Comparison
PET Unfilled vs PEEK
A side-by-side comparison of Polyethylene Terephthalate Unfilled and Polyether Ether Ketone.
Physical
Density
1.33-1.40 g/cm³
1.32 g/cm³
Water Absorption (24h)
0.1-0.3 %
0.15 %
Transparency
Transparent to Opaque (depending on grade)
Opaque (amber)
Shrinkage
1.0-2.0 %
1.1 – 1.4 %
Mechanical
Young's Modulus
3.0-4.0 GPa
3.6 GPa
Tensile Strength
50-70 MPa
100 MPa
Elongation at Break
5-50 %
50 %
Impact Strength (Izod)
3-7 kJ/m
55 J/m
Flexural Strength
—
170 MPa
Thermal
Glass Transition Temperature
65-80 °C
143 °C
Melting Point
250-265 °C
343 °C
Continuous Service Temperature
80-100 °C
260 °C
Heat Deflection Temperature
50-70 °C (1.8 MPa)
160 °C
Electrical
Dielectric Constant
3.0-3.5
3.2
Volume Resistivity
10^14-10^16 Ohm-cm
10¹⁶ Ω·cm
Dielectric Strength
15-25 kV/mm
—
Chemical resistance
Acids
Good
Excellent
Bases
Poor
Excellent
Solvents
Good (alcohols, oils)
Excellent
UV Resistance
Fair
Fair
Hydrolysis (steam)
—
Excellent
Sustainability
Recyclability
Highly Recyclable
Recyclable (specialty)
Recycling Code
1 (PET)
7
Carbon Footprint
Moderate
~30 kg CO₂e / kg