GPPS
ASTM D4549 · GB GB/T 4454 · ISO 1622
GPPS is general purpose polystyrene, an amorphous rigid transparent styrenic homopolymer covered by ASTM D4549 and GB/T 4454.
Reference datasheet — GPPS is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
GPPS grades and fills
GPPS is supplied in 5 conditions, soft to hard.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Foam-extrusion (PSP/XPS sheet) grade | High-MW, blowing-agent-compatible GPPS for foamed food trays and insulation sheet; properties are density-driven. | 1 | 3 | ||
Flame-retardant grade | Use where a UL 94 V-0/V-2 rating is mandatory (housings, electrical parts); loses clarity and some stiffness. | 38 | 1.8 | ||
High-flow / easy-flow injection grade | Pick for thin-wall, long-flow or multi-cavity moldings where fill pressure matters more than strength. | 42 | 2 | 84 Shore D | |
High-heat / high-molecular-weight (extrusion & sheet) grade | Low-MFR, low-lubricant grade for extruded sheet, thermoforming and slightly higher service temperature. | 50 | 3 | ||
20 % glass-fiber reinforced PS | Niche stiff/dimensionally-stable PS for low-cost structural brackets; opaque and abrasive to tooling. | 80 | 1.5 |
Supply forms, finishes and certifications
Ways GPPS is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
AS | Antistatic / ESD-modified grade | Coating |
FDA | Food-contact / medical (gamma-sterilizable) grade | Certification |
UV | UV-stabilized / light-stabilized grade | Grade option |
NATDefault | Natural / crystal clear injection grade | Standard supply |
What is GPPS?
GPPS is general purpose polystyrene, an amorphous rigid transparent styrenic homopolymer covered by ASTM D4549 and GB/T 4454. It is specified where the toughness of SAN or ABS is not required, offering low cost, optical clarity, dimensional stability and very easy injection molding and sheet extrusion; typical properties are 46 MPa tensile strength at 2.5 % elongation. The polymer is brittle and notch-sensitive, crazes on contact with solvents and greases, and has poor UV and heat resistance unless stabilized. HIPS is the nearest alternative when impact strength matters more than clarity. GPPS has a density of 1.05 g/cm³ (0.0379 lb/in³), lighter than 69% of polymer grades. Its glass-transition temperature is 100°C (212 °F). GPPS has a tensile strength of 46 MPa (6.67 ksi), weaker than 51% of polymer grades. Elongation at break is 2.5% and the elastic modulus is 3.2 GPa (0.464 Msi).
What is GPPS used for?
- Disposable cutlery/cups
- CD/DVD cases
- Packaging trays
- Toys
- Lab ware
Advantages
- Polishes to a fine finish — 85/100, better than 92% of polymer grades
- Readily welded — 80/100, better than 86% of polymer grades
- Low moisture uptake — 0.04%, better than 86% of polymer grades
- Stiff — 3.2 GPa (0.464 Msi), better than 77% of polymer grades
- Low embodied carbon — 3.4 kg CO₂/kg, better than 76% of polymer grades
Limitations
- Limited ductility — 2.5%, worse than 89% of polymer grades
- Needs corrosion protection — 60/100, worse than 89% of polymer grades
- Degrades in UV without stabilisers — 20/100, worse than 88% of polymer grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 87% of polymer grades
- Limited service temperature — 65°C (149 °F), worse than 83% of polymer grades
GPPS properties
Typical room-temperature values; bars are the position among polymer grades.
Physical6
GPPS has a density of 1.05 g/cm³ (0.0379 lb/in³), lighter than 69% of polymer grades. Its glass-transition temperature is 100°C (212 °F).
Mechanical16
GPPS has a tensile strength of 46 MPa (6.67 ksi), weaker than 51% of polymer grades. Elongation at break is 2.5% and the elastic modulus is 3.2 GPa (0.464 Msi).
Thermal11
GPPS is rated for continuous service to 65°C (149 °F). It conducts heat at 0.15 W/m·K (0.0867 BTU/hr·ft·°F), worse than 80% of polymer grades. Thermal expansion is 75 µm/m·K (41.7 µin/in·°F).
Electrical7
GPPS is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 89% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of GPPS takes about 92 MJ of energy and emits 3.4 kg of CO₂ — less than 74% of polymer grades. Typical recycled content is 0%.
Manufacturability8
GPPS's machinability is good (55/100, worse than 64% of polymer grades); weldability very good (80/100); formability fair (45/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. GPPS is highlighted; hover a dot for its name, or open the interactive family chart.
Working with GPPS
Is GPPS easy to machine?
Machines easily at high speed with sharp, positive-rake, polished tools and air cooling — but is notch-sensitive and crazes; avoid cutting fluids containing solvents and always drill with slow feed to prevent cracking.
Can GPPS be welded?
Excellent for ultrasonic, hot-plate/spin welding and solvent bonding (toluene/MEK-based or cyanoacrylate); solvent joints must be stress-relieved to avoid crazing.
Can GPPS be formed, bent or molded?
Very easy injection molding at 190–250 °C melt / 20–70 °C mold with 0.3–0.7 % shrinkage; extruded sheet thermoforms cleanly, but drying is unnecessary and over-shear causes yellowing and monomer odor.
GPPS chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| residual styrene monomer≤ 0.02 % typical for food/medical grades | 0 – 0.06 | 0.03 |
| mineral oil / internal lubricantflow & mold-release aid; higher in high-flow grades | 0 – 3 | 1.5 |
| stearate + antioxidant additives | 0 – 0.5 | 0.2 |
| styrene (polystyrene homopolymer)amorphous atactic homopolymer | ≥ 99 (balance) |
What surface finishes work on GPPS?
Reproduces high-gloss mold surfaces directly; accepts vacuum metallizing, hot stamping and UV/hard-coating, but solvent-based paints and adhesive tapes readily stress-crack the part.
Equivalent designations
Standards and trade names that resolve to GPPS in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- D4549
- ISO
- 1622
- GB (China)
- GB/T 4454
How much does GPPS cost?
GPPS is a budget-cost polymer ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
GPPS — frequently asked
What is GPPS used for?
GPPS is typically used for disposable cutlery/cups, CD/DVD cases, packaging trays, toys and lab ware. In short: cheapest clear thermoplastic; easiest styrenic to mold; brittle and solvent-sensitive.
What is the tensile strength of GPPS?
GPPS has a typical tensile strength of 46 MPa (6.67 ksi) — weaker than 51% of polymer grades. Strength varies by condition: see the 5 listed tempers.
Is GPPS easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Machines easily at high speed with sharp, positive-rake, polished tools and air cooling — but is notch-sensitive and crazes; avoid cutting fluids containing solvents and always drill with slow feed to prevent cracking.
Can GPPS be welded?
Yes — weldability is rated very good (80/100). Excellent for ultrasonic, hot-plate/spin welding and solvent bonding (toluene/MEK-based or cyanoacrylate); solvent joints must be stress-relieved to avoid crazing.
What surface finishes work on GPPS?
Reproduces high-gloss mold surfaces directly; accepts vacuum metallizing, hot stamping and UV/hard-coating, but solvent-based paints and adhesive tapes readily stress-crack the part.
Can GPPS be formed, bent or molded?
Very easy injection molding at 190–250 °C melt / 20–70 °C mold with 0.3–0.7 % shrinkage; extruded sheet thermoforms cleanly, but drying is unnecessary and over-shear causes yellowing and monomer odor.
What is the maximum service temperature of GPPS?
GPPS is rated for continuous use to about 65°C (149 °F), and briefly to 80°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does GPPS cost?
GPPS is a budget-cost polymer ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ISO 1622-1/-2 Plastics — Polystyrene (PS) moulding and extrusion materials — ISO (2012)
- ASTM D4549 Standard Classification System for Polystyrene Molding and Extrusion Materials — ASTM (2020)
- ASM Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- CAMPUS plastics database — GPPS injection/extrusion grades — CWFG / material producers (2024)
- General purpose polystyrene grade datasheets and processing guides — INEOS Styrolution / Trinseo / Total Energies / (Formosa Chemicals) (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.