Hybrid computer modeling system of extrusion processes for quality control of multi-assortment polymeric films

Abstract

A hybrid computer modeling system of extrusion processes has been developed, which includes mathematical models of various types. The system helps operators to solve the problems of quality control of multi-assortment polymeric films during change-over of production lines and in the mode of film production. The system includes a module for choice of extruder brands, a designer of virtual 3D extruder screw models, and modules for structural and parametric synthesis of mathematical models of extrusion processes and calculation of throughput, energy consumption of extruders, extrudate quality indices determining consumer characteristics of the film. The model library contains geometric models of screw elements of various types, static functional models of physical processes in channels of screw elements, empirical models of rheological properties of polymers, dynamic models for estimation of residence time, models for calculation of mixing degree, index of thermal destruction and color characteristics of extrudate. Static models have been developed on the basis of conservation and rheology laws. The method of synthesis of a cell-type hydrodynamic model with recycles has been developed. The system is adjusted according to the production method, the film type, throughput and energy consumption requirements. Modeling results are presented as tables, 2D and 3D graphs. Testing of the system according to the data of the productions of polyvinyl chloride and polyethylene films at plants in Russia, Germany has confirmed its operability.