Iterate Process
This page describes content that will only be available starting from REX 19.1 / PSI 17.1.
Iterate Process
The Iterate Process function is used to incorporate calculated values into an iterative computation. This can improve the simulation results, as calculated values such as temperature, pressure, or material degradation can influence the viscosity of the simulated polymer.
The first calculation of a process is always based on the assumption of simplified profiles. The initial temperature profile starts at the melting temperature of the polymer. After the grooved bush, or after 2.5 D, the temperature begins to rise linearly until the end of the screw—or up to just before the degassing zone in the case of degassing extruders. The final temperature is the given temperature of the necessary process parameters.
The initial pressure increases linearly from the pressure at the front edge of the feed hopper to the specified back pressure at the screw tip. In the case of vented extruders, the specified pressure is assumed already before the degassing section. From the beginning of the degassing zone, the pressure rises linearly again up to the end of the screw.
The initial melting profile starts at 15% of the screw length and ends at 80% of the screw length, or in the case of vented extruders, before the degassing section.
If the calculation is performed without using Iterate Process, only the initial profiles are used for the computation. A change in viscosity due to material degradation is neglected. The procedure of the Iterate Process function is illustrated in the following diagram:
