Plastic UHMWPE vs. SLA Resin Standard

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

Plastic UHMWPEBulk polymer (molded or machined)

SLA Resin Standard3D printed (SLA resin)

Mechanical	Plastic UHMWPE	SLA Resin Standard
Yield strength	20MPa1	not given (tensile used)
Ultimate tensile strength	43MPa1	60MPa2
Flexural strength	not sourced	105MPa2
Elongation at break	465%158.1x more ductile	8%2
Young's modulus (stiffness)	0.66GPa1	2.75GPa24.17x stiffer
Density	930kg/m³130% lighter	1,210kg/m³3
Strength to weight	21.5kN·m/kg	49.6kN·m/kg2.31x higher
Stiffness to weight	0.71MN·m/kg	2.27MN·m/kg3.2x higher
Poisson's ratio	not sourced	not sourced
Shear modulus	not sourced	not sourced
Bulk modulus	not sourced	not sourced
Speed of sound	842m/s	1,508m/s1.79x faster

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic UHMWPE	SLA Resin Standard
Thermal conductivity	0.4W/m·K4	0.54W/m·K535% more heat through a fin
Thermal expansion	200µm/m·K4	mean -30 to 140 °C114µm/m·K51.75x less
100 mm part over a 50 °C swing	1,000µm growth	571µm growth1.75x less
Specific heat	not sourced	1,800J/kg·K5
Heats up and cools (diffusivity)	not sourced	0.248mm²/s
Thermal shock resistance	not sourced	not sourced
Melting point	DSC 10 K/min130–138°C1	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

Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD

Sources5 documents: Celanese, Formlabs

Plastic UHMWPE: Celanese GUR 4120 (avg. molecular weight 4.7x10^6 g/mol), typical values on compression-molded specimens; CTE and thermal conductivity from Celanese's generic UHMWPE guide (grade not named)
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
GUR UHMW-PE Overview (GUR-015)CelanesePlastic UHMWPE · Yield strength: typical, tensile stress at yield ISO 527, 50 mm/minPlastic UHMWPE · Ultimate tensile strength: typical, tensile stress at break ISO 527, 50 mm/minPlastic UHMWPE · Elongation at break: typical, nominal elongation at break ISO 527Plastic UHMWPE · Young's modulus (stiffness): typical, tensile modulus ISO 527, 1 mm/minPlastic UHMWPE · Density: typicalPlastic UHMWPE · Melting point: DSC 10 K/minPlastic UHMWPE · Max service temperature: recommended max constant operating 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
GUR UHMW-PE Polymer Guide (GUR-003)Celanesearchived copyPlastic UHMWPE · Thermal conductivity: typical, unfilled (narrative value, generic Celanese UHMWPE)Plastic UHMWPE · Thermal expansion: typical, 20 to 100 °C (generic Celanese UHMWPE)
5
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 UHMWPE stronger than SLA Resin Standard?

SLA Resin Standard is stronger: its tensile strength is 60 MPa against yield strength 20 MPa for Plastic UHMWPE (3x).

Which is lighter, Plastic UHMWPE or SLA Resin Standard?

Plastic UHMWPE is lighter: 930 kg/m³ against 1,210 kg/m³ for SLA Resin Standard.

Which is stiffer, Plastic UHMWPE or SLA Resin Standard?

SLA Resin Standard is stiffer: Young's modulus 2.75 GPa against 0.66 GPa for Plastic UHMWPE, so the same part in SLA Resin Standard deflects less under the same load.

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

For the same stiffness or strength: SLA Resin Standard 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 UHMWPE	SLA Resin Standard
Stiff rod or tie (tension)	3.2x heavier	lighter
Stiff beam (bending)	1.57x heavier	lighter
Stiff panel or plate	24% heavier	lighter
Strong rod or tie	2.31x heavier	lighter
Strong beam	1.6x heavier	lighter
Strong panel or plate	33% 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, Plastic UHMWPE or SLA Resin Standard?

Plastic UHMWPE stretches further before it breaks: 465% elongation at break against 8% for SLA Resin Standard.

Thermal

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

SLA Resin Standard conducts heat better: 0.54 W/m·K against 0.4 W/m·K for Plastic UHMWPE.

Which expands less with temperature?

SLA Resin Standard expands less: 114 µm/m·K against 200 µm/m·K for Plastic UHMWPE.