染整专业英语课堂练习试题.docx

染整专业英语课堂练习试题.docx

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染整专业英语课堂练习试题

1Whatisfibre

Fibresarethefoundationoftextileindustry.Alltextilesaremadeoffibres.Alloftheproductionflowsandformulaeintextileswetproceccingstagesincludingpre-treatment,dyeing,printingandfinalfinishingaredesignedandconductedonthebasisofthepropertiesofthefibresfromwhichthetextilesaremade.Soitisnecessaryforustoreviewthefibre’sdefinitionandpropertiesbeforewediscussthewettreatmentoftextiles.

Whatisafibre?

Fibreisthesmallestvisibleunitofmatterthathasahighlengthtodiameterratio,finenessandflexibility.

Theabovedefinitionfortextilefibresisverybroad.Somanythingsaredemandedoffibresinmanydifferentuses.However,somecharacteristicscanbeidentifiedwhichalltextilefibresmusthaveiftheyaretobecommerciallysuccessful:

ahighlengthtodiameterratio,strength,extensibilityandelasticity,resistancetochemicals,heatandsunlight,andabilitytotakecolour.

Fibersareusuallygroupedinordertoresearchordiscussorapplythemconventiently.Mostoffibresarepolymer.Besedontheirchemicalcomposition,fibrescanbeclassifiedintomanygroupssuchascellulosicfibre,proteinfibre,viscosefibre,polyamidefibre,polyesterfibreandpolycrylicfibre,etc..Butthemostconvenientgroupingdividesthemintotwobasicgroupsaccoudingtotheirorigins:

i.e.naturalandman-madefibres.Naturalfibresrefertoallfibersthatoccurinfibreforminnature,includingcotton,linen,wool,silk,andsoon,whichhavebeenknownandusedforthousandsofyears.Asnaturalfibrescannotmeettherequirementofpeople,manypolymersthatdonotnaturallyexistintheformoffibrehavebeenprocessedintothefibreform,usuallybyforcingtheviscouspolymersthroughaspinneretthatconsistsofaseriesoftinyholesarrangedinacircle,andusedasfibres.Theseproductsareknownasman-madefibres.

Thetwobasicgroupscanthenbefurthersubdivided.Thenaturalfibrescanbesubdividedintothethreetypesofcellulosic,proteinandmineralfibresaccordingtotheirorigins.Man-madefibresareusuallysubdividedintofourgroups:

regenerated,modified,syntheticandmineralfibres,accordingtotheirpolymerorigins.

2Naturalfibres

Fiberisthebasicunitoffabric.Thetextilefibersmanybedividedintotwomajorgroups,namely,（a）naturalfibersand（b）man-madefibers.

Thechiefnaturalfibersnowinusearecotton,linen,woolandsilk.Theyvaryconsiderablyasregardstheirpropertiesandtheirproduction.

Cotton

Cottonisthemostimportantandwidelyusedvegetablefiber.Itisobtainedfromthecottonplantwhichgrowsinwarmmoistclimatesandinmostpartsoftheworld.In1980theleadingproducingcountriesareAmerica,Russia,China,IndiaandPakistan.Cottonfibersarecomposedlargelyofcellulose.Besidescellulose,rawcottoncontainsanumberofothersubstances,notablywaxes,pecticproductsandmineralsubstances.Thesearequitesmallinamount,say,notmorethan4percenttogether.Theyarereferredtoasimpuritiesbythemanufacturerofcottongoods.Generallytheseareobjectionableeffectsandwouldmakeitdifficulttocolourandfinishcottonfabricssatisfactorily,soitisalwaysafirststepintheartofdyeingandfinishingtopurifythecottonascompletelyaspossible.

Itisusedforapparelfabrics,forhouseholdordomesticgoods,andforindustrialapplications.Itsabilitytoacceptcolorandfinishes,combinedwithitscomfort,makeitapleasantchoiceforthefashion-mindedconsumer.Cottonisalsoextensivelyusedinblendswithman-madefiberstoachievenewcombinationsofpropertiesthatarenotavailableinthefibersseparately.

Cottonhassomedisadvantages,too.Itcreasesandwrinkleseasily.Itmaybeweakenedbymildewandmoldunlesstreatedtoresistthem.Itisreadilyattackedbyacidreagentsandsubstances,anditisslowlyaffectedbysunlight,causingyellowingandfiberdegradation.

Linen

Allvegetablefibersotherthancotton---theonlyunicellularvegetablefiber---aremulticellular.Thebestknownandmostabundantlyusedmulticellularfiberislinen.Thereareseveralotherssuchasjute,ramie

Linenfibersresemblecottoninsofarastheyconsistofcellulosebuthavealowercellulosecontent.Onanaveragethelinenfiberscontainonlyabout75percentofpurecellulose,theremainingmatterbeingagummypecticsubstance.Thesurfaceofeachfiberissmoothandthishelpstogivelinenmaterialstheircharacteristichighluster.Inmanyofitschemicalpropertieslinencloselyresemblescotton.Thus,itisresistanttoalkaliesandiseasilydeterioratedbyacids.Linenismainlyusedinthemanufactureofsailcloth,tentfabric,sewingthreads,fishinglines,table-clothandsheets.

Lesson3Woolandsilk

Woolistheanimalfiberofoutstandingimportance.Itisobtainedbyshearingthefibrouscoveringofsheepandisproducedinalmostallpartsoftheworld.Whenwoolisshornfromalivingsheepitiscalledfleeceorclipwool.

Chemicallywoolconsistsofacomplexprotein,asubstancewhichiscomposedofcarbon,hydrogen,oxygen,nitrogenandsulphur.Itdiffersfromcelluloseincontainingnitrogenandsulphur,anditisthepresenceofthesetwoadditionalelementsinthewoolmoleculewhichgiveswoolfiberspropertiesprofoundlydifferentfromthoseofthevegetablefibers.Woolfiberhasadensityof1.32,whichmakesitslightlylighterthancotton.Woolandotherhairfibershaveanelasticrecoveryof99%from2%and60%from35%extension,respectively.Thismakesthewoolfibershighlyresilient.Inotherwords,woolfibershaveatendencytoreturncompletelytotheiroriginalshapeaftersmalldeformations,whichisagreatimportance.

Woolhasseveraldisadvantages:

itisverysensitivetoalkalinesubstances;itisreadilyattackedbymothsunlesstreatedtoresistthem;itisdifficulttobleach;anditfeltseasily.

Silk

Silkisthematerialextrudedfromglandsinthebodyofthesilkworminspinningitscocoonorweb.Itistheonlynaturalfiberthatoccursintheformofalinecontinuousfilament.

Silkiswarmandpleasanttothetouchandisgenerallyconsideredcomfortabletowear.Itisreadilydyeablewithavarietyofdyesandhasanaffinityformetallicsalts.

Silkisessentiallyusedinluxurygoods.Ithasbeenabletowithstandcompetitionfromsyntheticfibersinmanyhigh-qualitytextileapplicationsbecauseofitsexcellentdyeingcharacteristics,highmoistureandlightabsorbency,andheat-preservingproperly.

LessonfourMan-MadeFibers

Naturalfibersarealreadyinfiberformasharvestedandarereadyforthestartofyarnspinningoperations.However,man-madefibersstartoutasplasticthatfirstbeconvertedintofiberform.Mostman-madefibersareformedbyforcingaviscouschemicalsubstancethroughaspinneretwhichconsistsofaseriesoftinyholesarrangedinacircle.Thestreamsemergingfromtheholesarethenhardenedorsolidifiedtoformfilaments.Theprocessofextrusionandhardeningiscalledspinning,nottobeconfusedwiththeyarnformingoperationofthesamename.

Theman-madefibersaredividedintotwobroadcategories:

（a）regeneratedfibersand（b）syntheticfibers.Theregeneratedfibersarethoseinwhichthefiber-formingmaterialisofnaturalorigin;Insecondclassoffibersismadebythechemicalsynthesisofsimplepolymer-formingmaterials.

RegeneratedFibers

Theregeneratedcellulosicfibersincludeviscose,cuprammonium,andacetaterayons.Thesethreeformsofrayontogetherconstitutethebulkofworldproductionhavinganaturalpolymer（cellulose）baseasrawmaterial.Ofthese,viscoserayoniscomparativelyeasiertoproduceandconsideredasthechiefrayonofthegroup

ViscoseRayonViscoserayonhasmanypropertiesincommonwithcotton.Butitisnecessarytopointoutatleasttwoimportantdifferenceswhichareimportantfromtheviewpointoftextilefinishing.Viscoserayonfibersconsistofcellulosesomewhatlooserormoreopened-upthanthatofcotton.Viscoserayonabsorbswatermorefreelyandismorereceptivetowardsdyes.Inbleachingandothertreatmentswhereovertreatmentcanresultinfiberdamage,viscoserayonbecomesdegradedmorerapidlythandoescotton.Theseconddifferencebetweenviscoserayonandcottonfibersisthattheviscoserayonfibersaresomuchsmoother.Thisnotonlycontributestotheirlusterbutitreducestheadhesionwhichisdesiredinyarnsandfabricstogivestabilityofshapeandsize.

Syntheticfibers

Thefirstsyntheticfibreisnylon（oneofpolyamidefibres）thatwascommerciallyproducedinUnitedStatein1939.Themainkindsofthesyntheticfibresinclude:

polyamide,polyesterandpolycrylicfibres,whichareusedintextileindustrywidely.

1polyamidefibres

Nylonfilamentsaresmoothandshiny.Whenviewedincross-section,nylonisusuallyperfectlyround.Itishighlyresistanttoalkalisandrelativelylessresistanttoacid.Nylonisverystrong,quite-dryingfibrewithhighwetstrengthandhasexcellentelasticity.Nylonhasalowerspecificgravitythanotherfibres.Thesepropertiesmakethemverysuitableforstockings,parachutefabrics,shirts,underwear,carpetandreinforcementofrubberintyresandbelts.　Nylonblendswellwithotherfibresandaddsstrengthtosuchblends.Nylonhaslowabsorbency,whichmakesitquickdrying.Inrecentyearsmanymodifiednylonfibreshavebeendevelopedandproducedtomeetsomeparticularrequirements.

Lesson5Pre-treatmentProcessesofTextiles

Beforethepretreatmentoffabricwithchemicalsolutions,itisnecessarytopreparethefabric.Thepreparationprocessesoffabricforthewettreatmentincludeexaminingofgraygoods,clothtu