High Impact Polystyrene (HIPS)
HIPS (High Impact Polystyrene) — is a modified polystyrene incorporating rubber (typically butadiene) into its structure. This gives the material significantly higher impact strength compared to General Purpose Polystyrene (GPPS), while maintaining excellent processability.
The material combines stiffness, manufacturability, and resistance to mechanical stress, making it highly sought after in industrial applications.
Key Features
- Enhanced impact resistance
- Good stiffness
- Ease of processing
- Matte or slightly glossy surface finish
- Easy to color
- Good dimensional stability
Physical and Mechanical Properties (Typical Values) | |
Property | Typical Values |
Density | 1.03 – 1.06 g/cm³ |
MFI (200°C / 5 kg) | 2 – 15 g/10 min (depending on grade) |
Tensile Strength | 20 – 30 MPa |
Flexural Modulus | 1700 – 2200 MPa |
Impact Strength (Izod) | 6 – 20 kJ/m² |
Glass Transition Temperature (Tg) | ~90 – 100 °C |
Service Temperature | up to 70 – 90 °C |
Specific parameters depend on the manufacturer and the material grade.
Melt Flow Index (MFI)
The melt flow index is selected based on the processing technology:
- 2 – 6 g/10 min — sheet extrusion, thermoforming
- 6 – 10 g/10 min — standard injection molding
- 10 – 15 g/10 min and above — thin-wall products
The material is well-suited for processing via:
- injection molding
- sheet extrusion
- thermoforming
Applications
- Household appliance housings (refrigerator inner liners)
- Electrical components
- Injection-molded parts
- Toys
- Packaging
- Sheets for thermoforming
- Advertising structures
Advantages
- Significantly higher impact strength compared to GPPS
- Excellent manufacturability
- Cost-effective material
- Easy to color
- Suitable for mass production
