Fundamentals of Global Modeling for Polymer Extrusion

Abstract

A review paper is presented on modeling for polymer extrusion for both single screw and twin-screw extrusion. An issue of global modeling is discussed, which includes modeling for solid conveying, melting, melt flow, and co-operation of the screw/die system. The classical approach to global modeling of the extrusion process, which is based on separate models for each section of the screw, i.e., solid transport section, melting and pre-melting sections, and the melt flow section is presented. In this case, the global model consists of the elementary models. A novel continuous concept of global modeling based on CFD (Computational Fluids Dynamics) computations is also presented, and a concept of using the DEM (Discrete Element Method) computation coupled with CFD computations is discussed.

Optimization for Starve Fed/Flood Fed Single Screw Extrusion of Polymeric Materials

“…The state-of-the-art for modeling of extrusion was presented in some fundamental books, e.g., by Rauwendaal [43], White and Potente [44], Tadmor and Gogos [45], Osswald and Hernandez-Ortiz [46], and Agassant et al [47], as well as in some papers, e.g., [48][49][50][51][52]. Wilczyński et al summarized and discussed this in a review paper [53].…”

“…A forward scheme of computations for flood fed extrusion and a backward scheme of computations for starve fed extrusion[53].…”

A hybrid additive manufacturing platform to create bulk and surface composition gradients on scaffolds for tissue regeneration

“…Computational modeling was used to understand flow and mixing behavior in extrusion screws with different thread cuts. Several specialized design features have been reported to modify these flows with the aim of improving mixing (19). Some features divide and re-combine the fluid multiple times to distribute materials being mixed more evenly, while others shear the materials in tight spaces to break aggregates.…”

A hybrid additive manufacturing platform to create bulk and surface composition gradients on scaffolds for tissue regeneration

“…Computational modeling was used to understand ow and mixing behavior in extrusion screws with different thread cuts. Several specialized design features have been reported to modify these ows with the aim of improving mixing [16] . Some features divide and recombine the uid multiple times to distribute materials being mixed more evenly, while others shear the materials in tight spaces to break aggregates.…”