydrolysis[21][22]Not documented
Mechanical Properties
Tensile strength (XY)MPa75 ± 6 (Bambu Lab) and 80.1 ± 1.8 (Polymaker Fiberon, dry/annealed) printed XY, ISO 527; Fiberon falls to 40.2 ± 2.1 conditioned to 4.57 % moisture. Stratasys FDM PA6/66-GF30-FR gives 60.2-61.1 at break and 61.7-62.3 at yield printed XZ (ASTM D638)[2][1][23]Not documented
Young's modulusMPa2850 ± 260 (Bambu Lab) and 5357 ± 211 (Polymaker Fiberon, dry) printed XY, ISO 527; Fiberon falls to 1794 ± 84 conditioned. Stratasys FDM PA6/66-GF30-FR gives 5600-5830 printed XZ against 3050-3140 in ZX (ASTM D638)[2][1][23]Not documented
Elongation at break%2.4 ± 0.2 dry (Polymaker Fiberon) to 3.9 ± 0.8 (Bambu Lab) printed XY, ISO 527; the Fiberon grade rises to 4.2 ± 0.7 conditioned[2][1]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[3]
Flexural modulusMPa3670 ± 140 printed XY, ISO 178 (Bambu Lab)[2]Not documented
Charpy impact, notchedkJ/m²10.0 ± 0.7 printed XY dry and 28.0 ± 1.0 conditioned, ISO 179 notched (Polymaker Fiberon); Bambu Lab 7.2 ± 2.3[1][2]Not documented
Other impact dataCharpy unnotched 27.2 ± 2.2 printed XY (Bambu Lab, ISO 179). Stratasys FDM PA6/66-GF30-FR gives Izod notched 74.6-77.1 J/m printed XZ against 17.2-22.1 in ZX (ASTM D256)[2][23]Not documented
Layer adhesion / Z tensileMPa27 ± 5 (Bambu Lab) and 60.7 ± 1.1 (Polymaker Fiberon, dry) printed Z, ISO 527 — the two makers differ by more than a factor of two; Fiberon falls to 26.3 ± 1.5 conditioned. Stratasys FDM PA6/66-GF30-FR gives 23.7-24.4 at break printed ZX (ASTM D638)[2][1][23]Not documented
Brittleness1–5Brittle — snaps with little warning; elongation at break 2.4 % in XY[1]Very ductile — bends far before failing[3]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M88 / R117 on extruded PA66-GF30 stock (ASTM D785)[24]81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[3]
Creep resistance / sustained load1–5Good. Ensinger lists high creep resistance as a headline property of extruded PA66-GF30 stock; the rating is held below Excellent because equilibrium moisture uptake of 3.33 % softens the matrix in service[24][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[25]
Fatigue / repeated-flex resistance1–5Good. Ensinger lists high fatigue strength as a headline property of extruded PA66-GF30 stock[24]Excellent — living hinges viable[16]
Elasticity / flexibility1–5Rigid[2]Rubbery / highly elastic[3]
Z strength as % of XY%36 (Bambu Lab) to 76 (Polymaker Fiberon), printed; Stratasys FDM PA6/66-GF30-FR gives 39-41 (ZX against XZ tensile at break, ASTM D638)[2][1][23]Not documented
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[3]
Thermal Properties
HDT at 0.45 MPa°C182 (Bambu Lab) and 191 (Polymaker Fiberon), ISO 75 at 0.45 MPa. Stratasys FDM PA6/66-GF30-FR gives 161 printed XY and 185 XZ (ASTM D648 at 66 psi)[2][1][23]Not documented
HDT at 1.8 MPa°C157 (Polymaker Fiberon) and 158 (Bambu Lab), ISO 75 at 1.8 MPa[2][1]Not documented
Glass transition (Tg)°C67 (Bambu Lab) and 70.4 (Polymaker Fiberon), DSC; Stratasys measures 51.5 on FDM PA6/66-GF30-FR (ASTM D7426)[2][1][23]Not documented
Melting point / Vicat°C214.5 (Polymaker Fiberon) and 219 (Bambu Lab) melting, DSC; Vicat 210–212 (ISO 306)[2][1]170 melting (Fiberlogy FiberFlex 30D, DSC)[3]
Thermal expansion (CTE)µm/m·K48.6 on extruded PA66-GF30 stock (ASTM D696; source states 2.7e-5 in/in/°F). Stratasys measures much higher on printed FDM PA6/66-GF30-FR — 95.4 over -20 to 5 °C and 214 over 25 to 80 °C in XY (ASTM E831)[24][23]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for the grades surveyed[21]Not documented
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows under UV[14]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[16]
Chemical resistanceWithstands oils, fuels and alkalis[14]Withstands industrial solvents and UV exposure (Polymaker)[16]
Water / humidity resistance in service1–5Absorbs water, properties shift[20]Not documented
Food contactNot food-contact certified as filament[14]Not food safe without specific certification (Polymaker)[16]
Biodegradability / compostabilityNot biodegradable[14]Not biodegradable[16]
RecyclabilityNot accepted in household plastic collection[14]Not accepted in household plastic collection[16]
Electrical & ESD propertiesSurface resistivity above 10¹² ohm — insulating (Polymaker Fiberon, ANSI/ESD S11.11)[1]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[26]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[26]
VOC emission rateµg/minUp to 180 caprolactam, the dominant VOC from nylon and the largest single-VOC rate in the study[26]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median for nylon — low for particles despite the highest VOC mass measured[26]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament[26]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[26]Open a window / occasional ventilation[26]
Dust & fibre handling hazardGlass fibre is bound in the matrix; avoid inhaling sanding dust[1]Not documented
Post-Processing
Sanding & machiningSands poorly — gums rather than powders[13]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[16]
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[13]Cyanoacrylate bonds TPU; no common solvent welds it[16]
Vapour / chemical smoothingNo practical vapour smoothing[13]No practical vapour smoothing[16]
Support material pairingNot documentedPolymaker warns TPU supports are often very difficult to remove[16]
Solvents & Solubility
Soluble inFormic acid, phenol, m-cresol and hexafluoroisopropanol dissolve the matrix at 23 °C, leaving the fibre; laboratory reagents.[27]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[28]
Softened or crazed byZinc chloride solutions stress-crack the nylon matrix, alcoholic calcium chloride dissolves it, mineral acids attack it.[27]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[28]
Solvent welding & smoothing agentNone — nylon's only solvents (formic acid, phenol, HFIP) degrade the part, and the fibre blocks surface flow anyway.[27]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[28]

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

  1. Fiberon PA6-GF25 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  2. Bambu Filament Technical Data Sheet — PA6-GF Bambu Lab · 2026-08 · tds
  3. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  4. Polymaker product catalogue Polymaker · 2026-08 · vendor
  5. SUNLU Nylon-6 Glass Fiber (PA6-GF) 3D Printer Filament 1 kg — product page SUNLU · 2026-08 · vendor
  6. Recreus product catalogue Recreus · 2026-08 · vendor
  7. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  8. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
  9. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  10. YXPOLYER PA6-GF Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  11. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  12. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  13. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  14. PA (Nylon) — material basics Polymaker Wiki · 2026-08 · doc
  15. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  16. TPU — material basics Polymaker Wiki · 2026-08 · doc
  17. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  18. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  19. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  20. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  21. Fiberon PA6-CF20 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  22. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  23. FDM PA6/66-GF30-FR — Material Data Sheet Stratasys · 2026-07 · tds
  24. TECAMID 66 GF30 black (PA66-GF30) — stock shape properties Ensinger · 2026-08 · tds
  25. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  26. 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
  27. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  28. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds