纺织英语第三版课文翻译电子版课文.docx

纺织英语第三版课文翻译电子版课文.docx

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纺织英语第三版课文翻译电子版课文

LessonOne

CottonGrowing

Cottonistheworld'smostwidelyusedfiber.Itspopularitystemsfrombothitsrelativeeaseofproductionanditsapplicabilitytoawidevarietyoftextileproducts.Thepriceofcottonyarn,however,isstronglydependentuponthecostoflabor,sothatintheindustrializednations,wherelaborisexpensive,cottonyarnsmayberelativelyhighpriced.

Untilrelativelyrecenttimes,however,cottonwasnotaswidelyusedaswoolandlinen.Thiswasbecauseitwaseasiertospinwoolorflaxintoyambecauseoftheirgreaterlength.Inaddition,cottonfibershavetobeseparatedfromtheseedstowhichtheycling.Thisprocedurewasverytediousandtime-consumingwhendonebyhand.Earlymachinerycouldbeusedononlythelongeststaplecotton.Solaborcoststendedtobeveryhigh.

Theinventionofthesaw-typecottonginmadepossibletheexploitationoftheshortstaplefiber,whichthrivedintheCarolinasandVirginiaoftheUnitedStates.Thedramaticincreaseinproductivity,coupledwiththelowcostoflaborinthesouthernUnitedStates,gavecottonacontinuallyexpandingportionoftheworldtextilemarket.Increasingmechanizationoffiberandyarnproductionhelpedkeepthecostofcottongoodslow.The,developmentofthetextilemachineryenlargedtheproductionbase.

Cottoncultivationrequireswarmclimateswithahighlevelofmoistureorirrigation.Thegrowingseasonisfromsixtosevenmonthslong.Duringthisperiodtheseedssproutandgrow,producingawhiteblossominabout100days.Theblossomproducesaseedpod,whichmaturesduringthenexttwomonths.Whenthepodbursts,thecottonfibersarereadyforpicking.

Beforeyammanufacture,cottonisgraded,sorted,andblendedtoinsureuniformyamquality.Cottonisgradedonthebasisofcolor,staplelength,fineness,andfreedomfromforeignmatter.IntheUnitedStates,cottonsaredividedintogradesaccordingtolengthofstaple,uniformity,strength,color,cleannessandflexibility.ThesearecomparedwithastandardsuppliedbytheUnitedStatesDepartmentofAgriculture.Thestandardprovides6gradesaboveand6gradesbelowtheMiddlinggrade.Themostcommongradesare:

（1）Strictgoodmiddling.

（2）Goodmiddling.

（3）Strictmiddling.

（4）Middling.

（5）Strictlowmiddling

（6）Lowmiddling.

（7）Strictgoodordinary.

Thecottonfibermaybefromtocmlong.Underthemicroscopeitappearsasaribbonlikestructurethatistwistedatirregularintervalsalongitslength.Thetwists,calledconvolutions,increasethefiber-to-fiberfrictionnecessarytosecureastrongspunyarn.Thefiberrangesincolorfromayellowishtopurewhite,andmaybeverylustrous.However,mostcottondull.

Across-sectionalviewrevealsthatthefiberiskidney-shapedwithcentralhollowcoreknownasthelumen.Thelumenprovidesachannelfornutrientswhiletheplantisgrowing.Thefiberconsistsofanoutershell,orcuticle,whichsurroundstheprimarywall.Theprimarywall,inturn,coversthesecondarywallsurroundingthelumen.Thecuticleisathin,hardshellwhichprotectsthefiberfrombruisinganddamageduringgrowth.Inuseasatextilefiber,thecuticleprovidesabrasionresistancetocotton.

LessonTwo

CottonPropertiesandUses

Arelativelyhighlevelofmoistureabsorptionandgoodwickingpropertieshelpmakecottononeofthemorecomfortablefibers.Becauseofthehydroxylgroupsinthecellulose,cottonhasahighattractionforwater.Aswaterentersthefiber,cottonswellsanditscrosssectionbecomesmorerounded.Thehighaffinityformoistureandtheabilitytoswellwhenwetallowcottontoabsorbaboutone-fourthofitsweightinwater.Thismeansthatinhotweatherperspirationfromthebodywillbeabsorbedincottonfabrics,transportedalongtheyarnstotheoutersurfaceoftheclothandevaporatedintotheair.Thus,thebodywillbeaidedinmaintainingitstemperature.

Unfortunately,thehydrophilicnatureofcottonmakesitsusceptibletowater-bornestains.Water-solublecolorantssuchasthoseincoffeeorgrapejuicewillpenetratethefiberalongwiththewater;whenthewaterevaporates,thecolorantistrappedinthefiber.Perhapsthemajordisadvantagetocottongoodsistheirtendencytowrinkleandthedifficultyofremovingwrinkles.Therigidityofcottonfiberreducestheabilityofyarnstoresistwrinkling.Whenthefibersarebenttoanewconfiguration,thehydrogenbondswhichholdthecellulosechainstogetherarerupturedandthemoleculesslideinordertominimizethestresswithinthefiber.Thehydrogenbondsreforminthenewpositions,sothatwhenthecrushingforceisremovedthefibersstayinthenewpositions.Itistheruptureandreformationofthehydrogenbondsthathelpstomaintainwrinkles,sothatcottongoodsmustbeironed.

Cottonisamoderatelystrongfiberwithgoodabrasionresistanceandgooddimensionalstability.Itisresistanttotheacids,alkalies,andorganicsolventsnormallyavailabletoconsumers.Butsinceitisanaturalmaterial,itissubjecttoattackbyinsects,moldsandfungus.Mostprominentisthetendencyforcottontomildewifallowedtoremaindamp.

Cottonresistssunlightandheatwell,althoughdirectexposuretoconstantstrongsunlightwillcauseyellowingandeventualdegradationofthefiber.Yellowingmayalsooccurwhencottongoodsaredriedingasdryers.Thecolorchangeistheresultofachemicalreactionbetweencelluloseandoxygenornitrogenoxidesinthehotairinthedryer.Cottonswillretaintheirwhitenesslongerwhenline-driedordriedintheelectricdryer.

Ofmajorinterestisthefactthatcottonyarnisstrongerwhenwetthanwhendry.Thispropertyisaconsequenceofthemacro-andmicro-structuralfeaturesofthefiber.Aswaterisabsorbed,thefiberswellsanditscrosssectionbecomesmorerounded.Usuallytheabsorptionofsuchalargeamountofforeignmaterialwouldcauseahighdegreeofinternalstressandleadtoweakeningofthefiber.Incotton,however,theabsorptionofwatercausesadecreaseintheinternalstresses.Thus,withlessinternalstressestoovercome,theswollenfiberbecomesstronger.Atthesametime,theswollenfiberswithintheyarnspressuponeachothermorestrongly.Theinternalfrictionstrengthenstheyarns.Inaddition,theabsorbedwateractsasaninternallubricantwhichimpartsahigherlevelofflexibilitytothefibers.Thisaccountsforthefactthatcottongarmentsaremoreeasilyironedwhendamp.Cottonfabricsaresusceptibletoshrinkageuponlaundering.

Perhapsmorethananyotherfiber,cottonsatisfiestherequirementsofapparel,homefurnishings,recreational,andindustrialuses.Itprovidesfabricsthatarestrong,lightweight,pliable,easilydried,andreadilylaundered.Inapparel,cottonprovidesgarmentsthatarecomfortable,readilydriedinbright,long-lastingcolors,andeasytocarefor.Themajordrawbacksareapropensityforcottonyamstoshrinkandforcottonclothtowrinkle.Shrinkagemaybecontrolledbytheapplicationofshrink-resistantfinishes.Durable-presspropertiesmaybeimpartedbychemicaltreatmentorbyblendingcottonwithmorewrinkle-resistantfibers,suchaspolyester.

Inhomefurnishings,cottonservesindurable,general-servicefabrics.Althoughtheymaylacktheformalappearanceofmaterialsmadefromotherfibers,cottongoodsprovideacomfortable,homeyenvironment.Cottonfabricshavebeenthemainstayofbedlinensandtowelsfordecades,becausetheyarecomfortable,durable,andmoisture-absorbent.Polyester/cottonblendsprovidethemodernconsumerwithno-ironsheetsandpillowcasesthatretainacrisp,freshfeel.

Forrecreationaluse,cottonhastraditionallybeenusedfortentingandcampinggear,boatsails,tennisshoesandsportswear.Cottonisparticularlywell-suitedfortent.Atentfabricmustbeableto"breath",sothattheoccupantsarenotsmotheredintheirowncarbondioxide.Furthermore,exchangeofairwiththeoutsideatmospherereducesthehumiditywithinthetentandkeepsitfrombecomingstuffy.Fabricswovenfromcottoncanbeopenenoughtoprovidegoodairpermeabilityforcomfort.Tentsshouldalsoshedwater,whenwetbyrain,cottonyarnsswell,reducingtheintersticesbetweentheyarnsandresistingthepenetrationofwater.Today,however,heavycanvasgearisbeingsupplantedbylight-weightnylonintentingequipment.

Cottoncord,twineandropesareusedinindustrytobind,hold,andlashallkindsofthings,frombalestoboats.Cottonyarnsareusedtoreinforcebeltsondrivemotorsandinworkclothing.

LessonFour

Wool

Theearlyhistoryofwoolislostinantiquity.Sheepskin,includingthehair,wasprobablyusedlongbeforeitwasdiscoveredthatthefiberscouldbespunintoyarnsorevenfeltedintofabric.Thereisnoevidencetosupportthetheorythatwoolwasthefirstfibertobeprocessedintofabric,butitseemscertainthat,asapartoftheskin,woolwasusedforcoveringandprotectionbyprehistoricpeopleslongbeforeyarnsandfabricsweremade.

TheearliestfragmentsofwoolfabrichavebeenfoundinEgypt,probablybecauseofthepreservingqualitiesoftheclimate.Thesehavebeendatedfrom4000to3500BC.TheearliestexampleofwoolfabricfoundinEuropehasbeendatedabout1500BC;itwasunearthedinarcheologicaldigsinGermany.Danishsiteshaveyieldedexcellentfragmentsofearlywoolfabricsdatedabout1300to1000BC.Thesefabricsareroughandcoarseandcontainconsiderablewildsheephair.

Woolisanaturalfiberofanimalorigin.Thoughvegetablefiberswereprobablythefirsttobeusedforspinningandweavingintocloth,animalfibersintheformofskinsweretheearliesttypeofclothing