On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders
Main Author: | |
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Publication Date: | 2022 |
Other Authors: | , |
Format: | Article |
Language: | eng |
Source: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Download full: | https://hdl.handle.net/1822/79797 |
Summary: | The use of real-time techniques to evaluate the global mixing performance of co-rotating twin-screw extruders is well consolidated, but much less is reported on the specific contribution of individual screw zones. This work uses on-line flow turbidity and birefringence to ascertain the mixing performance of kneading blocks with different geometries. For this purpose, one of the barrel segments of the extruder was modified in order to incorporate four sampling devices and slit dies containing optical windows were attached to them. The experiments consisted in reaching steady extrusion and then adding a small amount of tracer. Upon opening each sampling device, material was laterally detoured from the local screw channel, and its turbidity and birefringence were measured by the optical detector. Residence time distribution curves (RTD) were obtained at various axial positions along three different kneading blocks and under a range of screw speeds. It is hypothesized that K, a parameter related to the area under each RTD curve, is a good indicator of dispersive mixing, whereas variance can be used to assess distributive mixing. The experimental data confirmed that these mixing indices are sensitive to changes in processing conditions, and that they translate the expected behavior of each kneading block geometry. |
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On-line optical monitoring of the mixing performance in co-rotating twin-screw extrudersTwin-screw extrudersMixing performanceOn-line monitoringOptical characterizationKneading blockScience & TechnologyThe use of real-time techniques to evaluate the global mixing performance of co-rotating twin-screw extruders is well consolidated, but much less is reported on the specific contribution of individual screw zones. This work uses on-line flow turbidity and birefringence to ascertain the mixing performance of kneading blocks with different geometries. For this purpose, one of the barrel segments of the extruder was modified in order to incorporate four sampling devices and slit dies containing optical windows were attached to them. The experiments consisted in reaching steady extrusion and then adding a small amount of tracer. Upon opening each sampling device, material was laterally detoured from the local screw channel, and its turbidity and birefringence were measured by the optical detector. Residence time distribution curves (RTD) were obtained at various axial positions along three different kneading blocks and under a range of screw speeds. It is hypothesized that K, a parameter related to the area under each RTD curve, is a good indicator of dispersive mixing, whereas variance can be used to assess distributive mixing. The experimental data confirmed that these mixing indices are sensitive to changes in processing conditions, and that they translate the expected behavior of each kneading block geometry.This study was funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001 scholarship (00889834001-08) to F.O.C. Bernardo, PVE 30484/2013-01 to J.A.C., Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and PQ scholarship (311790/2013-5) to S.V.C.Multidisciplinary Digital Publishing Institute (MDPI)Universidade do MinhoBernardo, FelipeCovas, J. A.Canevarolo, Sebastião V.2022-03-142022-03-14T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/1822/79797engBernardo, F.; Covas, J.A.; Canevarolo, S.V. On-Line Optical Monitoring of the Mixing Performance in Co-Rotating Twin-Screw Extruders. Polymers 2022, 14, 1152. https://doi.org/10.3390/polym140611522073-436010.3390/polym140611521152https://www.mdpi.com/2073-4360/14/6/1152info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:49:56Zoai:repositorium.sdum.uminho.pt:1822/79797Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:48:33.125481Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
title |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
spellingShingle |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders Bernardo, Felipe Twin-screw extruders Mixing performance On-line monitoring Optical characterization Kneading block Science & Technology |
title_short |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
title_full |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
title_fullStr |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
title_full_unstemmed |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
title_sort |
On-line optical monitoring of the mixing performance in co-rotating twin-screw extruders |
author |
Bernardo, Felipe |
author_facet |
Bernardo, Felipe Covas, J. A. Canevarolo, Sebastião V. |
author_role |
author |
author2 |
Covas, J. A. Canevarolo, Sebastião V. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Bernardo, Felipe Covas, J. A. Canevarolo, Sebastião V. |
dc.subject.por.fl_str_mv |
Twin-screw extruders Mixing performance On-line monitoring Optical characterization Kneading block Science & Technology |
topic |
Twin-screw extruders Mixing performance On-line monitoring Optical characterization Kneading block Science & Technology |
description |
The use of real-time techniques to evaluate the global mixing performance of co-rotating twin-screw extruders is well consolidated, but much less is reported on the specific contribution of individual screw zones. This work uses on-line flow turbidity and birefringence to ascertain the mixing performance of kneading blocks with different geometries. For this purpose, one of the barrel segments of the extruder was modified in order to incorporate four sampling devices and slit dies containing optical windows were attached to them. The experiments consisted in reaching steady extrusion and then adding a small amount of tracer. Upon opening each sampling device, material was laterally detoured from the local screw channel, and its turbidity and birefringence were measured by the optical detector. Residence time distribution curves (RTD) were obtained at various axial positions along three different kneading blocks and under a range of screw speeds. It is hypothesized that K, a parameter related to the area under each RTD curve, is a good indicator of dispersive mixing, whereas variance can be used to assess distributive mixing. The experimental data confirmed that these mixing indices are sensitive to changes in processing conditions, and that they translate the expected behavior of each kneading block geometry. |
publishDate |
2022 |
dc.date.none.fl_str_mv |
2022-03-14 2022-03-14T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://hdl.handle.net/1822/79797 |
url |
https://hdl.handle.net/1822/79797 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Bernardo, F.; Covas, J.A.; Canevarolo, S.V. On-Line Optical Monitoring of the Mixing Performance in Co-Rotating Twin-Screw Extruders. Polymers 2022, 14, 1152. https://doi.org/10.3390/polym14061152 2073-4360 10.3390/polym14061152 1152 https://www.mdpi.com/2073-4360/14/6/1152 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Multidisciplinary Digital Publishing Institute (MDPI) |
publisher.none.fl_str_mv |
Multidisciplinary Digital Publishing Institute (MDPI) |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799133064054439936 |