GPPS Ningbo Liwan GP‑525
GPPS Ningbo Liwan GP‑525
Material Introduction: GPPS Ningbo Liwan GP‑525 is a general‑purpose polystyrene plastic. It is widely applied for its high transparency, high surface gloss, good flowability and favorable rigidity.
Main Applications
Daily‑use articles & toys: toys, daily‑life products, stationery, etc.
Packaging: cosmetic containers and other packaging fields.
Electrical components: instrument housings, lighting fixtures, household appliances, etc.
Others: indoor and outdoor decorations, fruit plates, etc.
Physical Properties
| Performance Category | Test Item | Test Standard | Unit | Typical Value / Range |
|---|---|---|---|---|
| Basic Properties | Melt Flow Rate (MFR) | ASTM D1238 | g/10min | 6.5‑8.0 |
| Density | ASTM D792 | g/cm³ | 1.04‑1.05 | |
| Mechanical Properties | Tensile Strength | ASTM D638 | MPa | 41‑43 |
| Flexural Strength | ASTM D790 | MPa | 73‑89 | |
| Flexural Modulus | ASTM D790 | MPa | 3038 | |
| Izod Notched Impact Strength | ASTM D256 | J/m | 15‑22 | |
| Elongation | ASTM D638 | % | 2‑2.1 | |
| Thermal Properties | Vicat Softening Temperature | ASTM D1525 | °C | 94‑98 |
| Heat‑Distortion Temperature (HDT) | ASTM D648 | °C | 85‑88 | |
| Optical Properties | Haze | ASTM D1003 | % | ≤ 0.5 |
| Other Properties | Residual Styrene Monomer | GB/T 16867 | ppm | < 500 |
Injection Molding Parameters
| Process Parameter | Reference Range / Recommendation | Remarks |
|---|---|---|
| Drying Treatment | 70‑80°C for 2‑3 hours | Although PS has low moisture absorption (less than 0.2 %), drying helps reduce product defects. |
| Barrel Temperature | 180‑240°C | Upper limit for flame‑retardant grade is 250°C. |
| Mold Temperature | 40‑70°C | Higher mold temperature improves gloss and reduces internal stress. |
| Injection Pressure | 200‑600 bar (approx. 20‑60 MPa) | Subject to part geometry and wall thickness. |
| Injection Speed | High injection speed recommended | High injection speed is preferred especially for complex‑shaped and thin‑wall parts. |
| Screw Speed | ‑ | Avoid excessive screw speed to prevent shear overheating or material degradation. |
| Runners and Gates | All conventional gate types are applicable | ‑ |
Extrusion Process Parameters
| Parameter Item | Typical Value / Range | Unit |
|---|---|---|
| Screw L/D Ratio | 25:1 ~ 30:1 | ‑ |
| Screw Compression Ratio | 2.0:1 ~ 2.5:1 | ‑ |
| Barrel Temperature (Feed Section) | 160‑180 | °C |
| Barrel Temperature (Compression Section) | 180‑200 | °C |
| Barrel Temperature (Metering Section) | 200‑220 | °C |
| Die Temperature | 200‑215 | °C |
| Melt Temperature | 210‑230 | °C |
| Mold Temperature | 60‑80 | °C |
Disclaimer: All above data is for reference only.
