化工英语.课件

PULPandPAPERBY:陈水平（1分）刘玉梅（1分）邹丰钦（1分）历福强（1分）

陈立新（1分）

DOyouknow?HOWMADEIT？Introductionto

PULPINGPROCESSCooking（煮）Screening（筛选）Refining（精炼）Washing

（洗涤）Bleaching（漂白）Sheeting（纸张）Packing（包装）PulpingProcessTwomainwaysofmakingpulp:1.Chemicalprocess（化学过程）Thewoodchipcookedinthechemicalliquortosoakanddispersethefiber.TomanychemicalusedtocookthewoodchipsincludeKraft,bisulfite,sulfite,andsoda.Relativelylowyield,lowfines,highbrightness,andhighstrength.2.Mechanicalprocess（机械加工）Usemechanicalactiontodispersefibersfromwood.Mechanicalpulpsarecommonlyproducedfromsoftwoodspecies(longfiber).Itshavetheadvantageofconvertingupo95%ofdryweighofthewoodintopulp,butrequireprodigiousamountofenergy.Higherbulkyandmorefinecontainingonthepulp,itscauselessstrengthpulp.KraftPulpingProcessBiomesdecreasingonKraftpulpingproductionsteps（硫酸盐法制桨流程）.100%（森林）63%Harvesting(木材）55%Woodhandling（木材处理

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

PulpMaintainingTheremaybeseveralprocessestomaintainpulp.Eachprocessservesaspecificfunction,whichrelatestothetypeofproductthatwillultimatebeproduced1.Refining（精炼）Thepulpisforcedbetweenasetofrotatingandstationaryplates,tobreakupuncookedchipsfromdigester.2.Screening（筛选）Thefiberbundles,oftencalledknotsorshives,removedfrompulpthroughascreen.InOutRejDil3.Washing（洗涤)Blackliquorinpulpisremovedandreplacewithwater4.Oxygendelignification(氧脱木素)Enhanceddelignificationwithoutsacrificingfiberquality.Kappareductionupto50-55O2EEDDBleachingSequences1.Chlorination(C)：Reactionwithelementalchlorineinacidicmedium2.AlkalineExtraction(E)：DissolutionofreactionproductswithNaOH3.Chlorinedioxide(D)：ReactionwithClO2inacidicmediumBleachingThepurposeofbleachingistoremoveremainingligninfrompulpandtobrightenthepulp.Brightnessofpulpmayincreasefrom40-55upto70-95.CPapermaking

TheprocessofgoingfromPulptoPaperObjectivesOfPapermakingGoodFormationPhysicalandOpticalProperties(物理和光学性能）HighCapacity(tonspaper/day)Papermaking

WettoDryStockPreparation(Wet-end)（储存准备）Refining,Screens,Cleaners,ChemicalAdditivesPapermachineHeadbox,FormingSection,PressSection,Dryers,SizePress,PaperReelDryEndCoating,Calendaring,Rewinding,PackagingPapermachineHeadboxandFormingSectionPressSectionDryerSectionSizePressPutssurfacecoatingofasizingagentonasheetUsuallystarchDecreaseswaterandairpermeabilityandincreasespaperstrength.CalendaringMeansto“presswitharoll”SmoothessurfaceofpapersheetPaperReel

TheEndoftheLineRewinder（复卷）Atlast,cutandrollpapertocustomerneeds.PaperpollutionTheproductionanduseofpaperhasanumberofadverseeffectsontheenvironmentwhichareknowncollectivelyaspaperpollution.Pulpmills

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

paperrecyclingcanbeasourceofpollutionduetothesludgeproducedduringdeinkingPaperpollutionPulpandpaperisthethirdlargestindustrialpollutertoair,water,andlandinbothCanadaandtheUnitedStates,andreleaseswellover100millionkgoftoxicpollutioneachyear.Worldwide,thepulp