Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts
The semi-hyperbolic (SHPB) die with and possibly without wall lubrication has been proposed as a device for measuring the elongational viscosity of polymeric fluids. Using numerical simulation under the condition of complete wall slip, it was found for two polyethylenes (LDPE and LLDPE) that the cal...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
De Gruyter
2010-06-01
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| Series: | Applied Rheology |
| Subjects: | |
| Online Access: | https://doi.org/10.3933/applrheol-20-34900 |
| _version_ | 1818664807277002752 |
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| author | Baird Donald G. Chan Tung W. McGrady Christopher Mazahir Syed M. |
| author_facet | Baird Donald G. Chan Tung W. McGrady Christopher Mazahir Syed M. |
| author_sort | Baird Donald G. |
| collection | DOAJ |
| description | The semi-hyperbolic (SHPB) die with and possibly without wall lubrication has been proposed as a device for measuring the elongational viscosity of polymeric fluids. Using numerical simulation under the condition of complete wall slip, it was found for two polyethylenes (LDPE and LLDPE) that the calculated elongational viscosity values agreed well with strain-averaged values, <ƞe>, obtained from independent measurements in stretching type rheometers. This is in agreement with the original hypothesis of Everage and Ballman (E-B). Numerical simulations showed that the Baird and Huang (B-H) approach for calculating <ƞe>, which accounts for the shear stress due to geometric considerations in the presence of complete slip, agreed with data better than did the E-B approach. Numerical simulations using varying degrees of wall slip indicated that reasonable values of <ƞe> could be obtained using the B-H approach with wall slip levels which could be most likely reached using a coating such as a flouroelastomer. The numerical simulations provided an explanation as to why the elongational viscosity values determined in the SHPB die for resins such as LDPE, which are extensional-strain hardening, are less sensitive to wall slip than non-strain-hardening resins such as LLDPE. |
| first_indexed | 2024-12-17T05:38:36Z |
| format | Article |
| id | doaj.art-f15799f71976437ea12537bcf7bc35d7 |
| institution | Directory Open Access Journal |
| issn | 1617-8106 |
| language | English |
| last_indexed | 2024-12-17T05:38:36Z |
| publishDate | 2010-06-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Applied Rheology |
| spelling | doaj.art-f15799f71976437ea12537bcf7bc35d72022-12-21T22:01:33ZengDe GruyterApplied Rheology1617-81062010-06-0120310.3933/applrheol-20-34900Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer MeltsBaird Donald G.0Chan Tung W.1McGrady Christopher2Mazahir Syed M.3Department of Chemical Engineering, Virginia Polytechnic Institute and State University,Blacksburg, USADepartment of Chemical Engineering, Virginia Polytechnic Institute and State University,Blacksburg, USADepartment of Chemical Engineering, Virginia Polytechnic Institute and State University,Blacksburg, USADepartment of Chemical Engineering, Virginia Polytechnic Institute and State University,Blacksburg, USAThe semi-hyperbolic (SHPB) die with and possibly without wall lubrication has been proposed as a device for measuring the elongational viscosity of polymeric fluids. Using numerical simulation under the condition of complete wall slip, it was found for two polyethylenes (LDPE and LLDPE) that the calculated elongational viscosity values agreed well with strain-averaged values, <ƞe>, obtained from independent measurements in stretching type rheometers. This is in agreement with the original hypothesis of Everage and Ballman (E-B). Numerical simulations showed that the Baird and Huang (B-H) approach for calculating <ƞe>, which accounts for the shear stress due to geometric considerations in the presence of complete slip, agreed with data better than did the E-B approach. Numerical simulations using varying degrees of wall slip indicated that reasonable values of <ƞe> could be obtained using the B-H approach with wall slip levels which could be most likely reached using a coating such as a flouroelastomer. The numerical simulations provided an explanation as to why the elongational viscosity values determined in the SHPB die for resins such as LDPE, which are extensional-strain hardening, are less sensitive to wall slip than non-strain-hardening resins such as LLDPE.https://doi.org/10.3933/applrheol-20-34900numerical simulationphan-thien and tanner modelsemi-hyperbolic dieextensional rheometersstrain-averaged elongational viscositypolyethylene |
| spellingShingle | Baird Donald G. Chan Tung W. McGrady Christopher Mazahir Syed M. Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts Applied Rheology numerical simulation phan-thien and tanner model semi-hyperbolic die extensional rheometers strain-averaged elongational viscosity polyethylene |
| title | Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts |
| title_full | Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts |
| title_fullStr | Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts |
| title_full_unstemmed | Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts |
| title_short | Evaluation of the Use of a Semi-hyperbolic Die for Measuring Elongational Viscosity of Polymer Melts |
| title_sort | evaluation of the use of a semi hyperbolic die for measuring elongational viscosity of polymer melts |
| topic | numerical simulation phan-thien and tanner model semi-hyperbolic die extensional rheometers strain-averaged elongational viscosity polyethylene |
| url | https://doi.org/10.3933/applrheol-20-34900 |
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