GPPS
General purpose polystyrene, glass-clear, hard and dimensionally stable. The grade family chosen when the part has to be transparent, rigid and cheap to mould.
Clarity and flow, at the cost of impact strength
GPPS is unmodified polystyrene. Without the rubber phase that HIPS carries, it stays optically clear and very stiff, and it flows exceptionally well, which is why it fills thin-wall tooling that tougher polymers struggle with.
The trade-off is brittleness. A GPPS part will craze and crack rather than deform, so it belongs in applications where appearance and rigidity matter more than surviving a drop. Where impact is a factor, HIPS is the right conversation.
- High-flow grades for thin-wall injection and complex tooling.
- Sheet grades for thermoforming and rigid packaging.
- Food-contact suitable grades available on request.
GPPS grades we supply
16 grades are currently available. Availability moves with producer allocation, so confirm the grade with us before you commit a production slot.
- GPPS 1160
- GPPS 1161
- GPPS 1460
- GPPS 1540
- GPPS 1551
- GPPS 1018
- GPPS 1028
- GPPS 1034
- GPPS 1038
- GPPS 1047
- GPPS 1067
- GPPS 1077
- GPPS 1084
- GPPS 1115
- GPPS 1144
- GPPS 1233
What decides the GPPS grade
Melt flow does most of the work in GPPS selection. After that it is a question of how the part is finished and what it touches.
- Melt flow rate: high for thin-wall and long-flow tooling, lower for sheet and heavier sections.
- Residual monomer: matters for food contact and for odour-sensitive applications.
- Heat deflection temperature: decides whether the part survives filling or sterilising.
- Optical clarity: haze and yellowness index for display and packaging parts.
- Internal lubricant: affects demoulding and cycle time on fast-running tools.
Typical GPPS applications
GPPS is the default when a part must be seen through and does not have to survive being dropped.
- Clear disposable cups and lids
- CD, cosmetic and gift packaging
- Rigid thermoformed trays
- Point-of-sale display parts
- Light diffusers and lenses
- Stationery and office mouldings
- Laboratory disposables
- Blending component for HIPS and EPS
Need a GPPS grade for a specific tool?
Send us the wall thickness, the flow length and the cycle time you are targeting. We will shortlist grades that will fill it.