Development of an in-line viscometer in an extrusion molding process

Chiu, Shih‐Hsuan; Yiu, Hsuan-Chi; Pong, Sheng-Hong

doi:10.1002/(sici)1097-4628(19970214)63:7<919::aid-app12>3.0.co;2-m

Cited by 22 publications

(10 citation statements)

References 1 publication

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“…Advantage of this method is a high speed of measurements what enables to use it for on-line measurements and monitoring of a manufacturing process [7].…”

Section: The Density Measurement Methodsmentioning

confidence: 99%

Viscosity and density measurement methods for polymer melts

Kažys

Rekuvienė

2012

ultra

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In this article review of density and viscosity measurement methods is presented, including ultrasonic pulse echo methods, which are capable to measure these properties of polymer melts. The methods are presented according to measurement principles, methodology, accuracy and possibility to measure density and viscosity of polymer melts on-line during extrusion process. Such measurements are very important for process automation, process monitoring and control. The ultrasonic pulse echo methods are separated from other methods, because very often they are superior to other techniques. The advantage of this technique is that at the same time sound velocity and attenuation in a plastic melt may be measured, what gives more information. For this purpose polarized shear waves as well as longitudinal, torsional and other types of waves in a wide frequency range may be employed.

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“…Advantage of this method is a high speed of measurements what enables to use it for on-line measurements and monitoring of a manufacturing process [7].…”

Section: The Density Measurement Methodsmentioning

confidence: 99%

Viscosity and density measurement methods for polymer melts

Kažys

Rekuvienė

2012

ultra

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“…However, the size of the screw speed step change (i.e., 300 rpm) used for simulation was unrealistic and also the reasons for the difference between experimental and simulation results were not discussed. Another work by Chiu et al [51] and Chiu and Pong [52,53] introduced a fuzzy gainscheduled PID controller (incorporating an in-line viscometer) to control the melt viscosity by manipulating the screw speed. A second order model related to the viscosity and screw speed was empirically developed (i.e., from plant step responses) to approximate the extruder dynamics.…”

Section: Viscosity Controlmentioning

confidence: 99%

Single screw extrusion control: A comprehensive review and directions for improvements

Abeykoon

2016

Control Engineering Practice

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Polymer extrusion is usually a complex process, particularly due to the coupled nature of process parameters, and hence highly prone to fluctuations. Although a number of different approaches have been attempted in research/industry over the last few decades for extrusion control, it is still experiencing some problems in achieving consistent product quality. Presently, most of the polymer processing extruders are equipped with PID controllers mainly for the control of the screw speed and barrel temperatures in their set limits. It seems that only both of these controllers are commonly used as the major aids of process control to achieve the required melt quality. Although, the quality of the melt output (i.e., a thermally homogeneous melt output which is constant in quantity and quality over the time) is the key variable in polymer extrusion, only a few control techniques are available which make control decisions by observing the actual melt flow quality. Therefore, the development of new control strategies which consider the actual melt quality, perhaps incorporating industrially popular nonlinear techniques such as artificial intelligence, should be highly valuable. In this work, a critical evaluation is made on the state-of-the-art of the previous control approaches in polymer extrusion in industry and research while identifying their limitations. Then, some of the possible directions for future research and also to develop an advanced process control strategy are presented by eliminating a few of the existing limitations.

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“…In-line Melt viscosity as a function of shear rate - [90] Capillary rheometer Barrel On-line Torque, shear stress, shear rate, melt flow index, linear viscoelastic behaviour Large deformations and relatively high shear rates associated with the flow in a capillary rheometer may affect the morphology of the material and consequently its rheological response. [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%

“…Chiu et al [90] developed a new in-line viscometer that can directly test melt viscosity as a function of shear rate. The viscometer contains a stress sensor and a shear rate sensor that were installed between the screw and the die of a single-screw extruder.…”

Section: Rheological Techniquesmentioning

confidence: 99%

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

Saerens

Vervaet

Remon

et al. 2014

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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Development of an in-line viscometer in an extrusion molding process

Cited by 22 publications

References 1 publication

Viscosity and density measurement methods for polymer melts

Viscosity and density measurement methods for polymer melts

Single screw extrusion control: A comprehensive review and directions for improvements

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

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