Solids Transport in Extruders

Campbell, Gregory A.; Dontula, N.

doi:10.3139/217.950030

Cited by 34 publications

(11 citation statements)

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“…Tadmor et al [2,36,37] introduced an energy balance considering the heat conduction into the solid bed. Campbell and Dontula [38] as well as Hyun and Spalding [39] defined an angle for the solid bed pressing force, which was not normal to the active flight of the screw. Chung [40,41] presented a different approach assuming that the solid bed moves because of the presence of molten polymer films at the metal surfaces.…”

Section: Solid Conveying Sectionmentioning

confidence: 99%

Fundamentals of Global Modeling for Polymer Extrusion

et al. 2019

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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.

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Section: Solid Conveying Sectionmentioning

confidence: 99%

Fundamentals of Global Modeling for Polymer Extrusion

et al. 2019

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“…The models of solid conveying zone are based on the mechanism of dry friction represented usually by the classic approach of Darnell and Moll [1] with subsequent modifications, e.g. [2][3][4][5][6]. They were also extended to describe the solid conveying in grooved barrels in isothermal an non-isothermal cases.…”

Section: Weryfikacja Dooewiadczalna Komputerowego Modelu Procesu Uplamentioning

confidence: 99%

Experimental verification of computer model for polymer plastication process in injection molding

et al. 2015

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This paper is a continuation of the work on a comprehensive model of the plastication process in injection molding. The aim of this research is the analysis of the results generated by the proposed model by comparing these results with the wide experimental characteristics of real plasticating system of injection molding machine for two polymers-PE-LD and PE-HD, differing in rheological and thermal properties due to the different physical structure of both polymers. It was found that the model correctly determines the dynamics of changes of characteristics of the plastication process by changing the input parameters of the process. The average quantitative differences between the experimental and theoretical characteristics do not exceed 20 %. Computer model still requires minor changes to improve compliance of model results with characteristics of real unit of injection molding machine, primarily for determining more accurate values of melt pressure and torque.

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“…In 1991, Zhu et al 9 proposed a nonplug flow-type theory by treating the inner friction as a parameter. In 1992, Campbell et al 10 reported the importance of a screw helix in conveying solids, and in 1995, Campbell and Dontula 11 suggested new models assuming the additional normal force acting on the solids bed is the same as the frictional force between the barrel and the solids bed.…”

Section: Introductionmentioning

confidence: 98%

A study on the rheological properties and processability of polycarbonate

Ahn

Kim

2002

J of Applied Polymer Sci

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ABSTRACT:The transport theory for the solids conveying zone in a single-screw extruder was applied to calculate the pressure distributions along the screw channel for several bisphenol A polycarbonate resins based on the screw revolution speed and the flow rate. The pressure distributions and the flow rates of the resins were related to the structural and rheological properties. When polymers have the same chemical structure and number-average molecular weight and the same mechanical properties, the polymer having a broader molecular weight distribution showed a lower glass transition temperature. For the polymer with broader MWD a relatively low pressure was developed along the screw channel, and an increased flow rate was observed. A relatively short melting length was also observed for this polymer and, accordingly, it was concluded that the polymer with a broader MWD has a better processability.

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Solids Transport in Extruders

Cited by 34 publications

References 0 publications

Fundamentals of Global Modeling for Polymer Extrusion

Fundamentals of Global Modeling for Polymer Extrusion

Experimental verification of computer model for polymer plastication process in injection molding

A study on the rheological properties and processability of polycarbonate

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