Development of Cryogenic Extrusion Techniques and Modelling of a Twin Screw Extruder: A Review

Ravikumar, Prashanth Shivanoor; Arumugam, Senthil; Gangradey, Ranjana; Mukherjee, Sayantan; Kasthurirengan, S.; Sadasivan, Sreeja; Gupta, Vishal; Aggarwal, Mahesh C.

doi:10.1007/s10894-021-00297-2

Cited by 3 publications

(3 citation statements)

References 99 publications

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“…That pressure when multiplied by the lateral stress ratio is used as the opposing pressure at the end of the feed channel. Then, the channel is back filled to calculate a pressure gradient using Equations ( 7) and (8). The concept using compressive modulus developed by Kim and Gogos [18][19][20] is used to calculate the pressure generated when the kneading disk closes on the volume of pellets in the opening.…”

Section: Ratementioning

confidence: 99%

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New 2.5‐Dtwin screw extruder model for the feed section of a co‐rotating twin screw extruder with comparisons to data

Campbell

Wetzel²,

Andersen³

et al. 2023

Polymer Engineering & Sci

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Many polymers are processed and compounded in co‐rotating, fully intermeshing twin screw (TS) extruders. The typical compounding process consists of multiple unit operations including feed introduction, conveying solids away from the feed zone, transitioning from the conveying zone to the kneading block (KB) melting zone, melting, a downstream feed zone, a downstream mixing zone, a devolatilization region, and a pressure generating discharge section. This paper will focus on the first of these unit operations, the conveying of pellets in a partially filled screw leading to compaction and pressure generation in the full screw channel prior to the KB melting zone. Mechanisms for pellet conveying, for heating the polymer pellets, and for developing pressure at the end of the solids conveying screw elements are first presented for low‐density polyethylene (LDPE). The predictions of the model are also compared with a classical set of experiments on high‐density polyethylene (HDPE). The model is then tested using published characteristics of a polyamide‐type polymer. This paper focuses on the physics and engineering concepts that are inherent in the feed section of the TS extruder where the pressure is calculated using the friction of the polymer pellets. The effects of throughput, Q, at a constant rotation speed, N, are examined. Low and high Q/N ratios have significantly different axial pressure profiles.

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Section: Ratementioning

confidence: 99%

“…There is an extensive body of literature regarding finite element modeling, a small sample of which includes. [7][8][9][10][11][12][13] In the analysis presented here, the shape of the channel is maintained, which leads to a "2+ D" dimensional representation.…”

Section: Introductionmentioning

confidence: 99%

New 2.5‐Dtwin screw extruder model for the feed section of a co‐rotating twin screw extruder with comparisons to data

Campbell

Wetzel²,

Andersen³

et al. 2023

Polymer Engineering & Sci

View full text Add to dashboard Cite

show abstract

“…This is a popular modeling technique for the TS extruder if one is not using finite element or finite difference methods. There is extensive literature regarding finite element modeling and a small sample includes References [8][9][10][11][12][13][14]. Kiani also discussed the utility and comparison of numerical methods and utilization of a spread sheet.…”

Section: Introductionmentioning

confidence: 99%

A new 2.5‐D twin screw extruder melting model with comparisons to data

Campbell,

Wetzel,

Andersen

et al. 2023

Polymer Engineering & Sci

View full text Add to dashboard Cite

Many polymers are processed and compounded in co‐rotating, fully intermeshing twin screw extruders. A typical compounding process consists of multiple unit operations including feed introduction, solids transport, transitioning from the conveying zone to the kneading block melting zone, melting, a downstream feed zone, a mixing zone, a devolatilization region, and a pressure generating discharge section. This paper will focus on the kneading block melting zone which typically includes a reverse pitch element so the kneaders remain full. Mechanisms for flow and energy input to pellets in kneading elements, including friction heating, pellet compression, energy diffusion, and viscous dissipation to form a melt phase: followed by viscous dissipation in a solid pellet/melt slurry, and heat transfer; are developed and implemented in a novel melting model. The model is validated with extrusion measurements and visualizations using low density polyethylene (LDPE). The predictions of the model are also compared with a classical set of experiments using high density polyethylene (HDPE). This paper describes the physics and engineering concepts that the authors feel are inherent in the melting section of the twin screw extruder where a large pressure peak is calculated using the friction and compression of the polymer pellets. The modeled increase in pellet bulk/surface temperature is due to the inclusion of four energy sources, pellet compression, thermal diffusion, friction energy dissipation, and viscous energy dissipation. This combined thermal dynamics based melting model results in a novel melting protocol. The melting mechanisms are coupled to flow regimes in the kneading blocks as melting progresses. The effects of throughput, Q, and screw rotation speed, N, are also examined.Highlights Novel 2.5D melting model for corotating, intermeshing twin‐screw extruders. Energy for melting; friction, deformation, diffusion, and viscous dissipation. The model helps elucidate mechanisms during melting in a twin‐screw extruder.

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Modeling of Twin Screw Extrusion of Polymeric Materials

Lewandowski

Wilczyński

2022

Polymers

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An issue of modeling of twin-screw extrusion of polymeric materials is reviewed. The paper is written in honor of Prof. James L. White who was a pioneer in studying this issue. A global approach to process modeling is presented which includes solid polymer transport, polymer plasticating, and the flow of molten polymer. The methodology of CFD modeling of twin-screw extrusion is presented as well as the examples of this modeling which show the details of the process. Optimization and scaling of twin-screw extrusion are also covered. And finally, the future prospects of developments and research of twin screw extrusion is discussed.

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Development of Cryogenic Extrusion Techniques and Modelling of a Twin Screw Extruder: A Review

Cited by 3 publications

References 99 publications

New 2.5‐Dtwin screw extruder model for the feed section of a co‐rotating twin screw extruder with comparisons to data

New 2.5‐Dtwin screw extruder model for the feed section of a co‐rotating twin screw extruder with comparisons to data

A new 2.5‐D twin screw extruder melting model with comparisons to data

Modeling of Twin Screw Extrusion of Polymeric Materials

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