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Residence time
→ For a graphical representation of the dwell time curve
For the calculation of the residence time the same conditions as for the calculation of the melting profile have to be fulfilled. In addition to this the injection time is required with PSI.
Realization of the theoretical principles
Up to Location of the melt vortex formation (OSW), the calculation of the minimum and average residence time does not differ because a block flow is assumed in this area. From the OSW, a distinction is made between the mean and minimum residence time. The mean residence time results in:
$$\bar{t} = \frac{V}{\dot{V}}$$ with the channel volume $V$ and the volume flow $\dot{V}$.
The minimum residence time results in:
$$\frac{t_{min}}{\bar{t}}=\frac{\dot{\pi}_m^{0,23(1-n)}}{2(1,249-0,589n)}$$
with the dimensionless mass throughput $\dot{\pi}_m$ and the Flow law exponents n.
PSI only: As soon as the calculated dwell time is equal to the dosing time, the standstill time and the injection time are added to it. This procedure is continued until the screw peak is reached.