GPPS

material

General Purpose Polystyrene, a clear, rigid thermoplastic polymer with excellent transparency, dimensional stability, and ease of processing, commonly used in packaging and consumer goods.

In Simple Terms

GPPS is the basic form of polystyrene plastic that's crystal clear and brittle. It's the material used to make disposable cups, food containers, and CD cases. Unlike HIPS, it doesn't contain rubber modifiers, making it transparent but more prone to cracking under impact.

Why It Matters

GPPS is a high-volume commodity resin critical to packaging, electronics, and consumer goods industries. Its excellent clarity, low cost, and easy processing make it essential for applications requiring transparency and dimensional precision at competitive pricing.

Technical Details

GPPS is an amorphous thermoplastic with typical properties including tensile strength of 35-55 MPa, flexural modulus of 2800-3200 MPa, and Vicat softening point around 95-105°C. Melt flow rates typically range from 1-25 g/10min, with molecular weights between 150,000-300,000 g/mol depending on grade specifications.

Real-World Examples

Packaging grade selection

A food packaging converter specifies GPPS with MFR 7-9 g/10min for thermoforming disposable containers, balancing processability with wall thickness uniformity

Quality control testing

Resin traders verify GPPS shipments using haze measurements and tensile testing per ASTM D638 to ensure optical clarity and mechanical property compliance

Price negotiation

A processor switches from virgin GPPS to post-industrial recycled GPPS blend to reduce material costs while maintaining transparency for non-critical applications