Polypropylene Random Copolymer (PP-R)
PP Random Copolymer — is a type of polypropylene where a small amount of ethylene (typically 1–7%) is incorporated into the polymer chain. This makes the material more flexible and impact-resistant compared to homopolymer, while maintaining excellent transparency and processability.
Key Features
- Enhanced impact resistance
- Improved clarity and transparency
- Excellent weldability
- Stable processing via injection molding and extrusion
- Higher resistance to stress cracking
Physical and Mechanical Properties (Typical Values) | |
Property | Typical Values |
Density | 0.895 – 0.905 g/cm³ |
MFI (230°C / 2.16 kg) | 1.5 – 30 g/10 min (depending on grade) |
Tensile Strength | 25 – 32 MPa |
Flexural Modulus | 900 – 1300 MPa |
Impact Strength (Izod) | higher than PP-H |
Melting Point | 140 – 150 °C |
Vicat Softening Temperature | 125 – 135 °C |
Values may vary depending on the manufacturer and the specific grade.
Melt Flow Index (MFI)
The melt flow rate is selected based on the technology:
- 1–4 g/10 min — pipes, sheets, extrusion
- 5–15 g/10 min — general-purpose injection molding
- 20–30 g/10 min and above — thin-wall injection molding
Applications
- Food containers
- Transparent packaging
- Medical devices
- Caps and closures
- Household goods
- Pipes (PP-R for hot and cold water systems)
- Thin-walled products
Advantages over Homopolymer (PP-H)
- Better impact strength at low temperatures
- Higher transparency
- Reduced brittleness
- Enhanced welding properties
