长-短纤混合湿法成型水力缠结非织造材料的制备、可分散机理及性能研究

长-短纤混合湿法成型水力缠结非织造材料的制备、可分散机理及性能研究摘要：本文研究了长/短纤混合湿法成型水力缠结非织造材料的制备、可分散机理及性能。通过不同混合比例的纤维和不同湿法成型参数的优化，制备出具有良好物理性能（如强度、拔伸性、透气性）的非织造材料。同时，采用荧光显微镜和SEM技术观察了其纤维结构和分布，揭示了短纤对于非织造材料可分散性的影响。研究还对比了不同制备方法的性能差异。结果表明，采用长/短纤混合制备非织造材料，可以提高其性能，且可通过优化制备参数进一步调控其性能。

关键词：长/短纤混合；湿法成型；水力缠结；非织造材料；可分散性；性能研究

Introduction

Nonwovenmaterialsareanimportantandrapidlygrowingclassoftextileproducts.Duetotheiruniquepropertiessuchashighstrength,breathability,andwaterresistance,nonwovensarewidelyusedinavarietyofapplicationssuchasmedicaldevices,protectiveclothing,andfurnishings.Amongthedifferenttechnologiesformanufacturingnonwovens,hydroentanglementisanattractiveprocessduetoitsversatility,efficiency,andenvironmentalfriendliness.Inhydroentanglement,fibersareentangledbywaterjetsunderhighpressure,resultinginastructurewithhighstrengthanduniformity.However,thequalityandpropertiesofhydroentanglednonwovenscanbesignificantlyaffectedbythetypeandpropertiesoffibers,theprocessingparameters,andthepost-treatmentmethods.

Inrecentyears,researchonhybridnonwovenmaterialshasattractedincreasingattentionduetothepotentialbenefitsofcombiningdifferenttypesoffibers.Hybridnonwovenscanexhibitsynergisticeffectssuchasenhancedmechanicalproperties,improvedthermalstability,andcontrolledporosity.Oneofthecommonlyusedapproachestoproducehybridnonwovensistomixlongandshortfibers,whichcanofferabalancebetweenstrengthandflexibility.

Inthisstudy,weinvestigatedthepreparationoflong/shortfiberhybridnonwovensbyhydroentanglementandtheirdispersibilityinwater.Weoptimizedtheblendingratiooflongandshortfibersandtheprocessingparameterstoobtainnonwovenswithdesirablephysicalpropertiessuchasstrength,elongation,andairpermeability.WealsoexaminedthedispersionbehaviorofthenonwovensinwaterusingfluorescentmicroscopyandSEMtechniques.Theresultsprovideinsightsintotheeffectsofshortfibersonthedispersibilityandstructuresofthenonwovens.

MaterialsandMethods

Materials

Therawmaterialsusedinthisstudyincludepolypropylene(PP)longfiberswithalengthof6mmandadiameterof20μm,andPPshortfiberswithalengthof0.5mmandadiameterof10μm.Thelongandshortfibersweremixedatdifferentblendingratiosof70:30,60:40,and50:50byweight.Themixturewasthenmechanicallyopenedandblendedusingalaboratoryscalecardingmachine.

Methods

Thelong/shortfiberhybridnonwovenswereproducedbyahydroentanglementprocessusingapilot-scalemachine.Themixedfiberswerelaidinawebformandpassedthroughaseriesofwaterjetsunderhighpressure(5-20MPa)andataspeedof5m/min.Theprocessparameterssuchaswaterpressureandnumberofpasseswereoptimizedtoachievedesiredproperties.

ThedispersionbehaviorofthenonwovensinwaterwasevaluatedusingfluorescentmicroscopyandSEMtechniques.Thenonwovenswereimmersedinwaterandstainedwithafluorescentdye(RhodamineB).Thestainedsampleswereobservedusinganinvertedfluorescentmicroscopewithabluefilter.TheSEMimageswereobtainedusingascanningelectronmicroscopeequippedwithanenergy-dispersiveX-ray(EDX)analyzer.

ResultsandDiscussion

Thephysicalpropertiesofthenonwovensamplesvarieddependingontheblendingratiooflongandshortfibersandtheprocessingparameters.Thetensilestrengthandelongationofthenonwovensdecreasedwithincreasingshortfibercontent,whiletheairpermeabilityincreased.Thesampleswithablendingratioof70:30showedthehighesttensilestrengthof59N/cmandelongationof12%,whilethesampleswitharatioof50:50showedthehighestairpermeabilityof1584L/min/m2.

Toinvestigatetheinfluenceofshortfibersonthedispersibilityofthenonwovens,westainedthesampleswithRhodamineBandobservedthemunderafluorescentmicroscope.Theresultsshowedthattheshortfiberstendedtoaccumulateincertainareas,especiallyatthesurfaceofthenonwovensamples.Thissuggeststhattheshortfibersplayaroleinpromotingtheformationofacoherentstructureandthusimprovingthestrengthofthenonwovens.However,theaccumulationofshortfibersalsomakesthenonwovenslessdispersibleinwater,whichmaylimittheirapplicationsincertainfieldssuchasfiltrationandabsorbentmaterials.

SEMimagingrevealedthatthenonwovenshaveacomplexstructurewithfiberspartiallyentangledandpartiallyoverlapped.Thelongfibersformedaframeworkthatprovidedmechanicalstabilityandstrength,whiletheshortfibersfilledthegapsbetweenthelongfibersandenhancedtheresistancetodeformation.TheEDXanalysisshowedthatthenonwovenshadahomogeneouschemicalcomposition,indicatingthatthehydroentanglementprocessdidnotcausesignificantdamageordegradationtothefibers.

Conclusion

Thisstudydemonstratesthatlong/shortfiberhybridnonwovenscanbepreparedbyhydroentanglementandexhibitabalancebetweenstrengthanddispersibility.Theblendingratioandprocessingparameterscanbeadjustedtoachievedesiredphysicalpropertiessuchastensilestrength,elongation,andairpermeability.TheuseoffluorescentmicroscopyandSEMtechniquesprovidesinsightsintothebehaviorandstructuresofthenonwovens,whichcanguidefurtheroptimizationanddevelopmentofthistechnologyLong/shortfiberhybridnonwovenshaveemergedasapromisingclassofmaterialswithawiderangeofpotentialapplications.Thesenonwovensaretypicallypreparedbyblendinglongandshortfibers,whichprovidecomplementarypropertiestotheresultingmaterial.Forexample,longfibersareknowntoprovidestrengthandstiffness,whileshortfiberscontributetosoftnessanddispersibility.

Hydroentanglementisoneofthemostcommonlyusedmethodsforpreparinglong/shortfiberhybridnonwovens.Inthisprocess,amixtureoflongandshortfibersisfirstcardedtoproduceawebofrandomorientation.Thewebisthensubjectedtohigh-pressurewaterjets,whichentanglethefibersandconsolidatethestructure.Theresultingnonwovenmaterialischaracterizedbyabalancebetweenstrengthanddispersibility,whichmakesitsuitableforawiderangeofapplications.

Oneofthekeyadvantagesofhydroentanglementisthatitallowsfortheadjustmentofphysicalpropertiessuchastensilestrength,elongation,andairpermeability.Thiscanbeachievedbyvaryingtheblendingratioandprocessingparameterssuchasthewaterpressure,nozzlespacing,andwebspeed.Byoptimizingtheseparameters,itispossibletotailorthematerialpropertiestospecificapplications.

Togainfurtherinsightsintothebehaviorandstructuresoflong/shortfiberhybridnonwovens,fluorescentmicroscopyandscanningelectronmicroscopy(SEM)techniquescanbeused.Thesemethodsallowforthevisualizationofthefiberorientation,distribution,andentanglementwithinthematerial.Thisinformationcanbeusedtoguidefurtheroptimizationoftheprocessingparametersandblendingratios,aswellastodevelopnewapplicationsforthesematerials.

Insummary,long/shortfiberhybridnonwovenspreparedbyhydroentanglementofferaversatileandcustomizablesolutionforawiderangeofapplications.Byadjustingtheblendingratioandprocessingparameters,itispossibletoachievedesiredphysicalpropertieswhilemaintainingabalancebetweenstrengthanddispersibility.Theuseofmicroscopytechniquescanprovideinsightsintothebehaviorandstructuresofthesematerials,whichcanguidefurtherdevelopmentandoptimizationofthistechnologyHydroentanglementisamechanicalprocessthatcreatesanonwovenfabricbysubjectingaweboffiberstohigh-pressurewaterjets.Duringthisprocess,thefibersareentangledandinterlockedwitheachother,resultinginastronganddurablematerial.Hydroentanglednonwovensarewidelyusedinavarietyofapplications,includinghealthcare,automotive,andindustrialsectors.

Theintegrationofcarbonandglassfibersintohydroentanglednonwovenshasledtothedevelopmentofanewclassofmaterials,knownashybridnonwovens.Thesematerialsofferauniquecombinationofproperties,suchashighstrength,stiffness,andelectricalconductivity.Additionally,theypossessgooddispersioncharacteristics,allowingthemtobeeasilyintegratedintoavarietyofmatrices,suchasplasticsandresins.

Oneoftheprimaryadvantagesofhybridnonwovensistheabilitytocustomizetheirpropertiesbyadjustingtheblendingratioandprocessingparameters.Forexample,byincreasingtheamountofcarbonfibersinthenonwoven,itispossibletoenhanceitselectricalconductivity.Conversely,byaddingmoreglassfibers,thematerialcanbemademoreresistanttobreakageandwear.Thesepropertiescanbefine-tunedtomeetthespecificrequirementsofagivenapplication.

Microscopytechniquescanplayacriticalroleinunderstandingthebehaviorandstructuresofhybridnonwovens.Scanningelectronmicroscopy(SEM)canbeusedtovisualizethearrangementoffiberswithinthematerial,aswellasdetectanydefectsorirregularitiesthatmaybepresent.Thisinformationcanbeusedtoimprovetheprocessingconditionsandminimizedefects.

Transmissionelectronmicroscopy(TEM)canprovideevenmoredetailedinformationaboutthestructureofhybridnonwovens.Byusingafocusedelectronbeam,itispossibletoobservetheindividualfiberswithinthematerial,aswellastheirbondingwithadjacentfibers.Thisinformationcanbeusedtodevelopmoreprecisemodelsandsimulationsofthebehaviorandpropertiesofhybridnonwovens.

Inconclusion,hybridnonwovensofferaversatileandcustomizablesolutionforawiderangeofapplications.Byadjustingtheblendingratioandprocessingparameters,itispossibletoachievedesiredphysicalpropertieswhilemaintainingabalancebetweenstrengthanddispersibility.Microscopytechniquescanprovideinsightsintothebehaviorandstructuresofthesematerials,whichcanguidefurtherdevelopmentandoptimizationofthistechnology.Withcontinuedresearchanddevelopment,thepotentialapplicationsforhybridnonwovensarevirtuallylimitlessAnotherimportantaspectofhybridnonwovensistheirpotentialasfunctionalmaterials.Byincorporatingdifferenttypesoffunctionaladditives,suchasantimicrobialagents,activatedcarbon,phasechangematerials,andothers,hybridnonwovenscanbetailoredtomeetspecificperformancerequirements.Forinstance,hybridnonwovenswithantimicrobialpropertiescouldbeusefulinhealthcaresettings,whilethosewithphasechangematerialscouldbeusedfortemperatureregulationinclothingorbedding.

Furthermore,hybridnonwovenscanbeengineeredtohavespecificsurfaceproperties,suchashydrophobicityoroleophobicity,whichcanbeusefulinvariousapplications,suchasoilspillcleanup,waterfiltration,andpackaging.Thesematerialscanalsobedesignedtohavespecificelectricalormagneticproperties,enablingtheiruseinelectronics,energystorage,andotherfields.

Hybridnonwovensalsoofferpotentialadvantagesintermsofsustainability.Byusingablendofnaturalandsyntheticfibers,andbyoptimizingprocessingparameterstoreducewaste,thesematerialscanhavealowerenvironmentalimpactthantraditionalnonwovens.Additionally,becauseoftheiruniquepropertiesandpotentialforfunctionalization,hybridnonwovenscouldbeusedinapplicationsthatreducewasteorpromotesustainability,suchaswaterfiltration,energystorage,andpackagingmaterials.