Kinetic and process modeling of thermal and mechanical degradation in ultrahigh speed twin screw extrusion

Farahanchi, Azadeh; Sobkowicz, Margaret J.

doi:10.1016/j.polymdegradstab.2017.02.009

Cited by 30 publications

(16 citation statements)

References 28 publications

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“…The approach is 1D non-isothermal along the screw length and allows the user to calculate the evolution of the main process parameters. In an ultra-high speed extrusion study [ 42 ], for example, the LUDOVIC ® software was used to calculate the thermomechanical flow parameters for various screw profiles and was found to offer a good correlation between the theoretical and experimental results.…”

Section: Process Modellingmentioning

confidence: 99%

The Modelling of Extrusion Processes for Polymers—A Review

2020

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Extrusion processes are widely used in industries that aim to produce advanced solutions for increasingly sophisticated demands in the plastic, food, and pharmaceutical sectors. Though the process has been in use since the 1930s, limited information is available on the analytical computation of extrusion. Generally, production has been carried out based on empirical experience and trial-and-error approaches. The development of industrial operations is, however, best addressed by modelling the processes involved, and the flow of polymer melts and fibers in extruders has been subjected to some previous studies. Also included an overview of design of a die as well as challenges in sheet/film production. This article systematically and critically reviews the literature related to the process design, machine design, process parameters, flow models, and flow analysis of extrusion with a focus on modelling the extrusion of composite materials.

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Section: Process Modellingmentioning

confidence: 99%

The Modelling of Extrusion Processes for Polymers—A Review

2020

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“…Potential applications of this model include predicting nutraceutical content, starch gelatinization, protein denaturation, and extrudate texture as a function of critical processing parameters: strain history, shear work, and shear power intensity (Suparno et al, ). Farahanchi et al (; Farahanchi & Sobkowicz, ) studied an ultra‐high speed TSE process. Their model was introduced in conjunction with experimental extrusion results to predict the evolution of depolymerization reaction at various operating conditions during ultra‐high speed TSE.…”

Section: Introductionmentioning

confidence: 99%

Effect of twin‐screw extrusion on gelatinization characteristics of oat powder

Wang

Xia

Wang

et al. 2019

J Food Process Engineering

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The effect of extrusion treatments on oat gelatinization, microstructure, and macroproperties were important during twin‐screw extrusion. In this work, single factor and orthogonal experiments were conducted to evaluate gelatinization degree, expansion ratio, water solubility index, and water absorption index of oat powder before and after extrusion. Results indicated that the optimum gelatinization degree was 96.92% under the conditions of 18% moisture content, 155°C barrel temperature, and 150 rpm screw rotating speed. According to appearance by scanning electron micrograph, the extruded oat changed from the original tightly wrapped texture to spongy and porous form with lower gelatinization temperature (88.00°C) than those without extrusion (91.35°C). Rapid viscosity analysis showed that extruded oat became more stable and easier to gelatinization, which was consistent to the in vitro digestion experiment, suggesting extruded oat could be applied as ready‐to‐eat food in the further application. Practical applications The purpose of this research was aimed to optimize the extrusion and ripening process of oat powder, to explore the effect of curing method on the characteristics of oat powder, and to compare the physical and chemical properties of oat powder before and after extrusion. Eventually, the optimized process of oat powder using twin‐screw extrusion technology improved the structural characteristics of oat powder and enhanced the digestibility of the product.

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“…The PPcoE/silica composite has the highest values of Δτ com , which also suggested that the molten composite mixture experienced highest shearing force during the extrusion process and may result in a massive chain cleavage. [ 25 ] The Δτ com of PPcoE/wollastonite was slightly higher, while Δτ com of PPcoE/kaolin was the lowest. On the other hand, a high Δτ com also implied that the composite had a strong drag effect on the extruder die wall, stretching PPcoE polymer chains and causing fillers blooming, and resulted in rough extrudate/pellet surfaces (Figure 4).…”

Section: Resultsmentioning

confidence: 99%

The thermal‐mechanical degradation of mineral‐filled polypropylene‐ethylene copolymer composites during extrusion process

et al. 2020

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This work proposes a new understanding of the side effect of mineral fillers in polymer compounding that caused different levels of thermo‐mechanical degradation (TMD) during extrusion. Three mineral fillers, silica (random shape), kaolin (platy), and wollastonite (needle‐like), were selected and compounded with the polypropylene‐ethylene copolymer (PPcoE) using a twin‐screw extruder. Their influences on the TMD of PPcoE were examined by checking the substances in the extrudates using Fourier transform infrared spectroscopy. The built‐up shear stress causing by mineral filler in PPcoE composite (Δτcom) as the root of TMD was measured and estimated using capillary rheometer. In this study, TMD is classified as two levels: chain scission and oxidization. These fillers were found to accelerate the TMD mechanism and generate the oxidised products during extrusion. The silica filler caused the highest Δτcom, the lowest tensile strength, and elongation at break of PPcoE composites. The kaolin filler gave the most potent accelerating effect on oxidization, resulted in the formation of tertiary alcohol, and the highest ester contents in PPcoE composites; although, its composite had the lowest Δτcom among the fillers. Lastly, wollastonite filler provided higher Δτcom than kaolin composite, the second‐highest formation of alkene products, yet better retention in elongation at break compared to the silica‐filled PPcoE composite. In general, the side effect of mineral filler on TMD was a larger particle size always comes with higher chain scission, simpler particle morphology gives a smoother built‐up shear stress and minimizes TMD, and filler having hydroxyl groups catalyzes the oxidization TMD.

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Kinetic and process modeling of thermal and mechanical degradation in ultrahigh speed twin screw extrusion

Cited by 30 publications

References 28 publications

The Modelling of Extrusion Processes for Polymers—A Review

The Modelling of Extrusion Processes for Polymers—A Review

Effect of twin‐screw extrusion on gelatinization characteristics of oat powder

The thermal‐mechanical degradation of mineral‐filled polypropylene‐ethylene copolymer composites during extrusion process

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