Comparison
PET Fiber Grade vs PLA
A side-by-side comparison of Polyethylene Terephthalate for Fiber Applications and Polylactic Acid.
Physical
Density
1.30-1.39 g/cm³
1.24 g/cm³
Water Absorption (24h)
0.1-0.5 %
0.5 %
Transparency
Can be opaque or clear (before spinning)
Semi-transparent
Shrinkage
0.5-1.5 %
0.3 – 0.5 %
Mechanical
Young's Modulus
2.5-4.0 GPa
3.5 GPa
Tensile Strength
50-70 MPa
50 – 65 MPa
Elongation at Break
10-50 %
6 %
Impact Strength (Izod)
30-60 J/m
16 J/m
Flexural Strength
—
80 MPa
Thermal
Glass Transition Temperature
65-85 °C
60 °C
Melting Point
250-260 °C
150 – 160 °C
Continuous Service Temperature
Up to 150 °C (intermittent)
45 °C
Heat Deflection Temperature
60-70 °C
55 °C
Electrical
Dielectric Constant
3.0-3.2
3.0
Volume Resistivity
10¹²-10¹⁴ Ω⋅cm
10¹⁴ Ω·cm
Dielectric Strength
15-25 kV/mm
—
Chemical resistance
Acids
Good resistance to dilute acids
Fair
Bases
Poor resistance to strong bases
Poor
Solvents
Insoluble in most solvents, but can be attacked by strong acids, bases, and chlorinated hydrocarbons
—
UV Resistance
Fair (requires stabilization)
Poor
Alcohols
—
Fair
Hydrolysis
—
Poor
Sustainability
Recyclability
Highly recyclable
Industrially compostable
Recycling Code
1 (PET)
7
Carbon Footprint
Moderate
~1.6 kg CO₂e / kg
Bio-based Content
—
100 %