scholarly journals A Novel Modeling Approach for Plastics Melting within a CFD-DEM Framework

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 227
Author(s):  
Alptekin Celik ◽  
Christian Bonten ◽  
Riccardo Togni ◽  
Christoph Kloss ◽  
Christoph Goniva
Keyword(s):  
Three Dimensional ◽  
Melting Rate ◽  
Experimental Results ◽  
Single Screw ◽  
Modeling Approach ◽  
Single Screw Extrusion ◽  
Three Dimensional Modeling ◽  
Solids Transport ◽  
Joint Consideration ◽  
Liquid States

Existing three-dimensional modeling approaches to single-screw extrusion can be classified according to the process sections. The discrete element method (DEM) allows describing solids transport in the feed section. The melt flow in the melt section can be calculated by means of computational fluid dynamics (CFD). However, the current state of the art only allows a separate consideration of the respective sections. A joint examination of the process sections still remains challenging. In this study, a novel modeling approach is presented, allowing a joint consideration of solids and melt transport and, beyond that, the formation of melt. For this purpose, the phase transition from the solid to liquid states is modeled for the first time within the framework CFDEMCoupling®, combining CFD and DEM by a novel melting model implemented in this study. In addition, a melting apparatus for the validation of the novel melting model is set up and put into operation. CFD-DEM simulations are carried out in order to calculate the melting rate and are compared to experimental results. A good agreement between the simulation and experimental results is found. From the findings, it can be assumed that the CFD-DEM simulation of single-screw extruder with a joint consideration of the feed and melt section is feasible.

scholarly journals Application of Network Analysis to Flow Systems with Alternating Wave Channels: Part B. (Superimposed Drag-Pressure Flows in Extrusion)

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1900
Author(s):  
Christian Marschik ◽  
Wolfgang Roland ◽  
Marius Dörner ◽  
Sarah Schaufler ◽  
Volker Schöppner ◽  
...  
Keyword(s):  
High Performance ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Wave Dispersion ◽  
Pressure Profile ◽  
Design And Optimization ◽  
Single Screw ◽  
Modeling Approach ◽  
Single Screw Extrusion ◽  
Pressure Flows

Due to progress in the development of screw designs over recent decades, numerous high-performance screws have become commercially available in single-screw extrusion. While some of these advanced designs have been studied intensively, others have received comparatively less attention. We developed and validated a semi-numerical network-theory-based modeling approach to predicting flows of shear-thinning polymer melts in wave-dispersion screws. In the first part (Part A), we systematically reduced the complexity of the flow analysis by omitting the influence of the screw rotation on the conveying behavior of the wave zone. In this part (Part B), we extended the original theory by considering the drag flow imposed by the screw. Two- and three-dimensional melt-conveying models were combined to predict locally the conveying characteristics of the wave channels in a discretized flow network. Extensive experiments were performed on a laboratory single-screw extruder, using various barrel designs and wave-dispersion screws. The predictions of our semi-numerical modeling approach for the axial pressure profile along the wave-dispersion zone accurately reproduce the experimental data. Removing the need for time-consuming numerical simulations, this modeling approach enables fast analyses of the conveying behavior of wave-dispersion zones, thereby offering a useful tool for design and optimization studies and process troubleshooting.

Development of a Forging Type Rapid Prototyping System; Automation of a Free Forging and Metal Hammering Working

2005 ◽  
Vol 17 (5) ◽  
pp. 523-528 ◽  
Author(s):  
Hidetake Tanaka ◽  
◽  
Naoki Asakawa ◽  
Masatoshi Hirao ◽  
Keyword(s):  
Rapid Prototyping ◽  
Three Dimensional ◽  
Experimental Results ◽  
Model Design ◽  
Plastic Working ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Cad Cam ◽  
Almost All ◽  
Rapid Prototyping System

The forging rapid prototyping we proposed based on CAD data involves numerically controlled free forging and metal hammer working as new three-dimensional modeling. Almost all products are now designed and developed using CAD/CAM, and rapid prototyping using CAD data is also used to model design previews or mock ups. Free forging and plastic working, however, have few ways to automate the process. We developed numerical controlled free forging and metal hammer working as new modeling for rapid prototyping. Experimental results demonstrate that our proposal provides feasible three-dimensional modeling as rapid prototyping.

Study of Modification of R-PP Foamability by Blending with PDMS

2011 ◽  
Vol 211-212 ◽  
pp. 550-554
Author(s):  
Ming Yi Wang ◽  
Lian Qing Ji ◽  
Jun Ma ◽  
Nan Qiao Zhou ◽  
Chul B. Park
Keyword(s):  
Carbon Dioxide ◽  
Population Density ◽  
Supercritical Carbon Dioxide ◽  
Cell Population ◽  
Expansion Ratio ◽  
Experimental Results ◽  
Blowing Agent ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Screw Extrusion

The effect of PDMS on foamability of R-PP was investigated using a single screw extrusion foaming system, with supercritical carbon dioxide as the blowing agent. Experimental results indicate that the addition of a small amount of PDMS will improve expansion ratio of R-PP foamed samples. Furthermore, compared with pure R-PP, cell-population density of foamed samples obtained from R-PP/PP-g-MAH/PDMS blends was obviously higher than that of pure R-PP foams.The experimental results show that blending with PDMS is beneficial for improving foaming performance of R-PP.

scholarly journals A Network-Theory-Based Comparative Study of Melt-Conveying Models in Single-Screw Extrusion: A. Isothermal Flow

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 929 ◽  
Author(s):  
Christian Marschik ◽  
Wolfgang Roland ◽  
Jürgen Miethlinger
Keyword(s):  
Comparative Study ◽  
Network Theory ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Polymer Melt ◽  
Pressure Profile ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Power Law Fluids ◽  
Flow Theories

In many extrusion processes, the metering section is the rate-controlling part of the screw. In this functional zone, the polymer melt is pressurized and readied to be pumped through the die. We have recently proposed a set of heuristic models for predicting the flow behavior of power-law fluids in two- and three-dimensional metering channels. These novel theories remove the need for numerical simulations and can be implemented easily in practice. Here we present a comparative study designed to validate these new methods against experimental data. Extensive experiments were performed on a well-instrumented laboratory single-screw extruder, using various materials, screw designs, and processing conditions. A network-theory-based simulation routine was written in MATLAB to replicate the flow in the metering zones in silico. The predictions of the three-dimensional heuristic melt-conveying model for the axial pressure profile along the screw are in excellent agreement with the experimental extrusion data. To demonstrate the usefulness of the novel melt-flow theories, we additionally compared the models to a modified Newtonian pumping model known from the literature.

Research on Three-Dimensional Modeling of Multi-Thread Single Screw Pump Rotor and Stator Based on UG

2010 ◽  
Vol 426-427 ◽  
pp. 114-117
Author(s):  
Xing Wei Sun ◽  
Qiao Yun Wang ◽  
Ke Wang ◽  
Lei Wang
Keyword(s):  
Three Dimensional ◽  
Machining Accuracy ◽  
Screw Pump ◽  
Single Screw ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Modeling Software ◽  
Three Dimensional Models ◽  
Spiral Surface ◽  
The Mathematical Model

Single screw pump is a kind of inside engaged biased rotation volume pump, which is widely applied in a number of major fields of the national economy. The key components are the rotor and the stator with complex spiral surface, which are meshing with each other. The machining accuracy of them makes effect on the working performance of single screw pump directly. In this paper, the operation principle of the single screw pump with large lead and multiple heads was represented, and the mathematical model of the rotor and the stator was established. The three-dimensional models of rotor and stator of single screw pump were put into effect with three-dimensional modeling software UG. This study has laid a theoretical foundation to the research of new manufacturing technology of the spiral curved surface and the development of the corresponding machine.

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