Injection Molding Cycle Time Calculator

Estimate the cooling time and total cycle time for a plate-like injection-moulded part from wall thickness, melt, mould and ejection temperatures.

Wall thickness s (mm)

Melt temperature T_m (°C)

Mould temperature T_w (°C)

Ejection temperature T_e (°C)

How to Use the Injection Molding Cycle Time Calculator

Enter the nominal wall thickness in millimetres.
Enter the melt, mould and ejection temperatures.
Click Calculate to see cooling and total cycle time.

Casos de Uso

•Quoting injection-moulded parts.
•Design-for-manufacture studies on wall thickness.
•Teaching polymer processing.

Fórmula

t_cool = s² · ln[(π/4) · (T_m − T_w) / (T_e − T_w)] / (π² · α). Cycle ≈ fill (2 s) + pack (3 s) + cool + eject (1 s).

Perguntas Frequentes

Why is cooling ~80% of the cycle?

Cooling scales with the square of wall thickness, while fill and pack are largely independent of it. Halving the wall thickness quarters the cooling time.

Which α should I use?

The calculator uses 0.1 mm²/s as a typical thermoplastic thermal diffusivity. ABS ≈ 0.09, PP ≈ 0.10, PA6 ≈ 0.12 mm²/s.

Is this exact?

It is a 1D flat-plate approximation (Ballman/Shusman). Ribs, gates and hot spots require a dedicated mould-flow simulation.