PSI - Paderborn Injection Molding Simulation

PSI is a joint research project realized by about twenty companies and the KTP of the University of Paderborn. The software is a program which simulates manufacturing processes in single screw plasticizing unit. The aim of the development is to enable a fast and global evaluation of the machine performance and to optimize the barrel and screw configuration and also the process parameters. This aim is achieved by the realization of mainly analytical and closed equations. Calculation intensive numeric procedures are mostly avoided here.
Calculation possibilities

Currently, the following calculations are possible in PSI:

  • Pressure and throughput calculation
  • Melt calculation
  • Temperature profile calculation
  • Calculation of the power consumption, residence times calculation
  • Calculation of the feeding behavior, mixing characteristic calculation
(figure 1) Graphical user interface
(figure 1) Graphical user interface
In addition to the calculation of "pure" polymers models to estimate the behavior of polymer blends and of polymer-filler compounds are implemented in PSI. Calculation process:

In figure 2 the calculation process PSI works with is shown. The central element of a simulation is the pressure-filler content calculation, the melting and the temperature calculation. On the basis of these calculations all other necessary parameters to evaluate and optimize the screw and barrel configuration can be calculated.
Bild 2: Berechnungsablauf
(figure 2) Calculation process
Simulation results:

The results of the simulation calculations can be either be shown in the form of diagrams or tables. The graphical output is created in such a way that the development of one parameter is illustrated along the screw length. Thus, it is possible to evaluate single screw zones. On the basis of these findings simple modifications at the screw design can be performed if necessary. Figures 3 and 4 exemplify the pressure profile respectively the melting profile of such a simulation calculation.
Picture 3: Pressure profile along the screw length
figure 3: Pressure profile along the screw length
Picture 4: Melting Profile (Solid width, melt proportion)
figure 4: Melting profile (solid width, melt proportion)
To compare and evaluate the effects of different influencing parameters, a so-called variation module has been implemented in PSI. In this variation module all parameters which influence the process can be varied. All variations of the process are calculated and can be included into a multi-graphic after performing the calculation.
Further program functions:

In addition to the real calculation, PSI offers further program functions which support the user during the optimization. Consequently, it is possible to calculate own functions in form of user-defined functions. In this case the user can adopt the values internally calculated in PSI to calculate his own company-specific values. This simplifies the calculation of these values so that for example the same specific material values will always be chosen for each condition within the process. An additional feature is the scale-up module. It permits the user, for instance, to transfer processes calculated on small laboratory extruders onto a bigger production line.

As a further function, PSI offers a tool for statistical test planning (DoE). With this, the relevant target and influencing parameters can be defined. Depending on the choice of the statistical model, the matrix for the reduced experimental design is developed automatically and every operating point is calculated. The connection of the results is then described in a regression model. Then, the user can see a graphical evaluation of the results and can effortlessly determine an optimal operating point for the screw concept at hand.

 Technical details:
Supported barrel designs:
  • smooth barrel, smooth barrel with inflow support, venting barrel

Supported screw zones:
  • Feed section, compression section, metering section, decompression section, barrier zone, wave zone, PIN-zone
  • conical shearing element, Maddock shearing element, Troester shearing element, spiral shearing element, cylindrical shear element; cross hole element, rhombus-shaped element, tooth mixing element
  • annular non-return valve

For further information about PSI, please contact Mr. Tobias Hallmann.

Demo

Anhänge
application/pdf iconPSI-Flyer_English.pdf