Plastic PMMA vs. SLA Resin Standard

Compare Plastic PMMA vs. SLA Resin Standard strength, stiffness, weight and thermal properties.

Plastic PMMABulk polymer (molded or machined)

SLA Resin Standard3D printed (SLA resin)

Mechanical	Plastic PMMA	SLA Resin Standard
Yield strength	not given (tensile used)	not given (tensile used)
Ultimate tensile strength	80MPa133% stronger	60MPa2
Compressive strength	110MPa1	not sourced
Flexural strength	115MPa1	105MPa2
Elongation at break	5.5%1	8%245% more ductile
Young's modulus (stiffness)	3.3GPa120% stiffer	2.75GPa2
Density	1,190kg/m³1	1,210kg/m³3
Strength to weight	67.2kN·m/kg36% higher	49.6kN·m/kg
Stiffness to weight	2.77MN·m/kg22% higher	2.27MN·m/kg
Poisson's ratio	0.371	not sourced
Shear modulus	1.2GPa	not sourced
Bulk modulus	4.23GPa	not sourced
Speed of sound	1,665m/s10% faster	1,508m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic PMMA	SLA Resin Standard
Thermal conductivity	0.19W/m·K1	0.54W/m·K42.84x more heat through a fin
Thermal expansion	0-50 °C70µm/m·K11.63x less	mean -30 to 140 °C114µm/m·K4
100 mm part over a 50 °C swing	350µm growth1.63x less	571µm growth
Specific heat	1,470J/kg·K1	1,800J/kg·K422% higher
Heats up and cools (diffusivity)	0.109mm²/s	0.248mm²/s2.28x faster
Thermal shock resistance	41.5W/m	not sourced
Max service temperature	80°C1	HDT 1.8 MPa59°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: Röhm, Formlabs

Plastic PMMA: Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1)
SLA Resin Standard: Formlabs Clear Resin V5 (FLGPCL05), TDS Rev. 01 March 20, 2024; printed on Form 4 at 100 µm, washed 5 min in >=99% IPA, post-cured 15 min at 60 °C in Form Cure. Orientation not stated.

1
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
2
Clear Resin V5 Technical Data Sheet (2024)Formlabsarchived copySLA Resin Standard · Ultimate tensile strength: typicalSLA Resin Standard · Flexural strength: typicalSLA Resin Standard · Elongation at break: typicalSLA Resin Standard · Young's modulus (stiffness): typicalSLA Resin Standard · Max service temperature: HDT 1.8 MPa
3
Clear Resin V5 Technical Data Sheet (web edition)FormlabsSLA Resin Standard · Density: typical, post-cured (same for 5 min ambient and 15 min at 60 °C), ASTM D792
4
Thermal Properties of Selected Formlabs SLA ResinsFormlabsSLA Resin Standard · Thermal conductivity: typical, post-cured, ASTM E1530SLA Resin Standard · Thermal expansion: mean -30 to 140 °C, post-cured (5 min ambient cure), TMA ASTM E831SLA Resin Standard · Specific heat: typical, 25 °C, post-cured (5 min ambient cure), DSC ASTM E1269

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.

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

Questions

Mechanical

Is Plastic PMMA stronger than SLA Resin Standard?

Plastic PMMA is stronger: its tensile strength is 80 MPa against 60 MPa for SLA Resin Standard (33%).

Which is lighter, Plastic PMMA or SLA Resin Standard?

Plastic PMMA is lighter: 1,190 kg/m³ against 1,210 kg/m³ for SLA Resin Standard.

Which is stiffer, Plastic PMMA or SLA Resin Standard?

Plastic PMMA is stiffer: Young's modulus 3.3 GPa against 2.75 GPa for SLA Resin Standard, so the same part in Plastic PMMA deflects less under the same load.

Which is lighter for the same job, Plastic PMMA or SLA Resin Standard?

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	Plastic PMMA	SLA Resin Standard
Stiff rod or tie (tension)	lighter	22% heavier
Stiff beam (bending)	lighter	11% heavier
Stiff panel or plate	lighter	8% heavier
Strong rod or tie	lighter	36% heavier
Strong beam	lighter	23% heavier
Strong panel or plate	lighter	17% heavier

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, Plastic PMMA or SLA Resin Standard?

SLA Resin Standard stretches further before it breaks: 8% elongation at break against 5.5% for Plastic PMMA.

Thermal

Which conducts heat better, Plastic PMMA or SLA Resin Standard?

SLA Resin Standard conducts heat better: 0.54 W/m·K against 0.19 W/m·K for Plastic PMMA.

Which expands less with temperature?

Plastic PMMA expands less: 70 µm/m·K against 114 µm/m·K for SLA Resin Standard.