Unfilled HDPE
Unfilled HDPE is a grade of HDPE. It has the lowest strength and highest ductility compared to the other variants of HDPE. The graph bars on the material properties cards below compare unfilled HDPE to: polyethylene plastics (top), all thermoplastics (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Compressive (Crushing) Strength
21 MPa 3.0 x 103 psi
Elastic (Young's, Tensile) Modulus
1.0 GPa 0.15 x 106 psi
Elongation at Break
100 %
Impact Strength: Notched Izod
260 J/m 4.8 ft-lb/in
Shear Modulus
0.85 GPa 0.12 x 106 psi
Tensile Strength: Ultimate (UTS)
24 MPa 3.4 x 103 psi
Thermal Properties
Glass Transition Temperature
-80 °C -110 °F
Heat Deflection Temperature At 1.82 MPa (264 psi)
40 °C 100 °F
Maximum Temperature: Autoignition
380 °C 720 °F
Maximum Temperature: Decomposition
410 °C 770 °F
Maximum Temperature: Mechanical
90 °C 190 °F
Melting Onset (Solidus)
130 °C 270 °F
Specific Heat Capacity
2400 J/kg-K 0.57 BTU/lb-°F
Thermal Conductivity
0.45 W/m-K 0.26 BTU/h-ft-°F
Thermal Expansion
130 µm/m-K
Vicat Softening Temperature
70 °C 160 °F
Other Material Properties
Density
1.0 g/cm3 59 lb/ft3
Dielectric Constant (Relative Permittivity) At 1 Hz
2.4
Common Calculations
Stiffness to Weight: Axial
0.58 points
Stiffness to Weight: Bending
35 points
Strength to Weight: Axial
6.9 points
Strength to Weight: Bending
19 points
Thermal Diffusivity
0.2 mm2/s
Thermal Shock Resistance
13 points
Followup Questions
Further Reading
ASTM D883: Standard Terminology Relating to Plastics
SPI Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., 5th ed., Michael L. Berins (editor), 2000
Modern Plastics Handbook, Charles A. Harper (editor), 1999
Plastics Materials, 7th ed., J. A. Brydson, 1999