Performance Comparison and Application Selection of PP, PE, PC, and Other Materials

Characteristics

PP (Polypropylene)

PE (Polyethylene)

PC (Polycarbonate)

Density (g/cm³)

Approximately 0.89-0.92, the lightest

0.91-0.96 (varies by type)

Approximately 1.2, relatively heavy

Heat Resistance

Excellent; the glass transition temperature is ~150℃, with even higher short-term heat resistance.

Low Temperature Resistance / Brittleness

Poor; prone to brittle fracture at low temperatures.

Excellent; can withstand temperatures as low as -70 to -100℃.

Good; maintains good impact strength at low temperatures.

Rigidity / Hardness

Moderate, superior to PE

Low, relatively flexible

High, with excellent mechanical strength

Translucent

Translucent to opaque (LDPE is translucent, while HDPE is opaque)

Excellent, with a light transmittance of up to 90%

Impact Strength

Good (especially HDPE)

Exceptionally excellent; it is the material used in bulletproof glass.

Chemical Stability

Resistant to most chemicals, especially acids and alkalis.

Resistant to most acids and alkalis.

Fair; weather-resistant but poor resistance to certain chemicals and hydrolysis.

Processing Characteristics

Good fluidity, with a relatively high shrinkage rate.

Good processability, but melt strength may be relatively low.

Requires high temperature (above 300℃) and thorough drying, with high processing requirements.

Cost

Low

Lowest (raw material price is usually lower than PP)

High (raw material price is about 2-3 times that of PP or higher)