類U型塑料擠出模頭設(shè)計研究.pdf

1、同濟大學機械工程學院碩士學位論文類U型塑料擠出模頭設(shè)計研究姓名：張廣冬申請學位級別：碩士專業(yè)：機械制造及其自動化指導(dǎo)教師：林建平20090301AbstractABSTRACTPlasticprofileextrusionhasahistoryofseveraldecadesandhasbeenwidelyusedinanyareasofproductionandlifeDuetothecomplexrheologicalpropert

2、iesofpolymersandthechangefulnessoffieldprocessconditions，thedesignofextrusiondieislongtermdependentonthedietryoutandrepairandthediecannotsatisfytherequirementofproductionpracticeforitshighcostandpoorstabilityThispaperhas

3、madesomemodificationofmoldflowequilibriumcoefficientatfirstandthecoe伍cientwhichiSbetterfornumericalanalysisandtheoreticalresearchhasbeenproposedThentheanalysisworkonkeyinfluencingfactorsofextrusionlikematerialproperties、

4、processparametersandconfigurationofdieheadhavebeendoneInpracticalproduction，thematerialandprocessparametersmainlyhaveimpactonthestableuseofdieandproductqualityandtherebyareonlyneedfineadjustment，whileconfigurationofdiehe

5、adhasinfluencemainlyonthefunctionrealizationandisrelativelymuchmoreimportantThefourthchaptermainlystudiestheinfluenceofdieheadconfigurationofplasticprofileonextractionprocessItisfoundthatthenonuniformsectionthicknesshast

6、hegreatesteffectandthenon—newtonianfeature(shearthinning)ofthefluidwillworsentheunevenexitvelocityAlthoughdifferentshapecombinationhasminoreffectonthemoldflowequilibriumcoefficient，itsvelocitydifferencescausethediversity

7、ofexitdeformationTheprominentmanifestationisthechangeofgeometricangleWitlltheaimtoeliminatetheinfluencesandgettheexpectedgeometricshape，somepredeformationmeasuresarenecessarytocompensatetheseinfluencesInaddition，thereaso

8、nabledistributionoffilletsiSfavorabletotheuniforillvelocityofthedieoutletAtlast，thedesignofsimilarUtypeplasticextrusiondieheadhasbeenstudiedinthispaperFirstmajorproblemsexistinginthetraditionalextrusiondiedesignareanalyz