3D Printing Info

Filament comparison

PLA Silk vs PPA

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

Silk PLA guidePPA (polyphthalamide) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PLA Silk comparisonsMore PPA comparisons
PLA Silk vs PPA — documented properties and sources
PropertySilk PLAPLAPPA (polyphthalamide)PA
Market snapshot
Listing priceUSD/kg; dated snapshots$19.49/kg median; $9.75–$24.99/kg across 15 dated product listings$45.49/kg median; $45.49–$45.49/kg across 1 dated product listings
Identity & Market
Base polymer / chemistryPLA with a gloss-forming additive package; suppliers publish the composition as polylactic acid only[1]Polyphthalamide — a semi-aromatic polyamide in which aromatic diacid units replace part of the aliphatic backbone; Raise3D and Bambu Lab both label it high-temperature nylon[2][3]
Densityg/cm³1.27 (ISO 1183)[1]1.21 (ISO 1183, Siraya Tech Fibreheart PPA)[4]
Typical priceUSD/kgMainstream 1 kg spools cluster near 20[5][6][7]One 1 kg listing on the market, at 45[8]
Price range across brandsUSD/kg10–25 across brands; CHCKX 10 in a 16-roll bundle, SUNLU 13, LANDU 18, YXPOLYER 20, Polymaker 22, Devil Design 25[9][10][11][12][13]45 for the only unfilled PPA filament found — Siraya Tech Fibreheart PPA at 1 kg; every other PPA in retail is carbon- or glass-filled[8]
Market availability1–5Stocked by most mainstream brands[5][9][14]Special order, 1–2 makers worldwide — Siraya Tech is the only brand found selling unfilled PPA filament[8]
Spool sizes & diameters1.75 mm; 1 and 1.1 kg spools; dual- and tri-colour coextruded variants[15][16]1.75 mm, 1 kg[8]
Typical applicationsDecorative prints where surface gloss matters more than strength[1]Gears, bearings and tooling that must hold load above the reach of PA6 or PA12, and parts exposed to fuels and industrial chemicals[4]
Diameter tolerance± mm±0.03 (Bambu Lab)[17]Not documented
Printing Parameters
Nozzle temperature°C210–240 — 20 °C above the plain PLA window[1]280–300 (Siraya Tech)[4]
Bed temperature°C35–45[1]70–80 (Siraya Tech)[4]
Enclosure / chamber requirement1–5Open frame is fine[1][18]Enclosure recommended — Siraya Tech advises an enclosure to hold temperature and limit warping on larger prints[4]
Part cooling fanFan on[1]20–60 % (Siraya Tech)[4]
Bed surface & adhesion aidCool Plate SuperTack, smooth PEI or textured PEI[1]PEI sheet with a glue stick, or a PVP glue coating[4]
Warping tendency1–5None[1]Not documented
Bed-adhesion difficulty1–5Sticks to anything[19]Not documented
Overall printing difficulty1–5Easy — minor profile tuning; hotter nozzle and slower cap of 250 mm/s[1]Advanced — enclosure, hardware upgrades, tuning; needs a 300 °C-class hot end and a dry spool[4]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely[18]Brass fine indefinitely — Siraya Tech states a hardened steel nozzle is not needed for the unfilled grade[4]
Abrasiveness1–5Non-abrasive[20][18]Non-abrasive when unfilled[4]
Nozzle clog risk1–5Very low[18]Moderate — needs dry filament and a clean nozzle; Siraya Tech tells users to dry only when moisture symptoms appear, rather than before every print[4]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed; PLA softens below 60 °C[21]Not documented
Hotend requirementNo special hot-end required[19]High-quality metal nozzle, 0.4–1.0 mm; hardened steel not required (Siraya Tech)[4]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.40 % saturated at 25 °C / 55 % RH[1]High (0.8–2 %) — Siraya Tech publishes 2.59 % by ISO 62 immersion for the unfilled grade; on the equilibrium basis Bambu Lab uses, its 15 % carbon-filled PPA reaches 1.30 % against 2.35 % for the same maker's PA6-CF[4][3][22]
Equilibrium moisture content at ~50 % RH%0.40 saturated at 25 °C / 55 % RH (Bambu Lab)[1]2.59 by ISO 62 water immersion (Siraya Tech, unfilled) — an immersion figure, not the 25 °C / 55 % RH equilibrium basis the filled grades are quoted on, so the two are not directly comparable[4]
Drying temperature & time55 °C for 8 h in a forced-air dryer, or 65–75 °C for 12 h on an X1 heatbed[1][23]80–100 °C for 4–6 h (Siraya Tech)[4]
Symptoms when wetBubbling and popping at the nozzle, stringing, rough surface and weak layers[24]Oozing, bubbles and a rough surface finish (Siraya Tech)[4]
Effect of moisture on strengthPolymaker rates PLA low-sensitivity — the loss shows as poor layer adhesion and brittle layers rather than a published strength figure[24]Siraya Tech publishes dry against saturated for the same grade: tensile 70 → 60 MPa, flexural 114 → 87 MPa, HDT at 1.8 MPa 73.5 → 48.5 °C, while Charpy rises 10 → 14.5 kJ/m²[4][8]
Storage requirementSealed with desiccant below 20 % RH; shelf life at ambient is long[25][19]Dry box below 15 % RH (Siraya Tech)[4]
Mechanical Properties
Tensile strength (XY)MPa33 (printed XY, ISO 527); eSun Silk broke 22 % below the 16-brand PLA mean on identical 4×4 mm bars[1][26]72 at break (printed, ASTM D638, Siraya Tech); the product page quotes 70 dry and 60 saturated[4][8]
Young's modulusMPa2130 (printed XY, ISO 527)[1]3600 (printed, ASTM D638, Siraya Tech)[4]
Elongation at break%2.8 (printed XY, ISO 527) — a quarter of PLA Basic at 12.2[1][25]10.5 at break (printed, ASTM D638, Siraya Tech)[4]
Flexural strengthMPa75 (printed XY, ISO 178)[1]115 (printed, ISO 178, Siraya Tech); 114 dry against 87 saturated on the product page[4][8]
Flexural modulusMPa2460 (printed XY, ISO 178)[1]3350 (printed, ISO 178, Siraya Tech)[4]
Charpy impact, notchedkJ/m²10.3 (printed XY, ISO 179, notched); unnotched 18.5[1]10.1 Charpy (printed, ISO 179, Siraya Tech); the data sheet does not state whether the specimen was notched[4]
Layer adhesion / Z tensileMPa25 (printed Z, ISO 527), and flexural Z collapses to 30 against 75 in XY; eSun Silk broke at 12.3 kg where twelve of the 16 plain PLAs managed 44.6–61.5 kg[1][26][27]Not documented
Brittleness1–5Brittle — snaps with little warning[1]Moderate — 10.5 % elongation at break puts it between PA6 and the fibre-filled grades[4]
Creep resistance / sustained load1–5Poor — no silk-specific creep data published; plain PLA sagged from 12 to 18.7–20.3 mm over 5 days at 1.25 kg[28][29]Good — Raise3D cites high creep resistance as a reason to choose the PPA matrix over other nylons[2]
Fatigue / repeated-flex resistance1–5Poor — no grade-specific S-N curve; plain printed PLA ran 38 000–49 000 cycles at 30 % of tensile strength (R = 0.2)[30][21]Not documented
Elasticity / flexibility1–5Rigid[1]Rigid — 3.6 GPa tensile modulus[4]
Z strength as % of XY%76 by tensile, 40 by flexural (printed, Bambu Lab)[1]Not documented
Wear resistance & frictionNot documentedSiraya Tech describes the unfilled grade as low-friction and self-lubricating, aimed at gears and bearings[4][8]
Thermal Properties
HDT at 0.45 MPa°C60 (ISO 75, 0.45 MPa)[1]81 dry and 61 saturated (printed, ISO 75 Method B at 0.45 MPa, Siraya Tech)[4]
HDT at 1.8 MPa°C56 (ISO 75, 1.8 MPa)[1]73.5 dry and 48.5 saturated (printed, ISO 75 Method A at 1.8 MPa, Siraya Tech) — unfilled PPA deflects near its Tg; the 190–227 °C figures quoted for PPA are carbon-filled grades[4][3]
Glass transition (Tg)°C57 (DSC)[1]80 (ASTM D3418, Siraya Tech)[4]
Melting point / Vicat°C158 peak melt (DSC); Vicat 66 °C[1]231 melting point (ASTM D3418) and 230 Vicat (ISO 306), Siraya Tech[4]
Continuous service temperature°C50 — a loaded bar begins to move at this temperature (My Tech Fun, eSun eSilk PLA)[27]Not documented
Annealing response50–55 °C for 6–12 h[1]Siraya Tech's product page offers annealing for strength while its own data sheet says annealing is not recommended because the print can warp; on its 15 % carbon-filled PPA, annealing lifts HDT at 1.8 MPa from 82.5 to 119 °C[4][8][31]
Flammability / UL 94Flammable; no UL 94 rating published by the major brands[25][32]Not documented
Environment & Chemical
UV resistance1–5Degrades within weeks outdoors[21][33]Not documented
Chemical resistanceGood against weak acids, oils and grease; poor against strong acids and alkalis; dissolved by chloroform, THF and hot benzene[32][21]Withstands fuels, oils and industrial chemicals; Bambu Lab rates semi-aromatic nylon better than general nylon against weak acids, weak alkalis and most organic solvents[4][3]
Water / humidity resistance in service1–5Good — insoluble in water[25]Absorbs water, properties shift — a saturated specimen loses about 15 % of its tensile strength and 25 °C of heat-deflection temperature[4][8]
Food contactBase resin is food-contact grade, but printed layer grooves harbour bacteria; Prusa advises against food use[21]Not documented
Biodegradability / compostabilityIndustrially compostable only — needs sustained 55 °C; not home compostable[34][21]Not documented
RecyclabilityMechanically recyclable; not accepted in household plastic collection[34]Not documented
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission[35]Not documented
Ventilation / filtration requirement1–5None needed in a normal room[35]Not documented
Post-Processing
Sanding & machiningWet sanding — dry sanding heats the surface by friction and smears it[33][21]Not documented
Gluing & solvent weldingCyanoacrylate for most joints; some grades partially dissolve and bond with acetone[21][36]Not documented
Vapour / chemical smoothingNo practical vapour smoothing — only chloroform, hot benzene or THF, which are laboratory-only[21]Not documented
Support material pairingSupport for PLA (Bambu Lab)[1]Compatible with quick-release support materials (Siraya Tech)[4]
Dimensional accuracy & detail55° overhangs and 30 mm bridges; gloss hides fine detail and is destroyed by sanding[1]Not documented
Solvents & Solubility
Soluble inChloroform: 10 % w/v in 2–4 h at 23 °C, every grade and morphology; THF and DMF only at 65 °C. Laboratory reagents.[37]Dissolved at 23 °C by formic acid, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — all laboratory reagents.[38]
Softened or crazed byAcetone, ethyl acetate and toluene plasticise it but dissolve <1 % even at 65 °C; submersion in acetone crazes and destroys parts.[37][39]Mineral acids, oxidants, halogens and zinc chloride solutions attack the amide bond; ordinary solvents do not.[38]
Solvent welding & smoothing agentChloroform vapour smooths and welds PLA at the cost of tensile strength; acetone does not smooth it at all.[40][39]None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[38]

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. Bambu Filament Technical Data Sheet V1.0 — PLA Silk+ Bambu Lab · 2026-08 · tds
  2. Raise3D Industrial PPA CF Technical Data Sheet V2.0 Raise3D · 2022-04 · tds
  3. Bambu Filament Technical Data Sheet V1.0 — PPA-CF Bambu Lab · 2026-08 · tds
  4. Siraya Tech Fibreheart PPA Technical Data Sheet Siraya Tech · 2026-08 · tds
  5. Panchroma Silk PLA collection Polymaker Shop · 2026-08 · vendor
  6. Spectrum PLA Silk — product listing 3DJake International · 2026-08 · vendor
  7. 3DJake ecoPLA Silk Black 1.75mm 1000g 3DJake International · 2026-08 · vendor
  8. Siraya Tech Fibreheart PPA Filament — product page Siraya Tech · 2026-08 · vendor
  9. Sunlu Silk PLA+ 1.75mm 1kg Sunlu Official Store · 2026-08 · vendor
  10. Bambu Lab PLA Silk 1.75mm 1kg 3D Universe · 2026-08 · vendor
  11. CHCKX 16 Pack Silk Dual Color PLA Filament Bundle CHCKX (Amazon US) · 2026-08 · vendor
  12. YXPOLYER Silk PLA Black&Gold product page YXPOLYER · 2026-08 · vendor
  13. LANDU Silk Tri-Color PLA Filament 1.75 mm 1 kg LANDU (Amazon US) · 2026-08 · vendor
  14. Overture Silk PLA 1.75mm Overture3D · 2026-08 · vendor
  15. eSUN PLA-Silk Magic 1.75mm eSUN Official Store · 2026-08 · vendor
  16. JAYO Silk PLA+ 1.75mm 1.1kg JAYO Official Store · 2026-08 · vendor
  17. PLA Basic — product page Bambu Lab US Store · 2026-08 · vendor
  18. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  19. PLA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  20. Prusament PLA — material page Prusa Polymers · 2026-08 · doc
  21. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  22. Bambu Filament Technical Data Sheet V3.0 — PA6-CF Bambu Lab · 2026-08 · tds
  23. Filament Drying Recommendations Bambu Lab Wiki · 2026-08 · doc
  24. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  25. Bambu Filament Technical Data Sheet V3.0 — PLA Basic Bambu Lab · 2026-08 · tds
  26. 16 PLA brand comparison test — results spreadsheet My Tech Fun (Igor Gaspar) · 2022-10 · test
  27. Testing eSun PLA filaments: PLA-ST vs PLA+ vs Silk PLA My Tech Fun (Igor Gaspar) · 2026-08 · test
  28. BambuLab PLA Basic vs PLA Tough vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  29. PolyTerra PLA vs PLA+ — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  30. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  31. Siraya Tech Fibreheart PPA-CF Technical Data Sheet Siraya Tech · 2026-08 · tds
  32. PolyLite PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  33. Prusament PLA Technical Data Sheet v1.0 Prusa Polymers · 2018-09 · tds
  34. Filamentive PLA (recycled) — product page Filamentive · 2026-08 · vendor
  35. 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
  36. Prusament rPLA Corn Pigment 1kg — product page Prusa Research · 2026-08 · vendor
  37. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  38. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  39. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  40. Effect of vapour smoothing in trichloromethane on 3D printed PLA — surface, mechanical and chemical structure Pitale, Keche & Chopra, Engineering Research Express 6(4) 045579 · 2024-12 · paper