Comparison
XPS Insulation vs PETG
A side-by-side comparison of Extruded Polystyrene Foam for Insulation and Polyethylene Terephthalate Glycol.
Physical
Density
0.03-0.04 g/cm³ (foam)
1.27 g/cm³
Water Absorption (24h)
<0.5 %
0.13 %
Transparency
Opaque
Transparent
Shrinkage
N/A (foam)
0.2 – 0.5 %
Mechanical
Young's Modulus
Highly variable (foam)
2.1 GPa
Tensile Strength
Highly variable (foam)
50 MPa
Elongation at Break
Highly variable (foam)
120 %
Impact Strength (Izod)
Good compressive strength
100 J/m
Flexural Strength
—
70 MPa
Thermal
Glass Transition Temperature
90-100 °C (solid PS)
80 °C
Melting Point
N/A (amorphous)
—
Continuous Service Temperature
70-78 °C
65 °C
Heat Deflection Temperature
N/A (foam)
70 °C
CTE
—
68 × 10⁻⁶ /K
Electrical
Dielectric Constant
Around 1.1 (foam)
3.3
Volume Resistivity
>10¹³ Ω⋅cm (foam)
10¹⁴ Ω·cm
Dielectric Strength
High (foam)
—
Chemical resistance
Acids
Good resistance
Good
Bases
Good resistance
Fair
Solvents
Attacked by aromatic hydrocarbons, esters, ketones
—
UV Resistance
Poor
Fair
Alcohols
—
Good
Oils
—
Good
Sustainability
Recyclability
Recyclable (challenging collection)
Recyclable
Recycling Code
6 (PS)
1
Carbon Footprint
Moderate
~2.7 kg CO₂e / kg
Bio-based Content
—
0 %