GPPS

GPPS (General Purpose Polystyrene) – Product Specifications

GPPS is a transparent, rigid, and brittle amorphous thermoplastic known for its excellent optical clarity, good dimensional stability, and ease of processing. It has low water absorption and good electrical insulation properties. Unlike HIPS, GPPS does not contain rubber impact modifiers, so it offers high stiffness and gloss but lower impact resistance. GPPS is widely used in applications requiring transparency and rigidity, such as disposable tableware, packaging, and consumer goods.

Key Parameters:

• Density: 1.04 – 1.05 g/cm³

• Melt Flow Index (MFI / MI): 6 – 20 g/10min (grade dependent)

• Tensile Strength (Yield): 35 – 55 MPa

• Flexural Modulus: 3100 – 3300 MPa

• Flexural Strength: 70 – 90 MPa

• Elongation at Break: 1.5 – 3.5% (brittle)

• Izod Impact Strength (notched): 1.5 – 2.5 kJ/m² (low impact resistance)

• Rockwell Hardness (M scale): 70 – 80

• Light Transmission: 85 – 90% (excellent clarity)

• Refractive Index: 1.59

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

• Vicat Softening Point: 95 – 105°C

• Water Absorption (24h): 0.03 – 0.10%

• Mold Shrinkage: 0.3 – 0.6%

• Flame Rating (UL94): HB

• Surface Finish: High gloss

• Processing Methods: Injection molding, extrusion (sheet, film), thermoforming

• Typical Applications: Disposable cups and lids (clear, rigid), food containers (clamshells, trays for fruits/salads/bakery), CD jewel cases, office supplies (pen barrels, rulers, paper trays), cosmetic packaging jars and boxes, housewares (cutlery trays, hangers, photo frames), medical labware (petri dishes, test tubes, pipette tips – non-sterile, disposable), toys (transparent parts), refrigerator interior components (crisper trays, bins for fruits and vegetables), point-of-sale displays, lighting diffusers and lenses (non-optical grade), sheet for thermoforming (blister packs, clamshells, display trays), audio cassette and video tape casings.