3D Printing Info

Filament comparison

PP vs TPU soft

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

Polypropylene (PP) guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PP comparisonsMore TPU soft comparisons
PP vs TPU soft — documented properties and sources
PropertyPolypropylene (PP)POLYOLEFINSoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$46.56/kg median; $31.99–$53.00/kg across 4 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPolypropylene — a semi-crystalline polyolefin with no polar groups, so it neither absorbs water nor bonds to most bed surfaces[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/cm³0.91 (Prusa PP composite, ISO 1183) — the lightest common filament[4]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[3]
Typical priceUSD/kg1 kg-equivalent spools span 27–53; the middle of the market is about 44[5][6][7][8]1 kg-equivalent spools cluster near 115[9][10][11]
Price range across brandsUSD/kg27–53 across brands; Reli3D 32 on Amazon, SUNLU 44 at 0.8 kg, Fiberlogy 49 at 750 g, IEMAI 3D 53, and the 3DJake PP listing spans 27–49[5][12][6][7][8]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[9][11][10]
Market availability1–5Available from several mainstream brands[12][6][5]Niche, a handful of specialist brands[3][13][9]
Spool sizes & diameters1.75 and 2.85 mm; 0.75 kg spools are common[6]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[3][9][14][10]
Typical applicationsLiving hinges, chemical-resistant containers, automotive clips and packaging prototypes[1]Highly compliant seals, soft grips and prosthetic liners[3]
Printing Parameters
Nozzle temperature°C210–230 (Braskem-type PE/PP window); Formfutura's Centaur PP melts at 205 ± 15 °C[1]Not documented
Bed temperature°CNot documented50–70 (Fiberlogy FiberFlex 30D)[3]
Enclosure / chamber requirement1–5Enclosure recommended — Simplify3D lists an enclosure as a hardware requirement and Polymaker advises one below 70 °C ambient to stop warping and cracking[15][2]Open frame is fine[3]
Part cooling fanPart cooling fan required (Simplify3D)[15]Not documented
Bed surface & adhesion aidPacking tape, a polypropylene sheet, or a PP-specific adhesive such as Magigoo PP — ordinary PLA and ABS adhesives do not hold it[15][2]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[16][17]
Warping tendency1–5High — enclosure needed for reliable large parts; PP's crystallinity drives shrinkage and Prusa recommends a brim on its PP grades[4][18]Not documented
Bed-adhesion difficulty1–5Very difficult — special plates or slurry required. PP bonds to almost nothing; a polypropylene-specific tape or adhesive is the normal answer[4][2]Not documented
Stringing / oozing tendency1–5Slight — Polymaker advises 1–2 mm retraction at 20–30 mm/s[2]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; bed adhesion is the whole problem[2][4]Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[14][17]
Extruder requirementNot documentedDirect drive only, with a constrained filament path; Bowden is not viable at this hardness[14][13]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades — Simplify3D states no special hotend is required[15]Brass fine indefinitely[19]
Abrasiveness1–5Non-abrasive when unfilled[15]Non-abrasive[19]
Nozzle clog risk1–5Low — Simplify3D lists no special hotend requirement for PP and clogging is not among its listed drawbacks[20][15]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][20]
Heat-creep / jam sensitivity1–5Slightly sensitive[15]Very high — softens in the cold zone readily[17]
Hotend requirementNo special hot-end required (Simplify3D)[15]No special hot-end required, but a direct-drive extruder is (Simplify3D)[16]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Negligible (<0.1 % EMC) — Prusa measures 0.03 % in 24 h and 0.04 % in 7 days on its PP composite, the lowest figures it publishes for any filament[4]Moderate[20]
Equilibrium moisture content at ~50 % RH%0.03 after 24 h and 0.04 after 7 days at 24 °C / 22 % RH (Prusa Polymers, measured on its PP composite)[4]Not documented
Drying temperature & timeNo drying step is published for PP; uptake is below the level that affects printing[4]Not documented
Symptoms when wetBubbling and popping at the nozzle; Polymaker still advises a 70 °C dry for 4–6 h despite the low uptake[2]Bubbling and popping at the nozzle, stringing and a rough surface[20]
Effect of moisture on strengthNot applicable in practice — with equilibrium uptake at 0.04 %, there is no moisture-driven strength loss to measure. Polymaker's sensitivity tiers put polyolefins below even PLA[4][20]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[20]
Storage requirementNo special storage needed[4]Sealed with desiccant; often kept in a dryer during the print[20]
Mechanical Properties
Tensile strength (XY)MPa12 at yield (Formfutura Centaur PP, ASTM D638)[1]Not documented
Young's modulusMPa724 on extruded PP stock (ASTM D638; converted from 105,000 psi)[21]Not documented
Elongation at break%Above 600 at break (Formfutura Centaur PP, ASTM D638)[1]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[3]
Flexural strengthMPa31.0 on extruded PP stock (ASTM D790; converted from 4500 psi)[21]Not documented
Flexural modulusMPa402 flexural modulus (Formfutura Centaur PP, ASTM D790) — an order of magnitude below any rigid filament[1]Not documented
Other impact dataIzod notched 112 J/m on extruded PP stock, converted from 2.1 ft-lb/in (ASTM D256)[21]Not documented
Brittleness1–5Very ductile — bends far before failing[1]Very ductile — bends far before failing[3]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell R102 (and M95) on extruded PP stock (ASTM D785)[21]81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[3]
Creep resistance / sustained load1–5Below average[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 resistance1–5Excellent — living hinges viable, the classic polypropylene application[1]Excellent — living hinges viable[17]
Elasticity / flexibility1–5Semi-flexible[1]Rubbery / highly elastic[3]
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[3]
Thermal Properties
HDT at 0.45 MPa°C74 on extruded PP stock (ASTM D648 at 66 psi; converted from 165 °F)[21]Not documented
Melting point / Vicat°C205 ± 15 melting (Formfutura Centaur PP)[1]170 melting (Fiberlogy FiberFlex 30D, DSC)[3]
Continuous service temperature°CBounded by a melting point of 205 ± 15 °C and by the 158 °C heat deflection of the carbon-filled grade; no loaded-bar service figure is published for unfilled PP[1][4]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for the grades surveyed[4]Not documented
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polypropylene chalks under UV[2]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[17]
Chemical resistanceExcellent against acids, alkalis and most solvents — the usual reason to choose PP[2]Withstands industrial solvents and UV exposure (Polymaker)[17]
Water / humidity resistance in service1–5Excellent — essentially unaffected[4]Not documented
Food contactPolypropylene is a common food-packaging polymer, but no filament here carries a food-contact certification[2]Not food safe without specific certification (Polymaker)[17]
Biodegradability / compostabilityNot biodegradable[2]Not biodegradable[17]
RecyclabilityMechanically recyclable as resin code 5, but printed waste is not accepted in household collection[2]Not accepted in household plastic collection[17]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission. Inferred: no polyolefin was among the nine filaments in the Azimi chamber study, so this is a family-level judgement rather than a measurement[23]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[23]
Ventilation / filtration requirement1–5Open a window / occasional ventilation. Inferred — no polyolefin was measured in the chamber study[23]Open a window / occasional ventilation[23]
Post-Processing
Sanding & machiningSands poorly — the waxy surface loads abrasive paper[15]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[17]
Painting & finishingPaint and adhesives do not key to untreated PP; flame or plasma treatment is normally needed first[2]Not documented
Gluing & solvent weldingNothing common bonds untreated PP; flame or plasma treatment is needed before adhesives key[2]Cyanoacrylate bonds TPU; no common solvent welds it[17]
Vapour / chemical smoothingNo practical vapour smoothing[15]No practical vapour smoothing[17]
Support material pairingPrints its own supports; no soluble support is rated for PP[15]Polymaker warns TPU supports are often very difficult to remove[17]
Dimensional accuracy & detailShrinkage and warping dominate; the low modulus means parts flex rather than hold tolerance[4]Not documented
Solvents & Solubility
Soluble inNone at room temperature; chloroform dissolves it at 60 °C and xylene at about 118 °C — the xylene-solubles route.[24][25]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[26]
Softened or crazed byXylene, decalin, CCl4 and chlorobenzene are heavily absorbed at 20 °C; oleum, chlorosulphonic acid and bromine destroy it.[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 agentNone — nothing softens PP at room temperature, so joints have to be welded thermally rather than chemically.[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

  1. Centaur PP Technical Data Sheet Formfutura · 2026-08 · tds
  2. PP — material basics Polymaker Wiki · 2026-08 · doc
  3. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  4. Prusament PP Carbon Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  5. SUNLU product catalogue SUNLU · 2026-08 · vendor
  6. Fiberlogy PP Natural — product page 3DJake International · 2026-08 · vendor
  7. Reli3D Low Warp PP Filament 1.75 mm 1 kg Black — Amazon listing Amazon.com · 2026-08 · vendor
  8. IEMAI 3D PP 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  9. Recreus product catalogue Recreus · 2026-08 · vendor
  10. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  11. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
  12. PP filament listing 3DJake International · 2026-08 · vendor
  13. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  14. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  15. Polypropylene — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  16. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. TPU — material basics Polymaker Wiki · 2026-08 · doc
  18. Prusament PP Glass Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  19. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  20. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  21. TECAFINE PP natural — stock shape properties Ensinger · 2026-08 · tds
  22. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  23. 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
  24. Pro-fax and Moplen polypropylene — Chemical Resistance Guide (20, 60 and 100 °C) LyondellBasell · 2026-08 · tds
  25. US 5,278,282 Polymer recycling by selective dissolution — xylene dissolution temperatures Nauman & Lynch, Rensselaer Polytechnic Institute · 1994-01 · paper
  26. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds