Technical analysis of adjustable melt rotation and numerical analysis of polymer flow using CFD

174 Pages·2015·4.86 MB·English

by  Michael John Wolbert

Lehigh University
Lehigh Preserve
Theses and Dissertations
2007
Technical analysis of adjustable melt rotation and
numerical analysis of polymer flow using CFD
software
Michael John Wolbert
Lehigh University
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Recommended Citation
Wolbert, Michael John, "Technical analysis of adjustable melt rotation and numerical analysis of polymer flow using CFD software"
(2007).Theses and Dissertations.Paper 970.
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Wolbert, Michael
John Jr.
Technical Analysis
of Adjustable Melt
Rotation and
Numerical Analysis
of Polymer Flow ...
May 2007
Technical Analysis ofAdjustable Melt Rotation and Numerical Analysis of
Polymer Flow using CFD Software
by
Michael John Wolbert Jr.
AThesis
Presented to the Graduate and Research Committee
ofLehigh University
In Candidacy for the Degree of
ivlaster ofScience
111
i\lechanical Engineering and i\lcchanics
Lehigh l1ninl"sity
:\lay.2007

Acknowledgments
I would like to thank Dr. John Coulter for his guidance and support
throughout this project. He is solely responsible for helping me make my decision to
attend Lehigh University to further my education. He is also responsible for keeping
me going through the many obstacles that occurred during my research project.
I would also like to thank Dr. John Beaumont of Penn State Behrend and
Kevin Boell of the Plastics CAE Center. Their advice and guidance was g~eatly
appreciated throughout my research project.
Finally I would like to thank the department of Mechanical Engineering and
Mechanics for providing me with the financial support that I needed in order for me
to attend Lehigh University while I pursued my Masters of Science degree. I would
also like to thank Greg Layser and Mike Casarrela who contributed in helping me
throughout my research project.
111
Table of Contents
Ackno\\'ledgn1ents iii
Table ofContents iv
<..:.:,:;
List ofTables vi
~i~~t~~~~~~~~~.::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::~~\i
Introduction 2
1.1 Purpose ofthe Study 2
1.2 Target Problem Description 3
I.3 Objectives ofthe Present Investigation .4
1.4 Thesis Outline 4
2 Fill Imbalances During Injection Molding 7
2.1 Multi-Cavity Runner Design 8
2.1.1 "Fishbone" and 'Tree" Runner 8
2.1.2 Geometrically Balanced Runner 11
2.2 Cause ofFill Imbalance 13
2.2.1 Components ofShear Induced Fill Imbalance 13
2.2.2 Theory ofShear Induced Fill Imbalances 17
2.3 Melt Rotation Technology 21
2.3. I Design ofMelt Rotation 22
2.3.2 Results ofMelt Rotation 24
2.4 Predicting Fill Imbalances 25
2.4.1 Extrusion Software 25
2.4.2 Injection Molding Software 26
2.5 Need for Further Studies 29
3 Numerical Study 30
3.1 Software Selection 30
3.2 Simulations Perfonned 31
3.3 Simulation Results 3]
3.3.1 Mesh Geometry 33
3.3.2 Primary Runner 34
3.3.3 Primary and Secondary Runner 3:-;
4 Experimental Study ofAdjustable i\1elt Rotation .42
4.1 i\1achinery .42
4.2 Reconfigurable 'Adjustable Tooling Denlopment .46
4.2.1 i\lold Plate:\ 47
4.2.2 i\lold Plate B ~~ 4~
4.2.3 Insert Design 49
4.3 i\laterials Studied 53
4.4 Trials 55
4.5 Process Condilit ns 5(,
1
I\"
--
4.6 Collection ofData 58
5 Adjustable Melt Rotation Results 60
5.\ Results for Polycarbonate (PC) 60
5.\.\ Lo\v Injection Rate : 60
5.1.2 Medium Injection Rate 63
5.\.3 High Injection Rate 66
5.\.4 Summary ofResults for PC 68
5.2 Results for Polypropylene (PP) 69
5.2.\ Low Injection Rate 70
5.2.2 Medium Injection Rate 72
5.2.3 High Injection Rate 74
5.2.4 Summary ofResults for PP 77
5.3 Results for Polyamide 6 (PA 6) 77
5.3.\ Low Injection Rate 78
5.3.2 Medium Injection Rate 80
5.3.3 High Injection Rate 82
5.3.4 Summary ofResults for PA 6 85
5.4 Results for Polybutylene Terephthalate (PBT) 86
5.4.\ Low Injection Rate 86
5.4.2 Medium Injection Rate 89
5.4.3 High Injection Rate 92
5.4.4 Summary ofResults for PBT 94
5.4.5 Summary ofResults for all Materials 96
6 Conclusions and Recommendations \00
6.\ Conclusions \00
6.2 Future \Vork \0\
References \05
Appendices 106
Appendix A- Mold and Insert Drawings \06
~ Appendix B- Test Results for PC \\2
,
Appendix C- Test Results for PP \2\
Appendix D- Test Results for PA 6 \30
Appendix E~ Test Results for PBT \39
\iita \4R
List of Tables
TABLE3-1:CROSSANDWLFPROPERTIES[II] 36
TABLE4-1:MATERIALSSTUDIED 54
TABLE4-2: PCPROCESSINGCONDITIONS 57
TABLE4-3: PPPROCESSINGCONDITIONS 57
TABLE4-4: PA6PROCESSINGCONDITIONS 57
TABLE4-5: PST30%GLASSFILLEDPROCESSINGCONDITIONS 57
TABLE5-1: PCLowFLOWRATECALCULATION 61
TABLE5-2: PCLowINJECTIONRATEFLowGROUPSAVERAGEWEIGHTS 62
TABLE5-3: PCMEDIUMFLOWRATECALCULATION 64
TABLE5-4: PCMEDIUMINJECTIONRATEFLOWGROUPSAVERAGE WEIGHTS 65
TABLE5-5: PCHIGHFLowRATECALCULATION 66
TABLE5-6: PCHIGHINJECTIONRATEFLowGROUPSAVERAGEWEIGHTS 67
TABLE5-7: PPLowFLOWRATECALCULATION 70
TABLE5-8: PPLowINJECTIONRATEFLOWGROUPSAVERAGE WEIGIITS 71
TABLE5-9: PPMEDIUMFLowRATECALCULATION 72
TABLE5-10: PPMEDIUMINJECTIONRATE FLOWGROUPSAVERAGE WEIGHTS 73
TABU 5-11: PPHIGHFLowRATECALCULATloN 75
TABU: 5-12: PPHIGHINJECTIONRATEFLowGROUPSAVERACiE WI'lCiHTS 76
TABU 5-13: PA6LowFLO\\'RATECALCULATlON ]X
TABLl' 5-14: PA6Low INJECTIONRATEFLowGROUPSA\TRACiE WEIGHTS 79
TABLE5-15: PA61\1EDIUMFLOWRATECALCULATION 80
TABLE 5-16: PA6MEDIUMINJECTIONRATEFLOWGROUPSAVERAGEWI'IGIITS 81
TABLE5-17: PA6HIGHFLOWRATECALCULATION 83
TABLE5-18: PA6HIGHINJECTIONRATEFLOWGROUPSA\'ERAGE WEIGHTS 84
TABLE5-19: PHTLowFLO\\'RATECALCULATlON 87
TABLE5-20: PHTLow INJECTIONRATEFLowGROlH'SA\TRAGE WEIGllTS 88
TABU 5-21: PHTMEDIUMFLOWRATECALCULATION 90
TABLE5-22: PHTMEDIUMINJECTIONRATE FLOWGROUPSA\TRAGEWEiGHTS 91
r.\BLl' 5-23: PHTHIGHFLOWRATECALCULATION 92
TABLl' 5-24: PHT1I1GHINJECTIONRATEFLOWGROllpSA\TR.\CiE \VI'ICiHTS 93
TABLE6-1: SA~'ETI~lE.MULTIPLEPOSITIONS 101
TABLE6-2: DIFFERENTINJITTIONRATES.SAME DATA 102
T.\BLl'6-3: PCN()R~L\LRUNNER Lo\\'INJECTIONRAT!' 103
TABLE6-4: PCMFLTROTATION6Lo\\'INJECTIONRAT!' 103
\'1
List of Figures
FIGURE2.1: "FISHI30NE"OR"TREE" RUNNER DESIGN 9
FIGURE2.2: "FISHI30NE"OR"TREE"RUNNER ARTIFICIALLYBALANCEDRUNNERDESIGN 11
FIGURE2.3:GEOMETRICALLYBALANCEDRUNNERDESIGN 12
FIGURE2.4: LAMINARPOISEUILLEFLOW[II] 14
FIGURE2.5: SHEARRATEPROFILEINRUNNER[2) 14
FIGURE2.6:SHEAR-THINNINGBEHAVIORS[3] 15
FIGURE2.7:CROSSSECTIONOFRUNNERSHOWINGLOCALSHEARHEATING[4] 16
FIGURE2.8: EFFECTOFTEMPERATUREON VISCOSITY [6] 17
FIGURE2.9:COMI3INEDEFFECTSON VISCOSITY[6] 18
FIGURE2.10:RUNNERDESIGNSWITHNoCAVITYTOCAVITY FILLIMI3ALANCE 19
FIGURE2.11: SEPARATIONOFMELTLAMINATESINTOSECONDARY RUNNER[2] 20
FIGURE2.12:CROSSSECTIONOFVISCOSITY ANDTEMPERATUREPROFILE[2] 20
FIGURE2.13:SEPARATIONOFMELTLAMINATESINTOTERTIARY RUNNER[2] 21
FIGURE2.14: SIDEVIEWOFMELTROTATIONTECHNOLOGY 22
FIGURE2.15: RELOCATIONOFMELTTopToBOTTOM [2] 23
FIGURE2.16: VERTICALSYMMETRYOFMELT[7] 23
FIGURE2.17: BEFOREANDAFTERMELTROTATIONTECHNOLOGY [7] 24
FIGURE2.18: FILL11\lllALANCESINTwoMATERIALSWITH ANDWITHOUTMELTROTATION [2] 24
FICilJRE2.19: USEOFIlypEREXTRUDETOSIMULATEIMBALANCE[8] 26
FIC,URE2.20: USEOFMOLDFLOWTOSIMULATEIMBALANCE[9] 27
FIGURE2.21:GEOMETRICALLYBALANCEDRUNNERSYSTEMSIMULATIONUSINGMOLDEX3D[10) 28
FICiURE2.22: MELTROTATIONTECIINOLOGY SIMULATIONUSINGt10LDEX3D[10] 28
FIGURE3.1: BASICMESII,FINER BASICMESH,REFINEDMESH 33
FIGURE3.2:NORM VELOCITY; BASICMESH,FINERBASICMESH,REFINEMESI1 34
FIGURE3.3: LOCALSHEARRATE;BASICMESII,FINER BASICMESII,REFINEMESII 34
FIGURE3.4: REFINEDMESHPRI1\IARY RUNNER 35
FIGURE3.5:NORM VELOCITY PRIMARYRUNNER;FLowRATE= 0.00127M)/S 37
FIGURE3.6: LOCALSHI'AR-RATEPRI1\IARY RUNNER;FLOWRATE= 0.001271\1)/S 37
FICiURE3.7: PRIMARY ANDSECONDARY RUNNERINTERSECTlON 38
FIC,URE3.x: LOCALSIIEAR-R/\TEPRI1\IARYANDSECONDARY RUNNER;CRESCENTS; 39
FIGURE3.9: RUNNER SECTIONSFR01\IINTERSECTIONTOENDOFSECONDARY RUNNER 39
FICiURE3.10: LOCALSHb\R-RATE PRIMARY ANDSECONDARYRUNNER;FLOWRATE =0.001271\I';s 40
FIC,L'RE3.11:VISCOUS ilEATlNG PRI\IARYANDSECONDARY RUNNER: FLow RATE =0.00127\I'/S 40
FIGLIRE3.12: FULLRUNNERSIIEAR-RATESI\ILILATION:FLo\\'RATE= 0.00127\1'/S .41
FICil'RE4.1: INJECTION t\IOLDINCl t\L\CIIINE Boy 15S 43
FICiURE4.2: DIU-AIR2000DRiTRA1\DVTC9THFR\10L\TOR 44
FIC,IIRE4.3: DeT2000LVDT.\NDL\H\'IFW8.0.................................................................. .. 44
Fllil'RE4.4: AcTL'L\HVIC-303SCALF .. 45
FICil'Rl-4.5:TopVIE\\'())MOLDAND1'1.\rEs......... .. 46
FIl,1RF4.(): SIDEVI1'\\'OF1\IOLDyq)I'L\rES...... .. 46
FICil'RF4.7:1\loLDPLHFA.............................. . 48
FIC,IRF4.8: 1\IOLDPL\H B...................................... .. 49
FICil'RF4.9:1\11'LTROT.HIONGIO\IFTRYDIV'R.\\1 [13].......... ...:'0
FICiL'RE4.10:ADJI'ST\HLF t\IFLTF1IPPl'RINSFRTA PI HI. 51
FIl,I'RF4.11: ADJl'ST\BLF1\IFLTROTATION IN"l-RTBPI \Tl. .. :'1
FIC'I·RI4.12: ADJl'STAlHF1\11ITFIIPPFRP I ' s . . . :'2
FICil'RF4.13: ST\'D\RDA PI\TF IV,ERT .. :'3
FlliIRl4.14: STA'P\RPB PI HI' I'SIRT.... .:'3
FIGURE5.1: PCTESTSPECIMENSATLow INJECTIONRATI: 62
FIGURE5.2: PCTESTRESULTS;Low INJECTIONRATE 63
FIGURE5.3: PCTESTSPECIMENSATMEDIUMINJECTIONRATE 64
FIGURE5.4: PCTESTRESULTS;MEDIUMINJECTIONRATE 65
FIGURE5.5: PCTESTSPECIMENSATHIGHINJECTIONRATE 67
FIGURE5.6: PCTESTRESULTS;HIGHINJECTIONRATE 6S
FIGURE5.7: PCTESTRESULTSSUMMARY 69
FIGURE50S: PPTESTSPECIMENSATLowINJECTIONRATE 71
FIGURE5.9: PPTESTRESULTS;LowINJECTIONRATE 72
FIGURE5.10: PPTESTSPECIMENSATMEDIUMINJECTIONRATE 73
FIGURE5.11: PPTESTRESULTS;MEDIUMINJECTIONRATE 74
FIGURE5.12: PPTESTSPECIMENSATHIGHINJECTIONRATE 75
FIGURE5.13: PPTESTRESULTS;HIGHINJECTIONRATE 76
FIGURE5.14: PPTESTRESULTSSUMMARY 77
FIGURE5.15: PA 6TESTSPECIMENSATLowINJECTIONRATE 79
FIGURE5.16: PA6TESTRESULTS; LowINJECTIONRATE SO
FIGURE5.17: PA6TESTSPECIMENSATMEDIUMINJECTIONRATE 81
FIGURE5.IS: PA6TESTRESULTS;MEDIUMINJECTIONRATE S2
FIGURE5.19: PA6TESTSPECIMENSATHIGHINJECTIONRATE 83
FIGURE5.20: PA6TESTRESULTS; HIGHINJECTIONRATE S4
FIGURE5.21: PA6TESTRESULTSSUMMARY S6
FIGURE5.22: PSTTESTSPECIMENSATLow INJECTIONRAT!'.. 88
FIGURE5.23: PSTTESTRESULTS; Low INJECTIONRATE 89
FIGURE5.24: PSTTESTSPECIMENSATMEDIUMINJECTIONRATE..: 90
FIGURE5.25: PSTTESTRESULTS;MEDIUMINJECTIONRATE 91
FIGURE5.26: PSTTESTSPECIMENSATHIGHINJECTIONRATE 93
FIGURE5.27: PSTTESTRESULTS; HIGIlINJECTIONRATE 94
FIGURE5.28: PSTTESTRESULTSSUMMARY 95
FIGURE5.29:OVERALL RESULTSFOR FOURMATERIALSATLowINJECTIONRATE 96
FIGURE5.30:OVERALLRESULTSFOR FOURMATERIALSATt\1EDIUM INJECTIONRAT!'.. 97
FIGURE5.31:OVERALL RESULTS FOR FOUR MATERIALSATHIGIlINJECTIONRATE 98