High Impact Polystyrene (HIPS)
HIPS (High Impact Polystyrene) is a modified polystyrene with rubber (usually butadiene) incorporated into its structure. This gives the material much higher impact strength than general-purpose polystyrene (GPPS) while keeping good processability.
The material combines rigidity, processability and resistance to mechanical stress, which makes it widely used in industry.
Key properties
- Increased impact resistance
- Good rigidity
- Easy processing
- Matte or slightly glossy surface
- Can be coloured
- 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 |
Modulus of elasticity | 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 particular material grade.
Melt flow (MFI)
The melt flow index is chosen according to the processing technology:
- 2 – 6 g/10 min — sheet extrusion, thermoforming
- 6 – 10 g/10 min — standard injection moulding
- 10 – 15 g/10 min and above — thin-walled products
The material is easily processed by:
- injection moulding
- sheet extrusion
- thermoforming
Applications
- Household appliance housings (inner refrigerator panels)
- Electrical products
- Moulded parts
- Toys
- Packaging
- Sheets for thermoforming
- Advertising structures
Advantages
- Significantly higher impact strength than GPPS
- Good processability
- Cost-effective material
- Easy to colour
- Suitable for mass production
