Online monitoring techniques for studying evolution of physical, rheological and chemical effects along the extruder

Covas, J. A.; Carneiro, O. S.; Machado, A. V.; Maia, João M.

doi:10.1179/146580104225018300

Cited by 32 publications

(20 citation statements)

References 31 publications

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“…Online measurement techniques have been implemented previously to study the evolution of blend morphologies, chemical reactions, and dispersion processes. [20][21][22][23][24][25][26] The SC was meant as a more universal device that would interface with any standard P/T port present on a commercial extruder. The SC acts as a three-position on/off valve for the collection of material out of a P/T port, with the ability to mold a sample of any geometry (a disk in this case) directly out of the extruder.…”

Section: Processing Equipmentmentioning

confidence: 99%

A New Extensional Mixing Element for Improved Dispersive Mixing in Twin‐Screw Extrusion, Part 2: Experimental Validation for Immiscible Polymer Blends

2016

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ABSTRACT:In Part 1 of this work, we presented a novel static extensional mixing element (EME) for twin-screw extrusion operations and validated the design in terms of the type of flow experienced by the melt upon dispersive mixing. In Part 2, we experimentally demonstrate the ability of the EME to yield improved dispersive mixing when compared with standard kneading-block-induced mixing for immiscible polypropylene/polystyrene blends of varying viscosity ratios between 0.3 and 10. The extensional flow characteristics of the EME improved the dispersion of polystyrene in the blends over all viscosity ratios, with improvements of 30% and above as measured by the cumulative area ratio measurements of polystyrene phases smaller than 1 μm 2 . The improvement in dispersive mixing seen from the EME for high viscosity ratio blends opens up applications in other areas, such as dispersion of nanoparticles or in reactive extrusion operations. C 2016 Wiley Periodicals, Inc. Adv Polym Technol 2016, 0, 21653; View this article online at wileyonlinelibrary.com.

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Section: Processing Equipmentmentioning

confidence: 99%

A New Extensional Mixing Element for Improved Dispersive Mixing in Twin‐Screw Extrusion, Part 2: Experimental Validation for Immiscible Polymer Blends

2016

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“…The extrusion is considered as a major technique in producing plastics and it is widely implemented in the case of polymer blends and plastic composites [12,13] . With increasing attentions in electromagnetic properties of plastic magnets [14][15][16] , this type of composites can also be obtained from the extruders.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic and Dynamic Mechanical Properties of Extruded Cobalt Ferrite-Polypropylene Composites

Hunyek

Sirisathitkul

2011

Polymer-Plastics Technology and Engineering

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Cobalt ferrites of 0-45 wt% were incorporated in polypropylene by the extrusion technique. With increasing magnetic loading, the magnetizations were linearly increased according to the rule of mixture and the electrical permittivity was also proportional to the loading as described by Wagner's equation. The magnetic permeability may be increased but was reduced to minimal at high frequencies because of the substantial coercive field of cobalt ferrites after the extrusion. Without considerable adsorption of polymer matrix on magnetic fillers, the storage and loss modulus from 30 to 180 C of polypropylene were decreased by cobalt ferrites additions.

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“…[91] Oscillatory rheometer Barrel On-line Linear viscoelastic behaviour - [91] Rotational rheometer Barrel On-line Morphology development, reaction kinetics, linear viscoelastic behaviour - [92] Barrel On-line Storage and loss modulus of polymer melts - [93] Extensional rheometer Die On-line Melt strength - [95] Slit die…”

Section: Diementioning

confidence: 99%

“…Covas et al [91] presented new equipment for monitoring the evolution of relevant characteristics of polymer systems along the screw axis. A sampling device was constructed, allowing the extraction of material from the screw channel.…”

Section: Rheological Techniquesmentioning

confidence: 99%

Process monitoring and visualization solutions for hot-melt extrusion: a review

Saerens

Vervaet

Remon

et al. 2013

Journal of Pharmacy and Pharmacology

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Objectives Hot-melt extrusion (HME) is applied as a continuous pharmaceutical manufacturing process for the production of a variety of dosage forms and formulations. To ensure the continuity of this process, the quality of the extrudates must be assessed continuously during manufacturing. The objective of this review is to provide an overview and evaluation of the available process analytical techniques which can be applied in hot-melt extrusion. Key Findings Pharmaceutical extruders are equipped with traditional (univariate) process monitoring tools, observing barrel and die temperatures, throughput, screw speed, torque, drive amperage, melt pressure and melt temperature. The relevance of several spectroscopic process analytical techniques for monitoring and control of pharmaceutical HME has been explored recently. Nevertheless, many other sensors visualizing HME and measuring diverse critical product and process parameters with potential use in pharmaceutical extrusion are available, and were thoroughly studied in polymer extrusion. The implementation of process analytical tools in HME serves two purposes: (1) improving process understanding by monitoring and visualizing the material behaviour and (2) monitoring and analysing critical product and process parameters for process control, allowing to maintain a desired process state and guaranteeing the quality of the end product. Summary This review is the first to provide an evaluation of the process analytical tools applied for pharmaceutical HME monitoring and control, and discusses techniques that have been used in polymer extrusion having potential for monitoring and control of pharmaceutical HME.

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Online monitoring techniques for studying evolution of physical, rheological and chemical effects along the extruder

Cited by 32 publications

References 31 publications

A New Extensional Mixing Element for Improved Dispersive Mixing in Twin‐Screw Extrusion, Part 2: Experimental Validation for Immiscible Polymer Blends

A New Extensional Mixing Element for Improved Dispersive Mixing in Twin‐Screw Extrusion, Part 2: Experimental Validation for Immiscible Polymer Blends

Electromagnetic and Dynamic Mechanical Properties of Extruded Cobalt Ferrite-Polypropylene Composites

Process monitoring and visualization solutions for hot-melt extrusion: a review

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