Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- en:start [2024/08/09 08:59] – admin
+++ en:start [2025/12/22 13:01] (aktuell) – [Preface] neelest
@@ Zeile 1: / Zeile 1: @@
-======REX 18 / PSI 16======
+======SIGMA 15======
+{{ :wiki:sigma_label_ktp_4c_ok.png?nolink&600 |}}
 {{ :installation_und_deinstallation:rex_label_ktp_4c_ok.png?600 |}}
 {{ :installation_und_deinstallation:psi_label_ktp_4c_ok.png?600 |}}
-===== Foreword =====
+===== Preface =====
+Making optimum use of an extruder from the economic point of view requires a comprehensive knowledge of the plasticizing process of polymeric materials. To date, decisions are made primarily on the basis of "empirical values" and experimental investigations. In the course of the past few years, the SIGMA simulation program has been developed to become an alternative to the frequently employed trial-and-error-approach. It can be used in the design and optimization of extruders from the process engineering point of view. Apart from permitting time and cost savings, the calculation additionally provides information on individual parameters which influence the plasticizing of the material. The plasticizing process is rendered highly transparent and made accessible to calculation.
+The following parameters can be calculated with the program:
+  * pressure profile
+  * filling degree distribution
+  * temperature profile
+  * melting curve
+  * residence time behavior
+  * drive power or requisite torque
+  * axial mixing coefficient
+  * degree of dispersion
+  * heating/cooling needed
-The screw is the heart of an extruder and an injection molding machine. No other component in plastics processing has such a significant influence on the quality of the on the quality of the end product and the cost-effectiveness of the process. In recent In recent years, it has been recognized that the "universal screws" developed in the past no longer meet today's requirements in many cases. Insufficient melt qualities, low melt throughputs or low machine efficiencies are forcing the plastics are forcing the plastics industry to break new ground. The trend is moving towards "small solutions" that are individually tailored to the material, the process and the product.
+The parameters listed above display differing degrees of mutual dependence. To achieve a physical-mathematical description of a problem of this complexity, solution methods were worked out for the individual parameters. When the individual models were implemented in a computer program, they were linked together to form a comprehensive model. The physical-mathematical computation models make allowance for the influencing factors of screw and barrel geometry, material behavior and process parameters.
-However, the complexity of the actual plasticizing process and the growing number of
+The following basic principles were applied during modelling:
-innovative screw and system concepts make it difficult to deal with this topic.
-topic. To this day, decisions are often made on the basis of experience and
-experimental investigations. As an alternative to the frequently used
-the REX/PSI simulation package was developed as an alternative to the often used "trial and error" method.
-and optimization of extruders (REX) and injection moulding plasticizing units (PSI).
-(PSI) injection molding plasticizing units.
-The software, which can be run on a standard PC workstation, can be used to simulate important parameters can be simulated to evaluate the process. In addition, various program features support various program features support the systematic optimization of individual geometric variables and the design of entire machine series.
+  * the models are based on simple physical considerations
+  * simple mathematical models
+  * the aim is to achieve a closed analytical solution, if necessary achieved by simplifications
+  * with a sequence of differential equations, it is possible to work towards a solution through the linearization of intermediate results on a semi-logarithmic or log-log plot
+  * if no closed analytically solution exists, approximation equations are used which are based on numerical solutions
+  * statistical processes within the plasticizing unit are described by means of defined distribution functions
-The simulation programs have been continuously developed since 1989 as part of a joint research project continuously developed further. By deriving more precise calculation models based on the three-dimensional
+Using closed solutions or experimentally verified approximation solutions made it possible to implement very quick solution algorithms, thereby giving very short computation times. In this way, SIGMA can be used as a target-oriented, engineering tool for the layout of extruders.
-finite element method and by implementing current screw geometries, the software is current screw geometries, the software is constantly being adapted to the growing needs of users.
-needs of users. These programs thus make a comprehensive contribution to the assessment and optimization of single-screw machines in industrial applications.
-This user manual explains how to use the software. The theoretical approaches on which the calculations are based are presented in a large number of publications and dissertations. A detailed literature can be found in the appendix.
+We would like to take this opportunity to thank all project participants once again, who made the development of this simulation software possible through their participation in the joint project.
-We would like to take this opportunity to thank all project participants once again,
-who made the development of this simulation software possible through their participation in the joint project.
-the development of this simulation software.
-Software Engineering Team REX/PSI (Email: software@ktp.upb.de)
+Software Engineering Team SIGMA (Email: software@ktp.upb.de)
 Paderborn