Polypropylene (PP): melt temperature, drying, shrinkage
Typical values for Polypropylene (PP, semi-crystalline) in injection moulding: melt temperature 205–240 °C, mould temperature 30–50 °C, shrinkage 1.2–2.0 %, 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
PP Polypropylene, semi-crystalline
Melt temperature 205–240 °C
Mould temperature 30–50 °C
- Drying
- not required
- Density
- 0.90 g/cm³
- Cavity pressure
- 200–500 bar
- Shrinkage
- 1.2–2.0 %
Typical values for standard grades from the Resinovo material guide. They do not replace the manufacturer’s datasheet.
PP at a glance
Polypropylene is a semi-crystalline commodity plastic with low density, tough and chemically resistant. Typical uses are packaging, household goods, vehicle interior parts and parts with a film hinge.
PP absorbs hardly any moisture, so drying is usually not needed. Because of the high shrinkage, pay attention to uniform wall thickness and cooling.
Processing data for PP
- Melt temperature: 205–240 °C
- Mould temperature: 30–50 °C
- Drying: no drying needed
- Density: 0.90 g/cm³
- Cavity pressure: 200–500 bar
- Processing shrinkage: 1.2–2.0 %
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 PP have?
The melt temperature for Polypropylene is 205–240 °C and the mould temperature 30–50 °C (typical values).
Does PP have to be dried before processing?
According to the typical value, no: Polypropylene absorbs hardly any moisture. For storage in a humid environment or with additives, the manufacturer’s datasheet applies.
How high is the shrinkage of PP?
The processing shrinkage of Polypropylene is 1.2–2.0 %. It depends on wall thickness, holding pressure, mould temperature and grade.
What cavity pressure applies to PP?
The range for Polypropylene is 200–500 bar. The clamping force calculator and the app start with the mean of 350 bar; you can adjust the value.
More on PP 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: HDPE · ABS · ASA · PA6 · PA66 · POM · PMMA · PC · PC/ABS · PET · PBT · PS · SAN · TPU · PEEK · PPS · PP-GF
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