Low Density Polyethylene (LDPE)
LDPE is a thermoplastic, further classified as a polyethylene plastic. It has a very low tensile strength among thermoplastics. In addition, it has a moderately high heat capacity and a fairly low density. The graph bars on the material properties cards below compare LDPE 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
Elastic (Young's, Tensile) Modulus
0.3 GPa 0.044 x 106 psi
Shear Modulus
0.21 GPa 0.030 x 106 psi
Tensile Strength: Ultimate (UTS)
7.0 MPa 1.0 x 103 psi
Thermal Properties
Glass Transition Temperature
-130 °C -190 °F
Maximum Temperature: Autoignition
380 °C 710 °F
Maximum Temperature: Decomposition
400 °C 750 °F
Melting Onset (Solidus)
110 °C 230 °F
Specific Heat Capacity
2300 J/kg-K 0.55 BTU/lb-°F
Thermal Conductivity
0.36 W/m-K 0.21 BTU/h-ft-°F
Thermal Expansion
220 µm/m-K
Vicat Softening Temperature
50 °C 120 °F
Other Material Properties
Density
0.92 g/cm3 57 lb/ft3
Dielectric Constant (Relative Permittivity) At 1 Hz
2.3
Common Calculations
Stiffness to Weight: Axial
0.18 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
2.1 points
Strength to Weight: Bending
8.8 points
Thermal Diffusivity
0.17 mm2/s
Thermal Shock Resistance
7.6 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