HIPS

HIPS (High Impact Polystyrene) – Product Specifications

HIPS is a modified version of GPPS (general purpose polystyrene) with added rubber (polybutadiene) to significantly improve impact resistance while maintaining good processability and dimensional stability. It offers a balanced combination of mechanical strength, stiffness, and ease of fabrication. HIPS is widely used in applications requiring moderate strength and good surface finish for printing or painting.

Key Parameters:

• Density: 1.04 – 1.06 g/cm³

• Melt Flow Index (MFI / MI): 3 – 15 g/10min (grade dependent)

• Tensile Strength (Yield): 15 – 30 MPa

• Flexural Modulus: 1500 – 2500 MPa

• Flexural Strength: 35 – 55 MPa

• Elongation at Break: 30 – 60%

• Izod Impact Strength (notched): 6 – 12 kJ/m² (unreinforced) — significantly higher than GPPS

• Rockwell Hardness (L scale): 45 – 70

• Heat Deflection Temperature (HDT): 70 – 85°C (at 1.82 MPa) / 80 – 95°C (at 0.45 MPa)

• Vicat Softening Point: 95 – 105°C

• Water Absorption (24h): 0.05 – 0.10%

• Mold Shrinkage: 0.4 – 0.7%

• Flame Rating (UL94): HB (standard grade)

• Surface Finish: Good (printable / paintable)

• Processing Methods: Injection molding, extrusion, thermoforming

• Typical Applications: Refrigerator liners and trays (door shelves, interior components), air conditioner housings, TV and monitor casings (rear covers), vending machine parts, toys (action figures, playsets, ride-on vehicles), promotional signage, point-of-purchase displays, medical device housings (non-sterile components), packaging trays (food and consumer goods), disposable cups and lids (thick-wall), office equipment housings (printers, copiers), food service trays, vanity cabinet doors (in bathrooms/k kitchens).