Plastic PBT GF30 vs. Plastic TPU

Compare Plastic PBT GF30 vs. Plastic TPU strength, stiffness, weight and thermal properties.

Plastic PBT GF30Bulk polymer (molded or machined)

Mechanical	Plastic PBT GF30	Plastic TPU
Yield strength	not given (tensile used)	not given (tensile used)
Ultimate tensile strength	stress at break140MPa15.91x stronger	23.7MPa2
Flexural strength	210MPa151.2x stronger in bending	4.1MPa2
Elongation at break	strain at break3%1	not sourced
Young's modulus (stiffness)	9.8GPa1146x stiffer	0.067GPa2
Density	1,530kg/m³1	1,220kg/m³225% lighter
Strength to weight	91.5kN·m/kg4.71x higher	19.4kN·m/kg
Stiffness to weight	6.41MN·m/kg117x higher	0.0549MN·m/kg
Poisson's ratio	not sourced	not sourced
Shear modulus	not sourced	not sourced
Bulk modulus	not sourced	not sourced
Speed of sound	2,531m/s10.8x faster	234m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic PBT GF30	Plastic TPU
Thermal conductivity	0.27W/m·K1	not sourced
Thermal expansion	longitudinal25µm/m·K1	not sourced
100 mm part over a 50 °C swing	125µm growth	not sourced
Specific heat	1,050J/kg·K1	not sourced
Heats up and cools (diffusivity)	0.168mm²/s	not sourced
Thermal shock resistance	not sourced	not sourced
Melting point	DSC223°C1	217°C2
Max service temperature	HDT 1.8 MPa205°C1	HDT 0.455 MPa50.3°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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Sources2 documents: BASF, UltiMaker

Plastic PBT GF30: BASF Ultradur B 4300 G6 (PBT, 30% glass fibre), injection moulding grade; product information sheet 09/2026, typical values for uncoloured product at 23 °C.
Plastic TPU: Ultimaker TPU 95A, 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 29, 2022.

1
Ultradur B 4300 G6 Product InformationBASFPlastic PBT GF30 · Ultimate tensile strength: stress at break, 23 °CPlastic PBT GF30 · Flexural strength: typical, 23 °CPlastic PBT GF30 · Elongation at break: strain at break, 23 °CPlastic PBT GF30 · Young's modulus (stiffness): typical, 23 °CPlastic PBT GF30 · Density: typicalPlastic PBT GF30 · Thermal conductivity: typical (DIN 52612-1)Plastic PBT GF30 · Thermal expansion: longitudinal (flow), mean 23-55 °CPlastic PBT GF30 · Specific heat: typical, 23 °CPlastic PBT GF30 · Melting point: DSC (ISO 11357)Plastic PBT GF30 · Max service temperature: HDT 1.8 MPa
2
Ultimaker TPU 95A Technical Data Sheet, v5.00UltiMakerarchived copyPlastic TPU · Ultimate tensile strength: typical, stress at breakPlastic TPU · Flexural strength: typicalPlastic TPU · Young's modulus (stiffness): typicalPlastic TPU · Density: typicalPlastic TPU · Melting point: typicalPlastic TPU · Max service temperature: HDT 0.455 MPa (printed specimens)

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.

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

Questions

Mechanical

Is Plastic PBT GF30 stronger than Plastic TPU?

Plastic PBT GF30 is stronger: its tensile strength is 140 MPa against 23.7 MPa for Plastic TPU (5.91x).

Which is lighter, Plastic PBT GF30 or Plastic TPU?

Plastic TPU is lighter: 1,220 kg/m³ against 1,530 kg/m³ for Plastic PBT GF30.

Which is stiffer, Plastic PBT GF30 or Plastic TPU?

Plastic PBT GF30 is stiffer: Young's modulus 9.8 GPa against 0.067 GPa for Plastic TPU, so the same part in Plastic PBT GF30 deflects less under the same load.

Which is lighter for the same job, Plastic PBT GF30 or Plastic TPU?

For the same stiffness or strength: Plastic PBT GF30 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 PBT GF30	Plastic TPU
Stiff rod or tie (tension)	lighter	117x heavier
Stiff beam (bending)	lighter	9.64x heavier
Stiff panel or plate	lighter	4.2x heavier
Strong rod or tie	lighter	4.71x heavier
Strong beam	lighter	2.61x heavier
Strong panel or plate	lighter	1.94x 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).