鞣前准备课件

鞣前准备

Aims:

notdecay,andlastforhundredsofyearsCharacteristic:Everyhideandskinisunique,andvariesnotonlyfromspeciestospecies,butevenbetweenindividualanimals.IntroductiontoLeatherIndustryWhatisLeatherTechnology？rawhidesandskinsleather

Tanners制革者

Usingmoderntechniques,tannershavetoproducetherelativelyuniformleather,andaddfurtherfeatures,suchascolour,softnessandfullness（丰满度）,totheleatheraccordingtocustomer’srequirements.IntroductiontoLeatherIndustryTheproductioninatannery

（制革厂）beam-house（鞣前准备）

operationstanning（鞣制）

operationspost-tanning（鞣后）

operationsfinishing（涂饰，整理）

operationsIntroductiontoLeatherIndustryThefollowingoperationsaretypicallycarriedoutinthesoaking（浸水）,unhairing（脱毛）,liming（浸灰）,

fleshing（去肉）

andsplitting（片皮，剖层）

IntroductiontoLeatherIndustrybeamhouseTypicallythefollowingoperationsarecarriedoutinthe

deliming（脱灰）,

bating（软化）,

pickling（浸酸）

andtanning.(usually,

deliming,bating,picklingbelongtobeamhouseprocesses.)IntroductiontoLeatherIndustrytanningareaInthetanningprocess,thecollagenfiberofthehideandskinisstabilizedbythetanningagentssothatthehideandskinisno1ongersusceptibletoputrefaction(腐败）,andthetannedhideandskiniscalledwet-blue（蓝湿皮）.

(qualitativechange)－－whichcanbetradedasintermediateproducts.However,manufacturingconsumerproductsneedsfurtherprocessingandfinishing.IntroductiontoLeatherIndustrygenerallyinvolve:

retanning(复鞣)

toimprovethehandle,

dyeing(染色)

withwater-solubledyestuffstoproduceevencolourovertheleathersurface,fatliquoring(加油)

tolubricatethefiberdrying.

Afterdrying,theleathermaybereferredtoascrust(坯革),whichisatradableintermediateproduct.IntroductiontoLeatherIndustry

Post-tanningoperationsaretogivetheleatherasthinafinishaspossiblewithoutharmingthenaturalcharacteristicsofleather,suchasitslookanditsabilitytobreathe.

IntroductiontoLeatherIndustryFinishingoperations

Bygrounding（涂底色）,coating（涂饰）,seasoning（喷光亮剂）,embossing（压花）

andironing（熨平）,theleatherwillhaveashiny（光亮的）

ormatt（消光的）,singleormulti-coloured,smoothorclearlygrainedsurface.

－－improvetheappearanceoftheleatherandtoprovidetheappropriatecharacteristicsintermsofcolour,gloss,andhandle

IntroductiontoLeatherIndustryOperationscarriedoutinthebeamhouse,

thetanningareaandthepost-tanningareaareoftenreferredtoaswetprocessing（湿操作,水场）,

astheyareperformedinprocessingvesselsfilledwithwater

towhichthenecessarychemicalsareaddedtoproducethedesiredreaction.IntroductiontoLeatherIndustryAfterpost-tanningtheleatherisdriedandsubsequentoperationsarereferredtoasdryprocessing（干操作）.IntroductiontoLeatherIndustrywetprocessing水场作业

fleshing削肉–削除多余的残肉及油脂Tanningprocess

鞣制工序

加化料除去毛发,脂肪,肉等不需要之生皮成分,经浸酸,加鞣剂鞣制,把生皮转化成蓝湿皮.蓝湿皮经分层,削匀就可复鞣,染色Splitting剖层

根据需要的厚度把蓝湿皮分削成上层与二层皮(split)Shaving

削匀与复鞣retanning:根据需要的厚度把蓝湿皮削到准确厚度；经复鞣赋予皮革以各种特性,如丰满柔软性；经染色可得各式各样的色彩.Samming,wringing

挤水,drying干燥,milling摔软

染色的皮挤压出水,绷板烘干,再摔软Finishing,dressing,doping,coating

涂饰工艺Mendtheblemishes补伤

Rollercoating

辊涂

Finishing,dressing,doping,coating

涂饰工艺

platingmachine,ironingmachine熨平机

sprayingmachine

喷涂机

Finishing,dressing,doping,coating

涂饰工艺

drawdrum摔软转鼓vibrationstakingmachine振荡式拉软机finishedleather成革finishedleatherfinishedleather

finishedleatherfinishedleatherfinishedleatherWhatisleather?Whatfeaturesdoesthetannerhavetoaddtheleatherduringtheleathermanufacture?Whatstepsdoesthetannerusuallytaketoproducewet-bluesfromrawhides?Whatstepsdoesthetannerusuallytaketofinishingleatherfromwet-blues?Whatoperationsdoweoftencallwet-processing?Whatoperationsdowecalldry-processing?Why?QuestionsTheproductionofleathercanbelookeduponastakingplaceinthreesteps.Thefirststepistoremovetheunwantedcomponents,what?…etc.,leavinganetworkoffibersofhideprotein.

ChapterOnebeam-house

operations

Thesecondstepistomakethisnetworkreactwithtanningmaterialstoproduceastabilizedfiberstructure.Thethirdstepistobuildontothetannedfibercharacteristicsoffullness,color,softnessandlubrication,andtofinishthefibersurface,toproduceausefulproduct.ChapterOnebeam-house

operationsThefirststepiscalledbeamhousework,istoremovetheunwantedcomponents,hair,fats,etc.,leavinganetworkoffibersofhideprotein.

Thisincludessoaking,trimming(修边）,fleshing,

unhairing,liming,scudding（净面）,deliming,bating,degreasing,pickling,depickling,etc.

ChapterOnebeam-house

operations

1.Wetback2.removetheunwantedcomponents,hair,epidermis,sebaceousglands,fats,sweatglands,interfibrillarsubstances,etc.,leavinganetworkoffibersofhideprotein3.destroyunwantedstructures,follicle,elastinfibers,pilimuscle,vein,etc.4.loosecollagenfibers,adjustpHtoafitpointfortanningChapterOnebeam-house

operationsPurposesofbeam-house

operations1.1

生皮在清水中的充水作用生皮在清水中会吸收水分,干皮由于吸收水分而逐渐增厚,增重,同时由僵硬变得柔软—充水.原因:

生皮—组分—亲水基团充水程度和充水速度:与干燥状况有关,干燥温度越高,处于干燥状态时间越长,蛋白质热变性程度,可溶性蛋白质因凝固而使胶原纤维粘结的程度越大,充水越慢.

鲜皮,15℃干燥的皮,37℃干燥的皮,太阳下晒干的皮??

盐干皮,甜干皮??ChapterOnebeam-house

operations1.生皮在清水,酸碱盐溶液中的充水和膨胀作用1.2

生皮在酸碱溶液中的膨胀作用

ChapterOnebeam-house

operations1.生皮在清水,酸碱盐溶液中的充水和膨胀作用1.2

生皮在酸碱溶液中的膨胀作用

----pH2.5-3(最大值)---7(最小)----11-12(最大值)---等电点7.5左右,不带电—膨胀度?等电点以下,带?电—膨胀度?等电点以上,带?电—膨胀度?

生皮的胶原纤维在酸碱中由于大量吸收水分而使其长度缩短,直径变粗的现象—膨胀ChapterOnebeam-house

operations1.生皮在清水,酸碱盐溶液中的充水和膨胀作用1.2生皮在酸碱溶液中的膨胀作用

渗透压理论解释,静电排斥理论和水合理论补充说明.

渗透压理论:PH远离PI时,裸皮胶原分子内和分子间的离子键交联大部分被打开,成为自由的-NH2,-COOH,使胶原原纤维内聚力降低,将皮看成半透膜,由于膜内基团不能扩散到膜外,且还可和酸碱结合,扩散的结果会使膜内离子浓度大于膜外离子浓度,在膜内外产生渗透压差,使皮外水分向皮内渗透,以稀释皮内的离子浓度,结果使皮充水膨胀.(但继续增加酸碱浓度,皮外离子浓度增加,反向进行)

ChapterOnebeam-house

operations1.生皮在清水,酸碱盐溶液中的充水和膨胀作用1.2生皮在酸碱溶液中的膨胀作用

静电排斥理论:酸碱液中,胶原分子中由离子键交联本身形成的内聚力被破坏,且胶原都带同种电荷,肽链之间,分子链之间会相互排斥,增大链间距离,有利于链间充水.

水合理论:由于离子键交联被破坏而变成自由的-NH2和-COOH,这些基团会发生水合,由于链间距离增大,部分氢键交联被破坏,使其进一步与水形成氢键,因此充入皮内的水有相当一部分以氢键或水合形式与胶原结合.ChapterOnebeam-house

operations1.生皮在清水,酸碱盐溶液中的充水和膨胀作用

PurposeInfluencefactors

additivestemperaturemechanicalactionlengthoftimeChapterOnebeam-house

operations2soaking

conditionofhidesandskins:preservationbasedondehydration.Nottoputrefy.dried:mostgoatskins,sometropicalcattlehidessalted:eitherintheformofbrine（盐水浸泡）

orsaltpackcures(盐腌堆跺保藏）.

Theskinshavetobewetbackandbroughttoaflaccidcondition

forsubsequentoperations.ChapterOnebeam-house

operations2soaking2.1purpose

Soakingisgenerallyaccomplishedbyplacingtheskinsinwater,whichmaycontainanadditive.

2soakingChapterOnebeam-house

operations2.2Thesoakingprocess

green-salted(盐鲜)

cattlehides(Wet-saltedhides盐腌皮):

inadrum,coldwaterBysoaking:

dissolvethecuringsalts,causesanosmotictake-upofwaterintothehidefibers,rehydrated;1oosenthecementingactionofdriedinter-fibrillaryproteinonthefibers;removesomeoftheglobularproteins,includingthebloodalbuminandothersolubleproteins.ChapterOnebeam-house

operations2soaking2.2Thesoakingprocess

indrumorpaddle,water2-5timestheweightofthehides(15-25℃),8-20hours.

Results:

Thebloodanddirtwerewashed,thehidesbecomecleanerandsofter,andincreaseinweightowingtotheabsorptionofwater.

judging:byfeel,cleanlinessandtheabsenceofsalt.

2soakingChapterOnebeam-house

operations2.2Thesoakingprocess

Dryhidesorskins:

longertime.

driedhideswithoutthebenefitofsalt,adhesionofonefibertoanother.

Mechanicalactionshouldbeavoidedintheearlystagessincethefibersaretoostiff--breakingofthefibers--damagetotheskins

forty-eighthours,changewateraftertwenty-fourhoursormoreoftheinitialsoak.Theinitialsoakmaycontainadisinfectant(杀菌剂)

orsomesoakingagents,--aidintherehydrationoftheskinsandallowprolongedsoakingwithreduceddangerofbacterialattack.ChapterOnebeam-house

operations2soaking2.2Thesoakingprocess

Soakingprocessisnotsimple,becauseputrefyingbacteriacanthriveassoonasthereisasurplusofwaterorthecuringagentiswashedout.

thebacteriadissolvedthehideaway－－putrid（腐烂）andthesoakliquorstink（变臭)offensively--theresultantleathermayshowtender(松软）

ordamagedgrain(烂面),looseness（松面）,andlackofsolidity（坚实性）,

particularlyinthebelly（腹部）

orthinnerareas.

2soakingChapterOnebeam-house

operations2.2Thesoakingprocess

Oneoftheearliestsignsofthisdamageisthehairslips（溜毛）.Inthelaterstageholesmayactuallyappear.

However,itisessentialtosoaktheskinswell,ifoneistoobtainuniformlytannedandfinishedleatherofgoodstrengthandflexibility.Howtomakeanappropriatesoaking?ChapterOnebeam-house

operations2soaking2.2Thesoakingprocess

theuseofadditiveschangesintemperaturedegreeofagitationlengthoftimeofsoaking2soakingChapterOnebeam-house

operations

2.3Influencefactors

AlkaliAction:loosenthehairandepidermis.0.1-0.3%ofcausticsoda(烧碱),oramilderalkali,suchassodaash(纯碱，碳酸钠）Attention:toomuchalkali---swell--distort（扭曲）thesurface--blockup(阻碍）theinter-fibrillaryspaces,--preventingthewaterfromreachingtheinside.

----leatherloosegrain.

ChapterOnebeam-house

operations2soaking

2.3Influencefactors

2.3.1Additives

Sodiumsulfide－－alkalinesolution,speedingupthelooseningofhairandepidermis--asmallquantityofsodiumsulfide(硫化钠）

orsodiumpolysulfide（多硫化钠）--thebeginningoftheunhairingoperationandchemicalactiononthekeratin（角蛋白）(hairmaterial)inthefollicle（毛囊）

andstartingtheunhairingprocess.2soakingChapterOnebeam-house

operations

2.3Influencefactors2.3.1Additives

3%saltsolution

Action：1.

removaloftheglobularproteins,speedingupsoaking2.disinfecting(杀菌),decreasingbacterialdegradationIfthecuredhide,thesaltfromthehideissufficienttoremovalofsomeofthesolubleprotein.

Inthecaseofdryhidesorprolongedsoakingsystems,theadditionofsaltwillpermithighertemperatureswithdecreasedofbacterialdamage.ChapterOnebeam-house

operations2soaking

2.3Influencefactors

2.3.1Additives

0.2-0.5%Wettingagentsparticularlyifthehidesorskinsareverygreasyand,therefore,difficulttowet.Action：1.Wetback2.Removesomeofthegrease2soakingChapterOnebeam-house

operations

2.3Influencefactors

2.3.1Additives

enzymepreparationsSpecialenzymepreparationsareavailabletoassistsoaking.PellvitC(TFL,德瑞),SuperRever4,SuperReverLiquidST

(意大利

Neochimica公司)etc.

Action：proteolytic（水解蛋白质的）

actionontheinterfiberproteins,givingasmoother,flattergrain.

ChapterOnebeam-house

operations2soaking

2.3Influencefactors

2.3.1Additives

enzymepreparationsProcess:Wet-saltedhide,25-27℃,0.15%-1%preparation,pH9-10,3-5hours.

Anothersystemfavouredfordryhides，usingenzymes,pH4-5,alittlenon-ionicwettingagent.ChapterOnebeam-house

operations2soaking

2.3Influencefactors

2.3.1Additives

Theremovalofthecuringsaltandrehydrationoftheskinintroducesbacterialgrowth.

Thecuredhidecarriesalargequantityofbacteria,canbecomeactive.

Thebacteriamaydamagethehidesandmaybedangeroustoman.

Therefore,insomecasesdisinfectantsareusedinsoaking.

2soakingChapterOnebeam-house

operations

2.3Influencefactors

2.3.2Disinfectants(Bactericides)（杀菌剂）

Somecasesdisinfectantsisnotnecessary.---asoftgreensaltedcondition(柔软的盐鲜皮状态）

andnobacterialdamagepriortosoaking---ashorttimesoakingChapterOnebeam-house

operations2soaking

Raisingthetemperature---aidinginthedispersionoftheglobularproteins---acceleratingthesoakingprocess.Caution:38℃,therateofbacterialactionmayincreaseveryquickly,givingloose,emptyleather,damagedgrainorevenholes.

2soakingChapterOnebeam-house

operations

2.3.3Temperature

2.3Influencefactors

signs:Afoulsmellandahairslip

Sokeeptemperatureatabout16-21℃,andifhighertemperaturesareusedorcannotbeavoided,higherproportionsof

bactericidesorshortertimesareused.2soakingChapterOnebeam-house

operations

2.3.3Temperature

2.3Influencefactors---Mechanicalactioncirculatesthewaterroundtheskinorhelpslooseningofcementingfibers.---Theactionofdrummingismoreviolentthanpaddling.

---Mechanicalactionincreasedwiththediameterofthedrum,thesizeoftheload,andthespeedofrotation,anddecreasedwiththeamountofwater.

ChapterOnebeam-house

operations2soaking

2.3Influencefactors2.3.4MechanicalAction

Normaldrumspeedsare3-5r.p.m.anddrummingmaybeintermittent,e.g.for5minuteseveryhour.

Drummingmayreducesoakingtimeby50%andondriedhidesbyevenmore.

ChapterOnebeam-house

operations2soaking

2.3Influencefactors2.3.4MechanicalAction

Howevertherearebigdangersofdamagingdriedhidesindrumsoaking,unlesstheyhavebeenpre-soakedwithoutmovement,Excessivedrummingmaymaketheresultantleathertoosoftandloose,particularlyinthethinpartsoftheskin,ordamagethegrainoftender,thinskinsbyrubbing.ChapterOnebeam-house

operations2soaking

2.3Influencefactors2.3.4MechanicalActionWhatisthepurposeofsoaking?Whyshouldweavoidmechanicalactionintheearlystagesduringthesoakingofdryhides?Whydowesaysoakingprocessisnotsimple?Whatdamagesmaybacteriacauseduringsoaking?Whatdamageswilltakeplaceiftoomuchalkaliisusedinsoaking?Whatpurposesdoessaltaccomplishinthesoak?Whataretheactionsofenzymepreparationsinsoaking?Howdoweusuallycontrolthetemperatureinsoaking?Why?Questions

Purpose:

removalhairorwool,epidermis,hairrootsheath,gettingapelt(裸皮）withasmoothergrain.ChapterOnebeam-house

operations3Unhairing

Methods:paintunhairing

sulphideunhairing

hair-destructionunhairingindrum（硫化物）灰碱法脱毛hair-savingunhairingindrum

enzymeunhairing

酶脱毛

enzymeassistedunhairing

酶助脱毛

oxidativeunhairing

氧化脱毛ChapterOnebeam-house

operations3Unhairing

3.1.1Paintunhairing（涂灰脱毛法）1.Method:

Thewashedorsoakedskinsaredrainedoffsurpluswater（控水）andthenpainted(涂脱毛糊）,swabbed（抹）orsprayed（喷）onthefleshsidewitha“paint”（脱毛糊）

Afterpainting,theskinsmaybefoldeddownthebackbone,fleshsideintokeepthepaintoffthehairorwool,andpiled(堆跺）orhunguntilthehairorwoolisloose.

ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairing1.Method:

Thesodiumsulfideandsuchlimeentertheskinfromthefleshside,penetratethroughthecorium,anddissolvetheyoungkeratincells,whichenclosethehairroots.woolispulled,usuallybyhandorbyanunhairingmachine.Thenliming,withalittleNa2Storemovesurplushairandepidermis.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairingtake5-12hoursorlong,dependingonthethicknessoftheskin,thetightnessofthefiberstructureandtheamountoffleshorfatleftontheskin.

ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairing2.Benefits:(1)recoveringhair(2)decreasinginfluenceofS2-andhydrolysateofhairstocircumstance(3)differentquantityofpaintmaybeappliedindifferentareasoftheskinordifferentskins–decreasingdifferenceofdifferentareas.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1PaintunhairingThemethodfitfor:withalargeamountofhairs,smallareas,thinskinsSuchas,sheepskins,goatskins,calfskins,yakhides

ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairing3.原理：毛干、毛根、表皮角蛋白结构不同毛根、表皮－－?角蛋白－－双硫键?，结构?

稳定性?，易破坏?毛干－－?角蛋白－－双硫键?，不易破坏?

控制时间长短，在毛根、表皮松动后，毛其它部位未破坏前，将毛推去，既脱毛又不破坏毛（回收毛）ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairing1。Be’=7。BK1。Be’=145-145/比重BK=(比重－1）/1000ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairing4.unhairing“paint”:

50partsCa(OH)2/Al2O3.2SiO2.2H2O高岭土

50partswater5-20partsNa2S/NaHS

溶解Na2S/NaHS，加入高岭土或熟石灰粉充分搅拌，调至25。Be’，放置一段时间使充分混匀。

Na2S一般20－70g/l,一般用两种浓度，如山羊皮背脊部50－70g/l,边腹部10－20g/l,为减轻膨胀，用NaHS代替部分Na2S。高岭土、熟石灰作用：增稠，防止脱毛糊流失，一般增稠至15－30。Be’，高岭土膨胀作用弱。多脂皮防止灰皂代替石灰。非离子渗透剂－－加速脱毛糊渗透胺类浸灰助剂－－减缓膨胀，促进脱毛ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.1Paintunhairing5.Pre-treating:

removingfatandfleshandallowingeasierpenetrationofthepaint;drainedoffsurpluswaterorsamming(挤水）;goodsoakingChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.2Hair-destructionUnhairinginDrumWhenthehairisoflittlevalue,theymaybedrummedintermittently（间歇性地）inarelativelystrongsodiumsulphidesolution.forexample:200%water,28℃2%-5%Na2S(60%)/NaHS2.5%Ca(OH)2ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.2Hair-destructionUnhairinginDrumWithin15minutesthehairlosesmostofitsfiberstructure.Afteronehourthehairandepidermisarereducedtoapulp,whichcanbereadilywashedoff,andthehidesbeginswellinggradually.limittheswelling---addingsalt;partofNaHSreplacingNa2S;Asthetemperatureincreasesto28-30℃,lessswellingoccurs,givingafinerflattergrain..ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.2Hair-destructionUnhairinginDrumSkin

hydrolysisisslowerandcanbecontrolledbytime.Afterthehairsarecompletelydissolved,thedrumisrunintermittently(5minuteseveryhour)forliming.Theunhairingandlimingarecarriedoutatthesametimeinsamebathfor16-18hours.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairingChapterOnebeam-house

operations

3.1.2Hair-destructionUnhairinginDrum原理：毛、表皮、毛根鞘－－角蛋白组成－－含大量胱氨酸残基－－分子中、分子间有许多双硫键交联，结构稳定性高利用Na2S/NaHS的还原作用破坏角蛋白分子中和分子间的双硫键交联，从而破坏角蛋白分子的结构稳定性，然后在碱性条件下将角蛋白分子的肽链水解成肽段或氨基酸，使毛、表皮毛根鞘被溶化而除去。ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairingChapterOnebeam-house

operations

3.1.2Hair-destructionUnhairinginDrum

由于Na2S/NaHS浓度高（>3g/l),还原性强，对角蛋白几乎无选择性，先接触先破坏。毛尖、表皮、毛干暴露在皮外，先被浆化和破坏，而毛根和毛根鞘深陷皮内，需较长时间。如果Na2S/NaHS浓度较低，或皮过早膨胀，或前工序胶原纤维松散不够，都会妨碍Na2S/NaHS对毛根的作用，使毛根、毛根鞘不能被彻底毁坏而残留在真皮中。因此，毁毛法难点在于彻底除去毛根和毛根鞘。ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairingChapterOnebeam-house

operations

3.1.2Hair-destructionUnhairinginDrumCaution:swellingorplumpinggradually(anduniformly)toavoidpebbled(卵石纹)grainoraccentuatedgrowthmarks（生长痕）intheneck（颈）orshoulder（肩）area.Mechanicalactiongentletoavoidpebbling,e.g.3r.p.m.,runningintermittentlyfor5-10minuteseveryhour.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairingChapterOnebeam-house

operations

3.1.2Hair-destructionUnhairinginDrum

Temperaturecontrolshouldbekeptconstant.Anincreasefrom16to27℃inthelimingtemperaturewillhalvethetimerequiredfordissolvingthehair,moresignificantly,itwilldoubletherateofsolutionofthecollagen.Normallytemperaturesof10-16℃areusedinEurope,butsomemodernprocessesgomuchhigherthanthisonshoeupperleather.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.2Hair-destructionUnhairinginDrum方法：先脱毛，然后同浴浸灰。脱毛时尽量减小脱毛液对皮的膨胀作用，增强脱毛效果。毛基本脱掉后，补加石灰和水使皮逐渐膨胀。脱毛阶段：C:小液比，0.3－0.7，皮膨胀程度小，Na2S/NaHS浓度高，转动时皮之间摩擦力大，利于毛、表皮去除。

T:不能太低，25－30℃

，温度低，膨胀程度大，脱毛作用弱，不易脱净。ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.2Hair-destructionUnhairinginDrum

材料：尽量用NaHS或Na2S/NaHS配合，降低膨胀度，增强还原力。Criteria（检查标准）：absenceofhair,especiallyshorthair,flatnessofgrain,absenceofpebbleandneckwrinkles，nohardareasintheneckorshoulderChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.2Hair-destructionUnhairinginDrum举例：黄牛盐腌皮脱毛浸灰浸水去肉后称重，脱毛浸灰：液比：0.7，温度：28℃

，70％NaHS1％，转30’，停30’，加60％Na2S2％，转30’，停30’，加石灰粉3％，水130％转30’，以后转5min/2h,总时间18－24h,水洗，去肉。ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrum

Inordertoreducehairdegradation(降解)andsulfidecontentineffluent,manyhair-savingunhairingmethodshavebeenestablished.Twocommercialmethods,Sirolime（色诺法）

andBlairHair,arebasedonlime-sulfideunhairing.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrumTheSirolimemethodwasdevelopedin1981byCSIRO(Commonwealth（国家，联邦）

ScientificandIndustrialResearchOrganization)LeatherResearchCenter,Australia.Method:

(1)浸NaHS，使其渗透到毛根附近，相对低的pH（8.6）保证NaHS不对毛发生作用（immunize免疫）。液比：0.3，70％NaHS1％转2h,排液（回收再用）ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrum（2）洗涤，短时洗洗去毛和皮表面的NaHS

，液比0.4，水洗5min;

(3)氧化，用漂白粉漂洗氧化除去毛上残留的NaHS

，而毛囊内仍有大量NaHS。液比：0.3，漂白粉0.1％，5min;

(4)脱毛，加石灰粉使pH提高到12以上，使NaHS

还原性增强，破坏毛根、毛根鞘，使毛与真皮联系减弱，转动摩擦脱落。过滤回收毛，废液循环利用。漂白液中加1％石灰粉，转30min,补加水30－40％，转50min.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrum(5)Relime

再浸灰，除去残留毛、表皮和毛根鞘，并对胶原适当分散。液比：0.5－0.6，60％NaHS2％，30min,加石灰粉3％，水80－100％，转1－2h,以后5m/2h,共浸灰16－18h。Results:

回收毛90％以上，降低废液中COD、BOD值约80％以上，废液中总氮降低90％以上，减少废液80％，回收硫化物40％。但步骤多，操作繁琐，脱毛时间长。ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrumTheBlairHairmethodwasdevelopedin1985byRohmandHassincooperationwithEagleOttawaLeatherCo.

ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrumMethod：

thehairisimmunizedbyalimetreatment，

thensodiumhydrosulphideisaddedandthehairgraduallyloosens,Whenthehairlooseningiscompleted，liquorispumped(用泵抽)outandfiltered,thenrelimingiscarriedoutbymeansoflime，hydrosulphide,andanauxiliary.UnhairingAssistFR-62.Thisproductisanaliphaticamine(脂肪胺）

whichhelpstocompletetheactiononhairrootsandepidermisandtopreventfurtherimmunizationor(bymeansofapHincrease)anyhydrogensulphidegeneration.Thetotalunhairingtimeisapproximately18.5hours.ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrum

Method（1）immunizing:液比：1.5，温度：27－28℃，石灰2％转5min,停25min,转5min,停25min,转5min;

（2）loosinghair:加片状NaHS1%转10min，停20min，转10min，停20min，转10min，这时90％毛已掉；

(3)removinghair:用27－28℃水洗30－45min，过滤

（4）reliming:液比：1.5，温度27℃，石灰2％，NaHS0.5%，FR-621％，阴离子表面活性剂0.2％，转10min，以后转5/h,共8h。废液回收利用，水洗液回收利用。ChapterOnebeam-house

operations3Unhairing3.1SulphideUnhairing

3.1.3Hair-savingUnhairinginDrumCaution:Themethodrequiresahighlevelofcontrol,asprocesstemperatureandtimearecritical.Over-immunizationleadingtohairpatches(残留在皮上的未脱掉的成片的毛）

isarealrisk.Notallhairsubstanceiseliminatedatthehairremovalstage;remai