FDM Polycarbonate vs. Plastic PMMA

Compare FDM Polycarbonate vs. Plastic PMMA strength, stiffness, weight and thermal properties.

Plastic PMMABulk polymer (molded or machined)

Mechanical	FDM Polycarbonate	Plastic PMMA
Yield strength	53.3MPa1	not given (tensile used)
Ultimate tensile strength	53.3MPa1	80MPa21.5x stronger
Compressive strength	not sourced	110MPa2
Flexural strength	89.4MPa1	115MPa229% stronger in bending
Elongation at break	9.2%11.67x more ductile	5.5%2
Young's modulus (stiffness)	2.39GPa1	3.3GPa238% stiffer
Density	range1,180–1,200kg/m³1	1,190kg/m³2
Strength to weight	44.8kN·m/kg	67.2kN·m/kg1.5x higher
Stiffness to weight	2.01MN·m/kg	2.77MN·m/kg38% higher
Poisson's ratio	base material0.383	0.372
Shear modulus	0.867GPa	1.2GPa39% stiffer in shear
Bulk modulus	3.33GPa	4.23GPa27% higher
Speed of sound	1,418m/s	1,665m/s17% faster

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	FDM Polycarbonate	Plastic PMMA
Thermal conductivity	base material0.2W/m·K4	0.19W/m·K2
Thermal expansion	base material65µm/m·K4	0-50 °C70µm/m·K2
100 mm part over a 50 °C swing	325µm growth8% less	350µm growth
Specific heat	not sourced	1,470J/kg·K2
Heats up and cools (diffusivity)	not sourced	0.109mm²/s
Thermal shock resistance	42.5W/m2% more resistant	41.5W/m
Glass transition	108°C1	not sourced
Max service temperature	HDT 0.455 MPa105°C1	80°C2

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

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Sources4 documents: UltiMaker, Röhm, Covestro

FDM Polycarbonate: Ultimaker PC, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 20, 2022.
Plastic PMMA: Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1)

1
Ultimaker PC Technical Data Sheet, v5.00UltiMakerarchived copyFDM Polycarbonate · Yield strength: typicalFDM Polycarbonate · Ultimate tensile strength: typical, peak stress (= stress at yield)FDM Polycarbonate · Flexural strength: typicalFDM Polycarbonate · Elongation at break: typicalFDM Polycarbonate · Young's modulus (stiffness): typicalFDM Polycarbonate · Density: rangeFDM Polycarbonate · Glass transition: typicalFDM Polycarbonate · Max service temperature: HDT 0.455 MPa (printed specimens)
2
PLEXIGLAS GS and XT Technical Information (Ref. No. 211-1)Röhmarchived copyPlastic PMMA · Ultimate tensile strength: typical, 23 °CPlastic PMMA · Compressive strength: compressive yield stress, typicalPlastic PMMA · Flexural strength: typicalPlastic PMMA · Elongation at break: typicalPlastic PMMA · Young's modulus (stiffness): typical, short-termPlastic PMMA · Density: typicalPlastic PMMA · Poisson's ratio: typicalPlastic PMMA · Thermal conductivity: typicalPlastic PMMA · Thermal expansion: 0-50 °CPlastic PMMA · Specific heat: typicalPlastic PMMA · Max service temperature: max. permanent service temperature
3
Engineering Polymers Part and Mold Design: Thermoplastics, A Design GuideCovestroarchived copyFDM Polycarbonate · Poisson's ratio: base material: polycarbonate family typical (Covestro Part and Mold Design guide, Table 3-1)
4
Makrolon 2405 Technical Data SheetCovestroFDM Polycarbonate · Thermal conductivity: base material: Covestro Makrolon 2405 injection-molding PC, typical, through-plane, 23 °CFDM Polycarbonate · Thermal expansion: base material: Covestro Makrolon 2405 injection-molding PC, typical, 23-55 °C, parallel

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

FDM Polycarbonate is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Mechanical

Is FDM Polycarbonate stronger than Plastic PMMA?

Plastic PMMA is stronger: its tensile strength is 80 MPa against yield strength 53.3 MPa for FDM Polycarbonate (1.5x).

Which is lighter, FDM Polycarbonate or Plastic PMMA?

FDM Polycarbonate is lighter: 1,190 kg/m³ against 1,190 kg/m³ for Plastic PMMA.

Which is stiffer, FDM Polycarbonate or Plastic PMMA?

Plastic PMMA is stiffer: Young's modulus 3.3 GPa against 2.39 GPa for FDM Polycarbonate, so the same part in Plastic PMMA deflects less under the same load.

Which is lighter for the same job, FDM Polycarbonate or Plastic PMMA?

For the same stiffness or strength: Plastic PMMA is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must be	FDM Polycarbonate	Plastic PMMA
Stiff rod or tie (tension)	38% heavier	lighter
Stiff beam (bending)	17% heavier	lighter
Stiff panel or plate	11% heavier	lighter
Strong rod or tie	1.5x heavier	lighter
Strong beam	31% heavier	lighter
Strong panel or plate	23% heavier	lighter

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Which is more ductile, FDM Polycarbonate or Plastic PMMA?

FDM Polycarbonate stretches further before it breaks: 9.2% elongation at break against 5.5% for Plastic PMMA.

Thermal

Which conducts heat better, FDM Polycarbonate or Plastic PMMA?

FDM Polycarbonate conducts heat better: 0.2 W/m·K against 0.19 W/m·K for Plastic PMMA.

Which expands less with temperature?

FDM Polycarbonate expands less: 65 µm/m·K against 70 µm/m·K for Plastic PMMA.