Introduction
Gravureprinting,referredtoasgravureprinting,isoneofthefourprintingmethods.Gravureprintingisadirectprintingmethodthatdirectlyimprintstheinkcontainedinthegravurepitsontothesubstrate.Theshadeoftheprintedpictureisdeterminedbythesizeanddepthofthepits.Ifthepitsaredeeper,Itcontainsmoreink,andtheinklayerleftonthesubstrateafterembossingisthicker;onthecontrary,ifthepitsareshallower,theamountofinkcontainedisless,andtheinklayerleftonthesubstrateafterembossingIt'sthinner.Theprintingplateofgravureprintingiscomposedofpitscorrespondingtotheoriginalimageandtextandthesurfaceoftheprintingplate.Duringprinting,theinkisfilledintothepits,andtheinkonthesurfaceoftheprintingplateisscrapedoffwithasqueegee.Thereisacertainpressurecontactbetweentheprintingplateandthesubstrate,andtheinkinthepitsistransferredtothesubstratetocompletetheprinting.Gravureprinting,asakindofprintingprocess,hastheadvantagesofthickinklayer,brightcolor,highsaturation,highprintingplatedurability,stableprintingquality,fastprintingspeedandotheradvantagesinprintingpackagingandgraphicpublishing.Occupyanextremelyimportantposition.Fromtheperspectiveofapplication,inforeigncountries,gravureprintingismainlyusedforfinepublicationssuchasmagazinesandproductcatalogs,packagingprintingandprintingofsecuritiessuchasbanknotesandstamps,anditisalsousedinspecialfieldssuchasdecorativematerials;inChina,gravureprintingPrintingismainlyusedforflexiblepackagingprinting.Withthedevelopmentofdomesticgravureprintingtechnology,ithasalsobeenwidelyusedinpaperpackaging,woodgraindecoration,leathermaterials,andpharmaceuticalpackaging.Ofcourse,gravureprintingalsohasitslimitations.Itsmaindisadvantagesare:complexpre-pressplate-makingtechnology,longcycle,highplate-makingcost;duetotheuseofvolatilesolvents,thehighcontentofharmfulgasesintheworkshopwillcausegreaterdamagetothehealthofworkers;gravureprintingPractitionersrequirerelativelyhighremuneration.
Developmenthistory
Oneofthebasicprintingmethods.Thegraphicsandtextoftheprintingplatearelowerthantheblankpart,andthewholepageisinkedwhenprinting,andthenthelayoutiswiped,sothatonlytheinkisleftinthegraphicsandtextpart,whichistransferredtothesubstrateandbecomesaprintedmatter.Itcanbedividedintothreetypes:engravingintaglio,photo-etchingintaglioandelectronicengraving.
Engravingintaglioisdevelopedfromtheartofprintmaking.Itwasinventedin1452bytheItaliangoldandsilversmithM.Finiguela.Atfirstitwasallhand-carved,butlateritwaschemicallyetched.Inmoderntimes,machineryhasbeenusedasmuchaspossible.Thelayoutiscomposedofpointsandlinesofdifferentdepthandthickness.Thelinesoftheprintedmatterareslightlyconvex,cleanandclear,andanti-counterfeiting,soitismostlyusedforprintingbanknotes,stampsandothervaluablesecurities.
PhotographiccorrosionintaglioInthelate19thcentury,thepainterK.Klick,whowasborninBohemia,usedhispredecessor'sphotographyandcarbonpaperprintingtoinventthephotogravureandtheintagliowithascraper.Printingmethod.Theinkedpartofthegraphiconthepageisaregulararrangementofsmallholes(cells),whicharegenerallysquareinshapeandthesamesize,butwithdifferentshadesanddifferentinkcapacities.Itsprintedmatterhasthickinkandcanachieveaprintingeffectthatiscompletelyconsistentwiththetoneleveloftheoriginalimage.Itisthemostcommontypeofgravureprinting,soitisalsocalledtraditionalgravure.Formorethanhalfacentury,severalnewphoto-corrosiveintaglioplateshavebeendeveloped.Forexample,referringtotheoffsetprintingdotstructure,theinkingholesaredifferentinsize,butthedepthisthesameorinconsistent,andtheprintingqualityisbetter.
Inthemiddleofthe20thcentury,electronicengravingofintaglioengravingmachinesbegantohaveintaglioelectronicengravingmachines.Itusesascanningheadandacomputer-controlleddiamondcuttertoengravepicturesandtextsonthedrum.Theinkingholesareintheshapeofaninvertedpyramid.Therearechangesindepth.Itsprintingqualityisnolessthanthatofphoto-corrosiongravure,andithastheadvantagesofsimpleoperation,shortplate-makingtime,andnowasteliquiddisposalproblems.
Moderngravureprintingplatesaremostlymadeonthesurfaceofaroundcylinder,andtheprintingmethodofroundpressingisadopted.Usuallytheimpressioncylinderisontopandtheplatecylinderisonthebottom.Thelowerpartoftheprintingplatecylinderisimmersedintheinktank,andtheplatesurfacegetsinkfromthetank(itisalsousedtoejectinkfromaninkpumportransferinktotheplatesurfacebyaninkrollerimmersedintheinktank).Athinsteelscraperisplacedabovetheinktanktopressonthesurfaceoftheplatecylindertoscrapeofftheinkontheplatesurfacewithoutgraphics(itcanalsobewipedwithacounter-rotatingwiperroller).Theinkremainingintheinkholes(orlines)ofthegraphicandtextonthelayoutistransferredtothepaper(plasticfilm,aluminumfoil,etc.)passingthroughwhenitistransferredtothetangentpointofthetwocylinders,andthegraphicandtextareprinted.
Comparedwithoffsetprintingorcopperplateembossingwhencopyingmonochromeorcolorphotographs,ithasthickinklayer,richlayers,goodprintingquality,lowwastepaperrate,printingplatedurability,long-termstorage,etc.Advantages,especiallygoodprintingeffectoncoarsepaper,cellophane,plasticfilmandmetalfoil.However,gravureprintingtakesalongtimeandhighcost,soonlycolorpictures,picturealbums,magazines,bookillustrations,postcards,trademarks,packaginganddecoration,securities,buildingdecorationmaterials,etc.withhighqualityrequirementsaresuitableforgravureprinting.Moreover,thenumberofprintedproductsislarge,sogravureprintingismorecost-effective.Inaddition,thequalityofprintedsmalltextisnotgood,sogravureprintingisnotrequiredfortext-basedbooksandperiodicals.
Becausethegravureinkmusteasilyentertheinkingholesoftheprintingplateandtransfertothepaper,ithasgoodfluidity,andvolatilebenzenesarecommonlyusedassolvents.Inordertopreventsolventsfrompollutingtheairandpreventingfires,attentionmustbepaidtosealingoffallsourcesofpollution,recoveringsolvents,andventilatingtheworkplace.Theresearchandapplicationofwater-basedgravureinksthatrequirenodegradationofprintingqualityareactivelybeingexploredathomeandabroad.
Types
Thetypesofgravureprintingaredividedintotwotypesaccordingtotheplatemakingmethod:engravinggravureandetchinggravure.
Engravingintaglio
Engravingintaglioistodirectlyengravethepitscorrespondingtotheoriginalimageandtextonthesurfaceoftheprintingplatecylinderwithacutter.Accordingtothecontrolmethodofthecutter,itcanbedividedintoHand-engravedintaglio,mechanicalengravedintaglioandelectronicengravedintaglio.
(1)Hand-engravedintaglio
Hand-engravedintaglioismadebytechniciansusingacarvingknifetohand-engravethesurfaceoftheprintingplatecylinderaccordingtotheoriginalgraphicsandtext.TheprintingplatematerialsareavailableCopperorsteelplate.Themanuallaborisheavy,theplate-makingcostislarge,andthecycleislong.However,thehand-engravedintagliohasclearlines,andtheprintedmatterhasastrongsenseoflayeringandisdifficulttoforge.Mostlyusedtoproduceprintedintaglioplatesforsecuritiesandhigh-qualityartworks.
(2)Mechanicalengravingintaglio
Mechanicalengravingintaglioismadebyengravingonthesurfaceoftheprintingplatecylinderwithamechanicallycontrolledcutter,whichreducestheheavylaborofmanualengraving,andmakestheplateThespeedisfast,thecycleisshorter,andtheplate-makingcostisalsolower.Mainlyusedtoproduceprintedintaglioplatesforsecurities.
Becauseofthehighcostoftheabovetwotypesofengravingandplate-making,theplate-makingcycleislong,sothescopeofuseislimited.Butthingsaredividedintotwoparts.Asfarasanti-counterfeitingpackagingisconcerned,hand-engravingintagliomaybethebestmethodofplatemaking.Becausesecretanti-counterfeitingisoneofthemainmethodsofanti-counterfeitingpackaging,technicianscanusevariousmethodstoengravesomesecretmarksduringtheprocessofhand-engravingtheintaglio.Thesesecretmarksonthehand-engravedintaglioarenoteasytobefound,anditismoredifficulttodistinguishthemontheprintedmatter.,Whichformsthesecretofanti-counterfeiting.
(3)Electronicengravingintaglio
Thiskindofplateisengravedonthesurfaceoftheprintingplatecylinderbytheelectroniccontroldevicetocontrolthecarvingknife.Usingtheelectronicengravingmachine,accordingtothephotoelectricprinciple,theengravingknifeiscontrolledtoengravethemeshonthesurfaceofthedrum,andtheareaanddepthofthemesharechangedatthesametime.
Corrodedintaglio
Thecorrodedintaglioismadebyetchinginkpitsonthesurfaceoftheplatecylinderbychemicaletchingaccordingtotheoriginalgraphicsandtext.Accordingtothedifferentmethodsofmanuscriptimageandtextconversion,thecorrosionintagliocanbedividedintoetchingintaglio,photointaglio,anddotintaglio.
Theetchingintaglioismadebyaplate-makingmethodthatcombinesengravingandetching.Thatis,theshapeoftheoriginalimageandtextisfirsthand-carved,andthentheintaglioismadebytheetchingmethod.
Photogravureiswidelyused,andisthemostwidelyusedprintingplateingravureprinting,mainlyusedforprintingpictures.
Dotgravureismainlyusedforpackaginganddecorationprintingandbuildingmaterialsprinting.
Factorsofproduction
Manuscripts
Manuscriptsingravurearemostlycontinuoustone.
Ink
Gravureprintinginkiscomposedofsolidresin,volatilesolvents,pigments,fillersandadditives.Itdoesnotcontainvegetableoil,andmostofitsdryingmethodsarevolatile.Gravureprintinginkscanbedividedintothreetypes:photocopyinggravureprintinginks;plasticgravureprintinginks;alcohol-solublegravureprintinginks.Theroleofthesolventintheinkis:dissolvingordispersingallsolidcomponentsintheink;wettingthesurfaceofthesubstratetobeprinted;adjustingthedryingspeedoftheink;adjustingtheconsistencyoftheinktomakeitsuitablefortheinkingrequirementsoftheprintingplate.
Theprintingplate
Asignificantdifferencebetweentheintaglioplateandotherplatesisthatthegraphicpartiscomposedofconcaveholeslowerthanthenon-graphicpart,andtheprintingplateismadeofmetalmaterials.Itisfinishedwithchromeandcopperplatedontheoutside.
Substrate
Thematerialofgravureprintingcanbeverywide,butitisoftenusedtoprinthigh-gradepaperandplasticfilm.
Printingmachinery
Gravureprintingmachineusuallyconsistsofeightparts,includingunwindingpart,guideroller,pressureroller,printingroller,inkingpart,doctorblade,dryer,receivingVolumepart,partofthegravureprintingmachinealsoincludespowersystem,calibrationsystemandelectricalsystem.
Productionprocess
Becauseofthehighdegreeofautomationoftheprintingmachineandthehighqualityofplatemaking,theprocessoperationofgravureprintingissimplerthanthatoflithographicprintingandeasytomaster.Theprocessflowisasfollows:
Pre-presspreparation→Pre-press→Adjustmentrules→Formalprinting→Post-pressprocessing
Pre-presspreparation
Thepreparationworkforgravureprintingincludes:prepareforprintingaccordingtotherequirementsoftheconstructionsheetItisnecessarytolubricatetheprintingpresswithmaterials,ink,squeegee,etc.
Plasticfilmisthemainsubstrateforgravureprinting.Commonlyusedplasticfilmsarepolyethylene,polypropylene,polyvinylchlorideandsoon.Becausetheplasticfilmhasasmoothsurfaceandpoorinkadhesion,thesurfaceofthefilmmustbetreatedbeforeprinting.Coronatreatmentisgenerallyused.Thismethodistopasstheplasticfilmthroughtwoelectrodes,andusehigh-frequencyoscillatingpulsestoforcetheairtoionizetoproduceadischargephenomenontoformacorona.Freeoxygenatomscombinewithoxygenmoleculestogenerateozoneandformthesurfaceofthefilm.Somestronggroupsand"burrs"thatareinvisibletothenakedeyewillincreasethesurfacetensionandroughnessofthefilm,whichisconducivetotheadhesionofinkandadhesive.
Gravureprinting,usingsolventvolatileink,lowviscosity,goodfluidity,andstrongadhesion.Commonlyusedsolventsaretoluene,xylene,gasoline,alcohol,etc.Addaproperamountofsolventtotheinkbeforeprinting,anditisbesttofilterbeforeuse.
Themainfeatureofthegravureprintingmachineistheuseofasqueegeetoscrapeofftheinkintheblankpartoftheprintingplate.Thesqueegeeisaspecialsteelsheetwithawidthof60mmto80mmandalengthof1000mmto1500mm(dependingonthesizeoftheprintingplatecylinder).Thesqueegeeblademustbeinastraightline.Ifthereisa"smallcrescent"scar,awideobliquelinewillappearontheprintedsheet,thatis,thephenomenonofemptybarswilloccur.
Theprintingplateisthebasisofprinting,anditisdirectlyrelatedtotheprintingquality.Theprintingplateneedstobereviewedbeforetheprinting.Checkwhetherthedotsareneatandcomplete,whetherthechrome-platedprintingplatehasde-chromiumphenomenon,andthetextprintingplaterequirescompletelinesandnobrokenpensandlesslines.Theprintingplatecanbeinstalledontheprintingpressonlyafterdetailedinspection.
Upgrade
Duringtheoperationofprintingplate,payspecialattentiontoprotectthelayoutfrombeingscratched,alignthegrippingrulesandpush-pullrules,andalsoaligntheprintingplate.Thecylinderisfastenedontheprintingmachinetopreventtheplatecylinderfromlooseningduringformalprinting.
Adjustmentrules
Afterthepre-printingpreparationsarecompleted,carefullycalibratetheprintingplate,checkthepaperfeeding,paperfeeding,paperdelivery,andpush-pullrules,andmakeappropriateadjustments.Correctthepressure,adjusttheinksupply,andadjustthesqueegee.
Theadjustmentofthesqueegeeismainlytoadjustthedistancebetweenthesqueegeeandtheprintingplateandtheangleofthesqueegee,sothatthepressureofthesqueegeeonthelayoutisevenwithoutdamagingtheprintingplate.
Formalprinting
Duringtheformalprintingprocess,youshouldalwayscheckwhetherthedotsareintact,whethertheoverprintisaccurate,whethertheinkisbright,whethertheinkviscosityanddryingareconsistentwiththeprintingspeedMatching,isitbecausethesqueegeeisnotevenlyscraped,therearemarks,cutlines,brokenedges,etc.ontheprintedsheet.
Theworksiteofgravureprintingshouldhavegoodventilationequipmenttoeliminateharmfulgases,andsolventrecoveryequipmentshouldbeused.Theelectricalappliancesontheprintingpressmusthaveexplosion-proofdevices,andtheymustbecheckedandrepairedfrequentlytoavoidfire.
Features
Theinkcarrieringravureprintingisthepitsengravedontheprintingplate.Theshapeofthepitsisexactlythesameastheoriginalimageandtext.Thereisnoinkonthesurfaceoftheprintingplate.Whentheprintingplateisincontactwiththesubstrate,theinkinthepitistransferredtothesurfaceofthesubstratetocompletetheprintingprocess.Therefore,gravureprintinghassomeuniquecharacteristicsthataredifferentfromotherprintingmethods,whicharediscussedseparatelybelow.
Anti-counterfeiting
Gravureprintingusespitscarvedaccordingtotheoriginalgraphicstocarryink.Thethicknessofthelinesandtheintensityoftheinkcanbearbitrarilycontrolledduringengraving,whichisnoteasytobeimitatedandForgery,especiallythedepthoftheinkpit,isveryunlikelytoberealisticallyengravedaccordingtotheprintedgraphics.Therefore,currentsecuritiessuchasbanknotes,stamps,stocks,etc.aregenerallyprintedwithgravure,whichhasagoodanti-counterfeitingeffect.Atpresent,somecompanies'trademarksandevenpackaginganddecorationhaveconsciouslyadoptedgravureprinting,whichshowsthatgravureprintingisamorevigorousanti-counterfeitingprintingmethod.
Widerange
Generalsoftmaterialscanbeusedassubstratesforgravureprinting.Suchasplastic,paper,aluminumfoil,etc.,especiallyforsomematerialsthatareeasytostretchanddeform,suchastextilematerials,etc.,havebetteradaptability,whichisunmatchedbyletterpressandplanographicprinting.
Highprintingquality
Gravureprintingusesalargeamountofink,thegraphicsandtextareconvex,andthelayersarerich,thelinesareclear,andthequalityishigh.Mostoftheprintingofbooks,magazines,magazines,packaginganddecorationisgravureprinting.
Massprinting
Gravureprintinghasalongplate-makingcycle,highefficiencyandhighcost.Buttheprintingplateisdurable,soitissuitableformassprinting.Thelargerthebatch,thehigherthebenefit,andthelowerthebenefitforprintingwithsmallerbatches.Therefore,thegravuremethodisnotsuitablefortheprintingofsmallbatchesoftrademarks.
Digitalplatemaking
Accordingtothecurrentdomesticactualsituation,therearethreemethodsfordigitalplatemakingofgravure:electronicengravingmachinemethod,laserengravingandpost-corrosionprocessingmethod,andlaseralloyelectroplatingDirectablationmethod.
Electronicengravingmachinemethod
Electronicengravingmachineisaprecisionmachinewithhighqualitystabilityapplyingmoderntechnologysuchasintegratedautomationcontrol.Allproductiondataofelectriccarvingiscollectedindigitalform,whichcanbeusedinsubsequentjobswithstrongreliability.Themanuscriptbecomesadigitalsignalfromthebeginningofbeingscannedandsenttothesoftwareforcolorseparationandthentransmittedtotheelectricengravingmachineorcolorproofingmachine,whichisverybeneficialtothestandardizationandstandardizationoftheproductionprocess,therebyensuringthequalityoftheprintedmatter.Moreover,theelectricengravingworkstationusesTIFFgraphicdatatotransfer,anditiseasilyintegratedandsettheworkingparameterconfigurationthroughtheHelioLightassemblyworkstation.Theengravingsoftwaregeneratestheelectro-engravingcurve,recordstheelectro-engravingparametersanddisplaystheengravingstatus,untiltheCDisburnedtosavethefile.(Convenientformultipleuseandrevision).
Theelectriccarvingcraftisrelativelymature,thecontrolissimple,andthelevelsarerestoredtolife.Thedisadvantageisthattheamountofinkappliedonthespotislimited,andtheinklayerhasinsufficienthidingpowerforsomeroughsubstrates;duetothepartitionbetweenthemechanicallyengravedmeshandthemesh,theedgeofthelinecomposedofthemeshisinevitablyjagged.,Whenprinting,smalltextisnotclearandeasytobreakorpaste.However,HaierofGermanyrecentlylaunchedXtremeengravingtechnology,whichcanreproducethemostsubtlepartsveryfinelyatascreencountofupto400lines/cm.Thefinetextcanindependentlyselecttherecordingresolutionwithoutrelyingonthenumberofengravingscreenlines.ThroughoptimizationTheinkflowsmoothesthecontoursandproducescontourlines.Itcannotonlyrealizeregularoutlets,butalsorealizeFMscreeningandcopying.
Laserengravingandpost-etchingprocess
Laserengravingandpost-etchingprocessisanotheradvanceddigitalplatemakingmethodafterelectro-engraving.Itisacceptedthroughinterfacelikeelectro-engravingTheimagefileprocessedbycolorseparationissenttothelasermodulator.Thelaseractsontheprotectivelayerpre-coatedonthesurfaceofthedrumtoexposethecopperorironbottom,andthenformsonthedrumafterdifferentperiodsofcorrosion.Dotpitsofdifferentsizes.
Thelaserengravingprocessovercomestheweaknessofelectro-engravedtextandthinlines,hairyandweakhair,andhighlightsthecharacteristicsofhighinkcontent,thickcolor,clearwriting,anddurability.Itissimilartotraditionalphotogravureplatemaking.Italsohastheadvantagesofhighscreenaccuracy,arbitraryeditingofthenetworkshape,andnoseams.Itissuitableforprintingplateswithparticularlysmallbuthighdefinitionrequirementssuchascigaretteprintingandanti-counterfeitingprinting.Itiswidelyusedinhigh-precisionanti-counterfeitingprintingsuchascurrency,securities,andticketing,aswellashigh-endtobaccoandalcoholpackaging.Itisproducedonfineembossingrollersandrubbercoatingrollers.Therearemoreadvantagesintheprocess.
Thereisalsoasensitizerlasermethod,whichusesavioletlasertoexposeandrinsethephotosensitivelayerofthegraphicpart.Theotherprocessesarebasicallythesameasthelaserengravingmethod.
Laserdirectablationofelectroplatedalloyplatemakingmethod
Thewideapplicationoflaserablationtechnologyingravurewillberapidlypopularizedwiththedevelopmentoflasertechnology.Itdoesnotrequiremechanicaladjustmentandfine-tuning.Linesandtextareclearer,anditiseasiertocontrollevelsthancorrosion.Thelatestlaserengravingmachineonthemarketcurrentlyuseshigh-resolutionlasersforfineengravingdirectlyonthesurfaceofthecopperdrum.Thecontour,dotdistributionanddepthoftheengravedinformationcanbearbitrarilychanged,soastoachievetheoutputeffectthatonlylaserimagesetterscouldachievebefore.
AdvantagesandDisadvantages
①Advantages:Theinkisabout90%expressiveandhasrichcolors.Strongcolorreproducibility.Strongpagetolerance.Thenumberofprintsishuge.Theapplicationrangeofpaperiswide,andmaterialsotherthanpapercanalsobeprinted.
②Disadvantages:theplate-makingfeeisexpensive,theprintingfeeisalsoexpensive,theplate-makingworkismorecomplicated,andasmallnumberofprintsisnotsuitable.
Applicationrangeofgravureprinting
Engravinggravureprinting,becauseofitsexquisitelinesandnoteasytocounterfeit,isusedintheprintingofsecurities,suchasbanknotes,stocks,giftcertificates,Stampsandcommercialcreditcertificatesorstationery,etc.Becauseofitshighcostofplatemakingandprinting,thereareveryfewusersofgeneralprintedmatter.Asforphotogravure,althoughitsplatemakingprocessismorecomplicatedanditscostismoreexpensive,itisnotsuitableforprintingasmallnumberofprints.Itisgenerallyusedinalargenumberofprintedmaterials,suchascolormagazinesandcurrentlypopularbuildingmaterialsprinting,etc.Bothareextremelysuitable.Becausegravureprintingadoptshigh-speedrotarytype,notonlythespeedisfast,buttheinkfilmismuchthickerthanthatofletterpressorlithography.
Control
Inadditiontobooks,newspapers,andmajorprintingpackaginganddecorationmaterials,gravureprintingshouldmeetthefollowingqualityrequirementsaccordingtothecharacteristicsofgravureprinting.
Monochromegravureprints,bright,mediumanddarktonesarewell-defined,coordinatedanddelicate.Theoutletsareclearandcomplete.Thelayoutisevenandtidy.
Colorintaglioprinting:theimageisbright,mediumanddarktoneswithdistinctlevels,coordinationandfineness.Thecolorisnaturalandharmonious.Theoutletsareclear,complete,andtheangleisaccurate.Theimageoutlineisclear,andtheoverprintingtoleranceisallowed.
Appearanceofprintedmatter:Thelayoutisclean,uniform,withoutobviousstains.Thepositionoftheimageandtextisaccurate.Thecoloroftheprintingplateisbasicallythesame,thesizeerroroffineprintsisnotmorethan0.5mm,thegeneralprintsarenotmorethan1.0mm,andtheoverprinterrorofthefrontandbacksidesisnotmorethan1.0mm.
Printingqualitycontrol
1.Automaticoverprintingdevice
Anautomaticoverprintingdeviceisinstalledonthewebgravureprintingmachine.Thedeviceiscomposedofscanninghead,pulsegenerator,electroniccontroller,regulatingmotor,overprintregulatingrollerandsoon.
Whentheoverprintmarkontheprintedsheetpassesthroughthescanninghead,thepulsesignalissenttotheelectroniccontroller.Iftheoverprintmarkofthesecondcoloriswrongbeforeorafterthemarkofthefirstcolor,thepulsetimewillbeUneven,sotheelectroniccontrollerstartstheadjustmentmotor,sothattheregisteradjustmentrollerbetweenthefirstcolorandthesecondcolorhasaslightmovementtoeliminatetheregistererror.
2.Electrostaticink-absorbingdevice
Gravureprintingmachinesaregenerallyequippedwithelectrostaticink-absorbingdevices.Thedeviceiscomposedofahigh-voltageadjustablegenerator,analuminumconductiveroller,aspecialimpressioncylinderwithconductivesurfaceandinsulatingbottomlayer,andaprotectionmechanismtoautomaticallycutoffstaticelectricityandovercurrentshort-circuitprotectionwhenthemachinestops.Theuseofstaticelectricitytoadsorbtheinkintheprintingplatecellstothesurfaceofthesubstratecanincreasetheinktransferratebyabout20%,especiallytomakethelevelofthebrightpartoftheprintedmatterrichlyreproduced.
Problems
Faultsingravureprintingaremainlycausedbyprintingplates,inks,substrates,squeegees,etc.
(1)Inkcolorunevenness
Thephenomenonofperiodicinkcolorchangesonprintedmatter.Theeliminationmethodsare:correcttheroundnessoftheplatecylinder,adjusttheangleandpressureofthesqueegeeorreplacewithanewsqueegee.
(2)Theimprintisfuzzyandfluffing
Theimageoftheprintedmatterishierarchicalandfuzzy,andburrsappearontheedgesoftheimageandtext.Eliminationmethodsinclude:removingstaticelectricityonthesurfaceofthesubstrate,addingapolarsolventtotheink,appropriatelyincreasingtheprintingpressure,andadjustingthepositionofthesqueegee.
(3)Blocking
Thephenomenonthattheinkdriesupinthecellsoftheprintingplate,orthecellsoftheprintingplatearefilledwithpaperwoolorpaperpowder,iscalledblockage.Theeliminationmethodsare:increasethecontentofthesolventintheink,reducethedryingspeedoftheink,andprintonpaperwithhighsurfacestrength.
(4)Inkoverflow
Thephenomenonofspotsonthesolidpartoftheprintedmatter.Theeliminationmethodsare:addhardvarnishtoincreasetheviscosityoftheink.Adjusttheangleofthesqueegee,increasetheprintingspeed,replacethedeep-cellprintingplatewithashallow-cellprintingplate,etc.
(5)Scratches
Therearetracesofsqueegeeontheprintedmatter.Theexclusionmethodsare:usecleaninkprintingwithnoforeignmattermixedin.Adjusttheviscosity,dryness,andadhesionoftheink.Useahigh-qualitysqueegeetoadjusttheanglebetweenthesqueegeeandtheprintingplate.
(6)Pigmentprecipitation
Thephenomenonthatthecolorontheprintedmatterbecomeslighter.Theexclusionmethodsare:printingwithinkswithgooddispersibilityandstableperformance.Addanti-cohesionandanti-precipitationadditivestotheink.Fullyrollandstirtheinkintheinktankfrequently.
(7)Dirty
Thereisinkstainontheprintedmatter.Theeliminationmethodsare:chooseprintinginkwithfastvolatilizationspeed,increasethedryingtemperatureorappropriatelyreducetheprintingspeed.
(8)Inkshedding
Theadhesionoftheinkprintedontheplasticfilmispoor,anditisaphenomenoninwhichtheinkisrubbedoffbyhandormechanicalforce.Theeliminationmethodsare:preventtheplasticfilmfromgettingdamp,selectinkprintingwithgoodaffinityfortheplasticfilm,andresurfacetheplasticfilmtoincreasethesurfacetension.
Scopeofapplication
1.Theanti-counterfeitingeffectofhand-engravedgravureprintingisbetter
Thesecretthatanti-counterfeitingisamajoraspectofcommodityanti-counterfeiting,Andthisisimplementedbythetrademark,hand-engravedgravureprintingprovidesthenecessarymeansforit.Hand-engravedgravureprintingiseasytoimplementsecretanti-counterfeitingduringplatemaking.Thedepthofthepitsduringengravingdeterminestheintensityoftheprints.Theimitatorcaneasilyimitatethesizeoftheimageandthethicknessoftheline,butitisdifficulttoimitatetheintensity.Printsofthesamelevel(thatis,thesamedeepinkpit).Thisisthemainreasonwhygravuremustbeusedforsecuritiesforalongtime.
Thelesstheprintvolume,thebettertheanti-counterfeitingeffect.Duetothelongcycleandhighcostofhand-carvingintaglioplates,thepriceofprintedproductsishigherwhentheprintvolumeissmall.Themainpurposeofcounterfeitersistopursueeconomicbenefits.Theyareunwillingtotakeanyriskswhentheyareunprofitableorprofitable.Therefore,itcanbesaidthattheanti-counterfeitingeffectofgravureprintingforsmallbatchesoftrademarksmaybebetterthanthatoflargebatchesofgravureprinting.
2.Plate-makingandprintingarecarriedoutintwoplaces
Theplate-makingandprintingindifferentplaceshaveagoodanti-counterfeitingeffect.Printinghousesgenerallyhavetheabilitytomakeplates,buttrademark-usingcompaniesshouldchooseadifferentunitforplatemakingwork,becauseoneofthekeytoanti-counterfeitingistoknowthelesspeoplethebetter.Theentireprocessoftrademarkdesignandprinting,sothatevenifthereareloopholesinonelink,otherlinksaresufficienttomeettheneedsofanti-counterfeiting.Whenthetrademarkisprintedintheprintingplant,thecompanymustsendresponsiblepersonneltothesitetosupervisetheprintingtopreventthetheftoftheprintingplateandthetheftofthetrademark.Afterprinting,theprintingplateshouldbetakenbackandstored.
3.Combinewithanti-counterfeitinginktechnology
Inkanti-counterfeitingtechnologyisalsoanaspectofsecretanti-counterfeiting,combininggravureprintingtechnologywithinkanti-counterfeitingtechnology,Realizethedoublesecretanti-counterfeiting,theanti-counterfeitingeffectwillbebetter.Someprintinganti-counterfeitinginkshavelargerpigmentparticlesandrequireathickerinklayer,whilethegravureprintinginklayeristhickerandtheprintedproducthasastrongertexture.Thecombinationofthetwowillachievedoubleanti-counterfeitinganddecorationeffects.Ifgravureprintingusesfluorescentink,itnotonlyguaranteesthemicroconvexityofgravureprinting,butalsoguaranteestheuserequirementsoffluorescentink,andthesecretanti-counterfeitingfunctionsofbotharealsoguaranteed.Theinkshouldbepreparedbyitself,andthenhandedovertotheprintingcompanyforuse.Afterprinting,theinkshouldberecoveredandstored,sothatabetteranti-counterfeitingeffectcanbeobtained.
Developmenttrend
1.Largeandmedium-sizedpackaginggravureprintingcompanieswilloccupythemainstream,especiallycigarettepackagegravureprintingcompaniesthatarepursuingeconomiesofscale,highqualityandhightechnology.
2.Duetoenvironmentalprotectionandhygienereasons,industriessuchasfood,medicine,tobacco,andwinearepayingmoreandmoreattentiontotheenvironmentalprotectionofpackagingmaterialsandprintingprocesses.Gravureprintingcompaniespaymoreattentiontotheenvironmentoftheprintingworkshop.Environmentally-friendlyinksandvarnisheswillbecomemoreandmorepopular,closedsqueegeesystemsandquick-changedeviceswillbepromotedandapplied,andgravureprintingmachinessuitableforwater-basedinkswillbewidelyadopted.
3.Theindependentdrivetechnologyofthegravureprintingmachineandtheelectronicshafttransmissionasthetechnologyplatformwillrealizethecomprehensiveupgradeofthegravureprintingmachine.Allkindsofgravureprintingmachineswilladoptelectronicshafttransmission.TheelectronicshaftdriveandregistersystemmainlycomefromJapanandEurope,buttheycanonlybeappliedtoasmallnumberofdomesticgravureprintingpresses.Thedevelopmentofadomesticoverprintsystemwillbethekeytoacomprehensiveupgradeofdomesticgravureprintingmachines.
4.Theratioofwide-formatgravurepressesandpapergravurepresseswillcontinuetoincrease.Ontheonehand,thedecorativeprinting(mainlywoodgrainpaperprinting)andcartongravureprintingmarketwillgrowrapidly.Ontheotherhand,therangeofflexiblepackaginggravureprintingmachineswillcontinuetoincrease,andthenumberoflargeformatgravureprintingmachineswillincreaserapidly.Paperandpaper-basedcompositegravureprintingmachines(woodgrainpapercigarettelabels,asepticpackaging,giftwrappingpaper,etc.)willgrowrapidly.
5.Theprocessingofthegravureproductionlinewillbemorediversified,andthefunctionconfigurationwillbecomestrongerandstronger,suchaspolishing,diecutting,crosscutting,softlabelcutting,etc.Correspondingly,gravureprintingmachinemanagementsystemsandremotetechnicalsupportsystemswillbemoreandmoreadopted.Atthesametime,inordertomeettheneedsofindividualization,allpartsfromunwinding,printing,in-lineprocessing,andwindingwillbemodularized,themostimportantofwhichwillbethegravurecartortheinterchangeofgravureandflexographicprinting.Smallcart.