Medium Density Polyethylene (MDPE)
MDPE is a thermoplastic, further classified as a polyethylene plastic. It has a moderately high heat capacity and a fairly low density among thermoplastics. The graph bars on the material properties cards below compare MDPE 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
0.6 GPa 0.087 x 106 psi
Shear Modulus
0.64 GPa 0.093 x 106 psi
Thermal Properties
Glass Transition Temperature
-80 °C -110 °F
Melting Onset (Solidus)
120 °C 250 °F
Specific Heat Capacity
2350 J/kg-K 0.56 BTU/lb-°F
Thermal Conductivity
0.4 W/m-K 0.23 BTU/h-ft-°F
Other Material Properties
Density
0.93 g/cm3 58 lb/ft3
Dielectric Constant (Relative Permittivity) At 1 Hz
2.3
Common Calculations
Stiffness to Weight: Axial
0.36 points
Stiffness to Weight: Bending
30 points
Thermal Diffusivity
0.18 mm2/s
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