外文翻譯-微孔膜防水透濕織物熱濕傳遞中織物表面凝結

CondensationofWaterVaporonWaterproofBreathableFabricsCondensationoccurswhenthelocalvaporpressurerisesabovethesaturationvaporpressureatthelocaltemperatureintheory.Anewmeasuringapparatusweremadetoobtaintemperatureandrelativehumiditysimultaneouslyforthepurposeofinvestigatingthemechanismofcondensationoccurredonthefabrics.Theexperimentconductedatthestandardconditionoftemperatureof20°Candrelativehumidityof65%.Theresultobtainedfromexperimentshowedthatcondensationcouldoccurunderthesituationclosedtosaturationlineasthetemperatureonfabricmaybelowerthandewpointofwatervaporinthemeasuringboxdependingontheexperimentconductedatanambientenvironmenttemperatureof20°C.TherangeoffabricsstudiedshowedthatPTFElaminatedfabricsexceptnylonginghamPTFElaminatedfabricfacilitatesthelossofwatervaporandthereforepreventcondensation.Itisnecessarytodevelopstudiesfromawiderangeoffabrics,especiallybreathablefabricsandunderbadexperimentconditioninordertodevelopfabrics,whichcouldeliminatecondensation,ortransportwatervaporthroughthefabricwhileremainingwaterproof.Keywords:condensation;waterproofbreathablefabric.IntroductionThehumanbodythroughtheprocessofmetabolismisconstantlygeneratingthermalenergyandmoisture,whichexchangethroughthetextilelayerswithitsenvironment.Asperspirationescapesfromthehumanbodywhenthewatervaportransferfromclothingislow.condensationdefinedaswaterdropletcollectedontheinnersurfaceoftheclothingmayoccur,providedthatthelocalvaporpressurerisesabovethesaturationvaporpressureatthelocaltemperature.KeighleyandRuckmansuggestedfromtheorythatthecondensationoccurringonthefabricsmaybepredictedifasaturationlineandwatervaporconcentrationlineisutilized.KeighleydevelopedamethodthatinvolvedmeasurementofwatervaporconcentrationutilizinginfraredabsorptionatthespecificfrequencyofastrongwatervaporabsorptionandRuckmanprovidedasolutiontotheproblemofcondensationontheinnersurfaceoffabricbyperforatingmetalcylindersimulatingtheperspiringhumanbodytoinvestigatethecouplemechanismsofwatervaportransferandheattransfer.Morerecently,RenandRuckmanstudiedthewatervaportransferratewhencondensationoccursonthesurfaceofdifferencetypeofwaterproofbreathablefabricstoascertainwhethertheamountofcondensationwillaffectthewatervaportransferrate.Amethodsprayingwaterontothehotsurfaceofthefabricwasemployedtosimulatedropletcondensation.whilstadiscussionofthemeritsofwaterproofbreathablefabricsfocusedontheabilityofthesefabricstoreducebothheatstressanduncomfortablesensationofwetnesswhileprovidingprotectionfromwindandrain.A1laboveresearchesfocusontheeffectofcondensationonheatandwatervaportransfer.Whilstnoresearchhasbeenconductedtostudywhetherthecondensationformedontheinnersurfaceofafabric.thispaperdescribedthedetailsofthemeasuringapparatusinvestigatedthemechanismofcondensationoccurredonthefabricsandalsopresentedtypicalmeasuringresultsforrepresentativeoffabricsincludedwaterproofbreathablefabrics.TheoriesCondensationoccurswhenthelocalvaporpressurerisesabovethesaturationvaporpressureatthelocaltemperature.Thesaturationlineisdescribedthewatervaporpressuregivingriseto100%relativehumidityataspecifictemperature,asshowninFig.1.IfimpeTil^rerC)瓏「IfimpeTil^rerC)瓏「1ThesmummJure〔吏-更n黑aidKHd-nA您4氏Thisisparticularlylikelytooccuronwaterprooffabricssinceundersuchconditionstherateoflossofwatervaporfromtheclothingwillbeverylowwithaconsequentiallyhighwatervaporpressurewithintheskinmicroclimate.TheinevitableCondensation,whichoccursunderthesecircumstances,leadstodiscomfortwithitsassociatedconsequenceinwear.Tafck1ApproxLnuitr MSpOtf呻i呃iHinforvarioutacti聽扇.4tiiTri(jMesbutiirWaltr咐軻『g-m":ad-1Rjuon^.附B-iii2kij/inE5WWalking^15.Sbn?bi-1IlMS占他ing妝1TgdL幽壬亦心與：笑i16M-232J)T?Fdiini136)-tWSriL2(00Oim㈣jLJdxler￡HaLr^LiECMJdim虛J；Ijddcr Lo*djiWFromaphysiologicalpoint,comfortcanbedefinedasthestatethatmaintainstheskinatatemperatureof33±2°Candarelative;;humidityoflessthan100%.i.e.noliquidwaterontheskinsurface.Thisstateiscontrolledbytheescapeofbodyproducedwatervaporandtheclothingabilitytotransmitthewatervapor.Tablelliststheamountofwatervaporproducedbythebodyindifferentactivitiesandindicateshowmuchwatervapormustbelostforcomforttobeachieved.Fig.2showsthemodelofwatervaportransfermechanismindifferencefabricsandshowsthatcondensationdependsuponthepropertiesofthefabrics.Themoredifficultthewatervaportransferthroughthefabricsis.thegreaterarethewatervaporconcentrationsattheinnerfabricsurface.Inn-CfSUffaLCFafarLfiOutcr^urifkceDistance罔辛2Watervgpofitar倍仙medWiisniindif^rmcc缶聞曲SamplesToinvestigatethecondensationformedontheinnerfabricsurface,14fabricsarelistedintable2.Threespecimensshallbetestedbythesamemethod.Theyincludetheconventionalfabrics,tightlywovenfabrics;microporousfilmfabricsandnonporousfilmfabrics.Microporousfilmfabrics.suchasPTFElaminatedfabrics(knownasbreathablefabrics)haveverysmallporous,whichallowwatervaportodiffusethroughbutpreventliquidwaterpenetration.Watervaporcanbeabsorbedbyanothertypeofbreathable

fabrics(nonporoushydrophilicfilmfabric)andbetransferredthroughthefabricsandemittedintotheairspacesbydesorptions.Tightlywovenfabricsusingtheso-calledmicrofibersthatarelessthan1decitexperfibercanbewovensodenselythatnointersticescanbeseenbetweenthefibersandthustheyresistwaterpenetration.Table2MeasunagfabricsSsmpksNo Malerialsg8m*3C-oDvcntiouaJfabrics1Nyloh/conmpl^indothno2Concncanvas233Tightlywovenfabrics3NylonpHefacebrocade1764FEpeachfaceclodh.124Micro-porouslilmfabrics5Nyforv7cottonplaincloth+PTFELaminawd1746Cocapoplin+PTFELaminaled2227Nylonginghmm十PTFELamindied97&PEptAchfacecloth+FTFELaminaied166gNylonpilefacebmcade+FTFELorniruted182Non-poroufiHimhtbrics10Nylpnuffeu+HydrophilicCoaled133]]Nylonoxford+HydrophiLiCoated18Q12Nylongingham+■PolythaneCoated8513NylongLngtian]+■PulyurethaiwCoatedJ1914Nyknpilefacebrocade*PolyurethaiKCoated126ConclusionToinvestigatethemechanismofcondensationoccurredonthefabrics,anewmeasuringapparatusweremadetoobtaintemperatureandrelativehumiditysimultaneously.TheexperimentconductedatthestandardconditionoftemperatureOf20ocandrelativehumidityof65%.TheresultobtainedfromexperimentshowedthatPTFElaminatedfabricsexceptnylonginghamPTFElaminatedfabricfacilitatethelossofwatervaporandthereforepreventcondensation.However,therangeoffabricsstudiedshowedthatcondensationcouldoccurunderthesituationclosedtosaturationline.Itisnecessarytodevelopstudiesfromawiderangeoffabrics.Especiallybreathablefabricsandunderbadexperimentconditioninordertodevelopfabrics,whichcouldeliminatecondensation,Ortransportwatervaporthroughthefabricwhileremainingwaterproof.作者：周小紅、殷寶璞、王善元國籍：中國出處：東華大學學院報（英文版）.第二期.卷19.2003.微孔膜防水透濕織物熱濕傳遞中織物表面凝結在理論上，凝結發(fā)生在當?shù)氐臍鉁叵庐敭數(shù)氐恼羝膲毫ι仙礁哂陲柡驼羝膲毫Φ臅r候。為了研究發(fā)生在織物表面的冷凝機制，一種能同步獲得溫度和對應的濕度的測量設備被設計了出來。實驗是在溫度20°C相對濕度為65%的條件下進行的。實驗結果表明,冷凝可能在靠近飽和線的情況下發(fā)生，因為在測量溫度為周圍環(huán)境溫度20C時，織物表面的溫度可能會低于水蒸氣的露點。各種面料的研究表明,聚四氟乙烯層壓織物除外尼龍格子聚四氟乙烯層壓織物有利于水汽的損失，因此防止水汽凝結。為了開發(fā)織物，有必要更廣泛的開發(fā)和研究面料，特別是透氣織物和在惡劣的條件下實驗。這些織物可以消除冷凝，或防止運輸水蒸汽通過。關鍵詞：凝結;防水;透氣;面料引言人體在代謝的過程中，人體不斷和外界環(huán)境不斷做熱能和水分的交換通過織物。當水蒸汽的運輸在衣服中比較慢，伴隨人體的代謝物就會從體內出來。冷凝定義為當水滴在衣服的內表面聚集時就發(fā)生，只要在在地方的溫度下水蒸汽的壓力高于飽和的水蒸汽的壓力情況下。Keighley和Ruckman在理論上提出，利用飽和蒸汽線和水蒸汽濃度線防止在織物上產生凝結的措施。Keighley利用紅外測試水蒸汽的濃度，Ruckman試制了打孔的滾筒模擬人體發(fā)汗，并測量通過織物散發(fā)的水蒸汽量。最近，Ren和Ruckman利用潑水法模擬在織物表面產生凝結，對不同的防水透濕織物的透濕性進行測試，研究凝結對織物透濕性能的影響。一種向織物熱表面噴水的方法的引進是模擬水滴的凝結。雖然織物的防水性和可透氣性集中在這些織物是否可以減少熱壓力和不舒適度與此同時在風雨里提供一定的保護。以上關于凝結的研究主要集中在凝結對熱、濕傳遞的影響，而至今為止，無論是理論還是實驗，缺少對織物表面凝結形成的判斷與研究。本文將介紹一種同時測量溫度與濕度的織物微氣候測試裝置，并對典型的一些織物在模擬人體出汗的環(huán)境中進行測試，對防水透濕織物表面凝結進行物理指標的表征，對防水透濕織物表面凝結成因進行研究。

理論冷凝是在當?shù)氐臏囟认庐數(shù)氐乃羝麎毫ι仙秊轱柡退羝麎毫r。飽和線是描述在特定的溫度下水蒸汽的壓力上升到100%的相對濕度，見圖1。1200010000P8000力61200010000P8000力6000壓汽4000水20000IQ50初3D溫度T(°C)

圖1飽和蒸汽壓線這些在防水織物上很容易發(fā)生，當在從衣物的水分壓力遺失率很低而皮膚的水分壓力比較高的情況下。凝結的必然,發(fā)生在這種情況下,與其相關的后果,導致在佩戴不適。表1由各種活動產生的近似新陳代謝的水蒸