广纺院纺织材料学英文课件01 Introduction to Textile Materials Science

IntroductiontoTextileMaterialsScienceCourseSyllabusTextbookKathrynL.Hatch,TextileScience,WestPublishingCompany,1993.

ReferencebookYao,M.et.al.TextileMaterials(inChinese),2nded.,TextileIndustryPublishingHouse,1990JustificationTextilematerialsarethebasicmaterials.Itiscrucialtoestablishabasicunderstandingofthesciencegoverningthebehaviorofthesematerials.ThecourseistaughtinabilingualsystemsuchthatthestudentswillhaveanopportunitytoenhancetheirEnglishabilitywhilelearningthekeyknowledgeintextiles.GradingGradesforthiscoursearedeterminedbyhomework (10%),twotests(30%each)andonefinalexam(30%).ThefinalgradewillbefromAtoFcorrespondingtothetotalscoreaccordingtothestudenthandbook.AttendanceAttendanceismandatory.Aclassrollwillbetakenatthebeginningofeachclass.Missingeverythreetimeswithoutreasonableexcusesinthesemesterwillhavecoursegradededucted10pointsoronelettergrade.Aperfectattendancerecordwillberewarded5pointsintheirtotalcoursegrade.HonorCodeStudentswillbeexpectedtoadheretotheguidelinesforacademicintegrity.ThatmeansthatANYactionthatgoesagainsttherulessetforthwhengivinghomeworkortestortakingclassrollwillbedealtwithinaverystrictfashion.Gradesarevaluable:honorandintegrityarepriceless.TopicalOutline

IntroductionReadingassignmentTextbook:KathrynL.Hatch,Chapter7,TextileScience,WestPublishingCompany,NewYork,USAHandoutswhenavailable.IntroductionExpectationsAttheconclusionofthissection,youshouldbeableto:ClassifyfibersDescribespinningprocessesforfibersDescribeapplicationandfuturedevelopmentoffiberindustryIntroductionWhatisafiber?LargelengthtowidthratioSmallenoughtobeflexibleTextilefibersMinimumlength:12.5mm,desirable:>20mm.StrongenoughtobeprocessedClassificationoffibersPolymericInorganicEngineeredUnconventionallyshapedClassificationoffibersPolymericNaturalfiberscottonwoolsilkothers:flex,jute,ramie,hempClassificationoffibersPolymericRegeneratedfibersHistory:inventedin1890’sbySchoenbeinCommerciallyavailablein1896ExamplesVicoseRayonCelluloseacetateCellulosetriacetateLycelClassificationoffibersPolymericSyntheticfibersHistoryWallaceCarothers

atduPontinventedaseriesofpolymersMajortypesPolyesterPolyamideNylonsAromaticKevlarNomaxClassificationsoffibersPolymericAcrylic(copolymersofPANandothervinylpolymers)ModacrylicPolyolifinPolyethylenePolypropyleneElastomericSpandex(polyurethane)PolyvinylalcoholPolyvinylchlorideClassificationsoffibersInorganic

NaturalasbestosManmadeglasscarbon/graphiteceramicmetalClassificationsoffibersEngineeredfibersBicomponentfibers:Sheath-coreSidebysideIslandinsea(matrixfibril)CitrusUnconventionallyshaped4DGHollowFibersandtheirpropertiesNaturalproteinfibershighresilienceabilitytodoworkagainstrestrainingforcesduringreturningfromdeformedstateHygroscopicorhydrophiliclikeswaterandabsorbswaterHighheatofwettingMostmechanicalpropertieschangewhenabsorbingwaterFibersandtheirpropertiesNaturalproteinfibersHarmedbyalkalis,e.g.NaOHHarmedbychlorinebleach&perspirationWeakened&yellowedbyUVlightNotreadilyflammableFibersandtheirpropertiesNaturalcellulosefibersHighmoistureabsorptionMechanicalpropertieschangeuponwaterabsorptionSwellsinwaterbutreversibleupondryingHighresistancetoalkalinedegradationLowresilienceFibersandtheirpropertiesManufacturedcellulosefibersLowtenacityMuchweakerwhenwetthandryLowabrasionresistanceMediumresistancetoUVlightDrycleaningorgentlecycleFibersandtheirpropertiesSyntheticfibersLowmoistureregainLowestsofteningtemperaturesHighlyoleophilic(loveoil)&hydrophobic(hatewater)HighestelectricalresistivityHighesttoughnessMediumtohighresilienceHighresistancetomoths,meldew&fungiChapter7

FiberMorphologyandFormationMorphologyStudyofsize,shape,andstructureoffibersMacrostructureFeatureswhicharediscerniblebyhumaneyes.length:Stapleorfilamentsize:widerangefrom<5to>70

mChapter7

FiberMorphologyandFormationMeasurementoffibersizeGravimetric:cutandweighweight/lengthlength/weightMicroscopicManualVibroscope(amachinethatmeasuresvibrationfrequenciesoffiberssubjectedtocertaintension)Chapter7

FiberMorphologyandFormationWhattomeasureSpecificsurface:Surfacearea/unitvolumeForuniformfibersofanycross-section:ss=perimeter/cross-sectionareaforroundfibers:Chapter7

FiberMorphologyandFormationLineardensityDirect:weightbased:continuousfibersandyarns(Mass/unitlength)denier(den,Nd):grams/9000mtex(tex,Nt

):grams/1000mdecitex(dtex,Ndt):grams/10,000mAsfiber/yarn#

Ý,fiber/yarndiameter

Ý

ForanydirectsystemChapter7

FiberMorphologyandFormationIndirect:Lengthbased:staplefibersCottoncountNc=#of840ydhanks/lbWorstedcountNw=#of560ydhanks/lb.

WoolencountNwr=#of1600ydhanks/lbAsyarn#

ß,yarndiameter

Ý

ForanyindirectsystemChapter7

FiberMorphologyandFormationChapter7

FiberMorphologyandFormationCalculationofdiameterfromlineardensityDirectsystemsChapter7

FiberMorphologyandFormationCalculationofdiameterfromlineardensityIndirectsystemsChapter7

FiberMorphologyandFormationExample1Chapter7

FiberMorphologyandFormationExample2Chapter7

FiberMorphologyandFormationExample3CalculatelineardensityfromdiameterChapter7

FiberMorphologyandFormationExample4CalculatelineardensityfromdiameterChapter7

FiberMorphologyandFormationExample5CalculatefiberlineardensityfromlengthandweightChapter7

FiberMorphologyandFormationExample6CalculatespecificsurfaceoftheabovetwofibersChapter7

FiberMorphologyandFormationDimensionalparametersrelevantonlytocotton:Maturity:thick,welldevelopedcellwallismatureImmaturityratio:Chapter7

FiberMorphologyandFormationFibersintexturedyarnsCrimp:2-Dor3-DwavinessalongfiberlengthCrimpaffectsCoverBulkInsulationExtensibilityHandCohesionLightreflection/lusterChapter7

FiberMorphologyandFormationTexturedyarnsNaturalfibers:naturalcrimpManufacturedfibers:crimpedbytexturingprocessesChapter7

FiberMorphologyandFormationMicrostructures:Featurescanbeobservedbyopticalmicroscope.Surfacecontour/longitudinalformsmooth striated convoluted serratedpitted lobed scalyCross-sectionalareashaperound kidneybean triangular flat dog-bone multi-lobalChapter7

FiberMorphologyandFormationSubmicroscopicstructureFeaturesmaybeobservedbyelectronmicroscope.Naturalfibers:distinctlayersManufacturedandsilk:uniformthroughoutexceptskin-coreeffectChapter7

FiberMorphologyandFormationFinestructure(molecularlevel)Descriptionofpolymerscomposingfibersmolecularlength,(degreeofpolymerization)width,shape,chemicalcomposition,andarrangementofpolymersandbondswhichholdthemtogetherChapter7

FiberMorphologyandFormationPolymers:(macromolecules)composedofcovalent-bondedstructuralunits(monomers)Types:HomopolymersCopolymersBlockpolymersChapter7

FiberMorphologyandFormationPolymers:Types:LinearBranchedNetwork(cross-linked)Chapter7

FiberMorphologyandFormationPolymers:ChemistryBackbones:-C-C-,-C-O-C-,-C-N-C-ConfigurationSidegroups:-H,-CH3,-OHChapter7

FiberMorphologyandFormationPolymers:OrientationandCrystallinityHighlyoriented:largeproportionofpolymerchainsarealignedwiththefiberaxisCrystallineregions:adjacentpolymersarepackedwithspatialorderAmorphousregions:nospatialorderChapter7

FiberMorphologyandFormationPolymers:IntermolecularforcesDifferenceinelectronegativityofthetwoatomsformingacovalentbond.Thelargethedifference,themorepolarthebond.Extremelylargedifferenceleadstoionicbond.Chapter7

FiberMorphologyandFormationPolymers:IntermolecularforcesBonds BoningEnergyVander

Waalsforces 4-8kJ/moleDipole-dipolebonds 20kJ/moleHydrogenbonds 40kJ/moleIonicbonds >650kJ/moleCovalentbonds >150kJ/moleChapter7

FiberMorphologyandFormationPolymerizationreactions:Twotypesofpolymerization:StepgrowthorcondensationpolymerizationChainoradditionpolymerizationChapter7

FiberMorphologyandFormationPolymerizationreactions:StepgrowthorcondensationpolymerizationExampleChapter7

FiberMorphologyandFormationPolymerizationreactions:Characteristicsofstepgrowthpolymerizationformationofeachcovalentbondinpolymerchainisaccompaniedbyreleasingofsmallbyproductmolecules,suchasH2O.dependentuponthecollisionsofreactiveendgroups.highconsumptionofmonomersbutslowmolecularweightincreaseChapter7

FiberMorphologyandFormationPolymerizationreactions:AdditionpolymerizationExample:polyethyleneInitiation:R•+CH2=CH2

RCH2CH2•PropagationRCH2CH2•+CH2=CH2

RCH2CH2CH2CH2•Chapter7

FiberMorphologyandFormationPolymerizationreactions:Characteristicsofadditionpolymerizationrequirehighlyreactiveinitiatorspeciestobeginsuccessiveadditionofmonomersnosmallmoleculesreleasedrelativelylowreactionratereactioncanlasttillveryhighmolecularweight(DP)terminationrequiredtocontrolDPthreestages:initiation,propagation,andterminationChapter7

FiberMorphologyandFormationManufacturedfiberformationFiberspinning:extrudingpolymermeltsorsolutionthroughaspinneretwithuptothousandsofholesChapter7

FiberMorphologyandFormationMeltspinningTherawmaterialhastohaveameltingtemperatureThermoplasticpolymersorglass,