Comparison
SMC/BMC for Automotive vs PA66
A side-by-side comparison of Sheet Molding Compound / Bulk Molding Compound and Polyamide 6,6 (Nylon).
Physical
Density
1.60-1.90 g/cm³
1.14 g/cm³
Water Absorption (24h)
0.1-0.5 %
1.2 %
Transparency
Opaque
Opaque
Shrinkage
0.5-1.5 %
1.5 – 2.0 %
Mechanical
Young's Modulus
10-20 GPa
3.0 GPa (dry)
Tensile Strength
80-150 MPa
80 MPa
Elongation at Break
1-3 %
60 %
Impact Strength (Izod)
20-50 J/m
50 J/m
Flexural Strength
—
110 MPa
Thermal
Glass Transition Temperature
80-120 °C
70 °C
Melting Point
N/A
255 – 265 °C
Continuous Service Temperature
100-150 °C
100 – 120 °C
Heat Deflection Temperature
80-120 °C
75 °C (unfilled)
Electrical
Dielectric Constant
4.5-6.0
4.0
Volume Resistivity
10^12-10^14 Ohm-cm
10¹² Ω·cm
Dielectric Strength
15-25 kV/mm
—
Chemical resistance
Acids
Good resistance
Poor
Bases
Moderate resistance
Good
Solvents
Good resistance to hydrocarbons
—
UV Resistance
Moderate without additives
Fair
Alcohols
—
Good
Oils & Fuels
—
Excellent
Sustainability
Recyclability
Difficult
Recyclable
Recycling Code
N/A
7
Carbon Footprint
Moderate
~7.4 kg CO₂e / kg
Bio-based Content
—
0 – 100 % (bio grades)