Polystyrene (PS): melt temperature, drying, shrinkage
Typical values for Polystyrene (PS, amorphous) in injection moulding: melt temperature 200–250 °C, mould temperature 20–50 °C, shrinkage 0.3–0.6 %, drying: no drying needed. The processing window below shows melt and mould temperature on one scale; the app covers more than 150 materials.
Processing window
PS Polystyrene, amorphous
Melt temperature 200–250 °C
Mould temperature 20–50 °C
- Drying
- not required
- Density
- 1.05 g/cm³
- Cavity pressure
- 300–700 bar
- Shrinkage
- 0.3–0.6 %
Typical values for standard grades from the Resinovo material guide. They do not replace the manufacturer’s datasheet.
PS at a glance
Polystyrene is amorphous, stiff, easy to process and transparent in the clear standard grade, but brittle. Typical uses are disposable items, packaging and housing parts.
PS absorbs hardly any moisture and usually needs no drying. Because of its brittleness, pay attention to draft angles and ejectors.
Processing data for PS
- Melt temperature: 200–250 °C
- Mould temperature: 20–50 °C
- Drying: no drying needed
- Density: 1.05 g/cm³
- Cavity pressure: 300–700 bar
- Processing shrinkage: 0.3–0.6 %
All values are typical figures for preselection. The manufacturer’s datasheet applies to the specific grade, and sampling on the machine decides the process.
Frequently asked questions
What processing temperature does PS have?
The melt temperature for Polystyrene is 200–250 °C and the mould temperature 20–50 °C (typical values).
Does PS have to be dried before processing?
According to the typical value, no: Polystyrene absorbs hardly any moisture. For storage in a humid environment or with additives, the manufacturer’s datasheet applies.
How high is the shrinkage of PS?
The processing shrinkage of Polystyrene is 0.3–0.6 %. It depends on wall thickness, holding pressure, mould temperature and grade.
What cavity pressure applies to PS?
The range for Polystyrene is 300–700 bar. The clamping force calculator and the app start with the mean of 500 bar; you can adjust the value.
More on PS in the app
All properties
Flow behaviour, MVR and MFR, thermal conductivity, heat deflection, mechanical properties, fire rating and processing notes.
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Density, cavity pressure and temperatures feed straight into the calculators and ResiCheck.
Read on
- Clamping force calculator
- Shot volume calculator
- Cooling time calculation
- Injection moulding defects: causes and remedies
- Material guide: all values at a glance
More materials: PP · HDPE · ABS · ASA · PA6 · PA66 · POM · PMMA · PC · PC/ABS · PET · PBT · SAN · TPU · PEEK · PPS · PP-GF
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