3D Printing Info

Filament comparison

PE vs PP-CF

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

Polyethylene (PE) guideCarbon-fibre PP (PP-CF) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PE comparisonsMore PP-CF comparisons
PE vs PP-CF — documented properties and sources
PropertyPolyethylene (PE)POLYOLEFINCarbon-fibre PP (PP-CF)POLYOLEFIN
Market snapshot
Listing priceUSD/kg; dated snapshots$87.72/kg median; $87.72–$87.72/kg across 1 dated product listings$107.68/kg median; $57.13–$120.00/kg across 3 dated product listings
Identity & Market
Base polymer / chemistryPolyethylene — the simplest polyolefin, non-polar and highly crystalline. The one retailed filament grade, Spectrum HDPE, uses what Spectrum calls Low Warp technology and is denser and stiffer than plain HDPE[1][2]Polypropylene reinforced with chopped carbon fibre[3][4]
Densityg/cm³1.10 (Spectrum HDPE filament, ISO 1183) against 0.95 for extruded HDPE stock — the filament is a modified formulation[1][2]0.91 (Prusament PP Carbon Fiber, ISO 1183)[3]
Typical priceUSD/kg1 kg-equivalent spools cluster near 88[5]1 kg-equivalent spools span 57–138; the middle of the market is about 108[6][7][8]
Price range across brandsUSD/kg87.72 — Spectrum's 500 g spools at 3DJAKE are the only PE filament listing found[5]57–138 across brands; Reli3D 57 at 700 g on Amazon, Prusament 108 direct from Prusa and 138 at Printed Solid, 3DXTech CarbonX PP+CF 120[6][9][7][8]
Market availability1–5Niche, a handful of specialist brands — Spectrum HDPE in six colours is the only PE filament in the 3DJAKE and igo3d product sitemaps, at MatterHackers or at Printed Solid, but it is a normal stocked item rather than a special order[10][11][9][5]Available from several mainstream brands[7][9]
Spool sizes & diameters1.75 mm; 500 g spools in six colours[5][10]1.75 mm; 0.65 kg spools[9][7]
Typical applicationsChemically resistant containers, packaging prototypes and consumer goods where HDPE is the production material[1]Lightweight chemical-resistant parts, automotive clips and ducting that must survive above 150 °C[12]
Diameter tolerance± mmNot documented±0.04 (Prusament)[3]
Printing Parameters
Nozzle temperature°C240-290 (Spectrum HDPE)[1]270 ± 10 (Prusament)[3]
Bed temperature°C80-100 (Spectrum HDPE)[1]85 ± 10 (Prusament)[3]
Enclosure / chamber requirement1–5Enclosure recommended — Spectrum recommends a closed chamber for larger prints[1]Enclosure recommended — Simplify3D lists an enclosure as a hardware requirement and Polymaker advises one below 70 °C ambient to stop warping and cracking[13][14]
Part cooling fan0-50 % part cooling (Spectrum HDPE)[1]Off — Prusa runs 0 % except 100 % on bridges[3]
Bed surface & adhesion aidSpectrum states no adhesive is necessary for its low-warp HDPE, depending on geometry[1]Not documented
Maximum volumetric flow (mm³/s; see test conditions)mm³/sNot documented3.2 at Prusa's 40 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[3][15]
Warping tendency1–5Moderate — needs adhesion aid or draught shield. Spectrum's low-warp grade is sold as printable on desktop machines, which is not true of plain polyethylene[1]High — enclosure needed for reliable large parts; Prusa recommends a brim[3]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive; Spectrum states no adhesive is necessary but recommends a closed chamber for large parts[1]Very difficult — special plates or slurry required[3]
Overall printing difficulty1–5Intermediate — dry filament and a tuned profile; Spectrum sells the grade as desktop-printable with no dry box and no hardened nozzle[1]Advanced — enclosure, hardware upgrades, tuning; hardened nozzle mandatory[3]
Extruder requirementNot documentedPrusa states a hardened nozzle is necessary and recommends a brim[3]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Spectrum states a ruby or hardened nozzle is not required[1]Hardened steel required — Prusa states plainly that a hardened nozzle is necessary[3]
Abrasiveness1–5Non-abrasive[1]Highly abrasive — standard CF composite[3]
Nozzle clog risk1–5Low — Spectrum lists no drybox and no ruby or hardened nozzle for HDPE, and very low moisture absorption[1]Moderate — needs dry filament and a clean nozzle; 3DXTech specifies a hardened 0.4 mm minimum nozzle and 0.25 mm layers or higher, and Prusa lists composites as a higher clogging risk[4][16]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Negligible (<0.1 % EMC) — Spectrum lists very low moisture absorption and no dry box[1]Negligible (<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[3]
Equilibrium moisture content at ~50 % RH%Not documented0.03 after 24 h and 0.04 after 7 days at 24 °C / 22 % RH (Prusa Polymers)[3]
Drying temperature & timeNo drying step published; Spectrum lists a dry box as not required[1]Not documented
Effect of moisture on strengthNot applicable in practice — Spectrum lists very low moisture absorption and no drybox requirement for HDPE[1]Not applicable in practice at 0.04 % equilibrium uptake[3]
Storage requirementStore dry at 18-25 °C out of sunlight; Spectrum quotes a 24-month shelf life[1]No special storage needed[3]
Mechanical Properties
Tensile strength (XY)MPa29 at break (Spectrum HDPE, ISO 527; specimen type not stated) against 25.5 at yield on extruded HDPE stock (ASTM D638, from 3700 psi)[1][2]21 ± 0.4 filament tensile yield (Prusament, ISO 527)[3]
Young's modulusMPa3500 (Spectrum HDPE, ISO 527) against 965 on extruded HDPE stock (ASTM D638, from 140,000 psi) — the filament grade is nearly four times stiffer than plain polyethylene[1][2]Not documented
Elongation at break%18 at break (Spectrum HDPE, ISO 527) against above 100 on extruded stock (ASTM D638)[1][2]Not documented
Flexural strengthMPa27.6 on extruded HDPE stock (ASTM D790; converted from 4000 psi)[2]Not documented
Flexural modulusMPa3200 (Spectrum HDPE, ISO 178) against 965 on extruded stock (ASTM D790, from 140,000 psi)[1][2]Not documented
Charpy impact, notchedkJ/m²Not documented14.5 ± 0.3 printed horizontal and 10.5 ± 0.8 printed vertical XZ (ISO 179-1, notched)[3]
Other impact dataCharpy 10 kJ/m2 (Spectrum HDPE, ISO 179-1; notch condition not stated); Izod 104 J/m on extruded stock, converted from 1.94 ft-lb/in (ASTM D256)[1][2]Not documented
Brittleness1–5Tough — absorbs impact, yields before breaking; 18 % elongation at break on the filament and above 100 % on extruded stock[1][2]Tough — absorbs impact, yields before breaking[3]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 67 and Rockwell R54 on extruded HDPE stock (ASTM D2240, D785); Spectrum quotes Rockwell 80 HRM for its filament (ISO 2039-2)[2][1]Rockwell R102 (and M95) on extruded unfilled PP stock (ASTM D785); no figure is published for a carbon-fibre PP filament[17]
Fatigue / repeated-flex resistance1–5Good — Spectrum lists outstanding abrasion and crack resistance for its HDPE, but no repeated-flex or fatigue test data was found for any PE filament[1]Good[18]
Elasticity / flexibility1–5Slightly flexible in thin sections — Spectrum's low-warp grade has a 3.5 GPa tensile modulus; plain extruded HDPE at 965 MPa is genuinely semi-flexible[1][2]Slightly flexible in thin sections[3]
Thermal Properties
HDT at 0.45 MPa°C75 on extruded HDPE stock (ASTM D648 at 66 psi; converted from 167 °F)[2]158 (ISO 75, 0.45 MPa) — far above unfilled PP and above most engineering filaments[3]
HDT at 1.8 MPa°CNot documented115 (ISO 75, 1.8 MPa)[3]
Continuous service temperature°C110 stated as heat resistance by Spectrum with no test standard given; extruded stock is rated 120 long-term maximum (converted from 248 °F) and brittle below -76[1][2]Not documented
Thermal expansion (CTE)µm/m·K117 (extruded HDPE stock, ASTM D696; source states 6.5e-5 in/in/°F)[2]Not documented
Environment & Chemical
UV resistance1–5Moderate — a season or two. Spectrum describes its HDPE as UV-stable and weather-resistant but publishes no exposure data[1]Not documented
Chemical resistanceExcellent chemical resistance to acids, bases, oils and solvents (Spectrum); Ensinger lists broad chemical compatibility for HDPE stock[1][2]Excellent against acids, alkalis and most solvents[14]
Water / humidity resistance in service1–5Excellent — essentially unaffected; Ensinger lists low moisture absorption for HDPE stock and Spectrum very low absorption for the filament[1][2]Excellent — essentially unaffected[3]
RecyclabilitySpectrum states the filament is fully recyclable; HDPE is resin code 2[1]Not documented
Health & Safety
Fume toxicity1–5Not documentedLow 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[19]
Ventilation / filtration requirement1–5Not documentedOpen a window / occasional ventilation. Inferred — no polyolefin was measured in the chamber study[19]
Dust & fibre handling hazardNot documentedCarbon fibre is bound in the matrix; sanding dust should not be inhaled[3]
Post-Processing
Sanding & machiningEasy to machine — Ensinger lists machinability as a headline property of HDPE stock[2]Not documented
Dimensional accuracy & detailSpectrum lists a shiny surface finish and no adhesive requirement; shrinkage remains the limit on large flat parts[1]Not documented
Solvents & Solubility
Soluble inNone at room temperature; xylene dissolves HDPE at about 105 °C and LDPE at 75 °C. Hot decalin does the same.[20][21]None at room temperature; chloroform dissolves the matrix at 60 °C and xylene at about 118 °C, leaving the fibre.[22][20]
Softened or crazed byToluene, xylene, styrene, chloroform, dichloromethane, MEK and trichloroethylene are all unsatisfactory at 21 °C.[21]Xylene, decalin, CCl4 and chlorobenzene are heavily absorbed at 20 °C; oleum, chlorosulphonic acid and bromine destroy it.[22]
Solvent welding & smoothing agentNone — polyethylene has no room-temperature solvent, so joints are made by heat welding.[21][20]None — nothing softens PP at room temperature, so joints have to be welded thermally rather than chemically.[22]

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. Spectrum HDPE Technical Data Sheet Spectrum Filaments · 2025-10 · tds
  2. TECAFINE HDPE natural — stock shape properties Ensinger · 2026-08 · tds
  3. Prusament PP Carbon Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  4. CarbonX PP+CF — product page 3DXTech · 2026-08 · vendor
  5. Spectrum HDPE Traffic Black, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  6. Prusament PP Carbon Fiber Black 650g — product page Prusa Research · 2026-08 · vendor
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. Reli3D Carbon Fiber PP Filament 1.75 mm 700 g Black — Amazon listing Amazon.com · 2026-08 · vendor
  9. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  10. 3DJAKE product catalogue 3DJAKE · 2026-08 · vendor
  11. igo3d product sitemap (17452 product URLs) igo3d · 2026-08 · vendor
  12. Prusament PP Carbon Fiber — material page Prusa Polymers · 2026-08 · doc
  13. Polypropylene — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  14. PP — material basics Polymaker Wiki · 2026-08 · doc
  15. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  16. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  17. TECAFINE PP natural — stock shape properties Ensinger · 2026-08 · tds
  18. Centaur PP Technical Data Sheet Formfutura · 2026-08 · tds
  19. 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
  20. US 5,278,282 Polymer recycling by selective dissolution — xylene dissolution temperatures Nauman & Lynch, Rensselaer Polytechnic Institute · 1994-01 · paper
  21. HDPE Chemical Resistance Guide (21 °C and 60 °C) INEOS Olefins & Polymers USA · 2026-08 · tds
  22. Pro-fax and Moplen polypropylene — Chemical Resistance Guide (20, 60 and 100 °C) LyondellBasell · 2026-08 · tds