化工英語.課件

PULPandPAPERBY:陳水平（1分）劉玉梅（1分）鄒豐欽（1分）歷福強(qiáng)（1分）

陳立新（1分）

DOyouknow?HOWMADEIT？Introductionto

PULPINGPROCESSCooking（煮）Screening（篩選）Refining（精煉）Washing

（洗滌）Bleaching（漂白）Sheeting（紙張）Packing（包裝）PulpingProcessTwomainwaysofmakingpulp:1.Chemicalprocess（化學(xué)過程）Thewoodchipcookedinthechemicalliquortosoakanddispersethefiber.TomanychemicalusedtocookthewoodchipsincludeKraft,bisulfite,sulfite,andsoda.Relativelylowyield,lowfines,highbrightness,andhighstrength.2.Mechanicalprocess（機(jī)械加工）Usemechanicalactiontodispersefibersfromwood.Mechanicalpulpsarecommonlyproducedfromsoftwoodspecies(longfiber).Itshavetheadvantageofconvertingupo95%ofdryweighofthewoodintopulp,butrequireprodigiousamountofenergy.Higherbulkyandmorefinecontainingonthepulp,itscauselessstrengthpulp.KraftPulpingProcessBiomesdecreasingonKraftpulpingproductionsteps（硫酸鹽法制槳流程）.100%（森林）63%Harvesting(木材）55%Woodhandling（木材處理

）25%Cooking（煮）24.5%Screening（篩選）24%Delignification（脫木素）23%Bleaching（漂白）Storage（存儲(chǔ)）KraftPulpingProcessInKraftpulpingprocess,thebiomesoftheplantwillbedecreasedineachproductionsteps.Harvesting,onlywoodcrownwithperforateddiameterthatusedtopulpmaking,thereisabout63%oftreemass.WoodHandling,thewoodisdebarkedandmilledintochipssize.Woodbarkandfineoccurredaretakeabout13%ofwoodcrownmass.Cooking,dispersethefiberbydilutethelignin.Theyieldofcookingprocessabout45%Screening,removethewoodknotandmassloseabout2%Oxygendelignification,removetheremainlignin,andmassabout2%Bleaching,bleachthefiberpigmentandyieldofbleachingprocessabout96%

PulpMaintainingTheremaybeseveralprocessestomaintainpulp.Eachprocessservesaspecificfunction,whichrelatestothetypeofproductthatwillultimatebeproduced1.Refining（精煉）Thepulpisforcedbetweenasetofrotatingandstationaryplates,tobreakupuncookedchipsfromdigester.2.Screening（篩選）Thefiberbundles,oftencalledknotsorshives,removedfrompulpthroughascreen.InOutRejDil3.Washing（洗滌)Blackliquorinpulpisremovedandreplacewithwater4.Oxygendelignification(氧脫木素)Enhanceddelignificationwithoutsacrificingfiberquality.Kappareductionupto50-55O2EEDDBleachingSequences1.Chlorination(C)：Reactionwithelementalchlorineinacidicmedium2.AlkalineExtraction(E)：DissolutionofreactionproductswithNaOH3.Chlorinedioxide(D)：ReactionwithClO2inacidicmediumBleachingThepurposeofbleachingistoremoveremainingligninfrompulpandtobrightenthepulp.Brightnessofpulpmayincreasefrom40-55upto70-95.CPapermaking

TheprocessofgoingfromPulptoPaperObjectivesOfPapermakingGoodFormationPhysicalandOpticalProperties(物理和光學(xué)性能）HighCapacity(tonspaper/day)Papermaking

WettoDryStockPreparation(Wet-end)（儲(chǔ)存準(zhǔn)備）Refining,Screens,Cleaners,ChemicalAdditivesPapermachineHeadbox,FormingSection,PressSection,Dryers,SizePress,PaperReelDryEndCoating,Calendaring,Rewinding,PackagingPapermachineHeadboxandFormingSectionPressSectionDryerSectionSizePressPutssurfacecoatingofasizingagentonasheetUsuallystarchDecreaseswaterandairpermeabilityandincreasespaperstrength.CalendaringMeansto“presswitharoll”SmoothessurfaceofpapersheetPaperReel

TheEndoftheLineRewinder（復(fù)卷）Atlast,cutandrollpapertocustomerneeds.PaperpollutionTheproductionanduseofpaperhasanumberofadverseeffectsontheenvironmentwhichareknowncollectivelyaspaperpollution.Pulpmills

（工廠）contributetoair,waterandlandpollution.Discardedpaperisamajorcomponentofmanylandfillsites,accountingforabout35percentbyweightofmunicipalsolidwaste(beforerecycling).Even

paperrecyclingcanbeasourceofpollutionduetothesludgeproducedduringdeinkingPaperpollutionPulpandpaperisthethirdlargestindustrialpollutertoair,water,andlandinbothCanadaandtheUnitedStates,andreleaseswellover100millionkgoftoxicpollutioneachyear.Worldwide,thepulp