General Purpose Polystyrene (GPPS)
GPPS (General Purpose Polystyrene) — is a transparent thermoplastic polymer produced by the polymerization of styrene. The material is characterized by high stiffness, excellent clarity, and a glossy surface. Due to its superior flow properties, it is widely used in injection molding and extrusion.
General Purpose Polystyrene is a cost-effective material for manufacturing transparent and rigid products.
Key Features
- High transparency (crystal clear)
- Glossy surface finish
- High stiffness
- Ease of processing
- Low impact resistance (brittle material)
- Low moisture absorption
Physical and Mechanical Properties (Typical Values) | |
Property | Typical Values |
Density | 1.04 – 1.06 g/cm³ |
MFI (200°C / 5 kg) | 2 – 20 g/10 min (depending on grade) |
Tensile Strength | 40 – 50 MPa |
Flexural Modulus | 2800 – 3200 MPa |
Impact Strength (Izod) | 1.5 – 3 kJ/m² |
Glass Transition Temperature (Tg) | ~95 – 105 °C |
Service Temperature | up to 70 – 80 °C |
Specific values depend on the manufacturer and the material grade.
Melt Flow Index (MFI)
The flow index is selected based on the application:
- 2 – 6 g/10 min — sheets, profiles, extrusion
- 6 – 15 g/10 min — standard injection molding
- 15 – 20 g/10 min and above — thin-wall products
High flowability ensures precise mold filling and excellent surface quality.
Applications
- Transparent packaging
- Disposable tableware
- Containers and blister packs
- Stationery products
- Household appliance housings
- Advertising and decorative elements
- Laboratory ware
Advantages
- Excellent transparency
- High rigidity
- Good detailing during molding
- Cost-efficiency
- Simple processing
