Comparison
HDPE Injection Molding vs PLA
A side-by-side comparison of High-Density Polyethylene for Injection Molding and Polylactic Acid.
Physical
Density
0.941-0.965 g/cm³
1.24 g/cm³
Water Absorption (24h)
<0.05 %
0.5 %
Transparency
Opaque
Semi-transparent
Shrinkage
1.5-3 %
0.3 – 0.5 %
Mechanical
Young's Modulus
0.8-1.5 GPa
3.5 GPa
Tensile Strength
20-35 MPa
50 – 65 MPa
Elongation at Break
50-300 %
6 %
Impact Strength (Izod)
No Break
16 J/m
Flexural Strength
—
80 MPa
Thermal
Glass Transition Temperature
-120 °C
60 °C
Melting Point
125-135 °C
150 – 160 °C
Continuous Service Temperature
80-100 °C
45 °C
Heat Deflection Temperature
50-65 °C
55 °C
Electrical
Dielectric Constant
2.25-2.35
3.0
Volume Resistivity
>10¹⁵ Ω⋅cm
10¹⁴ Ω·cm
Dielectric Strength
15-25 kV/mm
—
Chemical resistance
Acids
Excellent resistance
Fair
Bases
Excellent resistance
Poor
Solvents
Good resistance at room temperature, swells in hot aromatic hydrocarbons
—
UV Resistance
Poor (requires stabilization)
Poor
Alcohols
—
Fair
Hydrolysis
—
Poor
Sustainability
Recyclability
Recyclable
Industrially compostable
Recycling Code
2 (PE-HD)
7
Carbon Footprint
Moderate
~1.6 kg CO₂e / kg
Bio-based Content
—
100 %