Ultrasound-based measurement of liquid-layer thickness: A novel time-domain approach

Praher, B.; Steinbichler, Georg

doi:10.1016/j.ymssp.2016.05.016

Cited by 29 publications

(21 citation statements)

References 11 publications

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Section: Ultrasoundmentioning

confidence: 99%

“…Areas of application include measurement of melt temperature [ 30 ], melt inhomogeneity [ 31 ], melting behavior along the plasticizing screw [ 32 , 33 ], and density measurements [ 34 ]. Furthermore, there are applications in the field of condition monitoring, such as screw wear measurement [ 35 ]. Measurement of flow instabilities during co-extrusion is an interesting new field of application for ultrasonic systems in polymer processing.…”

Section: Technologies For In Situ Detection Of Interfacial Flow Instabilitiesmentioning

confidence: 99%

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In Situ Detection of Interfacial Flow Instabilities in Polymer Co-Extrusion Using Optical Coherence Tomography and Ultrasonic Techniques

et al. 2021

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Co-extrusion is a widely used processing technique for combining various polymers with different properties into a tailored multilayer product. Individual melt streams are combined in a die to form the desired shape. Under certain conditions, interfacial flow instabilities are observed; however, fundamental knowledge about their onset and about critical conditions in science and industry is scarce. Since reliable identification of interfacial co-extrusion flow instabilities is essential for successful operation, this work presents in situ measurement approaches using a novel co-extrusion demonstrator die, which is fed by two separate melt streams that form a well-controlled two-layer co-extrusion polymer melt flow. An interchangeable cover allows installation of an optical coherence tomography (OCT) sensor and of an ultrasonic (US) measurement system, where the former requires an optical window and the latter good direct coupling with the cover for assessment of the flow situation. The feasibility of both approaches was proven for a material combination that is typically found in multilayer packaging applications. Based on the measurement signals, various parameters are proposed for distinguishing reliably between stable and unstable flow conditions in both measurement systems. The approaches presented are well suited to monitoring for and systematically investigating co-extrusion flow instabilities and, thus, contribute to improving the fundamental knowledge about instability onset and critical conditions.

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Section: Ultrasoundmentioning

confidence: 99%

Section: Technologies For In Situ Detection Of Interfacial Flow Instabilitiesmentioning

confidence: 99%

In Situ Detection of Interfacial Flow Instabilities in Polymer Co-Extrusion Using Optical Coherence Tomography and Ultrasonic Techniques

et al. 2021

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“…A unified time-domain model has been proposed to determine the time interval from the overlapped echoes [24]. The reflected pulses are matched by superimposing many preconstructed standard signals with different amplitude and phases.…”

Section: Three-layered Structurementioning

confidence: 99%

Review of ultrasonic-based technology for oil film thickness measurement in lubrication

Dou

Jia

Zheng

et al. 2022

Tribology International

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“…Automated analyses of the reflected pulses were also realized, which means that the plasticization process can be monitored online at different axial positions along the barrel. Praher and Steinbichler [41] measured the clearance between screw and barrel in the plasticization unit of an injection molding machine, where the wear status of the tribomechanical screw-barrel system and unsuitable process conditions could be detected. Moreover, besides the melt content and melt condition in the plasticizing process being detected by ultrasound, a noninvasive ultrasound tomography system was also proposed by Praher et al [42,43].…”

Section: Ultrasound Ultrasound Waves Are Mechanical Wavesmentioning

confidence: 99%

Intelligent Injection Molding on Sensing, Optimization, and Control

Zhao

Zhang

Dong

et al. 2020

Advances in Polymer Technology

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Injection molding is one of the most significant material processing methods for mass production of plastic products. It is widely used in various industry sectors, and its products are ubiquitous in our daily life. The settings and optimization of the injection molding process dictate the geometric precision and mechanical properties of the final products. Therefore, sensing, optimization, and control of the injection molding process have a crucial influence on product quality and have become an active research field with abundant literature. This paper defines the concept of intelligent injection molding as the integral application of these three procedures—sensing, optimization, and control. This paper reviews recent studies on methods for the detection of relevant physical variables, optimization of process parameters, and control strategies of machine variables in the molding process. Finally, conclusions are drawn to discuss future research directions and technologies, as well as algorithms worthy of being explored and developed.

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Ultrasound-based measurement of liquid-layer thickness: A novel time-domain approach

Cited by 29 publications

References 11 publications

In Situ Detection of Interfacial Flow Instabilities in Polymer Co-Extrusion Using Optical Coherence Tomography and Ultrasonic Techniques

In Situ Detection of Interfacial Flow Instabilities in Polymer Co-Extrusion Using Optical Coherence Tomography and Ultrasonic Techniques

Review of ultrasonic-based technology for oil film thickness measurement in lubrication

Intelligent Injection Molding on Sensing, Optimization, and Control

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